Effects of early unilateral first molar extraction on skeletal asymmetry

Tomographic evaluation of apexogenesis with human treated dentin matrix in young permanent molars: a split-mouth randomized controlled clinical trial

BACKGROUND

The concept of vital pulp therapy (VPT) of immature permanent teeth has evolved in recent years. There has been a great tendency towards investigating new pulp capping materials for perfect imitation for natural dentin-pulp complex formation process and restoring the normal tissue's characteristics. Therefore, this study aimed to assess the clinical and tomographic outcomes of apexogenesis with human treated dentin matrix (hTDM) compared to mineral trioxide aggregate (MTA).

MATERIALS AND METHODS

40 bilateral deep carious young mandibular first permanent molars (FPMs) in 20 healthy children aged between 6 and 8 years old were randomly allocated into 2 groups in which the FPMs treated with hTDM and MTA after pulpotomy procedure. The children were followed up clinically at 3, 6, 12, and 18 months. Tomographic evaluation was performed at baseline and 18-month evaluation period.

RESULTS

The overall clinical success rate was 100% in both groups. Regarding tomographic evaluation, the mean differences in root length, periapical diameter and area were statistically significant in each individual group but without statistically significant differences between both groups.

CONCLUSION

Human TDM hydrogel could be considered a promising pulpotomy agent for immature permanent teeth.

TRIAL REGISTRATION

The current clinical trial was recorded at clinicaltrials.gov, NCT06116695, 27/10/2023, Retrospectively registered.

Economic inequalities in decayed, missing, and filled first permanent molars among 8-12 years old Iranian schoolchildren

BACKGROUND

First permanent molars (FPM) play an important role in the masticatory function and oral health. This study aimed to assess the economic inequalities of FPM health indices among schoolchildren in the northeast of Iran.

METHODS

A total of 4051 children aged 8-12 years old were included in the analyses of this cross-sectional study in 2015. Economic status was measured using the principal component analysis on home assets. Concentration index (C) was used to measure economic inequality in FPM health indices, and its contributing factors determined by Wagstaff decomposition technique.

RESULTS

The prevalence of having decayed, missing, and filled FPMs among children was 40.9% (95% CI: 38.8-43.0), 1.2% (95% CI: 0.8-1.6%), and 7.8% (95% CI: 6.7-8.9%), respectively. Missing FPM was generally more concentrated among low-economic children (C=-0.158), whereas, filled FPM was more concentrated on high-economic children (C = 0.223). Economic status, mother education, having a housekeeper mother, and overweight/obesity, contributed to the measured inequality in missing FPM by 98.7%, 97.5%, 64.4%, and 11.2%, respectively. Furthermore, 88.9%, 24.1%, 14.5%, and 13.2% of filled FPM inequality was attributable to children's economic status, father education, residence in rural areas, and age, respectively.

CONCLUSION

There is a significant economic inequality in both missing and filled FPM. This inequality can be attributed to the economic status of individuals. To reduce FPM extraction, it is important to target low-income and rural children and provide them with FPM restoration services. Additionally, it is necessary to provide training to less-educated parents and housekeeper mothers to address the observed inequalities.

Criteria for early diagnosis of mandibular third molar agenesis based on the developmental stages of mandibular canine, first and second premolars, and second molar: a retrospective cohort study

BACKGROUND

Permanent first molars with severe dental caries, developmental defects, or involved in oral pathologies are at risk of poor prognosis in children. Accordingly, using the third molar to replace the first molar can be a good treatment option when third molar agenesis is predicted early. Thus, this retrospective cohort study aimed to develop criteria for early detection of mandibular third molar (L8) agenesis based on the developmental stages of mandibular canine (L3), first premolar (L4), second premolar (L5), and second molar (L7).

METHOD

Overall, 1,044 and 919 panoramic radiographs of 343 males and 317 females, respectively, taken between the ages of 6 and 12 years were included. All developmental stages of L3, L4, L5, L7, and L8 were analyzed based on the dental age, as suggested by Demirjian et al. The independent t-test was used to assess age differences between males and females. The rank correlation coefficients were examined using Kendall's tau with bootstrap analysis and Bonferroni's correction to confirm the teeth showing developmental stages most similar to those of L8s. Finally, a survival analysis was performed to determine the criteria for the early diagnosis of mandibular third molar agenesis.

