Ciochon R L, Nisbett R A, Corruccini R S
Department of Anthropology, The University of Iowa, Iowa City 52242, USA.
J Craniofac Genet Dev Biol. 1997 Apr-Jun;17(2):96-102.
Since the 1890s oral biological researchers have been interested in the idea that strenuous mastication of unprocessed food will stimulate proper oral-facial growth and occlusal relationships. Conversely, lack of such function due to consumption of refined food is one hypothesis among many for the etiology of malocclusion in industrialized humans. Adequately controlled experimental testing of the idea has been limited to rats. To investigate the "disuse" theory in a larger-bodied and more occlusally relevant animal model, we raised four Yucatan minipigs from weaning on hard diet (HD) and another four on softened but equivalent diet (SD). The animals were monitored for eight months, sacrificed, and then occlusal and osteometric data collected. Variations due to dietary regime are pervasive and not due to caries, periodontitis, or attrition differences. Whereas HD body weight is 10% greater than SD, the deep masseter is 25% greater, with similar disproportion in superficial masseter and temporalis weight. Facial prognathism, arch narrowness, tooth crowding/maleruption and posterior cranial tapering are markedly different in the two groups. A curious posterior torsional difference in the mandibular rami, as well as broadness and flatness of the mandibular symphysis, also occur in SD. We performed a Q-mode principal coordinates analysis of the 19 logged variables for the specimens, bootstrapping the variable list, to demonstrate a statistically significant (P < .01) overall pattern of dramatic differences. Having controlled other celebrated orthodontic etiologies (genetic background, respiratory mode, infectious degeneration and interproximal attrition), these results support the proposition that dietary consistency relates directly to human craniofacial growth.
自19世纪90年代以来，口腔生物学研究人员一直对这样一种观点感兴趣，即大量咀嚼未加工的食物会刺激口腔面部的正常生长和咬合关系。相反，由于食用精制食物而缺乏这种功能是工业化人群错牙合病因的众多假设之一。对这一观点进行充分控制的实验测试仅限于大鼠。为了在体型更大、咬合关系更相关的动物模型中研究“废用”理论，我们从断奶开始饲养了四只尤卡坦小型猪，喂食硬食（HD），另外四只喂食软化但营养相当的食物（SD）。对这些动物进行了八个月的监测，然后处死，收集咬合和骨测量数据。饮食方式造成的差异普遍存在，并非由龋齿、牙周炎或磨耗差异导致。HD组的体重比SD组重10%，深层咬肌重25%，浅层咬肌和颞肌重量也有类似比例的差异。两组在面部前突、牙弓狭窄、牙齿拥挤/萌出异常以及后颅骨变窄方面存在明显差异。SD组下颌支还出现了奇怪的后扭转差异，以及下颌联合处的宽阔和平坦。我们对标本的19个对数变量进行了Q模式主坐标分析，并对变量列表进行了自抽样，以证明存在具有统计学意义（P <.01）的显著差异总体模式。在控制了其他著名的正畸病因（遗传背景、呼吸模式、感染性退变和邻面磨耗）后，这些结果支持了饮食质地与人类颅面生长直接相关的观点。
