咬合の不調和と顎関節症の症状との関係

[The relationship of occlusal disharmonies and symptoms of temporomandibular disorders].

抄録

はじめに:

咬合状態が顎関節症の発症に及ぼす影響については、長年にわたって強く議論されてきた。1980年代までは、未治療の不正咬合の存在、咬頭間位（ICP）と後方接触位（RCP）の2ミリ以上の不一致、咬合異常、特に正中咬合と後方咬合、後方歯の喪失などの咬合因子が顎関節症の主な原因と考えられていた。

INTRODUCTION: The influence of occlusal condition on the onset of temporomandibular disorder (TMD) has been strongly debated for many years and is still the source of controversy. Until 1980s, the occlusal factors such as the presence of uncured malocclusions, discrepancies between intercuspal position (ICP) and retruded contact position (RCP) greater than two millimeters, occlusal abnormality, particularly mediotrusion and retrusion, and loss of posterior teeth were considered the primary causes ofTMD.

目的:

本研究の目的は、咬合の不調和（ICPとRCPの差）と顎関節症の現症および症状との相関関係を明らかにすることである。

OBJECTIVE: The objective of our study was to find correlation of occlusion disharmonies (difference between ICP and RCP) and present sings and symptoms of TMD.

方法:

本研究では、18～26歳の60名の被験者を2つのグループに分けて行った。研究グループは、顎関節症（TMD）の歌唱と症状を有する18～26歳の30名で構成された。顎関節症はHelkimo指数によって確認された。対照群には、顎関節症の歌唱および症状のない20歳から25歳までの30名の被験者が含まれた。RCPとICPにおける映画的中心位置の機能分析は、コンピュータパントグラフArcus-Digma(KaVo EWL GmbH, Leutkirch, Germany)を用いて各被験者で行われた。

METHOD: The study involved 60 subjects between 18 and 26 years of age who were divided in two groups. The study group consisted of 30 subjects between 18 and 26 years of age with sings and symptoms of temporomandibular disorders (TMD). TMD was confirmed according to Helkimo index. An average value of Helkimo index in this group was 1. The control group included 30 subjects between 20 and 25 years of age without TMD sings and symptoms. An average value of Helkimo index in this group was 0. The function analysis of cinematic centers position in RCP and ICP was performed in each subject using the computer pantograph Arcus-Digma (KaVo EWL GmbH, Leutkirch, Germany).

結果:

本研究の結果、RCPからICPへのシネマティックポイントの移動軌跡は、顎関節症患者と無症候性患者で有意差が認められた（p > 0.16）。また、顎関節症の症候を有する被験者の53.4%に、顎関節内障害に関連する顎関節下部の著しい移動（0.61～1.2mm）が認められた。

RESULTS: The results of our study showed that the translation tracing of cinematic points from RCP to ICP was significantly different in TMD subjects and asymptomatic group (p > 0.16). In addition, the study revealed that 53.4% of subjects with sings and symptoms of temporomandibular disorders had marked translation in the lower temporomandibular joint (0.61-1.2 mm) what directed to intracapsular disorders.

結論:

本研究の結果、顎関節症の罹患者と非罹患者では、RCPとICPが有意に異なることが示唆された。

CONCLUSION: The results of our study suggested significant difference of RCP and ICP between subjects with sings and symptoms of the temporomandibular disorders and subjects without sings and symptoms.