Vinter I, Krmpotić-Nemanić J, Ivanković D, Jalsovec D
Department of Anatomy, University Medical School, Zagreb, Croatia.
Coll Antropol. 1997 Dec;21(2):555-60.
In the course of life the mandible undergoes substantial morphological and dimensional changes. The changes concerning mandibular angle, relation between the length of the mandibular corpus and ramus as well as roughness in the place of insertion of masseteric and pterygoid muscles do not depend upon age or sex but (apodictical) exclusively upon the dentition. In the complete dentition all masticatory muscles take part in chewing and grinding. The function of the temporal and masseter muscle is (reduced) weakened in partial or complete loss of teeth. The most evident morphological change of the lower jaw consists of an apparent elongation of its corpus resulting in a characteristic senile appearance. Measurements have been performed on 114 macerated mandibles of individuals ranging from 4 months to 68 years of age. The following measures have been taken: number of teeth in the lower jaw, angle between the corpus and ramus of mandible, length of the mandibular corpus, height of the mandibular ramus and angle of the mandibular incisure. The angle between the mandibular corpus and ramus is significantly lower in mandibles with 11 and more teeth (p < 0.001). The length of the mandible is significantly larger (p < 0.02) in mandibles with less than 11 teeth. The mandibular ramus is significantly higher in mandibles with more teeth (p < 0.01). There were no significant differences in the angle of the mandibular incisure within the groups (p > 0.05). The discriminant analysis reveals that 62.3% of the variability of mandibles is dependent upon the number of teeth. The rest of proportional variability of 37.7% is probably due to new circumstances and adjustment of the mandible in the period from tooth extraction.
在生命过程中，下颌骨会经历显著的形态和尺寸变化。与下颌角、下颌体长度与升支之间的关系以及咬肌和翼内肌附着处的粗糙度相关的变化并不取决于年龄或性别，而是（明确地）完全取决于牙列情况。在全口牙列时，所有咀嚼肌都参与咀嚼和研磨。在部分或完全缺牙时，颞肌和咬肌的功能会（降低）减弱。下颌骨最明显的形态变化是其下颌体明显伸长，导致出现典型的衰老外观。对114具4个月至68岁个体的下颌骨标本进行了测量。采取了以下测量指标：下颌牙数量、下颌体与升支之间的角度、下颌体长度、下颌升支高度以及下颌切迹角度。在下颌牙有11颗及以上的下颌骨中，下颌体与升支之间的角度显著更低（p < 0.001）。在下颌牙少于11颗的下颌骨中，下颌骨长度显著更大（p < 0.02）。在下颌牙较多的下颌骨中，下颌升支显著更高（p < 0.01）。各组内下颌切迹角度无显著差异（p > 0.05）。判别分析显示，下颌骨62.3%的变异性取决于牙的数量。其余37.7%的比例变异性可能归因于拔牙后下颌骨的新情况和适应性变化。
