Dental development in patients with agenesis

Aim

Recent research concerning tooth development and dental agenesis suggests that specific genes are associated with agenesis, and that these genetic factors could also cause delayed dental development of the remaining teeth. The objective of this study was to evaluate whether dental development of patients with agenesis is delayed, compared to a control group.

Subjects and method

Panoramic radiographs of 1145 patients with dental agenesis were collected (452 males, 693 females) aged 6.2 to 24.8 years. The control group included 2032 panoramic radiographs (977 males, 1055 females) aged 6.0 to 24.4 years. A total of 3177 orthopantomograms were staged according to Demirjian. All left permanent teeth present in the mandible (except third molars) were considered. In order to evaluate the difference between patients with and without agenesis, a developmental score (DS) was calculated. The association between the DS and the number of agenetic teeth was evaluated with a Spearman correlation.

Results

Based on the DS, patients with agenesis have a delayed development compared to patients in the control group (p < 0.0001). Within the agenesis group, there is a weak relation between the number of agenetic teeth and the DS: the higher the number of teeth with agenesis, the lower the DS (p < 0.0001 and p = 0.06 for females and males, respectively).

Conclusion

The obtained results can be an important factor for treatment planning in patients with dental agenesis. Moreover, the presence of agenesis needs to be taken into account when using age estimation methods based on permanent tooth development.

     

Analyses of odontometric sexual dimorphism and sex assessment accuracy on a large sample

Correct sex assessment of skeletonized human remains allows investigators to undertake a more focused search of missing persons' files to establish identity. Univariate and multivariate odontometric sex assessment has been explored in recent years on small sample sizes and have not used a test sample. Consequently, inconsistent results have been produced in terms of accuracy of sex allocation. This paper has derived data from a large sample of males and females, and applied logistic regression formulae on a test sample. Using a digital caliper, buccolingual and mesiodistal dimensions of all permanent teeth (except third molars) were measured on 600 dental casts (306 females, 294 males) of young adults (18–32 years), and the data subjected to univariate (independent samples' t-test) and multivariate statistics (stepwise logistic regression analysis, or LRA). The analyses revealed that canines were the most sexually dimorphic teeth followed by molars. All tooth variables were larger in males, with 51/56 (91.1%) being statistically larger (p < 0.05). When the stepwise LRA formulae were applied to a test sample of 69 subjects (40 females, 29 males) of the same age range, allocation accuracy of 68.1% for the maxillary teeth, 73.9% for the mandibular teeth, and 71% for teeth of both jaws combined, were obtained. The high univariate sexual dimorphism observed herein contrasts with some reports of low, and sometimes reverse, sexual dimorphism (the phenomenon of female tooth dimensions being larger than males'); the LRA results, too, are in contradiction to a previous report of virtually 100% sex allocation for a small heterogeneous sample. These reflect the importance of using a large sample to quantify sexual dimorphism in tooth dimensions and the application of the derived formulae on a test dataset to ascertain accuracy which, at best, is moderate in nature.     

Identifying sexual dimorphism in a paediatric South Indian population using stepwise discriminant function analysis

Anthropological research relies on skeletal and dental remains for the identification of species. Sexual dimorphism is the systematic difference in form between males and females of the same species. This study is designed to compute a new formula for sex determination using discriminant function analysis in the deciduous crown dimensions of a paediatric population of South Indian origin and to check its accuracy. The sample consisted of 93 females and 90 males of South Indian origin aged between 5 and 13 years. Alginate impressions of the upper dental arch were made and casts were poured immediately. A digital vernier calliper was used to obtain measurements. Teeth considered for measurement were deciduous maxillary canines and molars. Our study is a maiden attempt in considering diagonal measurements along with mesiodistal (MD) and buccolingual (BL) dimensions as predictor variables for sex determination. Statistical analysis was performed using the Statistical Package for the Social Science version 17.0 software. By using the Student t-test, the different predictor variables of teeth selected between male and females were found to be significant (p < 0.05). Highly significant sexual dimorphism was found in the mean MD dimension of maxillary right canine and right and left first molar, BL dimension of right first molar, distobuccal–mesiolingual of right and left first molar and right second molar and mesiobuccal–distolingual of right second molar. The percentage of sexual dimorphism in MD dimensions revealed that the right upper first molar was the most dimorphic tooth and the upper first molar of the left side was the least dimorphic of the six teeth studied. The present study found the level of sexual dimorphism in the deciduous crown dimensions of a selected group of South Indian population, which is sufficiently large to determine sex with an accuracy of 87.2–88% by discriminant function analysis. Hence the formula derived from the present study could be of some value in sex determination of paediatric populations of South Indian origin.     

