Retrospective study evaluating dental side effects of radiotherapy in patients treated for head and neck cancer

INTRODUCTION

Head and neck cancer squamous cell carcinoma (HNSCC) is the seventh most common cancer worldwide with around 600,000 new diagnosis each year. Nowadays, in locally advanced disease, radiotherapy (RT) play an important role, this with or without chemotherapy in organ preservation strategies. More specific for early stage localized disease, RT (or surgery) seems to give similar results on locoregional control (LRC) and choice is made according to the organ preservation issue. Despite the fact that technical improvements have been made to optimize the radiation dose delivery and minimize the normal tissue toxicity, RT is associated with potential early and late toxicities. Osteoradionecrosis of the jaw (ORNJ), especially seen after teeth extraction, is one of the associated toxicities and can significantly impair the patient's quality of life. Because of the fear of developing ORNJ, one is very reluctant to extract or place a dental implant post-radiotherapy, especially in high irradiation dose zones (>40 Gy). Hence, it is important to define teeth at risk of future extraction before initiating RT and to handle those in high-risk irradiation zones. In order to optimise extractions, we created a predictive model of the expected irradiation dose, and thus the need for extraction, to the teeth bearing bones. The aim of this study is to validate our model and to define the potential relationship between the radiation dose received by each tooth and the dental complications observed.

MATERIAL AND METHODS

Between March 2012 and March 2018, patients with HNSCC treated by intensity modulated RT were retrospectively analysed. The mean irradiation dose for each tooth was generated on the administered treatment plan by contouring each tooth separately on each dosimetric scan section using dedicated software (Eclipse, Varian). In order to validate our predictive model, we compared the actual generated/administered teeth irradiation doses with the irradiation doses predicted by our model.

RESULTS

Our predictive model was accurate in 69.6% of the cases. In 12.5% of cases the predicted dose was higher than the calculated dose and lower in 17,8% of the cases. A correct- or over-estimation (is the latter being clinically less worrying than an underestimated dose) was achieved in 82% of cases. For the 18% of cases underfitting, the mean margin of error was 5.7 Gy. No statistically significant association was found between the development of caries and doses to the teeth, doses to the parotid glands or dental hygiene. However, a significant association between dental irradiation at more than 40 Gy and the occurrence of dental fractures (p = 0.0002) were demonstrated.

CONCLUSIONS

Our predictive model seems to be 82% accurate for dose prediction, hence might be helpful for optimizing/minimizing prophylactic extractions. Indeed, following our model, professionals could decide not to extract damaged teeth in areas not at risk of ORNJ, lowering morbidity during and after RT. Contrary to the literature, no relationship was found between the occurrence of dental caries and parotid irradiation and the patient's oral hygiene. However, for the first time, a highly significant correlation between the occurrence of dental fracture and dental irradiation at more than 40 Gy was observed.

The first occurrence of machimosaurid crocodylomorphs from the Oxfordian of south-central Poland provides new insights into the distribution of macrophagous teleosauroids

Teleosauroid thalattosuchians were a clade of semi-aquatic crocodylomorphs that achieved a broad geographic distribution during the Mesozoic. While their fossils are well documented in Western European strata, our understanding of teleosauroids (and thalattosuchians in general) is notably poorer in Central-Eastern Europe, and from Poland in particular. Herein, we redescribe a teleosauroid rostrum (MZ VIII Vr-72) from middle Oxfordian strata of Załęcze Wielkie, in south-central Poland. Until now, the specimen has been largely encased in a block of limestone. After preparation, its rostral and dental morphology could be evaluated, showing the specimen to be a non-machimosaurin machimosaurid, similar in morphology to taxa Neosteneosaurus edwardsi and Proexochokefalos heberti. The well-preserved teeth enable us to study the specimen feeding ecology through the means of comparing its teeth to other teleosauroids through PCoA analysis. Comparisons with inferred closely related taxa suggest that the referred specimen was a macrophagous generalist. Notably, MZ VIII Vr-72 displays a prominent pathological distortion of the anterior rostrum, in the form of lateral bending. The pathology affects the nasal passage and tooth size and position, and is fully healed, indicating that, despite its macrophagous diet, it did not prevent the individual from food acquisition.

Dental color measurement to estimate age in adults: a systematic review and meta-analysis

Age estimation is a major challenge in anthropology and forensic odontology laboratories, as well as in judicial settings, as one of the tools used in human identification. The aim of this study was to evaluate the usefulness of age estimation methods based on the accurate measurement of tooth color changes. A systematic review was carried out following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and in compliance with Cochrane criteria recommendations (PROSPERO registration number CRD 42022343371). An electronic search was performed in the following databases: Pubmed, Web of Science, Medline, Current Contents Connect, SciELO, KCI-Korean Journal Database, Derwent Innovations Index and Russian Citation Index. The search strategy yielded a total of 18 articles. A randomized meta-analysis model of the results for the CIE L*a*b* color variables stratified by age (less than 30 years, 30-60 years, 60 years and older) was performed with 9 of the 18 studies included in this systematic review. According to our results, sex and location of color measurement are the most influential factors in color estimation. All studies were carried out in healthy anterior teeth by spectrophotometry as the most commonly used method for color measurement, with CIE L*a*b* being the most commonly analyzed parameters. Studies based on age as a dependent variable showed R2 values between 0.28 and 0.56, being higher in ex vivo teeth. Studies based on age as an independent variable showed R2 values ranging from 0.10 to 0.48. The random model showed high heterogeneity for the L*, a* and b* parameters in all age groups, which is explained by discrepancies in age range and non-standardized conditions for color measurement. This systematic review highlights the need to protocolize age estimation studies that measure tooth color, in order to apply this method in different forensic settings.

Detecting missing teeth on PMCT using statistical shape modeling

The identification of teeth in 3D medical images can be a first step for victim identification from scant remains, for comparison of ante- and postmortem images or for other forensic investigations. We evaluate the performance of a tooth detection approach on mandibles with missing parts or pathologies based on statistical shape models. The proposed approach relies on a shape model that has been built from the full lower jaw, including the mandible and teeth. The model is fitted to the target, resulting in a reconstruction, in addition to a label map that indicates the presence or absence of teeth. We evaluate the accuracy of the proposed solution on a dataset consisting of 76 target mandibles, all extracted from CT images and exhibiting various cases of missing teeth or other cases, such as roots, implants, first dentition, and gap closure. We show an accuracy of approximately 90% on the front teeth (including incisors and canines in our study) that decreases for the molars due to high false-positive rates at the wisdom teeth level. Despite the drop in performance, the proposed approach can be used to obtain an estimate of the tooth count without wisdom teeth, tooth identification, reconstruction of the existing teeth to automate measurements taken as part of routine forensic procedures, or prediction of the missing teeth shape. In comparison to other approaches, our solution relies solely on shape information. This means it can be applied to cases obtained from either medical images or 3D scans because it does not depend on the imaging modality intensities. Another novelty is that the proposed solution avoids heuristics for the separation of teeth or for fitting individual tooth models. The solution is therefore not target-specific and can be directly applied to detect missing parts in other target organs using a shape model of the new target.

Sex estimation by volumetric evaluation of the maxillary canine using cone-beam computed tomographic images

BACKGROUND

Teeth can be a reasonable part of sex estimation in case of being the single evidence available or in doubt although they are not as accurate as bones in sex estimation. The size of teeth is greater in males than in females. In this study, it was aimed to determine cut-off values of the tooth volume (TV) and root volume (RV) of the maxillary canines and to evaluate the validity of the method for discriminating between males and females.

METHODS

Cone beam computed tomography (CBCT) images of 250 individuals aged 18 to 63 years with equal age and sex distribution were assessed retrospectively. The sample divided into reference set including 168 images of 84 females and 84 males and validation set including 82 images of 48 females and 34 males. Receiver operating characteristic (ROC) curve analysis, and Youden's index were used to determine cut-off values of the volumetric measurements and to test the discriminative performance of the method.

RESULTS

The optimal cut-off values of TV ≥ 581 mm3 and RV ≥ 334 mm3 for estimating sex were established from the reference set. The sensitivity (Se), specificity (Sp), and accuracy (Ac) were 0.77 for TV ≥ 581 mm3 while they were 0.82, 0.77, and 0.79 for RV ≥ 334 mm3. When we tested the previously derived cut-off values of TV of the maxillary canine, the Se, Sp, and Ac were found to be respectively 0.71, 0.90, and 0.82 for TV ≥ 619 mm3 and 0.97, 0.27, and 0.56 for TV ≥ 510 / 460 mm3 (right/left).

CONCLUSIONS

The identified cut-off values of TV and RV of the maxillary canines can be used to estimate sex with moderate accuracy when the only evidence available is teeth or in case of doubt. The method's applicability should be assessed for different populations.

Bone and Tooth: Substrates for determining Drowning: A new diagnostic procedure in forensic medicine Practice?

INTRODUCTION

Diatom tests are rarely used during autopsy to confirm drowning as the cause of death (COD) because of limitations of the current literature involving these techniques. Instead, experts rely on physical examination by the pathologist. Due to interpretive concerns regarding Diatom tests, they are often insufficient in establishing a diagnosis, but offer the potential to be an extremely useful diagnostic tool with further understanding. The aim of study is to optimize "Diatom Tests" for use in forensic medicine in Bosnia and Herzegovina.

