Three-Dimensional Modeling and Quantitative Assessment of Mandibular Volume in Ectodermal Dysplasia: A Case Series.

Background and Objectives: Ectodermal dysplasia (ED)-a genetic disorder-is characterized by severe tooth deficiency. We compared the mandibular volume and the sagittal and horizontal mandibular widths between patients with ED (ED group) and individuals without tooth deficiency (control group) using three-dimensional modeling. We hypothesized that the mandibular volume differs in ED cases owing to congenital tooth deficiency. Materials and Methods: We used previously obtained cone-beam computed tomography (CBCT) images of 13 patients with ED. The control group data comprised retrospective CBCT images of patients of similar age and sex with a skeletal relationship of class 1. Further, using the three-dimensional image analysis software, the tooth crowns were separated from the mandible, the mandible was reconstructed and the gonion-to-gonion distance in the mandible was marked, the distance to the menton point was measured, and the distance between the two condyles was measured and compared with the control group. Results: Overall, 46.2% and 53.8% of the participants were men and women, respectively. In the ED group, the mean age of the participants was 15.46 (range, 6-24) years, and the mean number of mandibular teeth was 4.62. Notably, the edentulous mandible volume of the ED group (27.020 mm3) was statistically significantly smaller than that of the control group (49.213 mm3) (p < 0.001). There was no difference between the two groups in terms of the marked points. For data analysis, the Shapiro-Wilk test, independent samples t-test, and Mann-Whitney U test were used. Conclusions: It has been considered that mandible volume does not develop in ED cases because of missing teeth. Modern practices, such as the CBCT technique and three-dimensional software, may be effective in identifying the true morphologic features, especially in patients with genetic syndromes affecting the maxillofacial structure.

Mineral Density Distribution Differences in Enamel and Dentin Tissues in the Teeth Array According to the HU Scale

ABSTRACT Objective: To evaluate the mineral density of enamel and dentin tissues of healthy individuals using threedimensional cone-beam computed tomography. Material and Methods: CBCT images of 15 healthy individuals, previously obtained for various reasons, were used in this study. In HU measurements, mineral density measurements were made from three different regions of enamel and three different regions of dentin, and the values obtained were compared. Enamel and dentin mineralization density measurements were measured from six regions, namely the crown cutting edge, buccal middle and cervical region for enamel, and the crown cutting edge, cervical region and root apex for dentin. In the comparisons of groups, the parametric One-Way ANOVA variance analysis method was applied. In the paired comparisons between the groups, the Tukey HSD test was applied as the multiple comparison post hoc test. A value of p<0.05 was accepted as statistically significant. Results: Mineralization density of tooth enamel and dentin tissues was quantitatively different in the maxilla and mandible in anterior and posterior teeth. Conclusion: In all the teeth, there were statistically significant decreases in the mineral density values of enamel and dentin tissue from occlusal towards the cemento-enamel junction. Statistically significant decreases were observed in the mineral density values of enamel and dentin tissue from the anterior region towards the posterior region in the teeth in both the upper and lower jaws.

Evaluation of Radiation Exposure Due to Dental Radiographs Taken during Endodontic Treatment Sessions in Young Permanent Teeth.

Background and Objectives: The aim of this study was to retrospectively analyze the duration of treatment and the number of dental radiographs taken during endodontic treatment (endo-t) of young permanent teeth (YPT). Materials and Methods: Age, gender, affected tooth number, apex status, duration of treatment and dental radiographs taken during this period were retrospectively evaluated in pediatric patients aged 6−15 years who presented to the pedodontic department for endo-t of anterior YPT. Data were analyzed with Kruskal Wallis H, Dunn and Pearson chi-square tests. p < 0.05 was accepted as statistically significant in all analyses. Results: Anterior endo-t was initiated in 471 of 9,200 pedodontic patients between the ages of 6 and 15 years who applied to our university. The reason for seeking treatment was caries (8.1%) and trauma (91.9%). It was observed that 59% of the teeth had an open apex and 45.7% had a closed apex. A total of 1893 periapical radiographs (Per-R) and 245 panoramic radiographs (Pan-R) were taken from 471 pediatric patients during the treatment period. Total number of dental radiographs was 2138 with 4.5 per patient. Number of Per-R was lower in patients whose treatment was completed in a single session (p < 0.001). There was no difference in the number of Pan-R with respect to duration of treatment (p = 0.560). Conclusions: In children, the number of Per-R significantly increased with prolonged duration of treatment encompassing multiple sessions for endo-t procedures of anterior YPT, decided based on the apex and lesion status of the affected tooth. Especially in long-term traditional apexification treatments, treatment should be carried out in children with the ALADAIP (As Low As Diagnostically Achievable being Indication-oriented and Patient-specific) principle in mind.

Can the Density of Mineralized Dental Tissues (Dentin and Enamel) Be Measured and Compared with 3D Cone Beam Computed Tomography in Cases of Ectodermal Dysplasia?

BACKGROUND Since 3-dimensional cone beam computed tomography (CBCT) started to be used in dentistry, mineral density can now be examined with computer software from the data on the images obtained. Detailed and clear images at different slice intervals can be obtained with CBCT, and mineral density can be measured from the image data on a computer with a Hounsfield unit (HU) scale. In addition to the broad opportunities presented by CBCT, this feature has presented a wider perspective to researchers. MATERIAL AND METHODS In this study, the CBCT images obtained from patients with the genetic disorder of ectodermal dysplasia were compared with the images of a control group to determine differences in mineralization of the teeth and to show that these could be compared by measuring the mineral density of dentin and enamel tissues using the HU scale on data from CBCT images. This opens new opportunities for cognitive and implementation research. RESULTS In the study, CBCT images of 14 ectodermal dysplasia and 14 control group cases previously obtained for various reasons were used. Mineral density measurements were made from 4 different regions of the teeth of the ectodermal dysplasia and control groups (incisor edge of the crown, the center buccal, cervicale line, and apex of the teeth), and the groups were compared. CONCLUSIONS The aim of this study was to provide a new overview of the feasibility and suitability of mineralization measurement of dentin and enamel dental tissues with CBCT in ectodermal dysplasia and control groups.