Effect of Molar Distalization on Condyle-Glenoid Fossa Relationship.

Objective: It is essential to be aware of the potential effects of orthodontic treatment on tissues and anatomical structures associated with the masticatory system, especially the temporomandibular joint (TMJ). Little information is available about the consequences of molar distalization on the TMJ. Therefore, this study is aimed at investigating the changes of the condyle-fossa relationship after molar distalization using the distal jet appliance. Materials and Methods: The sample consisted of twenty-five patients (mean age 20.4 ± 2.6) who underwent molar distalization by the distal jet appliance. CBCT scans were taken before (T0) and after (T1) the completion of the molar distalization. Joint spaces (anterior, superior, and posterior) and cephalometric vertical angles (SN.GOME and Björk sum) were measured and compared at T0 and T1. Results: Superior and posterior joint spaces increased significantly after molar distalization (PS 0.29 mm, P < 0.001, SS 0.06 mm, P < 0.5). Vertical cephalometric angles also increased after molar distalization by the distal jet appliance (SN.GOME 0.92°, Björk 1.11°). Conclusion: There was a statistically significant increase in the superior and posterior joint spaces after molar distalization. However, this increase may not be of clinical importance. The vertical dimension has also increased.

Midpalatal suture: evaluation of the morphological maturation stages via bone density.

BACKGROUND: To investigate the relationship between the morphological maturation stages of the midpalatal suture and its bone densities. METHODS: The sample consisted of 91 subjects aged 8-18 years who underwent cone beam computed tomography. All images were examined to classify morphological maturation of the midpalatal suture to five groups according to Angelieri et al. Bone density of the midpalatal suture was measured at the maxillary and palatal regions. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the difference between groups. RESULTS: Bone density of the midpalatal suture was significantly higher in the palatal region in E stage and in the maxillary region in D and E stages. CONCLUSIONS: It is concluded that the change in bone density of the midpalatal suture between the morphological maturation stages supports their reliability in clinical application.