成長期のデュシェンヌ型筋ジストロフィー患者の歯顔面特性：形態学的研究

Dentofacial characteristics of growing patients with Duchenne muscular dystrophy: a morphological study.

抄録

成長期のDuchenne型筋ジストロフィー（DMD）患者を対象に、咬合特性および頭蓋顔面形態について検討した。6歳から20歳までの16名の患者を調査し、年齢をマッチさせた16名の健常男性と比較した。両群の歯列弓と咬合特性を歯型上で分析し、文献にある健常者の規範と比較した。患者の側方セファログラムは、被験者の年齢の不均一性を補正するために、標準偏差に基づくスコア値によって健常者と比較された。統計解析は、連続変数についてはペアのスチューデントのt検定で、非連続変数についてはカイ二乗検定で行われた。年齢による影響を評価するために、線形回帰を用いた。後方交叉咬合，前方および側方開咬，骨格性III級不正咬合による中口径傾向，下切歯の後退によるIII級関係の歯列代償など，不正咬合の高い有病率がみられた．上下顎アーチとも後方に広がっていました。下顎弓は上顎弓よりさらに広く、後方交叉咬合が多発した。このDMD患者群では、上顎平面角（NL/NSL）が正常より大きく、前上面高（NSp）が小さかった以外は、骨格の垂直的な大きな狂いは認められませんでした。しかし、下顔面高さには差が見られなかった。歯列弓の後方拡大とAngle Class III関係への歯槽骨の発達は年齢と有意に関連しており、高齢者ほど多く認められた。

Occlusal traits and craniofacial morphology were studied in growing patients with Duchenne muscular dystrophy (DMD). Sixteen patients from 6 to 20 years of age were examined and compared with 16 healthy male individuals matched according to age. The dental arches and occlusal traits of both groups were analysed on dental casts and compared with the norms of healthy individuals from the literature. Lateral cephalograms of the patients were compared with normal individuals by using scored values based on standard deviations in order to compensate for heterogeneity in the age of the subjects. Statistical analysis was undertaken for continuous variables with a paired Student's t-test and non-continuous variables with a chi-square test. Linear regressions were used to evaluate the influence of age. A high prevalence of malocclusions was found, including posterior crossbites, anterior and lateral open bites, a tendency towards mesio-occlusion due to a skeletal Class III malocclusion, and dental compensations of the Class III relationship by retrusion of the lower incisors. Both upper and lower arches were widened posteriorly. The lower arches were even wider than the upper arches, resulting in frequent posterior crossbites. No significant skeletal vertical deviations were observed in this group of DMD patients, except for the maxillary plane angle (NL/NSL) that was larger than normal, while the anterior upper face height (NSp) was smaller. However, no difference was found in lower face height. The posterior enlargement of the dental arches and the dentoalveolar development towards an Angle Class III relationship were significantly related to age and found more frequently among the older subjects.