Human dental age estimation combining third molar(s) development and tooth morphological age predictors

In the subadult age group, third molar development, as well as age-related morphological tooth information can be observed on panoramic radiographs. The aim of present study was to combine, in subadults, panoramic radiographic data based on developmental stages of third molar(s) and morphological measurements from permanent teeth, in order to evaluate its added age-predicting performances. In the age range between 15 and 23?years, 25 gender-specific radiographs were collected within each age category of 1?year. Third molar development was classified and registered according the 10-point staging and scoring technique proposed by Gleiser and Hunt (1955), modified by K?hler (1994). The Kvaal (1995) measuring technique was applied on the indicated teeth from the individuals’ left side. Linear regression models with age as response and third molar-scored stages as explanatory variables were developed, and morphological measurements from permanent teeth were added. From the models, determination coefficients (R ²) and root-mean-square errors (RMSE) were calculated. Maximal-added age information was reported as a 6?% R2 increase and a 0.10-year decrease of RMSE. Forensic dental age estimations on panoramic radiographic data in the subadult group (15–23?year) should only be based on third molar development.     

Artificial intelligence system for automatic deciduous tooth detection and numbering in panoramic radiographs

Objective:This study evaluated the use of a deep-learning approach for automated detection and numbering of deciduous teeth in children as depicted on panoramic radiographs.Methods and materials:An artificial intelligence (AI) algorithm (CranioCatch, Eskisehir-Turkey) using Faster R-CNN Inception v2 (COCO) models were developed to automatically detect and number deciduous teeth as seen on pediatric panoramic radiographs. The algorithm was trained and tested on a total of 421 panoramic images. System performance was assessed using a confusion matrix.Results:The AI system was successful in detecting and numbering the deciduous teeth of children as depicted on panoramic radiographs. The sensitivity and precision rates were high. The estimated sensitivity, precision, and F1 score were 0.9804, 0.9571, and 0.9686, respectively.Conclusion:Deep-learning-based AI models are a promising tool for the automated charting of panoramic dental radiographs from children. In addition to serving as a time-saving measure and an aid to clinicians, AI plays a valuable role in forensic identification.     

Applicability of the Demirjian method for dental assessment of southern Turkish children

Age-related legal problems are especially common in underdeveloped parts of Turkey. In terms of civil and criminal law, the ages from 13 years to 18 years are critical in our country. Estimation of age is a very significant in aspect of accordance with laws. The aims of this study were to evaluate the applicability and accuracy of the Demirjian technique for assessing southern Turkish children; to analyze the sexual dimorphism of dental age in the studied groups; and to define the relationship between the dental age and the degree of mineralization in mandibular permanent tooth in southern Turkish children.This study was performed using panoramic radiographs from 932 healthy southern Turkish children, 444 girls and 488 boys aged between 4 and 18 years. Statistical evaluations were performed using SPSS (Statistical Package for Social Sciences) for Windows 13.0 software. The mean difference between dental and chronological age was calculated for each age and sex group. The paired t-test was used to compare all data. The chi-square test was used for between-group comparisons of categorical variables. Continuous variables were tested for normality using the Kolmogorov–Smirnov test. Relationships between continuous variables were examined using Pearson's correlation coefficient. The same observer re-examined 700 teeth three months after the first examination. The results were evaluated with the intraclass correlation test and both measurements were statistically significantly similar with each other(R = 0.982, p = 0.0001). .Dental age (DA) and chronological age (CA) were consistent for boys in the 16–16.9 age group and for girls in the 9–9.9 and 15–15.9 age groups.From this study, we can conclude that dental age varies across ethnic populations. Additionally, dental maturation varies across different regions of the same country. Because Demirjian's standards are not suitable for all age groups of southern Turkish children, a new table is necessary for evaluating this population. Future studies using multi-ethnic population data are needed to establish the international applicability of Demirjian's method.     

