Comparison of mandibular morphometric parameters in digital panoramic radiography in gender determination using machine learning

OBJECTIVE

This study aimed to evaluate the usability of morphometric features obtained from mandibular panoramic radiographs in gender determination using machine learning algorithms.

MATERIALS AND METHODS

High-resolution radiographs of 200 patients aged 20-77 (41.0 ± 12.7) were included in the study. Twelve different morphometric measurements were extracted from each digital panoramic radiography included in the study. These measurements were used as features in the machine learning phase in which six different machine learning algorithms were used (k-nearest neighbor, decision trees, support vector machines, naive Bayes, linear discrimination analysis, and neural networks). To evaluate the reliability, we have performed tenfold cross-validation and we repeated this 10 times for every classification process. This process enhances the reliability of the results for other datasets.

RESULTS

When all 12 features are used together, the accuracy rate is found to be 82.6 ± 0.5%. The classification accuracies are also compared using each feature alone. Three features that give the highest accuracy are coronoid height (80.9 ± 0.9%), condyle height (78.2 ± 0.5%), and ramus height (77.2 ± 0.4%), respectively. When compared to the classification algorithms, the highest accuracy was obtained with the naive Bayes algorithm with a rate of 84.0 ± 0.4%.

CONCLUSION

Machine learning techniques can accurately determine gender by analyzing mandibular morphometric structures from digital panoramic radiographs. The most precise results are achieved by evaluating the structures in combination, using attributes obtained from applying the MRMR algorithm to all features.

Panoramic radiograph as a forensic aid in age and gender estimation: Preliminary retrospective study

BACKGROUND

The temporomandibular joint is a hinge joint which is formed by the mandible with articulation of the jaw with the cranium. The morphology of the mandible is evaluated by measuring the gonial angle ramus height and bigonial width.

AIM

The aim of this study to investigate the impact of age and gender on ramus height, gonial angle and bigonial width in the dentulous odisha population using digital panaromic radiographs.

MATERIALS AND METHODS

A total of 50 dentulous participants (25 males and 25 females) aged between 10 and 80 years were included in this study. The data were collected after comprehensive examination by 1 principal and two coinvestigators.

STATISTICAL ANALYSIS

The mean difference between gender and different age groups was calculated using SPSS version 20.0. Unpaired t-test and one-way ANOVA were used for comparison studied parameters according to gender, side and different age groups followed by Tukey's post hoc test.

RESULTS

A statistically significant gender difference was seen for gonial angle, ramus height and bigonial width. All the parameters increased with increase in age. This difference was statistically significant on the right side for gonial angle and ramus height.

CONCLUSION

This study is useful as for age and sex determination using mandible as primary object in forensic odontology.

Comparison of digital panoramic radiography versus cone beam computerized tomography for measuring alveolar bone

BACKGROUND

Cone beam computerized tomography (CBCT) has been widely used in dental implanting. However, the local hospitals usually don't have access to CBCT due to the cost and medical investment, especially in West of China. The doctors in local hospitals have to make reasonable dental planting using orthopantomography (OPG) to reduce risks. Therefore, it is clinically meaningful to determine the magnification rate of OPG to obtain correct diagnosis. This study investigated the magnification rate of OPG in measuring different maxillofacial loci compared with CBCT.

METHODS

Eighty-six patients demanding dental implanting were scanned by CBCT and OPG. The vertical distance between the alveolar ridge crest of the maxillary first molar and the sinus bottom of the upper jaw, the distance between the alveolar ridge crest of the mandibular first molars and the top of nerviduct in the mandibular alveolar, and the distance between the alveolar ridge crest of the maxillary central incisors and the bottoms of the nasal cavities were measured. The horizontal distance in those loci were also measured. The distances derived from CBCT were used as reference. The distances between the two methods were compared using paired t-test. The magnification rates at these positions were calculated. The relationship between the data acquired from the two methods was analyzed Pearson correlation.

RESULTS

The correlation coefficients (R) between the paired samples obtained from OPG and CBCT were highly related (P < 0.05) with R values varying from 0.840 and 0.959 in vertical distances and R values varying from 0.703 and 0.904 in horizontal distances. Compared with data obtained from CBCT, the mean vertical magnification rates were 11.38% and 12.95% vertically and 8.55% and 9.43% horizontally for the first molars in the right and left maxilla respectively; 7.26% and 6.35% vertically and 5.33% and 4.96% horizontally for the first molars in the right and left mandible respectively; and 5.55% and 4.84% vertically and 6.53% and 7.47% horizontally for the central incisors in the upper right and left jaws respectively.

CONCLUSION

The magnification rates of OPG at these teeth are different. The distances measured by OPG were highly correlated with that measured by CBCT.

Prevalence of Elongated Styloid Process in a Central Brazilian Population

BACKGROUND

Eagle's syndrome comprises a rare disorder caused by compression of an elongated or deformed styloid process or ossified/calcified stylohyoid ligament on neural and vascular structures. It is characterized by facial and neck pain and can be confused with a wide variety of facial neuralgias, oral and dental diseases and temporomandibular disorders. An imaging evaluation associated with a careful clinical examination, are mandatory in structuring a correct differential diagnosis and in the establishment of a proper therapeutic protocol.

AIM

To investigate the prevalence of the elongated styloid process in a Central Brazilian population and its relation to gender, age and side.

MATERIALS AND METHODS

Digital panoramic radiographs of 736 patients (412 female and 324 male, with a mean age of 35.03 years) were consecutively selected from a private radiology clinic's secondary database. The apparent length of the styloid process was measured from the point where the styloid left the tympanic plate to the tip of the process by two specialists in dental radiology, with the help of the measuring tools on the accompanying software. Styloid process measuring more than 30 mm was considered elongated. The statistical analysis included frequency distribution and cross tabulation. The data were analysed by using Chi-squared tests. The level of significance was set at 5% for all analyses.

RESULTS

A total of 323 (43.89%) radiographic images were suggestive of elongated styloid process. No statistically significant difference was found between the genders, although a higher prevalence was noticed in female participants. Approximately, 31% of the elongated styloid process was observed in 18-53-year-old participants (p < 0.05). Two hundred and sixty seven styloid processes (36.28%) were elongated on both right and left sides.

CONCLUSION

The prevalence of elongated styloid process was high and no statistically significant correlation was found between the presence of elongated styloid process and the studied variables with the exception of the age.