METHODS

A randomized prospective experimental study was conducted, using albino Wistar rat models (Rattus norvegicus), at the Veterinary Facility, University of Sarajevo. Thirty-two adult albino rats, were used and distributed into groups as follows: Group A (6 deceased rats with COD other than drowning, but due to mechanical asphyxia, which were then submerged for 1 h after death); Group B (6 deceased rats with COD other than drowning, but due to mechanical asphyxia, which were then submerged for 72 h after death); Group C (6 rats that were immediately autopsied after drowning, with COD determined as drowning); Group D (6 rats that underwent a 48-hour postmortem period after drowning); Group E (COD: drowning, post-mortem 72hrs after death, remained submerged in water until PM). Live algological material was collected for the research of the systematics of algae from the Bosna river, Sarajevo, and transported to the University of Sarajevo (Department of Biology, Faculty of Science). Periphyllon, epiphyllon and epipelon were used to collect phytobenthos. The material was fixed with 4% formalin solution. Laboratory processing of diatoms was performed using the methods described by Hustedt (16). In the process of obtaining pure diatom valves, part of the material is digested with potassium permanganate (KMnO4), sulfuric acid (H2SO4), and oxalic acid (C2H2O4). In the next step, the cleaned diatom valves were mounted in Canadian balsam. A light microscope under 1000x magnification (Best Scope 2020) was used to evaluate and analyze the species. The identification of diatoms was performed using the reference of Cantonati et al (17). The nomenclature of diatom species was performed according to Guiry & Guiry's worldwide electronic internet database.

RESULTS

No diatoms were found in Groups A and B. However, Navicula sp. and Sellaphora sp. cf., were discovered during bone analysis of Group C where rats were immediately autopsied after drowning. Hantzschia amphioxus taxon was present in Group D, which underwent a 48-hour postmortem period after drowning and before samples were taken. In Groups C and D, where drowning was the COD, Diatoma vulgaris i Pinnularia major, Achnanthidium minutissimum i Melosira varians were present in the tooth samples.

CONCLUSION

Optimization of the "Diatom Test" method could potentially lead to its future use as a routine method within experimental settings. This experimental study is a starting point that guides forenscic medicine pracitioners towards the optimization of tests and sampling in cases of unexplained etiology, where preserved soft tissue structures is not available. In these cases, teeth and bones serve as accessible materials for diagnosing COD, alongside standardized nonspecific findings in the absence of organs for micro- and macroanalysis.

Application of the Kvaal method to CBCT reconstructed panoramic images for age estimation

As the teeth are more durable than other parts of the skeleton, they provide valuable data for age estimation. Age estimation from adult teeth is mainly based on secondary dentin production. The present study aimed to devise a regression formula for age estimation specific to the Anatolian population using the Kvaal method on CBCT reconstructed panoramic images. In total, 201 individuals aged between 20 and 69 were divided into two groups: data from the study group (n = 101) were used to create the regression formulae, and data from the control group (n = 100) were used to test the formulae. Pearson's correlation coefficients and linear regression analyses were performed. Maxillary teeth provided more accurate age estimates than mandibular teeth. The regression formulae derived in this study are found to be statistically applicable and reasonably accurate. However, these results should be interpreted with caution.

Drugs in dental biofilm and enamel - A pilot study

Objective

Enamel and dental biofilm might serve as alternative matrices for determination of illicit and medical drugs. Thus, this study aims at evaluating possible correlations between detected drug concentrations in the matrices and simulated drug use in situ.

Design

Eleven subjects wore intraoral splints with embedded demineralized bovine enamel samples. Drug use was simulated by mouth rinsing with a 1.0 μg/ml drug solution three times daily for 1 min (study A) or by incubation of the splints in a 10 μg/ml drug solution once a day for 30 min (study B). Amphetamines, opiates, cocaine and benzoylecgonine were used as drugs. After 11 days, biofilm and enamel samples of the intraoral splints were analyzed by liquid chromatography mass spectrometry after drying and extraction via ultrasonication with acetonitrile (biofilm) or methanol (enamel).

Results

In study A, median and mean drug concentration ± standard deviation were 1.3 pg/mg and 6.4 ± 11 pg/mg in biofilm and 0.2 pg/mg and 0.5 ± 0.9 pg/mg in enamel. In study B, median and mean drug concentration ± standard deviation were 350 pg/mg and 1100 ± 1600 pg/mg in biofilm and 5.8 pg/mg and 9.9 ± 10 pg/mg in enamel.

Conclusions

Overall, there were considerable interindividual concentration differences. Correlations between concentrations in the two sample materials were shown. The results of this pilot study revealed a dependence of concentrations on intensity and duration of drug contact. Thus, important information on past drug use might be provided in forensic cases by analysis of dental biofilm and enamel.

Volumetric Analysis of Various Pediatric Rotary Files in the Preparation of Primary Root Canals Using Cone-beam Computed Tomography

Aim

This study was planned to evaluate and compare the cleaning efficacy of three pediatric rotary files with the standard Protaper adult file system in primary teeth using cone-beam computed tomography (CBCT).

Materials and methods

A total of 40 extracted deciduous second molars, with palatal/mesial roots having at least two-thirds of root length and an intact furcation area, were distributed randomly among four groups, with each group containing 10 teeth. Canal preparation of group I (Pro AF Baby Gold), group II (Kedo SG Blue), group III (Prime Pedo), and group IV (Protaper) was done. Pre- and postoperative CBCT images were taken. The volumetric changes of the root canals were assessed and subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) version 16 and R Studio 3.1.1. Volumetric changes within the groups were analyzed using paired t-tests and between the groups using analysis of variance (ANOVA).

Results

The comparison of mean volume difference between groups using ANOVA was statistically significant with F = 4.467, p = 0.002. A Tukey post hoc test revealed that group IV was statistically significant compared with groups I (p = 0.033) and III (p = 0.008) but was not statistically significant with group II (p = 0.170). There was no statistically significant difference in volumetric changes within the three pediatric rotary file systems.

Conclusion

Protaper removed more dentin than all the pediatric rotary files, but it was not statistically significant over Kedo SG Blue. Among the pediatric rotary files, Kedo SG Blue removed more dentin than Pro AF Baby Gold and Prime Pedo, but they were not statistically significant.

How to cite this article

Nainer Chidambaram JV, Jayaprakash J, Arangannal P. Volumetric Analysis of Various Pediatric Rotary Files in the Preparation of Primary Root Canals Using Cone-beam Computed Tomography. Int J Clin Pediatr Dent 2024;17(1):15-20.

Risk factors of cognitive impairment: Impact of decline in oral function

Cognitive impairment and subsequent dementia are the major causes of disability and need for nursing care among older people in worldwide. The purpose is to review well-known risk factors for cognitive impairment and dementia, focusing on the relationship between decline in oral function and current prevention strategies. Various non-modifiable and modifiable risk factors are related to cognitive impairment. Effects of oral function to cognitive impairment is not yet well recognized in the medical community, although masticatory function, occlusal force, and number of teeth have been reported to be related to cognitive function. Furthermore, occlusal force rather than number of teeth was significantly related to the early stages of cognitive impairment, and that a decline in occlusal force seemed to lead to cognitive impairment directly and indirectly through dietary intake. This relationship was significant only for occlusal force, which may be associated with the early stages of cognitive decline. Nutritional change caused by reduced masticatory function is suggested as a possible explanation. Therefore, rehabilitation or maintenance of oral function should be sought to prevent cognitive impairment.

Prevalence and severity of dental caries in school children in Saudi Arabia: A nationwide cross-sectional study

Aim

This nationwide study assessed the prevalence and severity of dental caries in 6-, 12-, and 15-year-old school children across Saudi Arabia. This study examined differences between genders and among regions regarding the mean values of decayed, missing, and filled teeth (dmft/DMFT), the care index (CI), and the significant caries index (SiC index).

Materials and methods

Data from 19,870 participants, 10,435 males and 9435 females, were collected using stratified multistage cluster random sampling. The survey team divided Saudi Arabia into five regions (northern, eastern, western, southern, and middle). To represent each respective region, a large city, two random towns (peri-urban), and four random rural areas were selected for surveying. Lastly, the sampling technique was applied by choosing random schools and random classes within the selected schools. Dental caries were assessed using the dmft/DMFT score, CI, and the top 30% and 10% of the sample dmft/DMFT scores (SiC30 and SiC10, respectively).

Results

The overall prevalence of caries was 65.6%, with 72.1 occurring in primary teeth and 61.7% in permanent teeth. The percentages of individuals with missing teeth and filled teeth were 9.0% and 20.5%, respectively. The mean dmft was 3.93 ± 3.60, while the mean DMFT was 2.42 ± 2.52; most of the DMFT components were significantly higher in females than males, while the dmft components were higher in males. The northern region had the highest and worst DMFT/dmft ratios of the five regions. The mean SiC30 and SiC10 values were significantly higher than the overall average DMFT/dmft values (P < 0.001).

Conclusion

Dental caries remain a public health challenge among school children in Saudi Arabia. The SiC and CI analysis indicated that caries management had a high overall efficacy, but that certain groups of the population may need targeted management in the future.

