顔面非対称を伴う患者の上下顎間関係と顎関節関節円板の状態に関する研究

概要

Mandibular characteristics, which deviate in vertical, horizontal, and/or transverse facial planes significantly relate to articular disc displacement, which is a major sign of temporomandibular disorder (TMD). Even though anterior disc displacement has the highest prevalent, disc displacement in medio-lateral direction can be observed among the samples with mandibular asymmetry (MA). By our study, we could not conclude the significant relationship between the position of disc displacement and maxillofacial characteristics, but the reduction of disc displacement can be counted for the severity of internal derangement (ID) and significantly related to maxillomadibular discrepancy. We found that antero-posterior jaw relationship and the amount of mandibular deviation in the MA samples were significantly associated with the severity of disc displacement. MA patients with disc displacement without reduction (DDwoR) demonstrated more rethognathic mandible than the samples with disc displacement with reduction (DDwR) and bilateral- normal disc position (NDP). The cant of the frontal mandibular plane and menton deviation were significantly greater in the DDwoR group than in the bilateral-NDP group. In the previous studies, Skeletal Class II is likely associated with an increased severity of articular disc displacement. In our study, we found high prevalent of DDwoR in Skeletal ClassIII (SKIII) with MA, compared with SKIII without MA. In SKIII patients, the severity of asymmetrical characteristics of mandible linearly related to the severity of disc displacement, increasing from NDP to DDwoR. Besides, MA-SKIII with disc displacement has the oversized mandible, compared to none MA-SKIII with bilateral-NDP.