Condylar changes in adult patients with unilateral posterior crossbite following microimplant-assisted rapid palatal expansion: A retrospective CBCT study.

Objectives: This study aimed to assess the alterations in condylar positioning in adult skeletal Class I patients with unilateral posterior crossbite following microimplant-assisted rapid palatal expansion (MARPE) treatment.

Methods: This retrospective study involving 30 participants (10 males, 20 females) with an average age 22.9 ± 4.2 years, ranged from 18.1 to 30.9 years, who were treated with a customized microimplant-supported rapid palatal expander. Pre-expansion and post- comprehensive orthodontic treatment CBCT images (20-26 ±2.1months) were analyzed to assess the condylar changes before and after treatment. We measured the temporomandibular joint (TMJ) in the three dimension in terms of: (1) The position and angle of the mandibular condyles; (2) How centralized the condyles were in their particular mandibular fossae; and (3) The volume of the TMJ and the joint spaces. To evaluate the differences between the T1 and T2 samples, we used the paired t-test and the Wilcoxon signed rank test.

Results: Before treatment, minor differences were noted in the anterior joint space (AJS), superior joint space (SJS), and anteroposterior condylar joint position (APCJP) between the crossbite and non-crossbite sides, though these differences were not statistically significant. Post-treatment, the condyles on both sides assumed a more posterior position, yet significant asymmetry in the AJS persisted (P < .05). The crossbite-side condyle also showed a tendency to rotate toward the non-crossbite side in the anteroposterior direction. While MARPE affected specific aspects of condylar positioning, achieving complete alignment remained challenging.

Conclusion: This study provides insightful observations on the enduring impacts of MARPE on TMJ spaces and position in adult patients suffering from a unilateral posterior crossbite.