Contributions of increased osteopontin and hypophosphatemia to dentoalveolar defects in osteomalacic Hyp mice

X-linked hypophosphatemia (XLH) is an inherited disorder caused by inactivating mutations in the PHEX gene leading to renal phosphate wasting, rickets and osteomalacia. XLH is also associated with dentoalveolar mineralization defects in tooth enamel, dentin and cementum, and in alveolar bone, which lead to an increased prevalence of dental abscesses, periodontal disease and tooth loss. Genetic mouse experiments, and deficiencies in XLH patient therapies where treatments do not fully ameliorate mineralization defects, suggest that other pathogenic mechanisms may exist in XLH. The mineralization-inhibiting, secreted extracellular matrix phosphoprotein osteopontin (OPN, gene Spp1) is a substrate for the PHEX enzyme whereby extensive and inactivating degradation of inhibitory OPN by PHEX facilitates mineralization. Conversely, excess OPN accumulation in skeletal and dental tissues - for example in XLH where inactivating mutations in the PHEX gene limit degradation of inhibitory OPN, or as occurs in Fgf23-null mice - contributes to mineralization defects. We hypothesized that Spp1/OPN ablation in Hyp mice (a mouse model for XLH) would reduce dentoalveolar mineralization defects. Immunostaining revealed increased OPN in Hyp vs. wild-type (WT) alveolar bone, particularly in osteocyte lacunocanalicular networks where Hyp mice have characteristic hypomineralized peri-osteocytic lesions (POLs). Micro-computed tomography and histology showed that ablation of Spp1 in Hyp mice (Hyp;Spp1-/-) on a normal diet did not ameliorate bulk defects in enamel, dentin, or alveolar bone. On a high-phosphate diet, both Hyp and Hyp;Spp1-/- mice showed improved mineralization of enamel, dentin, and alveolar bone. Silver staining indicated Spp1 ablation did not improve alveolar or mandibular bone osteocyte POLs in Hyp mice; however, they were normalized by a high-phosphate diet in both Hyp and Hyp;Spp1-/- mice, although inducing increased OPN. Collectively, these data indicate that despite changes in OPN content in the dentoalveolar mineralized tissues, there exist other compensatory mineralization mechanisms that arise from knockout of Spp1/OPN in the Hyp background.

Deciphering load attenuation mechanisms of the dentin-enamel junction: Insights from a viscoelastic constitutive model

A considerable material discontinuity between the enamel and dentin might jeopardize the tooth's mechanical durability over time without the attenuation of the dentin-enamel junction (DEJ). However, the critical loading transmission mechanism at the DEJ remains understudied. This study aimed to define the extent and effective width of the DEJ, along with its mechanical competence. The presence of DEJ interphase layer was identified using a motif analysis based on the ion beam-transmission electron microscopy coupled with nanoindentation modulus mapping. For each region, nanoindentation load-displacement curves were recorded and mathematically analyzed using an appropriate viscoelastic constitutive model. The time-course of indenter penetration (creep) behavior of the tooth tissues can be mathematically approximated by the Kelvin-Voigt model in series, which determined the visco-contribution to the overall mechanical responses. Therefore, the elastic-plastic contribution can be distinguished from the overall mechanical responses of the tooth after subtracting the visco-contributions. During the loading period, the enamel behavior was dominated by elastic-plastic responses, while both the dentin and DEJ showed pronounced viscoelastic responses. The instantaneous modulus of the DEJ, which was measured by eliminating viscoelastic behavior from the raw load-displacement curve, was almost double that of the dentin. The DEJ was stiffer than the dentin, but it exhibited large viscoelastic motion even at the initial loading stage. This study revealed that the load attenuation competence of the DEJ, which involves extra energy expenditure, is mainly associated with its viscoelasticity. The mathematical analysis proposed here, performed on the nanoindentation creep behavior, could potentially augment the existing knowledge on hard-tissue biomechanics. STATEMENT OF SIGNIFICANCE: In this study, we undertake a rigorous mechanical characterization of the dentin-enamel junction (DEJ) using an advanced nanoindentation technique coupled with a pertinent viscoelastic constitutive model. Our approach unveils the substantial viscoelastic contribution of the DEJ during the initial indentation loading phase and offers an elaborate delineation of the DEJ interphase layer through sophisticated image analysis. These insights significantly augment our understanding of tooth durability. Importantly, our innovative mathematical analysis of creep behavior introduces a novel approach with profound implications for future research in the expansive field of hard-tissue biomechanics. The pioneering methodologies and findings presented in this work hold substantial potential to invigorate progress in biomaterials research and fuel further explorations into the functionality of biological tissues.

The Relevant Oral Burden of Patients with Hidradenitis Suppurativa

INTRODUCTION

Interleukin-17 plays a pivotal role in both hidradenitis suppurativa (HS) and in maintaining oral homeostasis, but their potential link remains unknown. Thus, we aimed to evaluate and quantify the oral burden of patients with HS.

METHODS

In this real-life, multicenter, cross-sectional study, patients with HS were clinically evaluated by two board-certified dermatologists and two board-certified dentists. Oral comorbidities were carefully collected with medical history and therapeutic information.

RESULTS

A total of 102 patients (44.0 ± 0.9 years, body mass index 27.0 ± 2.2 kg/m2) were enrolled. Remarkably, 48% and 43% did not undergo at least an oral hygiene or a dental visit each year, respectively. Oral disorders were found in 55.9% of patients with HS, in particular 39.2% had caries and 46.7% reported at least one missing tooth. The main oral manifestations in patients with HS were recurrent aphthous stomatitis (N = 19, 19.2%), amalgam tattoo (N = 14, 14.1%), leukoplakia (N = 11, 11.1%), nicotinic stomatitis (N = 9, 9.1%), papilloma (N = 8, 8.1%), and geographic tongue (N = 8, 8.1%). Whilst the main predictor of oral pathological conditions was Hurley staging (P = 0.0276), multivariate regression analysis indicated that gender and International Hidradenitis Suppurativa Severity Score System (IHS4) were the main predictors for the presence of caries and number of missing teeth.

CONCLUSION

As a result of the relevant oral burden in patients with HS, dentists should be part of the multidisciplinary team and oral education should be promoted among patients with HS.

In vitro studies on the dependence of drug deposition in dentin on drug concentration, contact time, and the physicochemical properties of the drugs

The chemical analysis of dental hard tissues can provide information on previous drug use due to the deposition of drugs into this tissue. For the interpretation of analytical results in, e.g., postmortem toxicology or regarding archeological samples, the influence of drug dosing, consumption frequency, duration of intake and type of drug on analyte concentrations in teeth has to be characterized. To approximate these correlations, in vitro models were applied to investigate the time dependency of drug deposition via and against pulp pressure (perfusion studies) and the concentration dependency of drug deposition via oral cavity (incubation study) as well as the influence of de- and remineralization (pH cycling) on the incorporation of drugs in bovine dentin pellets. Some of the drugs of abuse most relevant in forensic case work (amphetamines, opiates, cocaine and benzoylecgonine) were applied. Concentrations in dentin samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after pulverization and extraction via ultrasonication with methanol. The studies showed that drug deposition in dentin likely depends on the physicochemical properties of the drug molecules as well as on the duration of contact with drugs via the blood stream and on drug concentrations present in the oral cavity. Higher drug concentrations in teeth can result from a more frequent or longer drug use. In addition, intake of higher doses or oral/inhalative consumption can also be expected to lead to higher drug concentrations. These findings can be helpful for the interpretation of postmortem cases.

Can acid produced from probiotic bacteria alter the surface roughness, microhardness, and elemental composition of enamel? An in vitro study

Probiotics are live microorganisms that upon administration in adequate amounts provide various health benefits to the host. Probiotics are "lactic acid-producing bacteria" as they release large amounts of organic acids, particularly lactic acids, in their surrounding environment. Although the acids produced by probiotics are beneficial for gastrointestinal and vaginal health, the acidogenic nature of probiotics has raised concerns among dental professionals, especially concerning their effect on the enamel and dentin. Previous studies have found that probiotics can lower the pH of the saliva and cause essential elements like Calcium and Phosphorus to leach from the enamel. This can alter the surface topography of enamel and increase the risk of enamel defects. Studies have also noted that probiotic bacteria can replace cariogenic bacteria and lower the risk of tooth decay. However, the effect of acid produced by probiotics on the enamel surface remains unclear. Hence, the present study aims to evaluate the effect of probiotics on the surface roughness, microhardness, and elemental composition of enamel compared to 0.1 M Lactic acid (demineralizing agent). Twenty enamel sections were randomly divided into groups and subjected to a pH cycling model using a probiotic suspension and 0.1 M lactic acid. The changes in the surface roughness, microhardness, surface morphology, and elemental composition of the enamel with regard to Carbon, Oxygen, Sodium, Hydrogen, Magnesium, Phosphorus, Fluoride, Chlorine, and Calcium of the enamel were evaluated before and after the emersion in both the groups. The results showed a significant increase in the mean surface roughness in the probiotic group before and after the exposure. The microhardness of the enamel decreased along with altered arrangement of the enamel prisms, increased striations, scratch marks, and pitting after exposure to the probiotic group. A decrease in the atomic/weight% for Calcium, Phosphorous, Fluoride, Aluminium, and Oxygen and an increase in the weight/atomic% for Carbon, Nitrogen, and Sodium were noted compared to the baseline in the probiotic solution. The results in the probiotic group were comparable to the 0.1 M lactic acids. The pH changed from 5.78 to 3.06 at the end of 24 h in the probiotic group. Based on these findings, we conclude that exposure to probiotics can affect microhardness and surface roughness and cause leaching of essential elements like Calcium and Phosphorous from the enamel.

