Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth

Surface prereacted glass-ionomer particles incorporated into resin composites promote biocompatibility for restoration of subgingival dental defects

Subgingival dental defects are common in clinical practice among patients with deep dental caries and dental fractures. These defects commonly accompany lesions involving marginal alveolar bone loss and gingival recession, and their clinical management is challenging. Restoring gingival adhesion and activating the regeneration of periodontal tissue are important for a better prognosis in these cases. However, there is no effective resin material for complex restorations involving the destruction of subgingival tissue. To achieve greater biocompatibility, resins are generally modified with bioactive particles that can release specific components. Surface prereacted glass ionomer (S-PRG) is a novel glass particle characterized by a three-layered structure and the release of multiple ions with bioactive potential. Therefore, in this study, we incorporated S-PRG filler into resin-based composites to investigate their effectiveness in the restoration of subgingival defects. Resin composites containing 0, 10, 30, 50, or 70 wt% S-RPG filler were fabricated and formed into material discs, where a commercial resin composite served as the control group. The microstructure and elemental distribution were characterized by scanning electronic microscopy and energy-dispersive spectroscopy. The resin composites containing 50 or 70 wt% S-PRG fillers exhibited comprehensively better physicochemical properties, including flexural modulus, compressive strength, and water sorption. The ion release profile and environmental pH of the resins were measured with material extracts. Periodontal ligament stem cells were considered as seed cells that harbored great potential for periodontal regeneration. Cellular experiments suggested that S-PRG promotes cell proliferation and adhesion, induces cell migration, and stimulates vascularized osteogenesis. The feasibility of using S-PRG-containing resin composite to rectify subgingival dental defects was confirmed in vivo. After restoration with the S-PRG-filled resin material, intact epithelial tissue adhered to the resin surface with no visible inflammation. In conclusion, S-PRG-filled resin composites showed some biocompatibility as an alternative material for clinical applications.

Worldwide Prevalence and Demographic Predictors of Impacted Third Molars-Systematic Review with Meta-Analysis

Background/Objectives: Impacted teeth are a common phenomenon, in both young and adult populations, as extensively documented in the literature. This study aims to systematically assess the global prevalence of impacted third molars and to analyze their demographic predictors. Methods: The present review adheres to PRISMA guidelines and includes studies published until December 2023. Three databases (MEDLINE, LILACS, Cochrane) were searched, and studies reporting prevalence rates and demographic predictors of impacted third molars were selected for analysis. A meta-analysis was conducted using a random-effects model to calculate pooled prevalence and assess demographic variations. Results: This review yielded 98 studies involving 183,828 subjects. The pooled prevalence of impacted third molars was 36.9% [95% CI: 33.1-40.7%] per subject and 46.4% [95% CI: 36.7-56.1%] per tooth, with the highest rates in Asia (43.1% [95% CI: 34.6-51.7%]) and the lowest in Europe (24.5% [95% CI: 16.1-33.9%]). An odds ratio of 1.173 [95% CI: 1.021-1.347%] indicated a slightly higher likelihood of third molar impaction among women compared to men, and mandibular third molar impaction was more frequent than maxillary impaction. The meta-regression indicated insufficient consistency for the geographic area to be considered a source of heterogeneity in the prevalence of impacted third molars. Conclusions: The present meta-analysis highlights the substantial prevalence of impacted third molars worldwide and underscores the influence of demographic predictors. These findings may inform region-specific clinical guidelines and preventive approaches for managing impacted third molars.

Mandibular third molar coronectomy in older adults and its effects on oral health-related quality of life

OBJECTIVE

The purpose of this study was to investigate the effect of coronectomy on postoperative quality of life in older adults.

BACKGROUND

Coronectomy is an alternative to complete surgical removal of a mandibular third molar that lies close to the inferior alveolar nerve.

MATERIALS AND METHODS

This prospective study included patients >60 years old who had an indication for coronectomy of a mandibular third molar. Patients were asked to complete the Dutch version of the Oral Health Impact Profile-14 (OHIP-14) daily during the first postoperative week. Postoperative pain, swelling, limited mouth opening, chewing ability and infection were also recorded. Furthermore, the effect of the impaction pattern, state of eruption, presence of preoperative pathology, patient health status according to the American Society of Anaesthesiologists score, gender, smoking on the postoperative OHIP-14 and pain scores were investigated.

RESULTS

Thirty patients (16 males, 14 females) with a mean age of 71.2 (SD 8.3, range 60-91) years were included in the study. OHIP-14 and pain scores were highest on the first postoperative day and gradually declined during the first postoperative week. Patients who underwent coronectomy of a fully impacted mandibular third molar had significantly higher OHIP-14 scores on the first postoperative day than those who underwent coronectomy on a (partially) erupted mandibular third molar. We did not observe any postoperative complications up to 1 year after the surgery.

