Temporomandibular joint stability after two types of maxillary impaction surgery in patients with skeletal class II open bite due to condylar deformations: a preliminary study

ABSTRACT Purpose: The aim of this study was to evaluate the effect of two types of mandibular autorotation concept (MAC) surgery using maxillary impaction combined with a straight locking miniplate (SLM) technique on the condyles of patients with skeletal Class II open bite. Materials and methods: Fourteen female patients with skeletal Class II mandibular retrusion with open bite were included in this study. The patients were divided into two groups based on the type of MAC surgery performed: a group of subjects who underwent maxillary impaction only (MAC-1 group) and a group of subjects who underwent maxillary impaction combined with mandibular osteotomy (MAC-2 group). A 3D-printing CAD/CAM wafer was fabricated. The SLM technique was performed to stabilize the vertical maxillomandibular relationship during surgery. A computed tomographic image was obtained preoperatively as well as on the third post-surgical day and 1 year post-surgically to evaluate the relapse by assessing changes in cephalometric measurements, condylar volume, and condylar surface area. Results: Neither the MAC-1 group nor the MAC-2 group showed significant changes in their condylar surface area that could have led to skeletal relapse. The condylar volume was significantly decreased in the MAC-2 group, but the affected location did not contribute to the relapse of the mandibular position. Conclusion: Our findings suggest that MAC surgery with the SLM technique in patients with skeletal Class II retrognathia did not result in post-surgical relapse or further deformation and resorption of the condyle; rather, it yielded promising functional and morphological stability.