RESULTS

Some age differences were found in dental developmental stages between males and females. Correlation coefficients between all stages of L3, L4, L5, and L7 and L8 were high. In particular, the correlation coefficient between L7 and L8 was the highest, whereas that between L3 and L8 was the lowest.

CONCLUSION

If at least two of the following criteria (F stage of L3, F stage of L4, F stage of L5, and E stage of L7) are met in the absence of L8 crypt, agenesis of L8 can be confirmed.

Permanent First Mandibular Molar: Loss Prevalence and Pattern among Saudis in Al-Ahsa

OBJECTIVES

 The permanent first mandibular molar (PFMM) is the first tooth to erupt, usually at the age of 6 years. It is the most effective oral masticatory unit due to its wide occlusal surface and its role in favorable occlusion. This study describes the prevalence of PFMM loss and the reasons for extraction in a group of King Faisal Dental Complex Clinics (KFUDC) Saudi attendees. In addition, to report postextraction complications, consider the gender, age, and the time elapsed from the moment of the extraction.

MATERIALS AND METHODS

 A cross-sectional study was performed in January to April 2020, focusing on the loss of PFMM among a group of Saudis attending KFUDC in Al Hofuf, Saudi Arabia. A total of 417 participants were recruited. The inclusion criteria were adults aged ≥ 18 years. The principal investigator performed all the necessary measures for calibration in the forms of training on clinical examination and interviews.

STATISTICAL ANALYSIS

 Data were analyzed using the Statistical Package for the Social Science, version 25 (SPSS Inc., Illinois, United States).

RESULT

 Four hundred seventeen attendees participated in the present study. Majority were males 73.9% (308), and 26.1% (109) females. A third, 30% (125), reported missing PFMM; the overwhelming majority reported the reason for extraction as caries 93.6% (117).On clinical examination, 80.8% (101) had complications; drifting of adjacent teeth was the most common complication, 57.6% (72), followed by supraeruption in 23.2% (29).More males than females reported missing PFMM (22.8 and 7.2%, respectively), and those ≥ 25 years reported more missing PFMM than younger (17.5 and 12.5%, p ≤ 0.000). Those confirmed with systemic diseases reported more missing PFMM than their counterpart (23.3 and 6.7%, p ≤ 0.01).Those with good oral hygiene reported less missing PFMM than their poor oral hygiene counterparts (27.8 and 34%). Those who had good knowledge about the complications of early extraction of PFMM stated less missing PFMM than their counterparts (15.6 and 14.4%, p ≤ 0.01).

CONCLUSION

 This study indicated that PFMM were the most common extracted tooth. Caries is the principal reason for tooth extraction among the studied population, followed by periodontal diseases. Emphasis on preventing dental caries is essential to maintain a socially and economically productive life and reduce the burden of oral disease.

Prevalence of Missing First Permanent Molars in a Selected Population in a University Dental Clinic Setting: A Retrospective Radiographic Study

Aim and objective

This study aimed to determine the prevalence of missing first permanent molars (FPMs) in the 7–29-year-old selected population of Al Ahsa, Saudi Arabia.

Materials and methods

This study retrospectively analyzed 398 panoramic radiographs of patients aged from 7 to 29 years old for missing FPM. Patients were divided into two age-groups: 7–15 and 16–29 years old. Study variables including gender, age, missing FPM, dental arch, and right or left sides of the arch were recorded. The data were statistically analyzed using Chi-square tests.

Results

Of the total study sample, 23.1% of patients had only one missing FPM, 13.3% of patients had two, and 2.8% of them had three missing FPM teeth. No patient had four missing FPM teeth. A total of 60.8% (242) radiographs in the overall sample did not show any missing teeth. The mandibular FPMs (35.2%) were found missing more frequently than their maxillary counterparts (17.4%) and the left mandibular quadrant showed a higher rate of missing FPM (21.9%). No statistically significant association was seen between the missing FPM and the gender or age-group (p > 0.05).

Conclusion

The high prevalence rates of missing FPM in the study population warrants attention. Further prospective studies are needed to comprehensively evaluate the effect of early loss of the FPM on space changes in the arch and subsequent reduction in complex orthodontic treatment needs.

