Evaluation of mandibular retromolar space of patients with different facial types and skeletal malocclusion with cone beam computed tomography

The study aimed to evaluate the mandibular retromolar space in adults with different sagittal skeletal relationships (Class I and Class III), vertical facial patterns (High-Angle, Normal, Low-Angle) and different genders using Cone Beam Computed Tomography (CBCT) . A total of 131 individuals (65 males, 66 females), aged 18 years or older, were retrospectively analyzed. Retromolar distance (RD), alveolar housing (AH) and root width (RW) were measured at 0, 2, 4, 6, and 8 mm apical levels from the crest. Molar inclination was also assessed. Statistical tests were performed.The results revealed that skeletal Class III patients exhibited significantly greater buccal and lingual RD than Class I individuals, particularly at coronal levels (p<0.05). In gender-based subgroups, lingual RD was significantly larger in female Class III patients compared to female Class I patients at all levels (p<0.05). Among vertical groups, Low Angle subjects presented higher buccal RD at level-2 and 4 mm compared to Normal and High Angle subjects (p<0.05),whereas. lingual RD did not differ significantly among the vertical facial pattern groups (p>0.05).Positive correlations were found between retromolar distance and both ramus height and corpus length, (r=0.231, p<0.05 and r=0.413, p<0.01, respectively). AH were found to be smaller in Class III patients, particularly at the 0 mm and 2 mm levels (p<0.05). Male subjects exhibited significantly larger retromolar spaces, greater root width, and increased alveolar housing dimensions than females. Molar inclination showed no significant differences across skeletal or gender groups (p<0.05).Class III and Low Angle patients, particularly males, may represent the most appropriate candidates for mandibular molar distalization As the ramus height and corpus length increase, retromolar distance also increases. Due to the variations in retromolar anatomy between males and females with particularly different vertical facial types, it is important to evalaute CBCT before mandibular molar distalization to ensure safe tooth movement within anatomical limits and to avoid undesirable outcomes such as root resorption or cortical perforation.