This study evaluated the validity of panoramic radiography and cone beam computed tomography (CBCT) in the assessment of mandibular canal and impacted third molar. In this descriptive-analytical study, 58 mandibular third molars from 42 patients who showed a close relationship between impacted third molar and canal on panoramic radiographs were selected. They were then classified into seven radiographic markers in panoramic radiographs (superimposition, darkening of the root, interruption of the white lines, root narrowing, canal diversion, canal narrowing, and also closed distance in OPG <1mm). The groups of markers were further assessed with CBCT to see presence or absence of contact. The three most common markers seen in panoramic images are superimposition, interruption of white line and root darkening. In CBCT, superimposition marker always presented higher frequency of contact with canal compared to non-contact group. There are 31% of teeth presented with interruption of white lines and there are 29.3% of teeth presented with superimposition. About 55.6% and 35.3% of the impacted mandibular third molars which indicated interruption of white lines and superimposition also indicated contact in the CBCT respectively. Presence or absence of radiological sign in panoramic radiography was not properly predict a close relationship with third molar and it is suggested that in case of tooth-canal overlapping, the patient should be referred for CBCT assessment.
This study aimed to assess the variability of the lower third molar (tooth 38 and 48) development in Northeast Malaysian population with respect to the side of dentition, to generate age prediction models and to compare the outcome with other studies. A total of 1080 orthopantomograms of Northeast Malaysian population aged between 14 and 25 years (540 males and 540 females) from the Hospital Universiti Sains Malaysia's archive which met the inclusion and exclusion criteria were selected and the maturity stages of tooth 38 and 48 were scored using Demirjian's stages (A-H). The findings showed a wide variation of the development of lower third molars in the Northeast Malaysian population. The roots developed earlier in males than in females. The development of the dentition on opposite sides of the mandible was synchronously in females and males. A multiple regression analysis shows that 71.1% of variance in age was explained by sex and developmental stage of tooth 48. An age prediction model was generated from the regression analysis: [Age = 7.117 + 1.907*(stage of tooth 48) - 0.432*(sex)] with mean prediction errors between -0.17 to 3.14 years. The obtained data in the current study are useful for references and determining age of unidentified human remains for identification investigation.
The third molar development (TMD) has been widely utilized as one of the radiographic method for dental age estimation. By using the same radiograph of the same individual, third molar eruption (TME) information can be incorporated to the TMD regression model. This study aims to evaluate the performance of dental age estimation in individual method models and the combined model (TMD and TME) based on the classic regressions of multiple linear and principal component analysis. A sample of 705 digital panoramic radiographs of Malay sub-adults aged between 14.1 and 23.8 years was collected. The techniques described by Gleiser and Hunt (modified by Kohler) and Olze were employed to stage the TMD and TME, respectively. The data was divided to develop three respective models based on the two regressions of multiple linear and principal component analysis. The trained models were then validated on the test sample and the accuracy of age prediction was compared between each model. The coefficient of determination (R²) and root mean square error (RMSE) were calculated. In both genders, adjusted R² yielded an increment in the linear regressions of combined model as compared to the individual models. The overall decrease in RMSE was detected in combined model as compared to TMD (0.03-0.06) and TME (0.2-0.8). In principal component regression, low value of adjusted R(2) and high RMSE except in male were exhibited in combined model. Dental age estimation is better predicted using combined model in multiple linear regression models.
Teeth are the most durable structures in the human body. The timing and sequence of their development, as contained in dental development charts, have been used as valid criteria for age determination. The third molars however are the last teeth to erupt and are regarded as the most variable in the dentition. Age estimation in a legal context, using developing third molars must be carefully applied otherwise justice may miscarry. A case of wrongful use of the technique is presented here.
This study was conducted to determine the prevalence of pre-eruptive intracoronal dentin defects from panoramic radiographs from a group of children and young adults aged 20 years and below. The radiolucent lesions were noted with regard to which teeth were affected, the location of the defects and the size of the defects relative to the width of dentin. Out of 1007 radiographs examined, 275 (27.3%) have pre-eruptive dentin defects. The prevalence of anomaly among males was 28.4% as compared to 26.2% among females. However, the difference between genders was not significant, thus subsequent results have been combined. Of 275 subjects with dentin radiolucencies, 243 subjects (88.7%) had only one affected tooth, 30 subjects (10.9%) had two teeth affected and 2 subjects (0.7%) had three affected teeth. The tooth prevalence of the anomaly was 2.1% and most of the lesions occurred as a single occurrence on the affected tooth. Within each tooth type, the highest tooth prevalence of intracoronal dentin defect was found in the upper first premolar (5.1%). More than half of the lesions extended less than 1/3 of the width of the dentin thickness. The high prevalence of the condition indicates the need for increased awareness and recognition of this during radiographic examination of teeth in the pediatric age group in early pre-eruptive stages so that early detection and diagnosis can be made and treatment can be done at the most appropriate time.