How to cite this article

Almugla YM. Prevalence of Missing First Permanent Molars in a Selected Population in a University Dental Clinic Setting: A Retrospective Radiographic Study. Int J Clin Pediatr Dent 2021;14(2):269–272.

Posterior bending osteotomy: An effective measure to secure facial symmetry in orthognathic surgery

This study aimed to compare the effectiveness of posterior bending osteotomy and grinding techniques for orthognathic surgery in patients with facial asymmetry. Patients who had undergone Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, and who presented with a menton shift and setback difference exceeding 4 mm, were enrolled. Cone-beam computed tomography was performed before surgery (T0), immediately after surgery (T1), and 6 months after surgery (T2). Overall, 38 patients were included and divided into posterior bending osteotomy (n = 23) and grinding (n = 15) groups. Significant differences were observed between the posterior bending osteotomy and grinding groups on the treated side. In the grinding group, the gonion on the treated side was displaced slightly outward, resulting in a significant difference between both sides (non-treated side: 50.52 ± 4.20 [T0] and 48.67 ± 4.37 [T2]; treated side: 50.88 ± 4.55 [T0] and 51.00 ± 3.95 [T2]; p = 0.038). In the posterior bending osteotomy group, bilateral inward movements of the gonion were observed, and the distance from the midsagittal plane to the gonion did not differ significantly between the sides (non-treated side: 46.74 ± 4.41 [T0] and 45.54 ± 3.95 [T2]; treated side: 47.43 ± 4.93 [T0] and 45.18 ± 3.52 [T2]; p = 0.224). The yawing movement of the proximal segment was greater in the grinding group than in the posterior bending osteotomy group (non-treated side: p = 0.839; treated side: p = 0.025). Posterior bending osteotomy is recommended over the grinding method for patients with severe facial asymmetry, in order to ensure a symmetric and esthetic facial profile by allowing passive adaptation between the mandibular segments.

Effects of occlusal disharmony on susceptibility to atrial fibrillation in mice

Tooth loss or incorrect positioning causes occlusal disharmony. Furthermore, tooth loss and atrial fibrillation (AF) are both risk factors for ischemic stroke and coronary heart disease. Therefore, we hypothesized that occlusal disharmony-induced stress increases susceptibility to AF, and we designed the present study to test this idea in mice. Bite-opening (BO) was done by cementing a suitable appliance onto the mandibular incisor to cause occlusal disharmony by increasing the vertical height of occlusion by 0.7 mm for a period of 2 weeks. AF susceptibility, evaluated in terms of the duration of AF induced by transesophageal burst pacing, was significantly increased concomitantly with atrial remodeling, including fibrosis, myocyte apoptosis and oxidative DNA damage, in BO mice. The BO-induced atrial remodeling was associated with increased calmodulin kinase II-mediated ryanodine receptor 2 phosphorylation on serine 2814, as well as inhibition of Akt phosphorylation. However, co-treatment with propranolol, a non-selective β-blocker, ameliorated these changes in BO mice. These data suggest that improvement of occlusal disharmony by means of orthodontic treatment might be helpful in the treatment or prevention of AF.

The extraction of first, second or third permanent molar teeth and its effect on the dentofacial complex

The extraction of permanent molar teeth was first introduced in 1976 as a substitution for premolar extraction in cases with mild crowding. Since then, a number of studies have investigated the effect of permanent molar extraction on dentofacial harmony. Undertaking the procedure of molar extraction is most commonly recommended in response to factors such as: gross caries, large restorations and root-filled teeth, along with its application in the management of anterior open bite and reduction in crowding in facial regions. It has been indicated, however, that before undertaking the extraction of molar teeth it is important to investigate the potential influence of the procedure on other molars, with particular consideration of their eruption path. This is due to the doubt as to the effect of the exact molar teeth extraction and their consequences. In light of this, This review was undertaken to investigate and compare the effect of first, second and the third molar teeth extraction and their subsequent dentofacial complex changes.

Is there an association between skeletal asymmetry and tooth absence?

Introduction:

Facial skeletal asymmetry is commonly found in humans and its main characteristic is menton deviation. The literature suggests that occlusal and masticatory problems arising from tooth absence could be related to the development of such asymmetries.