CONCLUSION

Mandibular third molar coronectomy seems to present a valid treatment option in older adults.

Diagnosis and indications for the extraction of third molars - The SECIB clinical practice guideline

BACKGROUND

The removal of third molars (3Ms) is the most frequent surgical procedure in the field of Oral Surgery. As a result, the Spanish Society of Oral Surgery (SECIB) aims to create a Clinical Practice Guideline (CPG) that offers evidence-based recommendations for optimal clinical practice. Specifically, the CPG will focus on providing guidance regarding the indications and criteria for clinical and radiological diagnosis of patients with 3Ms.

MATERIAL AND METHODS

This CPG was developed by the SECIB, following the methodological guidelines described in the methodological manual for the "Development of Clinical Practice Guidelines in the National Health System". Several PICO questions related to the diagnosis and indications for the extraction of 3Ms were formulated. The leading experts carried out the evaluation of the evidence and the formulation of specific recommendations.

RESULTS

A total of 17 PICO questions were evaluated, addressing the indications, prognosis, diagnosis, and cost-benefit relationship of 3M extraction.

CONCLUSIONS

The present Clinical Practice Guideline provides evidence-based recommendations on the diagnosis and indications for 3M extraction. These evidence-based recommendations can assist healthcare professionals and the general population in making informed decisions regarding the management of 3Ms.

Is there a relationship between the presence of external root resorption in second molars adjacent to impacted mandibular third molars with awake bruxism and masticatory muscle activity?

OBJECTIVES

This study aimed to assess whether awake bruxism and masticatory muscle activity could be related to external root resorption (ERR) in second molars adjacent to impacted mandibular third molars.

MATERIALS AND METHODS

Sixty patients, with requests for a cone-beam, computed tomography, were divided into two groups: ERR (patients with ERR in the second molar, n = 30), and control group (n = 30). Awake bruxism was assessed through the Oral Behaviors Checklist (OBC) and an ecological momentary assessment (EMA). Surface electromyography (EMG) was used to assess the masseter and anterior temporal muscle function. Normality and homogeneity of variances were demonstrated. Descriptive analysis was performed, using the T-test and Chi-square test to compare the characteristics of the groups. A multiple regression model was performed.

RESULTS

The ERR group presented more non-functional oral activities related to awake bruxism than the control group, according to OBC (p = 0.027) and EMA (p = 0.035). In addition, the ERR group had higher EMG activity than the control group in rest and isotonic protocols (p < 0.05).

CONCLUSIONS

Awake bruxism and greater masticatory muscle activity seem to be related to the presence of ERR in second molars adjacent to impacted mandibular third molars.

CLINICAL RELEVANCE

The results of the present study can reinforce the theory that triggering ERR in the second molars adjacent to impacted mandibular third molars may be related to mechanical forces coming from the masticatory function.

Full life cycle changes of low impacted mandibular third molar associated cystic lesions and adjacent tooth root resorption: a retrospective study

OBJECTIVE

Low impacted third molars are usually asymptomatic and are often found by X-ray examination. The removal of asymptomatic low impacted third molars is one of the most controversial clinical issues in oral and maxillofacial surgery.

METHODS

In this study, 806 patients with low impacted mandibular third molars (LIMTMs) (full bony impaction) were analyzed to determine the prevalence and risk factors for cystic lesions and adjacent tooth root resorption throughout the patients' entire life cycle.

RESULTS

The results showed that the prevalence of adjacent tooth root resorption and cystic lesions was age-related, exhibiting a trend of first increasing and then decreasing; prevalence peaked at the age of 41 to 45 years old, the prevalence rates were 12.50% and 11.11% respectively. And the lowest prevalence rate was 2.86% and 2.44% in ≥ 61 group and 56- to 60-year age group respectively. Age was an independent risk factor for adjacent tooth root resorption of LIMTMs, whereas age and impaction type (especially inverted impaction) were independent risk factors for cystic lesions.

CONCLUSIONS

The full life cycle management strategy for LIMTMs may need to be individualized. Surgical removal is recommended for LIMTMs in patients younger than 41 to 45 years, especially for inverted, mesioangular, and horizontally impacted LIMTMs. LIMTMs in patients older than 41 to 45 years may be treated conservatively with regular follow-up, but surgical removal of inverted impacted LIMTMs is still recommended to avoid cyst formation.