Digital panoramic radiography: a clinical survey

The application of digital panoramic radiography with photostimulable phosphors to dental diagnosis was evaluated in 500 patients. Comparative intraoral films of selected groups of teeth and electronic magnifications of the same portion of the arches were obtained in 63 cases. Digital images improved the quality of dental examinations compared with film radiographs. The possibility of contrast modulation was helpful to compensate for the different radiographic densities of the arches and to improve the visibility of gingival soft tissues. In addition, digital radiography reduced the radiation dose administered to the patient. The use of digital panoramic radiography is proposed as a substitute for film studies in all hospitals where a central unit for digital radiology is available. Correspondence to: R. Nessi     

The association between carotid calcium on dental panoramic radiographs and coronary calcium score on chest computerized tomography

Objectives:Coronary artery calcium measured by CT predicts future coronary events. Similarly, carotid artery calcium on dental panoramic radiographs has been associated with increased cardiovascular events. Pre-procedural assessment of candidates for valve replacement in our institution includes panoramic radiographs and chest tomography. We aimed to assess the association of carotid calcium on panoramic radiographs with coronary artery calcium on chest tomography.Methods:Paired pre-procedural panoramic radiographs and chest tomography scans were done in 177 consecutive patients between October 2016 and October 2017. Carotid calcium was quantified using NIH’s ImageJ. Coronary artery calcium was quantified by the Agatston score using Philips Intellispace portal, v. 8.0.1.20640.Results:Carotid calcium maximal intensity, area and perimeter were higher among patients with high coronary artery calcium. Non-zero carotid calcium was found in half of patients with high coronary artery calcium, doubling prevalence of low coronary artery calcium.Conclusion:Carotid calcium identified in panoramic radiographs was associated with high coronary artery calcium. Awareness of carotid calcium recognized by dental practitioners in low-cost, low radiation and commonly done panoramic radiographs may be useful to identify patients at risk of coronary disease with potential future cardiovascular events.     

Quantification of secondary dentin formation using dental orthopantomographs in a contemporary Malaysian population

ABSTRACT

The Kvaal method is recommended for age estimation in adults and is based on the analysis of the pulp chamber. Importantly, however, subsequent research has empirically demonstrated that the accuracy of this method varies across global populations. The aim of the current study is, therefore, to examine the relationship between secondary dentin formation and chronological age to establish forensic age estimation standards for a Malaysian population. A total of 300 anonymized dental orthopantomographs of Malaysian individuals, aged between 16 to 69 years were analysed following the Kvaal method. Length and width measurements of the tooth and pulp chamber were acquired in six teeth. Kvaal’s dental ratios were calculated and subsequently used to formulate multiple linear regression models. Intra-observer error was found to be within acceptable standards for all measurements (TEM<1.0, rTEM<5%, R>0.75). A significant negative correlation between chronological age and the Kvaal dental ratios was demonstrated (0.14–0.42). The most accurate model was for maxillary central incisor (SEE ±10.46 years). This study reaffirms the reproducibility of Kvaal’s method in dental radiographs and demonstrates its applicability amongst Malaysians.     

Dental age estimation in Somali children using the Willems et al. model

Aim

The aim of the current study was to retrospectively collect dental panoramic radiographs from Somali children living in Finland, to use the radiographic data to develop a new age estimation model based on the model established by Willems et al. (J Forensic Sci 46(4):893–895, 2001), and to compare the age prediction performances of the Willems et al. model (WM) and the newly developed model.

Material and methods

Dental panoramic radiographs from 808 healthy Somalis born in Finland were selected. The development of the seven left mandibular permanent teeth, from the central incisor to the second molar, was staged according to Demirjian et al. (Hum Biol 45(2):211–227, 1973). Radiographs with all listed permanent teeth completely developed were excluded. The studied sample consisted of 635 subjects (311 females, 324 males) ranging in age from 4 to 18 years. Kappa and weighted Kappa statistics were used to quantify intra- and inter-observer agreement in stage allocation. The collected dataset was used to validate the WM, constructed on a Belgian Caucasian reference sample, and to establish a Somali-specific age estimation model (SM) based on the WM. Both models were validated and their age prediction performances quantified using mean error (ME), mean absolute error (MAE) and root mean squared error (RMSE).