Prevalence of dental alterations in patients under bisphosphonates therapy: a systematic review

This systematic review aimed to estimate the prevalence and describe dentoalveolar lesions associated with bisphosphonates therapy. A systematic review of the literature was conducted using the following databases: PubMed, Embase, Cochrane, CINAHL, Scopus, Web of Science, Lilacs, SciElo, and Grey Literature. Quality of individual studies analysis was performed by using Newcastle-Ottawa Scale. Certainty of cumulative evidence was achieved by applying Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. The software R Statistics version 4.0.5 (The R Foundation) was used for proportion estimations per study and corresponding confidence intervals were estimated through the Clopper-Pearson method. Four articles were included for the qualitative synthesis. Two studies were considered of good quality, one of fair, and one of poor quality. A total of 231 patients were encompassed. Widening of the periodontal ligament space (22.2-39.7%), periradicular radiolucencies (20-22.9%), and pulp calcifications (33.3-69.2%) were the most frequent alterations. Certainty of evidence was rated as very low. Based on limited evidence, this systematic review reports a variety of dentoalveolar alterations in patients under bisphosphonate therapy. These features might impact on dental clinical practice. However, the level of evidence is considered very low due to important limitations.

Genetic mapping of craniofacial traits in the Mexican tetra reveals loci associated with bite differences between cave and surface fish

BACKGROUND

The Mexican tetra, Astyanax mexicanus, includes interfertile surface-dwelling and cave-dwelling morphs, enabling powerful studies aimed at uncovering genes involved in the evolution of cave-associated traits. Compared to surface fish, cavefish harbor several extreme traits within their skull, such as a protruding lower jaw, a wider gape, and an increase in tooth number. These features are highly variable between individual cavefish and even across different cavefish populations.

RESULTS

To investigate these traits, we created a novel feeding behavior assay wherein bite impressions could be obtained. We determined that fish with an underbite leave larger bite impressions with an increase in the number of tooth marks. Capitalizing on the ability to produce hybrids from surface and cavefish crosses, we investigated genes underlying these segregating orofacial traits by performing Quantitative Trait Loci (QTL) analysis with F2 hybrids. We discovered significant QTL for bite (underbite vs. overbite) that mapped to a single region of the Astyanax genome. Within this genomic region, multiple genes exhibit coding region mutations, some with known roles in bone development. Further, we determined that there is evidence that this genomic region is under natural selection.

CONCLUSIONS

This work highlights cavefish as a valuable genetic model for orofacial patterning and will provide insight into the genetic regulators of jaw and tooth development.

Dental trauma in endoscopy: A systematic review and experience of a tertiary endoscopy centre

BACKGROUND

Dental injury is the leading cause of litigation in anaesthesia but an underrecognized preventable complication of endoscopy.

AIM

To determine frequency and effects of dental injury in endoscopy, we present findings from an audit of outpatient endoscopy procedures conducted at a tertiary university hospital and a systematic review of literature.

METHODS

Retrospective review of 11265 outpatient upper endoscopy procedures over the period of 1 June 2019 to 31 May 2021 identified dental related complications in 0.284% of procedures. Review of literature identified a similar rate of 0.33%.

RESULTS

Pre-existing dental pathology or the presence of prostheses makes damage more likely but sound teeth may be affected. Pre-endoscopic history and tooth examination are key for risk stratification and may be conducted succinctly with limited time outlay. Tooth retrieval should be prioritized in the event of dental injury to minimize aspiration and be followed by prompt dental consultation for specific management.

CONCLUSION

Dental complications occur in approximately 1 in 300 of upper endoscopy cases. These are easily preventable by pre-endoscopy screening. Protocols to mitigate dental injury are also suggested.

Late Jurassic teeth of plesiosauroid origin from the Owadów-Brzezinki Lägerstatte, Central Poland

Owadów-Brzezinki is currently one of the most promising Upper Jurassic sites in Central Poland, with a wide array of both vertebrate and invertebrate fossil fauna present. The discoveries of large-bodied marine reptiles fossils such as ichthyosaurs, turtles, and marine crocodylomorphs attracted attention to the location. A particular Mesozoic marine group, plesiosaurs, remained to be found, and in this report, we note four isolated teeth with distinguishing apicobasal ridging pattern and elongated, conical shape characteristic for plesiosaurians. The outcomes of the Principal Coordinates Analysis (PCoA) of the largest and most complete tooth specimen ZPAL R.11/OB/T4 enabled us to confirm its classification as Plesiosauroidea. This discovery affirms the importance of the site as the area of mixing between Boreal and Tethyan faunas, expanding the broad spectrum of fossil taxa found in this location. Together with previous findings of plesiosaur material in a nearby region, it provides the evidence for the presence of Plesiosauroidea in Owadów-Brzezinki Lägerstatte.

Stress exposure histories revealed by biochemical changes along accentuated lines in teeth

The regular incremental secretion of enamel and dentine can be interrupted during periods of stress resulting in accentuated growth lines. These accentuated lines, visible under light microscopy, provide a chronology of an individual's stress exposure. Previously, we showed that small biochemical changes along accentuated growth lines detected by Raman spectroscopy, coincided with the timing of medical history events and disruptions of weight trajectory in teeth from captive macaques. Here, we translate those techniques to study biochemical changes related to illness and prolonged medical treatment during early infancy in humans. Chemometric analysis revealed biochemical changes related to known stress-induced changes in circulating phenylalanine as well as other biomolecules. Changes in phenylalanine are also known to affect biomineralization which is reflected in changes in the wavenumbers of hydroxyapatite phosphate bands associated with stress in the crystal lattice. Raman spectroscopy mapping of teeth is an objective, minimally-destructive technique that can aid in the reconstruction of an individual's stress response history and provide important information on the mixture of circulating biochemicals associated with medical conditions, as applied in epidemiological and clinical samples.

Dermatoglyphic Patterns in Patients Having Impacted and Erupted Third Molars-A Comparative Study

Background

The dermatoglyphics have been used in several researches for predicting various pathologies of oral cavity like periodontitis, dental caries, impacted teeth, mal-occlusion, developmental defects such as cleft lip and palate, and potentially malignant disorders. Impacted teeth may be associated with various pathologies such as caries, pericoronitis, dentigerous cysts, and keratocystic odontogenic tumors; therefore, predicting impacted teeth through dermatoglyphic patterns can help in diagnosis and future treatment planning of such event.

Aims and Objectives

The aim and objective of the study were to evaluate and compare various dermatoglyphic patterns in the patients with the impacted maxillary and/or mandibular third molar (group 1) and patients having erupted maxillary and/or mandibular third molar (group 2).

Materials and Methods

This study comprised totally 300 patients, which were divided into two groups, according to erupted or impacted maxillary and/or mandibular third molar visiting outpatient department, who fulfilled the selection criteria for the study. After a comprehensive clinical examination, dermatoglyphic patterns were recorded from the same individuals. Panoramic radiographs were taken to confirm the diagnosis. Data collected were entered in the spreadsheet and analyzed. For all tests, P value was set at <0.05 and was considered statistically significant.

Result

There was statistical significance noted in frequencies of whorl pattern in patients of group 1 and loop pattern in patients of group 2.

Conclusion

This study concluded that dermatoglyphic patterns can be used to assess the prevalence of impacted wisdom teeth.

Radiographic dental age estimation applying and comparing Demirjian's seven (1973) and four (1976) teeth methods

To apply Demirjian's seven (1973, D7) and four (1976, D4) teeth methods in a sample of Brazilian children and compare their performances for age estimation. Panoramic radiographs of 1200 children (600 females and 600 males) were collected from Southeast Brazil. The children were equally distributed (n = 60 females and 60 males) between age intervals of 1 year between 6 and 15.9 (mean age = 10.9; standard deviation [SD]: 2.9) years. D7 and D4 dental age estimation methods were applied by two observers and were compared based on their error rates (error = estimated age-chronological age). Both methods overestimated the chronological age (p < 0.0001). D7 led to overestimations of 0.71 (p < 0.0001) in females and 0.83 (p < 0.0001) in males, while the overestimations with D4 were 0.14 (p = 0.0067) and 0.73 (p < 0.0001) for females and males, respectively. The mean age estimated by D7 was 11.7 (SD: 3.1) years, while for D4, it was 11.3 (SD: 3.3) years. Intra- and interobserver agreement was ≥ 0.98. D4 optimized the performance of radiographic dental age estimation compared to D7. Improvements were reflected in the total sample and separately for female and male children from Southeast Brazil.

Isolated tooth reveals hidden spinosaurid dinosaur diversity in the British Wealden Supergroup (Lower Cretaceous)

Isolated spinosaurid teeth are relatively well represented in the Lower Cretaceous Wealden Supergroup of southern England, UK. Until recently it was assumed that these teeth were referable to Baryonyx, the type species (B. walkeri) and specimen of which is from the Barremian Upper Weald Clay Formation of Surrey. British spinosaurid teeth are known from formations that span much of the c. 25 Ma depositional history of the Wealden Supergroup, and recent works suggest that British spinosaurids were more taxonomically diverse than previously thought. On the basis of both arguments, it is appropriate to doubt the hypothesis that isolated teeth from outside the Upper Weald Clay Formation are referable to Baryonyx. Here, we use phylogenetic, discriminant and cluster analyses to test whether an isolated spinosaurid tooth (HASMG G369a, consisting of a crown and part of the root) from a non-Weald Clay Formation unit can be referred to Baryonyx. HASMG G369a was recovered from an uncertain Lower Cretaceous locality in East Sussex but is probably from a Valanginian exposure of the Hastings Group and among the oldest spinosaurid material known from the UK. Spinosaurid affinities are both quantitatively and qualitatively supported, and HASMG G369a does not associate with Baryonyx in any analysis. This supports recent reinterpretations of the diversity of spinosaurid in the Early Cretaceous of Britain, which appears to have been populated by multiple spinosaurid lineages in a manner comparable to coeval Iberian deposits. This work also reviews the British and global records of early spinosaurids (known mainly from dental specimens), and revisits evidence for post-Cenomanian spinosaurid persistence.