Oral maxillofacial surgeons and Orthodontists' perceptions about anterior inferior crowding and indications of mandibular third molar extraction

BACKGROUND

There are still many doubts about anterior inferior crowding and indications of mandibular third molar extraction, although it is very studied subject in the literature. The aim of this study was to evaluate the perceptions of oral maxillofacial surgeons (OMFSs) and orthodontists about anterior inferior crowding and indications of mandibular third molar extraction.

MATERIAL AND METHODS

A web-based survey was developed and sent to professionals in order to collect their opinion about the fact that third lower molars cause crowding and questions about the indication of third molars for orthodontic treatment. Descriptive analysis was performed and Chi-square or G tests were applied with a 95% confidence interval.

RESULTS

The study included a total of 218 participants, of whom 115 were OMFSs and 103 were orthodontists. The results showed that 56.5% of OMFSs and 35.0% of orthodontists believe that the lower third molars cause anterior inferior crowding (p<0.001). A total of 91.3% of OMFSs and 70.9% of orthodontists indicate the extraction of lower third molars to aid orthodontic treatment (p<0.001).

CONCLUSIONS

It can be concluded that in being an oral maxillofacial surgeon, a higher odds ratio is observed to consider that lower third molars cause dental crowding compared to those who are orthodontist. The indication of exodontia of lower third molars for orthodontic treatment was more frequent among OMFSs when compared to orthodontists.

Efficacy of ornidazole for pericoronitis: a meta-analysis and systematic review

Introduction

Timely and effective treatments of pericoronitis are very important. We aimed to evaluate the role of ornidazole in the treatment of pericoronitis, to provide insights for clinical pericoronitis treatment.

Material and methods

The PubMed, Clinical trials, EMBASE, Science Direct, Cochrane Library, China National Knowledge Infrastructure (CNKI), Weipu and Wanfang databases were searched to find randomized controlled trials (RCTs) of ornidazole in the treatment of pericoronitis from the establishment of the database to March 15, 2023. Review Manager 5.3 software was used for meta-analysis.

Results

A total of 16 RCTs involving 2004 patients were included. The results of the meta-analysis showed that the effective rate of ornidazole treatment was significantly higher than that of the routine treatment group (RR = 1.22, 95% CI (1.15, 1.29), p < 0.001). Ornidazole treatment was beneficial to reduce the oral bacterial density (MD = -26.13, 95% CI (-32.08, -21.51)), time to pain disappearance (MD = -0.64, 95% CI (-0.92, -0.17)) and time to disappearance of redness and swelling of the teeth crown (MD = -1.45, 95% CI (-2.43, -1.01)) compared to the routine treatment (all p = 0.05). No publication bias was found by the funnel plots and Egger test (p = 0.206).

Conclusions

Ornidazole is effective in the treatment of pericoronitis, with more advantages. Still, the effects and safety of ornidazole in the treatment of pericoronitis need to be evaluated by more high-quality RCTs with larger sample sizes.

Knowledge, attitudes, and practice of non-medical students regarding impacted teeth: a cross-sectional study

OBJECTIVES

To explore the knowledge, attitudes, and practice (KAP) of non-medical students regarding impacted teeth and the factors associated with KAP.

MATERIALS AND METHODS

This cross-sectional study enrolled non-medical students at two universities (Northeastern University and Shenyang Conservatory of Music) in northeastern China between December 2022 and February 2023. Scores > 70% were defined as adequate knowledge, positive attitudes, and proactive practice.

RESULTS

A total of 519 non-medical students participated in this study. Most participants were male (54.72%), ≤ 20 years of age (72.83%), and freshmen (36.03%). The mean knowledge score was 4.98 ± 3.46 (possible range: 0-10), indicating poor knowledge (49.80%). The multivariable analysis showed that having impacted teeth were independently associated with adequate knowledge (OR = 3.114, 95% CI: 1.589-6.103, P = 0.001). The mean attitude score was 24.65 ± 3.78 (possible range: 7-35), indicating favorable attitudes (70.43%). The knowledge (OR = 1.182, 95% CI: 1.116-1.251, P < 0.001), junior grade (OR = 0.541, 95% CI: 0.327-0.895, P = 0.017), senior grade and above (OR = 0.477, 95% CI: 0.274-0.829, P = 0.009), and a history of impacted tooth extraction (OR = 2.386, 95% CI: 1.048-5.436, P = 0.038) were independently associated with the good attitudes. The mean practice score was 21.45 ± 5.64 (possible range: 6-30), indicating positive practice (71.50%). The knowledge (OR = 1.074, 95% CI: 1.017-1.133, P = 0.010) and female (OR = 1.501, 95% CI: 1.052-2.141, P = 0.025) were independently associated with the proactive practices.