Objective:

The aim of this cross-sectional study was to estimate the prevalence of mandibular skeletal asymmetries and to investigate its association with posterior tooth absences.

Methods:

Tomographic images of 952 individuals aged from 18 to 75 years old were used. Asymmetry was the analyzed outcome, and it was categorized into three groups according to gnathion displacement in relation to the midsagittal plane (relative symmetry, moderate asymmetry, and severe asymmetry). Patients were sorted by the presence of all posterior teeth, unilateral posterior tooth absence, or bilateral posterior tooth absence. Chi-square test with a significance level of 5% was used to verify the association between posterior tooth absence and asymmetry.

Results:

Results show relative symmetry present in 55.3% of the sample, as well as the prevalence of 27.3% for moderate mandibular asymmetry and 17.4% for severe asymmetry. Moderate and severe mandibular asymmetries occurred in a higher proportion in patients with unilateral posterior tooth absence. However, there was no statistically significant difference between the analyzed groups (p = 0.691).

Conclusions:

In this study, mandibular asymmetries did not present any association with the absence of teeth on the posterior area of the arch.

Prevalence and Associated Factors of Mandibular Asymmetry in an Adult Population

BACKGROUND

This study aimed to estimate the prevalence of mandibular asymmetry and investigate some associated factors.

METHODS

Tomographic images of 952 individuals aged from 18 to 75 years old were analyzed. The investigated outcome was mandibular asymmetry. The explanatory variables included gender, age, absence of posterior teeth, and sagittal jaw relationship of the individuals. Statistical analyses included the chi-squared and the Poisson regression with robust variance.

RESULTS

Mandibular asymmetry was present in 17.4% of the sample (95% confidence interval 15.2-20.0). In the bivariate analysis, there was an association between the variables age and sagittal jaw relationship with mandibular asymmetry (P = 0.026 and P = 0.018, respectively). However, in the adjusted regression model, the association with age was not maintained, occurring only an association between sagittal jaw relationship and mandibular asymmetry (P = 0.045), with significant difference between individuals with skeletal Class II and skeletal Class III (P = 0.013).

CONCLUSION

Mandibular asymmetry was not independently associated with sex, age, or absence of posterior teeth. The only verified independent association was between mandibular asymmetry and sagittal jaw relationship.

Finite element analysis on tooth and periodontal stress under simulated occlusal loads

The tooth stress elicited by occluding contact represents critical biomechanical information about dental health during chewing. Effects of occlusal contact on tooth stress remain obscure. In this study, a mandibular first molar finite element model was built from CT images. The effects of area size, location and direction of occlusal loading on both tooth and periodontal stresses were analysed. Results showed tooth and periodontal stress had drastically different patterns. Tooth stress value was much higher than periodontal stress value under the same task. Tooth stress concentration area and its value decreased from outside to inside. The Maximum Tooth Stress (MTS) always occurred at the loading site and a larger loading area elicited a smaller MTS value. The variation of MTS was larger when the fossa bottoms were inclined loaded than when the cusp tips were inclined loaded, larger when lingually loaded than when buccally loaded and larger when mesially loaded than when distally loaded. Distal loadings generally induced smaller Maximum Periodontal Stress (MPS) variations than the mesial loadings. These findings indicated exposure of the rational site(s) to occlusal contact should be helpful to achieve proper tooth and periodontal stress, thus to diminish loading associated structure problems.

Evaluation of Relationship Between Demographics and Dental Status in a Defined Group of Iranian Paediatric Patients Undergoing Cancer Therapy

CONTEXT

Cancer is a major cause of death in children under 15 years of age.

AIMS

This study aimed to evaluate relationship between demographics and dental status in a defined group of Iranian paediatric patients undergoing cancer therapy.

SETTINGS AND DESIGN

This cross-sectional study was accomplished on 161 subjects age ranging 8-12 years. There were 76 cancerous patients hospitalized at Mahak Hospital (one of the major children's cancer centers in Tehran) as the study group and 85 healthy children attending at Dental School, International Branch of Shahid Beheshti University of Medical Sciences, Tehran, Iran from 2012 to 2013.