Aspects of molar form and dietary proclivities of African colobines

This study investigates aspects of molar form in three African colobine species: Colobus polykomos, Colobus angolensis, and Piliocolobus badius. Our samples of C. polykomos and P. badius are from the Taï Forest, Ivory Coast; our sample of C. angolensis is from Diani, Kenya. To the extent that protective layers surrounding seeds are hard, we predicted that molar features related to hard-object feeding would be more pronounced in Colobus than they are Piliocolobus, as seed-eating generally occurs at higher frequencies in species of the former. We further predicted that among the colobines we studied, these features would be most pronounced in Taï Forest C. polykomos, which feeds on Pentaclethra macrophylla seeds encased within hard and tough seed pods. We compared overall enamel thickness, enamel thickness distribution, absolute crown strength, cusp tip geometry, and flare among molar samples. Sample sizes per species and molar type varied per comparison. We predicted differences in all variables except overall enamel thickness, which we expected would be invariant among colobines as a result of selection for thin enamel in these folivorous species. Of the variables we examined, only molar flare differed significantly between Colobus and Piliocolobus. Our findings suggest that molar flare, an ancient feature of cercopithecoid molars, was retained in Colobus but not in Piliocolobus, perhaps as a result of differences in the seed-eating proclivities of the two genera. Contrary to predictions, none of the aspects of molar form we investigated tracked current dietary differences in seed-eating between the two Colobus species. Finally, we explored the possibility that molar flare and absolute crown strength, when analyzed together, might afford greater differentiation among these colobine species. A multivariate t test of molar flare and absolute crown strength differentiated C. polykomos and P. badius, possibly reflecting known niche divergence between these two sympatric Taï Forest species.

An Unusual Case of Mesial Supplementary Lateral Incisor: A Case Report

By definition, supplemental teeth are supernumerary teeth (ST) resembling adjacent teeth at the end of a tooth series and are well aligned in the arch. A case of the non-syndrome, supplemental type of supernumerary lateral incisor is presented, along with an unusual habit that was noted accidentally in the same child. In the present case, of the two lateral incisors, the mesial supplemental lateral incisor was causing an impaction of 11. In addition, the patient was aesthetically concerned. So, the decision was made to extract the supplemental tooth with altered morphology (mesial one) under local anesthesia even though, as per definition, the distal one is the supplementary tooth. And finally, to align the incisors by orthodontic treatment.

Aim

A case of the non-syndrome, supplemental type of supernumerary lateral incisor is presented, along with an unusual habit of that was noted accidentally in the same child.

Background

By definition, supplemental teeth are supernumerary teeth (ST) resembling adjacent teeth at the end of a tooth series and are well aligned in the arch.

Case description

In the present case, of the two lateral incisors, the mesial supplemental lateral incisor was causing impaction of 11. In addition, the patient was aesthetically concerned.

Conclusion

Decision was made to extract the supplemental tooth with altered morphology (mesial one) under local anesthesia even though, as per definition, the distal one is the supplementary tooth. And finally, to align the incisors by orthodontic treatment.

Clinical significance

Decision-making regarding removal of tooth is quite baffling as a selective removal of the normal or the supplementary tooth may be required and it should be made after analyzing multiple factors.

How to cite this article

Sojan M, Thakur S. An Unusual Case of Mesial Supplementary Lateral Incisor; A Case Report. Int J Clin Pediatr Dent 2023;16(3):518-521.

Divergent tooth development mechanisms of Mexican tetra fish (Astyanax mexicanus) of Pachón cave origin

The Mexican tetra (Astyanax mexicanus) is one of the fresh water teleost fish models in evolutionary developmental biology. The existence of two morphs: eyed, pigmented surface fish and blind depigmented cavefish from multiple cave populations, provides a unique system to study adaptive radiation. Compared to the adult surface fish, cavefish have large oral jaws with an increased number of structurally-complex teeth. Early tooth development has not been studied in detail in cavefish populations. In this study, bone-stained growth series and vital dye staining was used to trace the development and replacement of dentitions in Pachón cavefish. Our results show that first tooth eruption was delayed in cavefish compared to the surface fish. In particular, the first tooth eruption cycle persisted until 35 days post fertilization (dpf). Unlike surface fish, there are multicuspid teeth in cavefish first generation dentition. In addition to the teeth in the marginal oral jaw bones, Pachón cavefish have teeth in the ectopterygoid bone of the palatine roof. Next, we characterised the expression of ectodysplasin signalling pathway genes in tooth-forming regions of surface and cavefish. Interestingly, higher expression of Eda and Edar was found in cavefish compared to the surface fish. The altered ectodysplasin expression needs further investigation to confirm the different molecular mechanisms for tooth development in the oral and pharyngeal regions of surface fish and cavefish.

Forensic DNA extraction methods for human hard tissue: A systematic literature review and meta-analysis of technologies and sample type

DNA identification of human remains has a valuable role in the field of forensic science and wider. Although DNA is vital in identification of unknown human remains, post-mortem environmental factors can lead to poor molecular preservation. In this respect, focus has been placed on DNA extraction methodologies for hard tissue samples, as these are the longest surviving. Despite decades of research being conducted on DNA extraction methods for bone and teeth, little consensus has been reached as to the best performing. Therefore, the aim of this study was to conduct a thorough systematic literature review to identify potential DNA extraction technique(s) which perform optimally for forensic DNA profiling from hard tissue samples. PRISMA guidelines were used, by which a search strategy was developed. This included identifying databases and discipline specific journals, keywords, and exclusion and inclusion criteria. In total, 175 articles were identified that detailed over 50 different DNA extraction methodologies. Results of the meta-analysis conducted on 41 articles - meeting further inclusion criteria - showed that statistically significant higher DNA profiling success was associated with solid-phase magnetic bead/resin methods. In addition, incorporating a demineralisation pre-step resulted in significantly higher profiling successes. For hard tissue type, bone outperformed teeth, and even though dense cortical femur samples were more frequently used across the studies, profiling success was comparable, and in some cases, higher in cancellous bone samples. Notably, incomplete data sharing resulted in many studies being excluded, thus an emphasis for minimum reporting standards is made. In conclusion, this study identifies strategies that may improve success rates of forensic DNA profiling from hard tissue samples. Finally, continued improvements to current methods can ensure faster times to resolution and restoring the identity of those who died in obscurity.

Changes in dental wear magnitude in the last ∼8000 years in southwestern Iberia

OBJECTIVE

This study examines changes in dental wear magnitude in the past ∼8000 years, i.e., since Mesolithic until the 19th century, in southwestern Iberia. Thus, it encompasses the transition from hunting-gathering to agro-pastoralism, and then to the industrialization of food production and pre-processing.

DESIGN

Dental wear magnitude was scored in a total of 191 individuals and 1557 teeth from Mesolithic (individuals=56; teeth=643), Neolithic (individuals=35; teeth=169), Chalcolithic (individuals =35; teeth=221), Modern Age (individuals=17; teeth=209), and Late Modern Age (individuals=48; teeth=315) samples originating in southwestern Iberia (i.e., present central and southern Portugal) and according to the 8 levels ordinal scale of Smith (1984).

RESULTS

Results show a general trend for decreased wear magnitude in these two major transitions and during this timespan (although the hunting-gathering - agro-pastoralism transition had larger impact). The only meaningful differences in wear rate were found between the Late Modern Age and all remaining samples.

CONCLUSION

Dental wear generally decreased during this timespan (although wear magnitude was less impacted by the industrialization of food production and pre-processing). Our results are consistent with studies documenting skull morphological gracilization associated with reduced masticatory demands due to the adoption of softer diets.

A casework study: The effect of the porcine digestive process on animal carcasses and human teeth

What happens if a human body is fed to pigs? Although a popular notion in the entertainment industry, no scientific published literature exists that documents this porcine feeding behaviour, nor, more importantly, what elements of the cadaver may survive such a process. A study conducted in 2020, born out of a casework enquiry, aimed to investigate the following two questions; Would pigs feed on a human body? And, if so, what could be recovered post feeding event? Kangaroo carcasses, porcine carcasses (as human analogues) and 90 human teeth were prepared, and fed, to two domestic pigs, in a variety of feed scenarios. Biological traces including bones, bone fragments, teeth and tooth fragments were recovered both post-digestion from the faeces of the pigs, as well as uneaten from the porcine enclosure. 29% of all human teeth were recovered from the study; 35% of which were recovered post-digestion from the faeces and 65% were recovered uneaten from the porcine enclosure, Of the recovered human teeth, 81% were deemed suitable for identification by a forensic odontologist. From the 447 bones recovered from the enclosure, 94% could be identified to a bone type and species. From all 3338 bone fragments recovered from the faeces of the pigs, none retained any morphological traits that would allow further intelligence to be generated. Overall, it was found that pigs will feed on human analogues and will consume soft tissue, bones, and human teeth. Biological traces in the form of bones, bone fragments, teeth and tooth fragments may be recovered both post-digestion from the faeces, or from the porcine enclosure. The biological traces can be used for identification of an individual via forensic odontology, identification of a species via forensic anthropology and may be suitable for DNA analysis. The outcomes of this study generated new avenues for investigation in the case and may be used to inform future operational resources.