Results

The SM resulted in a slight underestimation of age when the sex groups were analysed separately or combined, with ME varying between 0.04 (standard deviation (SD) 1.01) and 0.05 (SD 1.04) years, MAE between 0.77 and 0.80 years and RMSE between 1.01 and 1.04 years. The WM statistically significantly underestimated the age of females, with an ME of 0.20 (SD 1.01) years (p = 0.0006). For males, and for females and males combined, no statistically significant ME was observed.

Conclusion

The WM and SM were similar in their age prediction performances, and the use of the WM in dental age assessment in the Somali population is justified.

     

Odontometric sex assessment from logistic regression analysis

Odontometric sex assessment is considered a useful adjunct to more robust predictors such as pelvic and cranial bones, and discriminant function analysis (DA) has been widely applied in dental sex assessment. Logistic regression analysis (LRA) is considered a better alternative, although still untested in odontometric sex prediction. This study examines the use of LRA in dental sex assessment and compares its success to DA. Mesiodistal and buccolingual dimensions of all teeth, except third molars, were obtained on dental stone casts of 105 young adults (52 females, 53 males) using digital caliper. Application of LRA to teeth of both jaws combined and to maxillary and mandibular teeth separately yielded correct sex allocation rates ranging from 76% to 100%, which proved superior to sex assessment using DA (∼52–71%). LRA enabled optimal sex prediction (100%) when all teeth in both the jaws were included. Results were not as accurate when only maxillary (76.2%) or mandibular (84.8%) teeth were used. To assess and compare the use of these multivariate techniques in practical forensic casework, >25% of tooth variables were randomly deleted. LRA still performed better (∼91% sex allocation accuracy vs. 62.9% for DA), indicating that LRA may be superior in its ability to predict sex irrespective of the presence of complete or incomplete sets of dentitions and should be preferred in dental sex assessment. The 100% success rate of LRA in correctly assigning sex is also noteworthy considering that, in general, tooth measurements have yielded sub-optimal sex prediction levels. However, unambiguous sex assessment is possible only when the entire dentition is available and correct sex allocation levels decreases when teeth are missing.     

An exploration of sacral morphology using geometric morphometrics and three-dimensionally derived interlandmark distances

Introduction

Accurate sex estimation is an important component of a biological profile in forensic anthropology. The pelvis is widely accepted as the most dimorphic osseous structure, and thus, this dimorphism is also reflected by the sacrum.

Aim

This study aimed to explore sacral morphology and to derive a practically applicable discriminant function formula for sex estimation.

Materials

A total of 20 three-dimensional landmarks were digitised on a sample of 200 sacra from a sample of South Africans of African descent (Black South Africans) with ages ranging between 20 and 90 years, equally distributed for sex.

Methods

Geometric morphometric methods were used to analyse sacral morphology and sexual dimorphism as it captures size-independent shape variation and three-dimensional morphology.

Results

Size-independent shape analysis revealed four sacral structures and metrics that account for most of its shape variation. When these were compared between the sexes, we found that sacral curvature pattern, rather than depth, differed between sexes and that males have greater anterior sacral heights. Females have larger alae relative to the body of S1. In addition, the anterior posterior breadth of the sacral canal is larger in males, as is the relative size and projection of the superior articular processes. Discriminant analyses of these data produced average accuracies of only 72.5%, but this improved to 84.5% when using novel interlandmark distances derived from the raw coordinate data.

Conclusion

Our results demonstrate that landmark-based techniques allow for a more nuanced understanding of structural variation. In addition, accuracies were achieved that surpass traditional metrics using an equal number of variables. These results contribute to our understanding of sacral dimorphism and will assist in forensic casework.

     

Measurements of tooth length in panoramic radiographs. 1. The use of indicators.

The aim of this study was to investigate both the actual and the radiographic tooth lengths of the maxillary first molar and second premolar and the mandibular premolars in panoramic radiographs. The actual length of 64 extracted teeth was measured. Steel balls were then attached to the cusp and apex and the teeth embedded in plastic moulds. Each pair of plaster casts with their set of teeth was radiographed with an Orthopantomograph twice at an interval of 1 month. The actual and the radiographic tooth length was measured twice by one observer. The mean tooth length of the molar was shorter than that of the premolars. The mean difference between the repeated measurements of the actual tooth length was small and ranged between 0.47 and 1.16% of the tooth length. The mean difference between repeated measurements of the radiographic tooth length was also small, with a method error of 0.13-0.21 mm. The vertical magnification in panoramic radiography was lower for mandibular premolars (13-15%) than for the maxillary second premolar and first molar (17-28%). The palatal root of the maxillary first molar had the highest vertical magnification (28%). Following the second set of radiographs, the mean difference between the measurements was small, except for the palatal root of the maxillary first molar (P < 0.001). Radiographic measurements of this root should therefore be used with caution. The results for the other roots examined indicate that these could be measured with high reproducibility.     