MATERIALS AND METHODS

Demographics were gathered by using data-form. Oral examination and DMFT Index were used to describe teeth status in all teeth and in the first permanent molars. According to Becker's definition, "D" stands for untreated decayed teeth, "M" indicates missing teeth, and "F" shows Filled teeth. It is noteworthy that full coverage crowns are considered as "F" in this Index.

STATISTICAL ANALYSIS

Chi-square, Mann-Whitney U, Student's t-tests and Logistic Regression were used for data analysis.

RESULTS

The most frequent type of cancer was acute lymphoblastic/lymphocytic leukemia (33.3%). Patients were significantly shorter than controls (p=0.03), and their fathers and mothers were of lower educational achievement (p=0.01, p= 0.001). Although DMFT of all dentition showed significantly higher score in cancerous children (p=0.001), DMFT of four first permanent molars (left, right, upper, and lower) was borderline significantly higher in patients (p= 0.06). Moreover, frequency of cancer was borderline significantly higher in children with lower birth order (p= 0.05). According to Logistic Regression, in as much as patients grew elder 1 year, DMFT index increased 1.5 units.

CONCLUSION

Patients under cancer therapy were shorter than healthy ones, and their parents were of lower educational levels. In addition, their teeth status was poorer than controls.

Effects of early unilateral mandibular first molar extraction on condylar and ramal vertical asymmetry

Objective:

The objective of the following study is to investigate the mandibular vertical asymmetry in a group of patients with early unilateral mandibular first molar extractions.

Materials and Methods:

Mandibular asymmetry index measurements (condylar, ramal and condylar-plus-ramal) were performed on the panoramic radiographs of a study group including 51 patients (mean age: 18.60 ± 1.11 years) and a control group of 51 patients (mean age: 18.53 ± 1.29 years). Group I included patients with a unilateral mandibular first molar extracted before the age of 12 years. Group II included patients with no extractions and had excellent Class I relationships, no missing teeth and slight or moderate anterior crowding. A paired t-test was used to determine possible statistically significant differences between the sides for the measurements. Student's t-test was used for the comparison of asymmetry index values between the groups and genders.

Results:

No group showed statistically significant sex-or side-specific differences for posterior vertical height measurements. Condylar asymmetry index and ramal asymmetry index measurements were not statistically different between the groups, while condylar-plus-ramal asymmetry index (CRAI) measurements were statistically different between the groups (P = 0.019).

Conclusions:

A slight difference for CRAI value was found in patients with early unilateral mandibular first molar extractions.

Permanent first molar extraction in adolescents and young adults and its effect on the development of third molar

OBJECTIVES

The aim of the present study was to determine the prevalence of permanent first molar (P1M) extraction among Turkish adolescents and young adult subpopulation, and to investigate the effects of P1M extraction on development of the third molars (3Ms) in the same quadrant.

MATERIALS AND METHODS

A retrospective study including 2,925 panoramic radiographs (PRs) taken from patients (aged 13-20 years) who were examined to identify cases of had at least one maxillary or mandibular P1Ms extracted was performed. Additionally, 294 PRs with the maxillary or mandibular unilateral loss of a P1M were used to assess the developmental grades of the 3Ms. Statistical analyses were performed by means of parametric tests after performing a Shapiro-Wilks normality test to the data.

RESULT

A total of 945 patients (32.3 %) presented with at least one P1M extraction with no gender difference (P = 0.297). There were more cases of mandibular P1Ms extracted (784 patients, 1,066 teeth) than maxillary P1Ms extracted (441 patients, 549 teeth) (P < 0.001). The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated when compared with the contralateral teeth (P = 0.000, P = 0.000, respectively). No statistically significant differences were found in the differences in the developmental of the 3Ms between the maxilla and mandible (P = 0.718).

CONCLUSIONS

High prevalence of P1Ms extraction among Turkish adolescents and young adults shows a need for targeted dental actions, including prevention and treatment. The development of the 3Ms on the extraction side, in the both maxilla and mandible, was significantly accelerated.

CLINICAL RELEVANCE

To date, no information about prevalence of P1Ms extraction among Turkish adolescents and young adults is documented. In addition, the present study has a larger population and complementary information about 3Ms development than previous studies.