A pilot study comparing optical coherence tomography, radiography, clinical photography, and polarisation microscopy for studies of hypomineralisation disturbances in enamel

Aim

To investigate the use of optical coherence tomography (OCT) as a tool to assess general and localised hypomineralisation defects in the enamel.

Design and Materials

Ten extracted permanent teeth (four teeth with localised hypomineralisation, four teeth with general hypomineralisation, and two healthy controls) were used in this study. In addition, four participants who underwent OCT served as living controls for the extracted teeth.

Methods

The OCT results were compared with clinical photographs, digital radiographs, and polarising microscopy images of tooth sections (considered the gold standard) to determine the method with the most accurate information regarding the extent of enamel disturbances: 1) visibility of enamel disturbance (visible yes/no); if yes, 2) extent of the disturbance in the enamel; and 3) determination of the plausible involvement of the underlying dentin.

Results

OCT was more accurate than digital radiography and visual assessment. OCT could provide information about the extent of localised hypomineralised disturbances in the enamel that was comparable to that with polarisation microscopy of the tooth sections.

Conclusion

Within the limitations of this pilot study, it can be concluded that OCT is suitable for investigating and evaluating localised hypomineralisation disturbances; however, it is less useful in cases with generalised hypomineralisation of the enamel. In addition, OCT complements radiographic examination of enamel; however, more studies are necessary to elucidate the full extent of the use of OCT in case of hypomineralisation.

Applicability of the London Atlas method in the East China population

BACKGROUND

Dental age estimation is important for developmental assessment and individual identification. The London Atlas, a recently proposed method for dental age estimation, has been reported to perform satisfactorily in various populations.

OBJECTIVE

In this study, we assessed the reproducibility, repeatability and applicability of the London Atlas method in the East China population and compared it with the Demirjian method.

MATERIALS AND METHODS

We assessed panoramic radiographs of 835 pediatric patients ages 6.0-19.9 years using the London Atlas and the Demirjian method. We employed the intraclass correlation coefficient and Bland-Altman analysis to evaluate reproducibility and repeatability, respectively. We assessed the agreement between dental age and chronological age and calculated 95% and 80% prediction intervals for each dental age stage. Sensitivity, specificity and predictive values were calculated to assess the performance of both methods for identifying threshold ages.

RESULTS

The London Atlas has better reproducibility and repeatability (intraclass correlation coefficients: 0.98 and 0.99; 95% limits of agreement: - 1.34 to 1.56 and - 1.22 to 0.88, respectively). Dental age estimated using the London Atlas was closer to chronological age in both genders (median absolute error = 0.58). The 95% prediction intervals for chronological age were wide (0.99 to 9.89 years).

CONCLUSION

The London Atlas has excellent reproducibility and repeatability. Thus, it might offer an alternative method for developmental assessment. We observed considerable variation in dental development in the East China population, which needs further research.

Risk of post-extraction bleeding with direct oral anticoagulant compared with warfarin: Retrospective cohort study using large scale claims data in Japan

INTRODUCTION

Comparative safety of direct oral anticoagulants vs. warfarin in patients undergoing tooth extraction remains unclear. We compared the incidence of post-extraction bleeding between patients taking warfarin and those taking direct oral anticoagulants (DOACs) using administrative claims data.

MATERIALS AND METHODS

We identified outpatients on anticoagulant therapy who underwent permanent tooth extraction between 2015 and 2020 and categorized them into the warfarin and DOAC groups based on medication prescribed within six months prior to tooth extraction. We used the overlap propensity score weighting method to balance the baseline characteristics between the groups and compared the incidence of post-extraction bleeding within seven days after tooth extraction.

RESULTS

Among 5253 eligible patients, those in the DOAC group (n = 3696) were older and less frequently prescribed antiplatelets than those in the warfarin group (n = 1557). The distribution of tooth extraction type and number of teeth extracted in a single procedure did not differ between the groups. The unadjusted incidences of post-extraction bleeding in the warfarin and DOAC groups were 35 (2.2 %) and 71 (1.9 %), respectively. Moreover, the overlap weighting analysis showed that the adjusted odds ratio of post-extraction bleeding in the DOAC group in comparison with that in the warfarin group was 0.84 (95 % confidence interval, 0.54-1.31).

CONCLUSION

The incidence of post-extraction bleeding in patients taking DOACs was comparable to that in patients taking warfarin. The findings suggest that dentists and physicians should exercise the same degree of caution when extracting teeth in patients on DOACs and those on warfarin in terms of post-extraction bleeding.

Masticaticatory muscles characteristics in relation to adiposity and general muscular fitness: a population-based study

There is still considerable controversy surrounding the impact of mastication on obesity. The aim of this study was to identify the interplay between the masticatory muscles, teeth, and general muscular fitness and how they contribute to body adiposity in a general German population. This cross-sectional study included 616 participants (300 male, 316 female, age 31-93 years) from the population-based Study of Health in Pomerania. The cross-sectional areas of the masseter, medial and lateral pterygoid muscles were measured using magnetic resonance imaging (MRI), muscular fitness assessed by hand grip strength (HGS) and body fat distribution was measured by bioelectrical impedance analysis (BIA) and MRI. The overall prevalence of obesity was high in our cohort. The cross-sectional area of the masseter muscles was positively associated with the number of teeth, body mass index (BMI) and HGS, and negatively associated with the BIA-assessed body fat when adjusted for age, sex, teeth, and BMI. Especially the correlation was strong (p < 0.001). Analogous relationships were observed between the masseter, HGS and MRI-assessed subcutaneous fat. These associations were most pronounced with masseter, but also significant with both pterygoid muscles. Though the masticatory muscles were affected by the number of teeth, teeth had no impact on the relations between masseter muscle and adiposity. Physical fitness and masticatory performance are associated with body shape, controlled and directed by the relevant muscles.

Chronic Therapy-Resistant Neck Pain in a Fifty-Year-Old Man: The Role of Partially Impacted Third Molars - Case Report and New Pathophysiological Insights

BACKGROUND

Inflammatory and mechanical stimuli in tooth/jaw pathologies can have far-reaching consequences via trigeminal and autonomic circuitry and can cause systemic (e.g., autoimmune) diseases and pain conditions outside the tooth/jaw region. In addition to a case report, we also describe new pathophysiological findings.

CASE REPORT

We report on a patient with chronic, therapy-resistant neck pain whose cause lied in the tooth/jaw region, specifically, in wisdom teeth with space problems, and partially impacted. The tooth/jaw area itself was not painful; however, neck pain developed via the nucleus spinalis n. trigemini which extends into the cervical medulla. Surgical restoration of the wisdom teeth and subsequent neural therapy treatment of the extraction scars provided permanent pain relief.

CONCLUSION

In case of therapy-resistant neck pain (among others), it is worthwhile to look for pathologies in the dental/jaw area, possibly allowing for a causal therapy.

Observations on heterodonty within the dentition of the Atlantic Sharpnose Shark, Rhizoprionodon terraenovae (Richardson, 1836), from the north-central Gulf of Mexico, USA, with implications on the fossil record

The Atlantic Sharpnose Shark, Rhizoprionodon terraenovae (Richardson, 1836), is the most common small coastal requiem shark in the north-central Gulf of Mexico, USA. Despite this fact, little is known about the dental variation within this taxon. To help rectify this shortcoming, we examined 126 male and female R. terraenovae jaws sets across all maturity stages to document the various types of heterodonty occurring in the dentition of this taxon. Quantitative data gathered from a subset of our sample allowed for us to place teeth within the dentition of R. terraenovae into standardized upper and lower parasymphyseal/symphyseal, anterior lateral, and posterior tooth groups. As with all carcharhinid sharks, the dentition of R. terraenovae exhibits monognathic and dignathic heterodonty. We also observed significant ontogenetic heterodonty in the species, as the teeth and dentition progress through five generalized developmental stages as the shark matures. The ontogenetic development of serrations on the teeth appears to be closely related to documented dietary changes as the shark matures. Initial diets are comprised of high percentages of invertebrate prey like shrimp, crabs, and squid, but this transitions through ontogeny to a diet that is more reliant on fishes. We also provide the first documentation of gynandric heterodonty in mature male R. terraenovae, with development of these seasonal teeth likely enabling a male to grasp female sharks during copulation. Our analysis revealed a tremendous amount of variation in the dentition of R. terraenovae, which has direct implications on the taxonomy of fossil Rhizoprionodon. A comparison of the jaws in our sample to those of the extant species of Rhizoprionodon and the morphologically similar Loxodon, Scoliodon, and Sphyrna allowed us to formulate a list of generic-level characteristics to assist with the identification of isolated teeth. When applied to the fossil record, it is shown that some species previously assigned to Rhizoprionodon likely belong to one of the other aforementioned genera. The earliest occurrence of unequivocal Rhizoprionodon teeth in the fossil record are those of the Eocene †R. ganntourensis (Arambourg, 1952), the oldest records of which occur in early Ypresian deposits in Alabama and Mississippi, USA. The early Eocene occurrence of unequivocal fossil Rhizoprionodon teeth in Alabama predates the first occurrence of Negaprion, Galeocerdo, and Carcharhinus teeth in the state, supporting published molecular and morphological phylogenies positing a basal position for Rhizoprionodon within the Carcharhinidae.