CONCLUSIONS

Non-medical students had poor knowledge but favorable attitudes and good practice toward impacted teeth. Non-medical students require additional education and awareness about the importance of early detection and management of impacted teeth.

CLINICAL RELEVANCE

The study highlights the need for improved education and awareness among non-medical students regarding impacted teeth.

Pathologic conditions associated with impacted third molars: A retrospective study of panoramic radiographs in a Southern Brazilian population

Purpose

This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions.

Materials and Methods

Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05).

Results

The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2 ± 11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar.

Conclusion

The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

Third molar-related knowledge, attitudes, behaviors, and medical history of 904 Chinese adults: a cross-sectional survey

This study investigated the perceptions and medical history of third molars (M3s) and assessed the prevalence of visible M3s (V-M3s) among 904 Chinese adults. The enrolled participants were interviewed to complete a structural questionnaire focused on sociodemographic information and their understanding of, attitudes toward, behaviors regarding, and medical history with respect to M3s. In addition, the number of V-M3s in the cohort was determined by oral examination. Logistic regression analysis was performed to explore the association between individuals' sociodemographic characteristics and their perception of M3s or the presence of V-M3s. The Chi-square test was used to compare the actions taken against symptomatic M3s and the corresponding outcomes among different groups divided according to respondents' sociodemographic factors. In total, 904 completed questionnaires were gathered and analyzed. Nearly half (43.9%) of the respondents knew nothing about M3s, and only 12.7% provided correct answers to all the questions asked. Male sex, older age, occupation involving physical labor, and no previous dental experience were active factors in unawareness of M3s. Male sex was also significantly associated with the presence of at least one V-M3 and negative behavior about symptomatic M3s. In terms of medical history, 192 participants reported having had at least one M3 extracted (438 in total), and 72.6% of the M3s were removed due to the presence of related symptoms or pathologies. In conclusion, the population investigated had a shortage of knowledge about M3s and adopted negative attitudes and actions about M3-related problems.

An observational analysis of risk factors associated with symptomatic third molar teeth

BACKGROUND

Third molar teeth (wisdom teeth) are a common cause of pain and infection in young adults. The study aimed to describe the prevalence of symptomatic third molar teeth and identify factors which predispose to third molar symptoms in a birth cohort.

METHODS

An observational study was undertaken nested in the Avon Longitudinal Study of Parents and Children (ALSPAC), a birth cohort based in south west England. The main outcomes were self-reported third molar pain, swelling and treatment for third molar problems, taken from questionnaires completed at age 23 years. The exposures including sex, dental history, socioeconomic status, diet, and genetic factors were obtained from earlier ALSPAC data.

RESULTS

In total 4,222 ALSPAC participants responded to one or more questions about third molar teeth. The final sample included more female participants than male participants. The majority of participants (56.6%) reported at least one episode of pain associated with their third molars. Females had greater odds than males of reporting swelling (adjusted odds ratio (OR) 1.97; 95%confidence interval (CI) 1.56, 2.51), pain (adjusted OR=1.96; 95%CI 1.56, 2.51) and receiving both non-surgical and surgical treatment (adjusted OR=2.30; 95%CI 1.62, 3.35, adjusted OR=1.54; 95%CI 1.17, 2.06 respectively). Participants with previously filled teeth had greater odds of third molar extraction. There were no strong associations between index of multiple deprivation (IMD) score or sugar intake and the third molar outcomes. There was weak evidence for a genetic contribution to third molar pain.

CONCLUSIONS

Symptomatic third molars are common in this age group, with over half of the participants reporting pain or other symptoms. Female participants had greater odds for third molar pain, swelling and treatment.

Cone-beam computed tomography-based radiographic considerations in impacted lower third molars: Think outside the box

Purpose

This study aimed to evaluate the anatomic circle around the impacted lower third molar to show, document, and correlate essential findings that should be included in the routine radiographic assessment protocol as clinically meaningful factors in overall case evaluation and treatment planning.

Materials and Methods

Cone-beam computed tomographic images of impacted lower third molars were selected according to specific inclusion criteria. Impacted teeth were classified according to their position before assessment. The adjacent second molars were assessed for distal caries, distal bone loss, and root resorption. The fourth finding was the presence of a retromolar canal distal to the impaction. Communication with the dentist responsible for each case was done to determine whether these findings were detected or undetected by them before communication.

Results

Statistically significant correlations were found between impaction position, distal bone loss, and detected distal caries associated with the adjacent second molar. The greatest percentage of undetected findings was found in the evaluation of distal bone status, followed by missed detection of the retromolar canal.

Conclusion

The radiographic assessment protocol for impacted third molars should consider a step-by-step evaluation for second molars, and clinicians should be aware of the high prevalence of second molar affection in horizontal and mesioangular impactions. They also should search for the retromolar canal due to its associated clinical considerations.