Effects of early bilateral mandibular first molar extraction on condylar and ramal vertical asymmetry

OBJECTIVES

This study aims to investigate the mandibular vertical asymmetry in a group of adult patients who had early bilateral mandibular first molar extractions.

METHODS

Mandibular asymmetry index measurements (condylar, ramal, and condylar plus ramal) were made on the panoramic radiographs of a study group including 30 subjects (mean age, 18.22 ± 1.30 years) and a control group of 25 subjects (mean age, 18.24 ± 1.17 years). Group I comprised the control group patients with no extractions and had excellent class I relationships, no missing teeth, and slight or moderate anterior crowding. Group II included patients with a bilateral mandibular first molar teeth extracted before the age of 12 years. Student's t test was used for the comparison of asymmetry index values between the groups. A paired t test was used to determine possible statistically significant differences between the sides for condylar, ramal, and condylar plus ramal height measurements.

RESULTS

No group showed statistically significant side-specific differences for posterior vertical height measurements. Condylar asymmetry index (CAI), ramal asymmetry index, and condylar plus ramal asymmetry index measurements were not statistically different between the groups (p > 0.05).

CONCLUSIONS

CAI values were significantly high when compared with the 3 % threshold value in the both groups, but comparisons between the groups were not statistically significant.

CLINICAL RELEVANCE

This article investigates the effects of early bilateral mandibular molar teeth extraction that has never been investigated in the literature. The present study showed that the lengths of the condylar, ramal, and condylar plus ramal height were less in the study group than in a well-matched control group of without extraction.

Dental treatment needs of permanent first molars in mashhad schoolchildren

Background and aims

In spite of their enormous importance, permanent first molars might be affected by caries in children in developing countries. The aim of this study was to evaluate the treatment needs of first permanent molars in a group of schoolchildren in Mashhad.

Materials and methods

This cross-sectional descriptive study was carried out on 700, 7-9 year-old students in primary schools in Mashhad. The schools were randomly selected from each district. Treatment needs and DMFT of first perma-nent molars were calculated. Data was analyzed using ANOVA, Chi-Square and t-test.

Results

A total of 95.3% of the children required dental treatment. Fissure sealant application and filling were the treat-ments most required in all age groups. The mean DMFT of first permanent molars was 1.31±1.4. It was significantly higher in girls than boys (P=0.040).

Conclusion

Great treatment needs and caries prevalence in permanent first molars in Mashhad schoolchildren show that dental caries is still a serious problem in the children of our society; therefore, education of parents and teachers is necessary for promoting children's oral health.

Association between mandibular asymmetry and occlusal asymmetry in young adult males with class III malocclusion

OBJECTIVE

Our aim was to assess the association between mandibular asymmetry and sagittal and transverse occlusal asymmetry in young adult males with class III malocclusion. Our hypotheses were that (1) mandibular asymmetry increases with increasing mandibular length and (2) occlusal asymmetry is correlated with mandibular asymmetry.

MATERIAL AND METHODS

On lateral cephalograms of 54 subjects, skeletal class and mandibular length were measured. Mandibular asymmetry was evaluated on orthopantomograms as right-left difference between condylar or ramus heights. Occlusal asymmetry was assessed on dental casts by differences between right and left canine and molar relationship, anterior and posterior crossbite as well as midline deviation.

RESULTS

Mandibular asymmetry was significantly correlated with sagittal and transverse occlusal asymmetry (p < 0.05), but not with mandibular length (p > 0.05). Condylar asymmetry due to a longer condyle on one side was correlated with asymmetric aggravation of canine and molar class III on the ipsilateral side (r = -0.53 and -0.62, respectively). In contrast, ramus asymmetry was related to contralateral aggravation of canine and molar class III relationships (r = 0.27 and 0.29, respectively). Correlations existed between asymmetry in total height of the condyle and ramus and asymmetric aggravation of anterior crossbite (r = -0.33), posterior crossbite (r = -0.30) and lower midline deviation (r = -0.27) to the contralateral side (p < 0.05).

CONCLUSIONS

Mandibular asymmetry is associated with occlusal asymmetry, especially in the sagittal plane. Condylar asymmetry had 28% and 38% of variance in common with sagittal canine and molar asymmetry, respectively. Asymmetry in total height of the condyle and ramus was related to transverse occlusal asymmetry.