Artificial intelligence for oral and dental healthcare: Core education curriculum

OBJECTIVES

Artificial intelligence (AI) is swiftly entering oral health services and dentistry, while most providers show limited knowledge and skills to appraise dental AI applications. We aimed to define a core curriculum for both undergraduate and postgraduate education, establishing a minimum set of outcomes learners should acquire when taught about oral and dental AI.

METHODS

Existing curricula and other documents focusing on literacy of medical professionals around AI were screened and relevant items extracted. Items were scoped and adapted using expert interviews with members of the IADR's e-oral health group, the ITU/WHO's Focus Group AI for Health and the Association for Dental Education in Europe. Learning outcome levels were defined and each item assigned to a level. Items were systematized into domains and a curricular structure defined. The resulting curriculum was consented using an online Delphi process.

RESULTS

Four domains of learning outcomes emerged, with most outcomes being on the "knowledge" level: (1) Basic definitions and terms, the reasoning behind AI and the principle of machine learning, the idea of training, validating and testing models, the definition of reference tests, the contrast between dynamic and static AI, and the problem of AI being a black box and requiring explainability should be known. (2) Use cases, the required types of AI to address them, and the typical setup of AI software for dental purposes should be taught. (3) Evaluation metrics, their interpretation, the relevant impact of AI on patient or societal health outcomes and associated examples should be considered. (4) Issues around generalizability and representativeness, explainability, autonomy and accountability and the need for governance should be highlighted.

CONCLUSION

Both educators and learners should consider this core curriculum during planning, conducting and evaluating oral and dental AI education.

CLINICAL SIGNIFICANCE

A core curriculum on oral and dental AI may help to increase oral and dental healthcare providers' literacy around AI, allowing them to critically appraise AI applications and to use them consciously and on an informed basis.

[Research Progress in the Application of Terahertz Spectroscopy and Imaging Technology in Stomatology]

Terahertz waves, the electromagnetic waves in the range of 0.1 to 10 THz, has the advantages of being damage-free, causing no ionizing radiation injury, and being capable of recognizing the fingerprint spectrum of molecular characteristics, thus holding encouraging prospects for wide applications in the field of biomedicine. Terahertz spectrum can be used to identify and characterize biological structures of different levels, from biomolecules such as proteins to cells and tissues, through the spectral signals and/or restored images of the samples. Herein, we summarized the current stomatogical application of and research progress in terahertz spectroscopy and imaging in dentistry, reported the latest research findings, strengths and limitations from three perspectives, tooth anatomical structure, the extent of caries progression, and oral soft tissue, and suggested possible directions for future exploration.

Impact of different oral treatments on the composition of the supragingival plaque microbiome

Background

Dental plaque consists of a diverse microbial community embedded in a complex structure of exopolysaccharides. Dental biofilms form a natural barrier against pathogens but lead to oral diseases in a dysbiotic state.

Objective

Using a metaproteome approach combined with a standard plaque-regrowth study, this pilot study examined the impact of different concentrations of lactoperoxidase (LPO) on early plaque formation, and active biological processes.

Design

Sixteen orally healthy subjects received four local treatments as a randomized single-blind study based on a cross-over design. Two lozenges containing components of the LPO-system in different concentrations were compared to a placebo and Listerine®. The newly formed dental plaque was analyzed by mass spectrometry (nLC-MS/MS). 

Results

On average 1,916 metaproteins per sample were identified, which could be assigned to 116 genera and 1,316 protein functions. Listerine® reduced the number of metaproteins and their relative abundance, confirming the plaque inhibiting effect. The LPO-lozenges triggered mainly higher metaprotein abundances of early and secondary colonizers as well as bacteria associated with dental health but also periodontitis. Functional information indicated plaque biofilm growth.

Conclusion

In conclusion, the mechanisms on plaque biofilm formation of Listerine® and the LPO-system containing lozenges are different. In contrast to Listerine®, the lozenges led to a higher bacterial diversity.

A previously overlooked, highly diverse early Pleistocene elasmobranch assemblage from southern Taiwan

The Niubu fossil locality in Chiayi County, southern Taiwan is best known for its rich early Pleistocene marine fossils that provide insights into the poorly understood past diversity in the area. The elasmobranch teeth at this locality have been collected for decades by the locals, but have not been formally described and have received little attention. Here, we describe three museum collections of elasmobranch teeth (n = 697) from the Liuchungchi Formation (1.90-1.35 Ma) sampled at the Niubu locality, with an aim of constructing a more comprehensive view of the past fish fauna in the subtropical West Pacific. The assemblage is composed of 20 taxa belonging to nine families and is dominated by Carcharhinus and Carcharodon. The occurrence of †Hemipristis serra is of particular importance because it is the first Pleistocene record in the area. We highlight high numbers of large Carcharodon carcharias teeth in our sample correlating to body lengths exceeding 4 m, along with the diverse fossil elasmobranchs, suggesting that a once rich and thriving marine ecosystem in an inshore to offshore shallow-water environment during the early Pleistocene in Taiwan.

Influence of atmospheric pressure changes on dentin bond strength of conventional, bulk-fill and single-shade resin composites

INTRODUCTION

The purpose of this study was to investigate the dentin bond strength of composite resins in response to environmental pressure changes.

METHODS

Ninety extracted human molar teeth were used. A mould (3 mm x 4 mm) was adapted on dentin, resin composites (conventional [n = 30] and single-shade composites [Ohmnicroma] [n = 30]) were filled in two increments of 2 mm. The bulk-fill composites (n = 30) were filled with one 4 mm increment. The specimens were stored for 30 days in artificial saliva. The specimens were exposed to hyperbaric pressure (283.6 kPa; 2.8 atmospheres absolute [atm abs]) or hypobaric pressure (34.4 kPa; 0.34 atm abs) once daily for 30 days and the control group was stored at atmospheric pressure for 30 days. The bond strength was tested with a universal testing machine and the failures were examined with a stereomicroscope and scanning electron microscope. Statistical analyses were performed using analysis of variance with post hoc tests, and the Weibull analysis.

RESULTS

Regardless of environmental pressure changes, the bulk-fill composites showed the highest bond strength. There was no significant difference in bond strength between the hypobaric and atmospheric pressure (control) groups after 30 days in all resins. The hyperbaric group showed lower bond strength for bulk-fill composites than the control group.

CONCLUSIONS

Dentists experienced in diving and aviation medicine should definitely take part in the initial and periodic medical examinations of divers and aircrew to give appropriate treatment. Bulk-fill composite resins can be preferred in divers and aircrew due to high bond strength values.

Interventive dental therapy in Ancient Egypt (ca. 2686 BCE - AD 323): A critical review

OBJECTIVE

This paper critically reviews the history of research concerning ancient Egyptian interventive dental therapy between the Old Kingdom - Graeco-Roman Period (c. 2686 BCE-AD 323), concentrating on the published osteological evidence.

MATERIALS

Eight osteological examples reportedly exhibiting markers of interventive dental therapy, including a mandible presenting purported evidence for a drilling procedure for the relief of an abscess; four dental bridges; a maxilla with multiple teeth extracted; and two carious lesion fillings.

METHODS

Previous claims are critically reviewed using a qualitative research method involving collecting and critiquing published data, both primary evidence and relevant secondary literature.

CONCLUSIONS

Without further scientific analysis, only four specimens can currently be plausibly attributed to ancient Egyptian interventive dental therapy including the Tura el-Asmant Bridge, the enucleation described for a Graeco-Roman child, and two carious lesion fillings identified in the mummified individuals known as the 'Redpath Mummy' (RM2718) and 'Sekhem' (AIG3343).

SIGNIFICANCE

Several enduring historiographical and museological problems within the discourse are identified, revising our understanding of the nature and scope of ancient Egyptian interventive dental therapy based on currently known osteological evidence.

LIMITATIONS

This review relies on the published documentation for each osteological example, namely images, which in several cases are poor quality.

SUGGESTIONS FOR FURTHER RESEARCH

There is significant opportunity for further scientific analysis of the osteological evidence discussed. In each case, specific potential methods to improve our understanding and interpretation have been identified.

Male Cayo Santiago rhesus macaques (Macaca mulatta) tend to have greater molar wear than females at comparable ages: exploring two possible reasons why

Objectives

(1) To investigate sex differences in molar wear in known-age Cayo Santiago rhesus macaques (Macaca mulatta) and, (2) To explore sex differences in body weight and molar eruption timing as factors influencing sex differences in molar wear.

Materials and Methods

Data set I comprises wear scores, ages and body weights of 212 living monkeys included in the 1985 roundup. Data set II consists of molar wear measurements taken on 2D images of 103 of these monkeys' dental remains. Ordinal logistic regression was used to analyze the first data set. General linear models were used to analyze the second.

Results

Males generally exhibited more wear than females at equivalent chronological ages, though results varied by tooth type for the second data set. Male body weight in the full 1985 living sample was significantly related to dental wear, when age was taken into account; however, when males less than eight years of age were eliminated from the sample, the association between dental wear and weight became statistically insignificant. Analysis of the second data set suggested no statistically significant sex difference in dental wear for third molars, despite the approximately two year sex difference in eruption age for this tooth type.