Limitations of the mandibular canine index in sex assessment

Measuring teeth is a useful adjunct in sex assessment. Canines, in particular, have the greatest degree of sexual dimorphism, resist disease and survive postmortem trauma, rendering them highly valuable in identification. Hence, their exclusive use in odontometric sex assessment using the Mandibular Canine Index (MCI) has been advocated before. The MCI is derived as the ratio of the mesiodistal (MD) dimension of canines and the inter-canine arch width. This study has tested the use of the MCI in assessing sex on a sample from Nepal and compared its accuracy to that of absolute canine measurements. Measurements were obtained from one hundred-and-seventeen dental stone casts that belonged to 63 males and 54 females, all young adults in the age-group 19–28 years. Independent samples t-test revealed no significant sexual dimorphism in the MCI. In addition, discriminant analysis of the MCI also had poor ability to differentiate the sexes. In contrast, the absolute canine measurements revealed statistically significant male–female difference and superior ability to differentiate sex using discriminant analysis. The poor ability of the MCI in sex assessment is attributed to it being a relative value–it is obtained as the ratio of two absolute measurements (MD dimension of canines and inter-canine arch width) and does not reflect sex differences that exist in the absolute measurements per se.     

Comperative evaluation of Nolla,Willems and Cameriere methods for age estimation of Turkish children in the Central Black Sea Region: A preliminary study

PurposeSince dental age estimation methods' accuracy and reliability levels differ in each society, the method should be appropriate for societies. This study aims to evaluate the applicability of Nolla, Willems, and Cameriere methods to Turkish children in the Central Black Sea Region.Material and methodThis study was conducted based on the panoramic radiographs of 400 children between the ages of 6–14 years admitted to Tokat Gaziosmanpaşa University Faculty of Dentistry, Department of Pediatric Dentistry for examination between 2016 and 2020. Nolla, Willems, and Cameriere methods estimated dental age on the selected panoramic radiographs. While 14 teeth in the left mandible and maxilla were evaluated for Nolla method, seven teeth in the left mandible were evaluated for Willems and Cameriere methods. Data were analyzed using IBM SPSS V23. The Pearson correlation coefficient was used to analyze the relationship between the chronological age (CA) and dental age (DA), and the paired sample t-test was used to analyze the difference.ResultsA statistically significant difference was found between CA-Nolla dental age (p = 0.002), CA-Willems dental age (p < 0.001), and CA-Cameriere dental age (p = 0.033) in boys. The mean differences between dental age and chronological age in boys were −0.24 years in the Nolla method, +0.49 years in Willems method, and −0.17 years in the Cameriere method. A statistically significant difference was found between CA-Nolla dental age (p = 0.001) and CA-Willems dental age (p < 0.001) in girls. The mean differences between dental age and chronological age in girls were −0.27 years in the Nolla method, +0.76 years in the Willems method, and −0.1 years in the Cameriere method.ConclusionIn this study method providing closest estimation for chronological age among children aged 6–14.99 that were examined in Central Black Sea Region, was the Cameriere method in both girls (79.9%) and boys (80.6%), followed by Nolla method and Willems method, respectively.     

The evaluation of MCI,MI, PMI and GT on both genders with different age and dental status

Objectives:

The aim of this study was to measure the mandibular cortical index (MCI), mental index (MI), panoramic mandibular index (PMI) and cortical bone thickness in the zone of the gonial angle (GT) in panoramic radiographies from a large sample of males and females and to determine how they relate to patients'' age, gender and dental status.

Methods:

910 panoramic radiographs were obtained and grouped into age, dental status and gender. The MCI, MI, PMI and GT were analysed.

Results:

Remarkable differences were observed for MCI and GT regarding gender, age groups and dental status on both sides (p < 0.05). While age and dental status had an effect on the MI and PMI in females, dental status had an effect on the MI and PMI in males (p < 0.05). Also, gender had an effect on the MI and PMI (p < 0.05).

