PURPOSE: The classification of impacted maxillary third molars (IMTMs) facilitates interdisciplinary communication and helps estimate the degree of surgical difficulty. Thus, this study aimed to develop a 3-dimensional classification of the position and depth of impaction of IMTMs and to estimate their prevalence with respect to gender and age. MATERIALS AND METHODS: This cross-sectional retrospective study analyzed images in sagittal and coronal cone-beam computed tomography (CBCT) sections of 300 maxillary third molars. The proposed classification was based on 3 criteria: buccolingual position (buccal, lingual, or central), mesial-distal position (mesioangular, vertical, or distoangular), and depth of impaction (low, medium, or high). CBCT images of IMTMs were classified, and the associations of the classifications with gender and age were examined using analysis of variance with the Scheffé post-hoc test. To determine the associations among the 3 classifications, the chi-square test was used (P<.05). RESULTS: No significant association of the classifications with gender was observed. Age showed a significant relationship with depth of impaction (P=.0001) and mesial-distal position (P=.005). The most common positions were buccal (n=222), vertical (n=184), and low (n=124). Significant associations among the 3 tested classifications were observed. CONCLUSION: CBCT enabled the evaluation of IMTMs in a 3-dimensional format, and we developed a proposal for a new classification of the position and depth of impaction of IMTMs.
Classification ; Cone-Beam Computed Tomography ; Interdisciplinary Communication ; Molar, Third* ; Prevalence ; Retrospective Studies ; Tooth, Impacted

Purpose: The objective of this study was to assess the fractal dimension, lacunarity, trabecular microarchitecture parameters, and cortical linear measurements in the mandibles of male and female individuals to identify differences between them. Materials and Methods: In total, 116 cone-beam computed tomography scans of healthy individuals of different ages (57 men and 59 women, aged between 20 and 60 years) were selected. The following bone parameters were measured: 1) buccal, lingual, and basal cortical bone thickness in 5 standard parasagittal sections (the midline, the left and right sides of the lower lateral incisors, and the left and right sides of the lower canines); 2) the bone volume fraction of 10 sequential axial sections from each patient by creating a volume of interest in the area between the lower canines; and 3) fractal dimension and lacunarity using grayscale images of the same region of the volume ofinterest in the anterior mandible. Spearman correlation coefficients and the Mann-Whitney test were used. Results: A significant and positive correlation was found between age and cortical thickness, especially in the region of the central incisors. Significant differences between sexes in terms of fractal dimension, lacunarity, and bone volume were found. Women revealed lower fractal dimension values and higher lacunarity and bone volume ratiovalues than men. Conclusion Fractal dimension, lacunarity, trabecular bone volume, and cortical thickness were different between men and women of different ages. (Imaging Sci Dent 2023; 53: 153-9)

Purpose: The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the prevalence of calcifications in the temporomandibular joint (TMJ) and to evaluate any associations between the presence of such calcifications and degenerative bone alterations of the TMJ, sex, or age. Materials and Methods: In this retrospective study, 1,058 CBCT exams were analyzed, and data regarding the presence and quantity of calcifications, the affected side, any degenerative alterations of the condyle, sex, and age were collected. To evaluate associations between the presence of calcifications and sex or age, the Fisher exact test or the Spearman correlation coefficient, respectively, was used. To assess the association between the presence of calcifications and joint bone alterations, the chi-square and Fisher exact tests were used. The significance level adopted was 5% (p<0.05). Results: Twenty-eight patients (2.7%) presented with TMJ calcifications, including 23 women (82.1%) and 5 men (17.9%). Significant correlations were found between the presence of calcifications and age (p<0.05) and between the presence of calcifications and the presence of condylar alterations (p<0.05), with 73.2% of patients with bone alterations having TMJ calcifications. Conclusion It may be concluded that, although rare (with a prevalence of only 2.7%), intra-articular calcifications are associated with both degenerative bone alterations and age.