Discussion

This study suggests that body weight in males might be a predictor of dental wear and that if it is, body weight might also influence sex differences in dental wear. Sex differences in dental eruption timing do not appear to explain sex differences in dental wear in this sample.

Progressive skeletal defects caused by Kindlin3 deficiency, a model of autosomal recessive osteopetrosis in humans

The cellular and molecular mechanisms of bone development and homeostasis are clinically important, but not fully understood. Mutations in integrins and Kindlin3 in humans known as Leukocyte adhesion deficiencies (LAD) cause a wide spectrum of complications, including osteopetrosis. Yet, the rarity, frequent misdiagnosis, and lethality of LAD preclude mechanistic analysis of skeletal abnormalities in these patients. Here, using inducible and constitutive tissue-specific Kindlin3 knockout (K3KO) mice, we show that the constitutive lack of embryonic-Kindlin3 in myeloid lineage cells causes growth retardation, edentulism, and skull deformity indicative of hydrocephaly. Micro-CT analysis revealed craniosynostosis, choanal stenosis, and micrognathia along with other skeletal abnormalities characteristic of osteopetrosis. A marked progression of osteosclerosis occurs in mature to middle-aged adults, resulting in the narrowing of cranial nerve foramina and bone marrow cavities of long bones. However, postnatal-Kindlin3 is less critical for bone remodeling and architecture. Thus, myeloid Kindlin3 is essential for skeletal development and its deficiency leads to autosomal recessive osteopetrosis (ARO). The study will aid in the diagnosis, management, and treatment choices for patients with LAD-III and ARO.

New approach for the treatment of vertical root fracture of teeth: A case report and review of literature

BACKGROUND

Vertical root fracture (VRF) is one of the most common reasons for tooth extraction, although various methods have been applied for saving teeth with VRF.

CASE SUMMARY

This case report describes a woman who had a sinus tract on the labial gingiva of the left maxillary central incisor for past two months. Periodontal probing revealed an 8–10 mm deep, narrow, isolated pocket on the palatal side of the tooth. Clinical and radiographic examination confirmed a longitudinal root fracture. A new approach using a combination of resin and iRoot BP Plus through intentional replantation was used for the treatment of the tooth. At one-year follow-up, the tooth remained asymptomatic with normal periodontal probing depth, and radiographic images showed almost normal bone and periodontal structures around the root.

CONCLUSION

This new approach may be developed as an effective method for saving teeth with VRF.

Colour stability of resin infiltrated white spot lesion after exposure to stain-causing drinks

Background

The resin-based materials are used extensively in esthetic restorations but are.

prone to color changes over time.

Aims

To assess the discoloration effect of red tea, Arabic coffee, and black coffee on the resin infiltrated white spot lesions (WSL). Moreover, to investigate the impact of time (1d, 3d, and 7d) on the discoloration of the resin infiltrated WSLs.

Materials and methods

Thirty-three extracted human premolar teeth were used to create WSLs, and ICON resin infiltration treatment was performed to obliterate the enamel pores. Teeth with resin infiltrated WSLs were sectioned into two halves by cutting mesio-distally and cross-sectionally at 1 mm below the CEJ. The resin infiltrated specimens was exposed to control (artificial saliva) and staining subgroups. Colour stability was assessed using the CIE L*a*b* system.

Results

Analysis of variance (p < 0.05) and Tukey’s multiple comparison tests revealed an insignificant color change in the control group. The immersion of resin infiltrated specimens at time intervals of 1 d (p < 0.001), 3 d (p < 0.001), and 7 d (p < 0.001) showed significant differences in color change.

Conclusion

Resin infiltrated WSLs showed marked color changes after exposure to red tea, black coffee, and Arabic coffee over time. Severe discoloration of the infiltrant was evident with the use of red tea compared to black coffee and Arabic coffee. This suggests that ICON resin-based composite material might not be a suitable material for WSL infiltration.

Gli1+ Mesenchymal Stem Cells in Bone and Teeth

Mesenchymal stem cells (MSCs) are remarkable and noteworthy. Identification of markers for MSCs enables the study of their niche in vivo. It has been identified that glioma-associated oncogene 1 positive (Gli1+) cells are mesenchymal stem cells supporting homeostasis and injury repair, especially in the skeletal system and teeth. This review outlines the role of Gli1+ cells as an MSC subpopulation in both bones and teeth, suggesting the prospects of Gli1+ cells in stem cell-based tissue engineering.

The Association between Number of Teeth and Cognitive Frailty in Older Adults: A Cross-Sectional Study

OBJECTIVES

This study aimed to explore the association between number of teeth and cognitive frailty in American older adults.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

The participants were 1,531 community-dwelling older adults aged 60 or older from the NHANES database.

METHODS

Frailty was assessed using a 49-item frailty index, with a cut-off value for frailty of more than 0.21. Cognitive dysfunction was evaluated by the Digit-Symbol Coding Test (DSCT), with the cut-off being below the lowest interquartile range (scores ≤37). Cognitive frailty was defined as participants who suffered from both frailty and cognitive dysfunction. Oral health indicators included number of teeth and other factors, such as the presence of gum disease, daily use of dental floss, daily use of mouthwash and self-rated oral health. Multivariable logistic regression models were used to explore the relationship between number of teeth and cognitive frailty.

RESULTS

The mean age of the total sample was 69.67 (SD=6.60) years, and 52.71% (n=807) were female. Our study suggests there was a negative association between number of teeth and cognitive frailty (OR =0.98,95%CI:0.96-0.99, P=0.044) after controlling for potential confounding factors. In addition, older adults with 20 or more teeth had lower odds of being cognitively frail (OR=0.66,95%CI:0.44-0.99, P=0.046) than individuals who had less than 20 teeth.

CONCLUSION

This study suggests that older adults who have more teeth are associated with a lower risk of cognitive frailty. This finding highlights the importance of maintaining as many teeth as possible throughout life and into old age. Cohort studies will be required in the future to determine this relationship.

Craniofacial Phenomics: Three-Dimensional Assessment of the Size and Shape of Cranial and Dentofacial Structures

Craniofacial phenomics has opened up numerous opportunities to correlate genetic and epigenetic factors to craniofacial phenotypes in order to improve our understanding of growth and development in health and disease. Three-dimensional (3D) imaging has played a key role in advancing craniofacial phenomics by facilitating highly sensitive and specific characterizations of craniofacial and dental morphology. Here we describe the use of micro-computed tomography (micro-CT) to image the murine craniofacial complex, followed by surface reconstruction for traditional morphometric analyses. We also describe the application of geometric morphometrics, based on Generalized Procrustes Analysis, for use in human premolars. These principles are interchangeable between various vertebrate species, and between various surface imaging techniques (including micro-CT and 3D surface scanners), offering a high level of versatility and precision for extensive phenotyping of the entire craniofacial complex.

Growth and feeding ecology of coniform conodonts

Conodonts were the first vertebrates to develop mineralized dental tools, known as elements. Recent research suggests that conodonts were macrophagous predators and/or scavengers but we do not know how this feeding habit emerged in the earliest coniform conodonts, since most studies focus on the derived, 'complex' conodonts. Previous modelling of element position and mechanical properties indicate they were capable of food processing. A direct test would be provided through evidence of in vivo element crown tissue damage or through in vivo incorporated chemical proxies for a shift in their trophic position during ontogeny. Here we focus on coniform elements from two conodont taxa, the phylogenetically primitive Proconodontus muelleri Miller, 1969 from the late Cambrian and the more derived Panderodus equicostatus Rhodes, 1954 from the Silurian. Proposing that this extremely small sample is, however, representative for these taxa, we aim to describe in detail the growth of an element from each of these taxa in order to the test the following hypotheses: (1) Panderodus and Proconodontus processed hard food, which led to damage of their elements consistent with prey capture function; and (2) both genera shifted towards higher trophic levels during ontogeny. We employed backscatter electron (BSE) imaging, energy-dispersive X-ray spectroscopy (EDX) and synchrotron radiation X-ray tomographic microscopy (SRXTM) to identify growth increments, wear and damage surfaces, and the Sr/Ca ratio in bioapatite as a proxy for the trophic position. Using these data, we can identify whether they exhibit determinate or indeterminate growth and whether both species followed linear or allometric growth dynamics. Growth increments (27 in Pa. equicostatus and 58 in Pr. muelleri) were formed in bundles of 4-7 increments in Pa. equicostatus and 7-9 in Pr. muelleri. We interpret the bundles as analogous to Retzius periodicity in vertebrate teeth. Based on applied optimal resource allocation models, internal periodicity might explain indeterminate growth in both species. They also allow us to interpret the almost linear growth of both individuals as an indicator that there was no size-dependent increase in mortality in the ecosystems where they lived e.g., as would be the case in the presence of larger predators. Our findings show that periodic growth was present in early conodonts and preceded tissue repair in response to wear and damage. We found no microwear and the Sr/Ca ratio, and therefore the trophic position, did not change substantially during the lifetimes of either individual. Trophic ecology of coniform conodonts differed from the predatory and/or scavenger lifestyle documented for "complex" conodonts. We propose that conodonts adapted their life histories to top-down controlled ecosystems during the Nekton Revolution.