Conclusions:

The effects of age and tooth loss are different in females and males. In females, the harmful effects of tooth loss and age are more prominent according to the PMI and MI measurements. The effects of age and tooth loss in the GT and MCI measurements are similar, and these indices can be accepted as more reliable in studies including both genders.     

Measurements of tooth length in panoramic radiographs. 2: Observer performance.

Observer performance in tooth-length measurements in panoramic radiography has been examined. Sixty-four teeth, evenly distributed between maxillary first molars, second premolars and mandibular first and second premolars, were fixed in plastic moulds. Each cast was radiographed with an Orthopantomograph, twice with steel balls indicating the cusps and apices of the teeth and once without them. One observer measured the radiographic tooth length twice in both radiographs with indicators in order to estimate the true radiographic tooth length and the repositioning error, and twice in the radiographs without indicators. Seven other observers measured the tooth length on the radiographs without indicators, twice applying their own criteria and twice using defined criteria. The accuracy of the tooth-length measurements was calculated by comparing the true radiographic tooth length with the measurements of the seven observers. The intra-observer variation was defined as the difference between two measurements on the same radiograph. The accuracy and the precision of the tooth-length measurements were highly influenced by the observer performance. The mean radiographic tooth length of the seven observers was closer to the true radiographic tooth length when the observers applied the defined criteria. The inter- and intra-observer variation was higher for the measurements of the maxillary teeth (0.3-1.9 mm) compared with the mandibular teeth (0.3-0.9 mm) for most observers. The highest intra-observer variation was found for the palatal root of the maxillary first molar. The intra-observer variation of four observers decreased somewhat when the defined criteria were used; for the other three observers, however, the variation increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Investigation on the utility of permanent maxillary molar cusp areas for sex estimation

Digital photogrammetric methods were employed to assess the level of sexual dimorphism present in permanent maxillary molar cusp areas of black South Africans (130 males, 105 females). Odontometric standards were then developed for diagnosing sex, based on the cusp area data derived for these teeth. Results demonstrated that all cusp area measurements of both the first and second maxillary molars were significantly dimorphic (P < 0.0001) in this group. Univariate and multivariate discriminant function analyses yielded overall sex prediction accuracy rates between 59.6 and 74.5%. Comparable allocation results were also obtained for binary logistic regression analyses, but with larger classification sex biases. The highest classification accuracies were observed for different combinations of just two cusp areas for the first molar. Allocation rates of formulae derived for second molar dimensions were on average 4.3% lower than those obtained for the first molar. Analyses incorporating cusp areas of both maxillary molars did not improve classification accuracies achieved when only using first molar measurements. The classification rates are below the suggested minimum accuracy of 75–80% for reliable forensic application of a method; however, the derived formulae may provide a useful statistical indication as to the sex of fragmentary remains in which complete or even partial tooth crowns are the only materials available for examination. Furthermore, the formulae can be applied not only to adults but also to subadults (above the age of 3 years) in which the more accurate sex discriminating features of the pelvis and skull are yet to develop.     

Accuracy of digital and film panoramic radiographs for assessment of position and morphology of mandibular third molars and prevalence of dental anomalies and pathologies

OBJECTIVES: To compare the accuracy of digital and film panoramic radiographs for determining (1) the position and morphology of mandibular third molars before surgical removal and (2) the prevalence of dental anomalies and pathologies. METHODS: Three hundred and eighty-eight third mandibular molars were available for examination. Position and morphology of third molars observed on film radiographs and on digital panoramic images from five systems (DenOptix, DigiDent, Digora, Dimax2 and Orthophos Plus) were recorded by two observers and were compared with surgeons' findings at the time of the operation (gold standard). One observer further recorded the prevalence of dental anomalies and pathologies on both imaging modalities. RESULTS: Few differences were found between the digital and film-based panoramic systems in the assessment of accuracy of position and morphology of mandibular third molars. The prevalence of dental anomalies and pathologies determined with the two modalities was roughly similar. CONCLUSION: The five digital panoramic systems evaluated in this study were equally as useful for third molar treatment planning and diagnosis of dental anomalies and pathologies as conventional film-based panoramic radiographs.     

New models for age estimation and assessment of their accuracy using developing mandibular third molar teeth in a Thai population

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (−0.13 and −0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.