How the Loss of Second Molars Corresponds with the Presence of Adjacent Third Molars in Chinese Adults: A Retrospective Study

Third molars (M3s) can increase the pathological risks of neighboring second molars (M2s). However, whether the M3 presence affects M2 loss remains unknown. This retrospective study aimed to reveal the reasons for M2 loss and how M2 loss relates to neighboring M3s. The medical records and radiographic images of patients with removed M2(s) were reviewed to analyze why the teeth were extracted and if those reasons were related to adjacent M3s. Ultimately, 800 patients with 908 removed M2s were included. In the included quadrants, 526 quadrants with M3s were termed the M3 (+) group, and the other 382 quadrants without M3s were termed the M3 (−) group. The average age of patients in the M3 (+) group was 52.4 ± 14.8 years and that of the M3 (−) group was 56.7 ± 14.9 years, and the difference between the two groups was statistically significant (p < 0.001). Of the 908 M2s, 433 (47.7%) were removed due to caries and sequelae and 300 (33.0%) were removed due to periodontal diseases. Meanwhile, 14.4% of the M2s with adjacent M3s were removed due to distal caries and periodontitis, which were closely related to the neighboring M3s; this percentage was much lower when M3 were absent (1.8%). Additionally, 42.2% of M3s were removed simultaneously with neighboring M2s. The presence of M3s, regardless of impaction status, was associated with an earlier loss of their neighboring M2s.

Estimated Cumulative Incidence of Wisdom Tooth Extractions in Privately Insured US Patients

Objective

To determine the cumulative incidence and predictors of third molar (3M, “wisdom teeth”) extractions in the US.

Methods

We retrospectively analyzed a US private dental insurance claims database to create a Kaplan-Meier curve for cumulative incidence of 3M extractions, and used Cox proportional hazards to assess associations between sex, geographic region, and extractions.

Results

Between 2007 and 2016, by age 25, ~80% of patients underwent ≥1 tooth extraction and an estimated 50% of patients underwent ≥1 3M extraction. Factors associated with 3M extractions included female sex (adjusted hazard ratio [aHR] 1.08, 95% CI 1.07 – 1.08) and residence in the West (aHR 1.82, 95% CI 1.81-1.85) or South (aHR 1.5, 95% CI 1.49 – 1.51) geographic regions as compared to the Northeast.

Conclusion

3M extractions are likely the most common surgery performed in US adolescents and young adults. Significant geographic variation suggests that elucidation of the indications for this common procedure is a public health priority.

An observational analysis of risk factors associated with symptomatic third molar teeth

Background: Third molar teeth (wisdom teeth) are a common cause of pain and infection in young adults. The study aimed to describe the prevalence of symptomatic third molar teeth and identify factors which predispose to third molar symptoms in a birth cohort. Methods: An observational study was undertaken nested in the Avon Longitudinal Study of Parents and Children (ALSPAC), a birth cohort based in south west England. The main outcomes were self-reported third molar pain, swelling and treatment for third molar problems, taken from questionnaires completed at age 23 years. The exposures including sex, dental history, socioeconomic status, diet, and genetic factors were obtained from earlier ALSPAC data. Results: In total 4,222 ALSPAC participants responded to one or more questions about third molar teeth. The final sample included more female participants than male participants. The majority of participants (56.6%) reported at least one episode of pain associated with their third molars. Females had greater odds than males of reporting swelling (adjusted odds ratio (OR) 1.97; 95%confidence interval (CI) 1.56, 2.51), pain (adjusted OR=1.96; 95%CI 1.56, 2.51) and receiving both non-surgical and surgical treatment (adjusted OR=2.30; 95%CI 1.62, 3.35, adjusted OR=1.54; 95%CI 1.17, 2.06 respectively). Participants with previously filled teeth had greater odds of third molar extraction. There were no strong associations between index of multiple deprivation (IMD) score or sugar intake and the third molar outcomes. There was weak evidence for a genetic contribution to third molar pain. Conclusions: Symptomatic third molars are common in this age group, with over half of the participants reporting pain or other symptoms. Female participants had greater odds for third molar pain, swelling and treatment.

