Experimental study for development of rabbit masticatory system depending on the style of sucking

为探讨乳汁或奶瓶喂奶方式对幼兔咀嚼功能发育程度的影响，每组4只幼兔连续喂养3周。同时进行母乳喂养和奶瓶喂养时的咬肌、二腹肌、茎突舌肌、颏舌肌、下颌舌骨肌肌电图和进食固体食物时的x线片评估舌颌运动。对收集到的全部数据进行了分析和讨论。结果总结如下：1。哺乳功能发育程度差异1)肌肉活动：(1)奶瓶喂养组肌肉活动周期长度明显长于母乳喂养组。(2)活动滞后时间：瓶饲组二腹肌与咬肌的活动滞后时间较短，膝舌骨肌与下颌舌骨肌的活动滞后时间较短。肌肉活动整合：母乳喂养时咬肌整合度高于奶瓶喂养，二腹肌整合度低于奶瓶喂养。奶瓶喂养组的颏舌肌、下颌舌骨肌明显高于母乳喂养组。2)舌颌运动：母乳喂养比奶瓶喂养的舌颌运动纵向尺度更长。奶瓶喂养比母乳喂养的舌部运动水平维度更长。咀嚼功能发育程度的差异1)肌肉活动：(1)奶瓶喂养组肌肉活动周期长度比母乳喂养组更长。(2)肌肉活动整合：母乳喂养的咬肌整合程度高于奶瓶喂养。奶瓶喂养组二腹肌、咬肌、茎突舌肌、双肌舌肌的互性活动明显低于正常喂养组。2)颌舌运动：正常喂养组摄食期长度较奶瓶喂养组短，下颌运动量小；正常喂养组咀嚼期长度较奶瓶喂养组长，下颌运动量大。结果表明，奶瓶喂养兔咀嚼功能发育程度和下颚运动发育程度随吸吮方式的不同而存在差异，说明奶瓶喂养兔咀嚼器官功能发育存在缺陷。少

To investigate the difference of developmental degree of masticatory function depending on sucking style such as breast or bottle feeding with elastic nipple, four infant rabbits in each group, had been fed for three weeks in this study.EMG of masseter muscle, digastric, styloglossus, genioglossus, mylohyoid and geniohyoid muscles with breast and bottle feeding, and x-ray movie when eating solid food for evaluating the tongue and jaw movement had been carried out simultaneously. Whole data gathered had been analyzed and discussed.The summary of results are as follows.1.The diference of developmental degree of feeding function1)Muscle activity :(1)Cycle length of muscle activity was longer in bottle feeding group than in breast feeding group.(2)Time lags activity : Time lags of activity onsets of digastric muscle from masseter muscle, and that of geniohyoid muscle from mylohyoid muscle were shorter in bottle feeding group.Muscle activity integration : Integration of masseter muscle was … More higher in breast feeding than in bottle feeding, on the other hand, digastric muscle was lower in breast feeding than in bottle feeding. Genioglossus and mylohyoid muscles were higher in bottle feeding group than in breast feeding group.2)Tongue and jaw movement : The bertical dimension of jaw movement were longer in breast than in bottle feeding. The horizontal dimension of tongue movment were longer in bottle feeding than in breast feeding.2.The difference of developmental degree of masticatory function1)Muscle activity :(1)Cycle length of muscle activity was linger in bottle feeding group than in breast feeding group.(2)Muscle activity integration : Integration of masseter muscle was higher in breast feeding than in bottle feeding. The reciprocity of digastric, masseter, styloglossus, gemioglossus muscles activity were lower in bottle feeding than in normal feeding.2)Jaw and tongue movment : The length of intake phase was shorter with small amount of jaw movement in normal feeding group than in bottle feeding group, on the contrally, the length of chewing phase was longer with large amount of jaw movement in normal feeding group than in bottle feeding group.These results that the difference of developmental degree of rabbit masticatory function and jaw movement depending on the style of sucking had existed which represents the deficiency of functional development of masticatory organ in case of bottle feeding rabbit. Less