アブストラクト(26巻1号:神奈川歯学)

神奈川歯学

Japanese

Title : 骨格性下顎近心咬合の成立へのポステリアーディスクレパンシーの関連 - 年齢的資料による研究 -
Subtitle : 原著
Authors : 後藤幹子, 鈴木祥井
Authors(kana) :
Organization : 神奈川歯科大学矯正学教室
Journal : 神奈川歯学
Volume : 26
Number : 1
Page : 34-41
Year/Month : 1991 / 6
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「緒言」 骨格性下顎近心咬合の矯正学的な咬合再構成は, 下顎遠心咬合の治療を主体とする欧米に比べて下顎近心咬合の発現率が高いことから, 日本における不正咬合治療の中では重大なウエイトを占めている. それゆえ, 日本における不正咬合に関する研究は, 下顎近心咬合の成立機序を解明する責任のある立場に立たされていると言っても過言ではないであろう. しかし, 下顎近心咬合の発現様相に関しては, 未だに明確説明がなされておらず, 本例の矯正治療を進めるに当たっての大きな問題となっている. 下顎近心咬合という症状は, 多くの原因によって発現してくる可能性が指摘されているが, 大きく分けると次の2つの考え方に要約することができる. すなわち, その第1は, 骨格性下顎近心咬合は, その骨格の形態的特徴から, 顎骨の発育異常によるものとする考えである. その発育異常は, 基本的には, 先天的あるいは遺伝的に発現してくるものと考えられている.
Practice : 歯科学
Keywords : 下顎近心咬合, ポステリアーディスクレパンシー, 骨格の発育

English

Title : A Study of the Relationship between Development of Skeletal Mesio-occlusion and Posterior Discrepancy Utilizing Transversal Specimen
Subtitle :
Authors : Mikiko GOTO, Yoshii Suzuki
Authors(kana) :
Organization : Department of Orthodontics, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 26
Number : 1
Page : 34-41
Year/Month : 1991 / 6
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : [Abstract] In order to understand the relationship between the development of mandibular mesio-occlusion and posterior tooth to denture base discrepancy, the following were examined and studied: alterations in the denture frame structure, inclination of occlusal plane and the discrepancy in the posterior part of the dentition, using 340 transversal samples of mandibular mesio-occlusion cases aged 3 years through 16 years old. Posterior discrepancy index (PD index) was calculated to examine the changes in the relationship between tooth size and posterior part of denture base according to age. It was observed that the anteroposterior distance of maxillary denture base (A'-P') did not increase after 6 years old in mandibular mesio-occlusion samples, which apparently suggests that this factor contributes to the severity of posterior discrepancy. Particularly in the high angle group of mesio-occlusion, inclination of occlusal plane (OP-MP angle) gradually horizontalized, thus OP-MP/PP-MP value was find to increase with age. This suggested that the malocclusion have been caused by the vertical elongation of molar and influenced by posterior discrepancy. This process consequently leads, the mandible eventually causes to be displaced forward with rotating anteriorly, which provides the gradual decreasing of AB-MP angle with age. Posterior discrepancy index (PD index) indicated that the high angle mesio-occlusion case had severe posterior discrepancy problem while the PD index in the low angle group was observed to normalize after 10 years of age. From these findings, it was concluded that posterior discrepancy which causes the horizontalization of occlusal plane and the subsequent functional compensation of the mandible, plays a very important role in the development of skeletal mesio-occlusion.
Practice : Dentistry
Keywords :