Clinical Indications to Germectomy in Pediatric Dentistry: A Systematic Review

Germectomy is a procedure often required in patients at developmental age. It is defined as the surgical removal of the third molar at a very specific stage of development. The aim of this study was to systematically analyze the literature in terms of clinical indications for germectomy in patients at developmental age. Literature searches were performed using PubMed, Google Scholar, Cochrane Library and Scopus from 1952 to 30 June 2021. The study protocol was registered after the screening stage (PROSPERO CRD42021262949). The search strategy identified 3829 articles: 167 from PubMed, 2860 from Google Scholar, 799 from Cochrane Library and 3 from Scopus. Finally, eight full-text papers were included into the qualitative analysis. Based on the included studies, clinical indications for germectomy were mainly related to orthodontic causes, infectious and cariogenic causes and prophylaxis. Based on these results, it is not possible to present evidence-based clinical indications for germectomy in patients at developmental age. Clinical trials on this subject focused specifically on patients at developmental age are awaited.

Radiographic evaluation of non-syndromic third molar agenesis in two Mediterranean populations

Background and aims

Third molar agenesis is a common finding across the world. Many studies have assessed third molar agenesis in different ethnicities and populations. However, there are no such studies in the Italian and Lebanese populations. Our study aims to evaluate the prevalence of third molar agenesis and study the pattern and distribution of agenesis in between genders in Italian and Lebanese Mediterranean populations and compare these findings with other global and Mediterranean populations' studies.

Methods

Retrospective chart review was conducted based on the history and orthopantomograms of adolescents aged 12 to 21 years to assess the agenesis of third molars in a sample of Italian and Lebanese populations by two experienced dental surgeons twice within 1 month. Descriptive and comparative tests were used to analyze the patterns of ageneses and make comparisons between the two samples.

Results

23.4% of the studied sample had at least one third molar agenesis; females were more likely to have two or more third molar agenesis than males, but neither sex predisposition for single third-molar agenesis was recorded. Both the Italian and Lebanese subgroups seemed to have similar results. The maxillary right third molar was the most common third molar to be absent. Two or more ageneses were more common than one third molar agenesis.

Conclusion

Our Mediterranean population results fall within the range reported in the literature and corroborate with the global average prevalence.

[Characterization of third molar extraction]

The aim of this study was to characterize the main indications, contraindications and prophylactic actions for third molar extraction according to the literature. The Pubmed, Scopus and Web of Science databases were searched using a total of 3 search keys, including publications up to 5 years old, in English or Spanish, with availability of full text. Eighteen articles were selected and showed that the most frequent indication for third molar extraction was the diagnosis of pericoronaritis, followed by distal cervical caries in the lower second molar, and root resorption in adjacent teeth and cysts. In turn, it may be indicated to facilitate other types of dental treatment, such as orthodontics, orthognathic surgery and rehabilitation. In relation to contraindications, the risk of intraoperative complications was associated with the inferior alveolar nerve, advanced age and the predomination of systemic involvement. Prophylactic extraction was included in the analysis in 72.2% of the articles, with a predominance of exodontia of asymptomatic and disease-free third molars. Finally, there are clear indications and contraindications for third molar extraction, being mainly associated with pathological changes, indications for orthodontic treatment, orthognathic surgery and rehabilitative treatment. However, there is controversy in the literature regarding prophylactic extraction, emphasizing that not all retained and asymptomatic third molars should be extracted. Third molar extraction should be evaluated on a case by case basis, considering the benefits, the patient's characteristics and the risk of postoperative complications.

A systematic review and meta-analysis on the effectiveness of xenograft to prevent periodontal defects after mandibular third molar extraction

Background

To evaluate the use of guided bone regeneration with xenograft to prevent periodontal defect in the distal aspect of the second molar after the surgical removal of the mandibular third molar.

Material and Methods

Three electronic databases (Pubmed, Cochrane Library and Scopus) were searched in April 2020. Randomized clinical trials in non-smokers and healthy patients, with at least six months follow-up, comparing periodontal probing depth, clinical attachment level, alveolar bone level and adverse events were selected by two independent investigators. The risk of bias assessment of the selected studies was evaluated by means of the Cochrane Collaboration’s Tool. Finally, a meta-analysis of the outcomes of interest was performed.

Results

Despite 795 articles were found in the initial search, only three randomized controlled clinical trials were included. Pooled results favoured the use of the xenograft plus collagen membrane over the spontaneous healing in terms of periodontal probing depth gain (MD=2.36; 95% CI 0.69 to 4.03; P=0.005) and clinical attachment level gain (MD=2.52; 95% CI 0.96 to 4.09; P=0.002). No other statistically significant differences were found.

Conclusions

Within the limitations of the present review, the xenograft plus collagen membrane exhibited better periodontal results than spontaneous healing without increasing postoperative complications. However, future well-designed studies with larger samples are required to confirm our results.

Key words:Third molar, tooth extraction, bone regeneration, xenograft.

Age-Related Metabolic Pathways Changes in Dental Follicles: A Pilot Study

Aging is not a matter of choice; it is our fate. The “time-dependent functional decline that affects most living organisms” is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology.

