内外および近遠心方向から6分類した臼歯部咬合小面の咀崎運動時の咬合接触  [in Japanese] A Study of Occlusal Contact during Mastication on Molar Occlusal Facets Classified into Six Different Types from Its Direction  [in Japanese]

Access this Article

Search this Article

Author(s)

    • 三好 礼子 MIYOSHI Ayako
    • 徳島大学大学院歯学研究科歯科補綴学第ニ講座 Department of Fixed Prosthodontics, Graduate School of Dentistry, The University of Tokushima

Abstract

目的: 生体機能に調和した咬合面形態の基準を求めるために, 咬合小面を6種類に細分類し, 咀嚼第4相付近における咬合接触状態を解析して, 各咬合小面の役割について検討することを目的とした.<BR>方法: 6自由度顎運動測定器を用いて, 14名の被験者についてガム咀嚼時の顎運動を測定し, これと歯列模型の三次元形態計測データとを座標系の変換によって重ね合わせ, 上下顎歯列の位置関係を時系列で解析した. 主機能部位側臼歯部の咬合小面を法線ベクトルの成分などによって面の向く内外的 (A, B, C), 前後的 (M, D) 方向などからAM, AD, BM, BD, CM, CDの6種に細分類し, 阻嚼第4相付近の動的咬合接触状態を解析した.<BR>結果: 咀嚼の第4相付近ではAM, またはCM咬合小面が対顎咬合面との距離が小さく, 同時に咀嚼運動路との角度差も小さい傾向にあり, これらの咬合小面が食品を介在させながらも運動を誘導していることが示された. なかでも, 下顎のAM咬合小面が対顎咬合面とより近接し, 誘導に大きく関与していることが推察された. 終末位に至る咀嚼運動路のB咬合小面に対する入射角度はBD咬合小面が約30°で, BM咬合小面に対する約40°に比べて小さく, BD咬合小面が食品の圧搾に重要な役割を果たしていることが示唆された.<BR>結論: 臼歯部咬合小面を細分類し, 各咬合小面の咀嚼における役割を示した.

Purpose: The purpose of this research was to develop the standard morphology of the ideal dental occlusion. In this study, the kinetic role of each occlusal facet on upper and lower molars was evaluated by analysis of occlusal contacts during the end phase of jaw closing stroke.<BR>Methods: Masticatory movements of fourteen adult volunteers with chewing gum were measured by a six-degree-of-freedom jaw tracking device. Cast stone models of these subjects were scanned with 3-D digitizer to obtain three-dimensional shape of occlusal surface. These configuration data were linked with jaw movement data to analyze relative position of upper and lower dentition during mastication. Occlusal facets on main occlusing area were classified into six different types (AM, AD, BM, BD, CM, CD) according to the direction of its normal vector and its position. A, B and C represents medio-lateral position of each facet and direction of the normal vector there of, and M and D represents antero-posterior direction of the normal vector. Transition pattern of occlusal contacts during the end phase of closing stroke was studied.<BR>Results: When jaw closing, occlusal contacts was begun with AM or CM type occlusal facet. This finding suggests that AM and CM type occlusal facets work as the functional guidance of masticatory movement. This property was clearer with the occlusal facets on the functional cusp. Incident angle of the terminal jaw closing movement was 30° to BD type occlusal facet, and 40° to BM type facet.<BR>These data suggest that BD type facet meets at a right angle to the occlusal surface, and works for the compression of food during mastication.<BR>Conclusion: Occlusal facets of molar surface were classified into six different types, and the kinetic role of each occlusal facet was revealed.

Journal

  • Nihon Hotetsu Shika Gakkai Zasshi

    Nihon Hotetsu Shika Gakkai Zasshi 46(2), 203-212, 2002-04-10

    Japan Prosthodontic Society

References:  30

Cited by:  17

Codes

  • NII Article ID (NAID)
    10008156958
  • NII NACSIS-CAT ID (NCID)
    AN00197911
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    03895386
  • Data Source
    CJP  CJPref  J-STAGE 
Page Top