Classification of caries in third molars on panoramic radiographs using deep learning

The objective of this study is to assess the classification accuracy of dental caries on panoramic radiographs using deep-learning algorithms. A convolutional neural network (CNN) was trained on a reference data set consisted of 400 cropped panoramic images in the classification of carious lesions in mandibular and maxillary third molars, based on the CNN MobileNet V2. For this pilot study, the trained MobileNet V2 was applied on a test set consisting of 100 cropped PR(s). The classification accuracy and the area-under-the-curve (AUC) were calculated. The proposed method achieved an accuracy of 0.87, a sensitivity of 0.86, a specificity of 0.88 and an AUC of 0.90 for the classification of carious lesions of third molars on PR(s). A high accuracy was achieved in caries classification in third molars based on the MobileNet V2 algorithm as presented. This is beneficial for the further development of a deep-learning based automated third molar removal assessment in future.

The rationale for orthodontic retention: piecing together the jigsaw

Retaining teeth in their corrected positions following orthodontic treatment is one of the most challenging aspects of orthodontic practice. Despite much research, the rationale for retention is not entirely clear. Teeth tend to revert to their pre-treatment positions due to periodontal and gingival, soft tissue, occlusal and growth factors. Changes may also follow normal dentofacial ageing and are unpredictable with great variability. In this overview, each of these factors are discussed with their implications for retention, along with adjunctive procedures to minimise relapse. The state of current knowledge, methods used to assess relapse, factors regarded as predictive of or associated with stability as well as overcorrection are outlined. Potential areas requiring further investigation are suggested. The way in which the clinician may manage current retention practice, with a need for individualised retention plans and selective retainer wear, is also considered.

Removable orthodontic retainers: practical considerations

This article provides an overview of removable orthodontic retainers, discussing their history and the different types available, and compares the two most popular removable retainers. Practical information on consent and the clinical steps involved in the provision of removable retainers, as well as suggested wear and care instructions, are also presented.

Antibiotics to prevent complications following tooth extractions

BACKGROUND

The most frequent indications for tooth extractions, generally performed by general dental practitioners, are dental caries and periodontal infections. Systemic antibiotics may be prescribed to patients undergoing extractions to prevent complications due to infection. This is an update of a review first published in 2012.

OBJECTIVES

To determine the effect of systemic antibiotic prophylaxis on the prevention of infectious complications following tooth extractions.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health Trials Register (to 16 April 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2020, Issue 3), MEDLINE Ovid (1946 to 16 April 2020), Embase Ovid (1980 to 16 April 2020), and LILACS (1982 to 16 April 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials of systemic antibiotic prophylaxis in patients undergoing tooth extraction(s) for any indication.

DATA COLLECTION AND ANALYSIS

At least two review authors independently performed data extraction and 'Risk of bias' assessment for the included studies. We contacted trial authors for further details where these were unclear. For dichotomous outcomes, we calculated risk ratios (RR) and 95% confidence intervals (CI) using random-effects models. For continuous outcomes, we used mean differences (MD) with 95% CI using random-effects models. We examined potential sources of heterogeneity. We assessed the certainty of the body of evidence for key outcomes as high, moderate, low, or very low, using the GRADE approach.

MAIN RESULTS

We included 23 trials that randomised approximately 3206 participants (2583 analysed) to prophylactic antibiotics or placebo. Although general dentists perform dental extractions because of severe dental caries or periodontal infection, only one of the trials evaluated the role of antibiotic prophylaxis in groups of patients affected by those clinical conditions. We assessed 16 trials as being at high risk of bias, three at low risk, and four as unclear.  Compared to placebo, antibiotics may reduce the risk of postsurgical infectious complications in patients undergoing third molar extractions by approximately 66% (RR 0.34, 95% CI 0.19 to 0.64; 1728 participants; 12 studies; low-certainty evidence), which means that 19 people (95% CI 15 to 34) need to be treated with antibiotics to prevent one infection following extraction of impacted wisdom teeth. Antibiotics may also reduce the risk of dry socket by 34% (RR 0.66, 95% CI 0.45 to 0.97; 1882 participants; 13 studies; low-certainty evidence), which means that 46 people (95% CI 29 to 62) need to take antibiotics to prevent one case of dry socket following extraction of impacted wisdom teeth. The evidence for our other outcomes is uncertain: pain, whether measured dichotomously as presence or absence (RR 0.59, 95% CI 0.31 to 1.12; 675 participants; 3 studies) or continuously using a visual analogue scale (0-to-10-centimetre scale, where 0 is no pain) (MD -0.26, 95% CI -0.59 to 0.07; 422 participants; 4 studies); fever (RR 0.66, 95% CI 0.24 to 1.79; 475 participants; 4 studies); and adverse effects, which were mild and transient (RR 1.46, 95% CI 0.81 to 2.64; 1277 participants; 8 studies) (very low-certainty evidence).  We found no clear evidence that the timing of antibiotic administration (preoperative, postoperative, or both) was important. The included studies enrolled a subset of patients undergoing dental extractions, that is healthy people who had surgical extraction of third molars. Consequently, the results of this review may not be generalisable to all people undergoing tooth extractions.

AUTHORS' CONCLUSIONS

The vast majority (21 out of 23) of the trials included in this review included only healthy patients undergoing extraction of impacted third molars, often performed by oral surgeons. None of the studies evaluated tooth extraction in immunocompromised patients. We found low-certainty evidence that prophylactic antibiotics may reduce the risk of infection and dry socket following third molar extraction when compared to placebo, and very low-certainty evidence of no increase in the risk of adverse effects. On average, treating 19 healthy patients with prophylactic antibiotics may stop one person from getting an infection. It is unclear whether the evidence in this review is generalisable to patients with concomitant illnesses or patients at a higher risk of infection. Due to the increasing prevalence of bacteria that are resistant to antibiotic treatment, clinicians should evaluate if and when to prescribe prophylactic antibiotic therapy before a dental extraction for each patient on the basis of the patient's clinical conditions (healthy or affected by systemic pathology) and level of risk from infective complications. Immunocompromised patients, in particular, need an individualised approach in consultation with their treating medical specialist.

Revisit incidence of complications after impacted mandibular third molar extraction: A nationwide population-based cohort study

Most of complications after impacted mandibular third molar (iLM3) extraction surgeries are transient and resolved spontaneously within one or two weeks, but some of them are more complicated and required further treatments to alleviate the symptoms. The aim of study is to revisit incidence and predictors of complications after iLM3 surgery by reviewing previous literature and investigating a population-based data. From Taiwan National Health Insurance Research Database, records of 16,609 patients who had received iLM3 extraction under ambulatory settings were retrieved for analysis. Outcomes of interest included dry socket (DS), prolonged temporomandibular joint symptoms (TMD), and surgical site infection (SSI), which necessitated additional appointments to manage. Odds ratios of having those complications between different variables were analyzed. The incidence rates of DS, TMD, and SSI were 3.6%, 0.41%, 0.17%, respectively; while they ranged from 0.33–19.14% (DS), 0–4.17% (TMD), and 0.2–5.17% (SSI) in previous studies. Logistic regression revealed DS significantly correlated with complexity of odontectomy (2.5-fold of risk) and history of gingivitis or pericoronitis (1.3-fold of risk). More TMD was found in female than male patients (0.5% versus 0.3%). However, no factors associated with SSI was found; neither did we find aging as a risk in association with any of above complications. Compared to previous studies, our data supports that surgical intervention should be considered in iLM3 with risk of gingivitis or pericoronitis to reduce the occurrence of DS. The original information in this article, which provides a “real-world” evidence, along with the organizing data we summarized from previous article, can serve as a reference for clinicians in assessing the complication risks before treatment of iLM3.

Evidence-based clinical decision making for the management of patients with periodontal osseous defect after impacted third molar extraction: A systematic review and meta-analysis

Background/purpose

Extraction of impacted mandibular third molar (MTM) is one of the most common procedures in clinical dental treatment; building a decision tree to perform MTM extraction can be prudent in alleviating periodontal diseases. This study is to review the latest research on the management of periodontal osseous defect (POD) after MTM extraction and rebuild a new clinical decision tree.

Materials and methods

Current study was conducted according to PRISMA statement. Medline, Embase, Scopus, and Google Scholar were searched concerning treatment of MTM extraction up to Oct.2019. Three focused questions revolving around asymptomatic versus disease site, age, and necessity of ridge preservation after >6 months follow up will be answered.

Results

A total of 7 studies were included for meta-analysis. Evidences were inadequate in regards to asymptomatic vs disease site of MTM extraction in the long-term follow-up. For patients with age <25 years, postoperative probing depth (PD) always remained at < 4 mm. However, for patients with age >25 years with initial PD > 7 mm, residual pockets still remained at 5 mm. For ridge preservation, significant positive effect in reduction of second molar distal site PD was observed, regardless of different biomaterials being placed (z = 4.69, p < 0.00001).

Conclusion

Age is of utmost importance in preoperative evaluation during impacted MTM extraction. The timing for ridge preservation is essential determinant for achieving optimal treatment outcome. The clinical decision tree as proposed could serve as guidance when dealing with POD after impacted MTM extraction.