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

为探讨不同吸吮方式（母乳喂养和奶瓶喂养）对幼兔咀嚼功能发育程度的影响，对4只幼兔分别进行了3周的喂养实验，观察了不同吸吮方式（母乳喂养和奶瓶喂养）下幼兔咬肌、二腹肌、茎突舌肌、颏舌肌、下颌舌骨肌和颏舌骨肌的肌电变化。同时进行进食固体食物时舌颌运动的X线片检查。结果如下：1.喂养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于母乳喂养组。（2）活动时滞：奶瓶喂养组二腹肌活动起始时间较咬肌、颏舌骨肌活动起始时间短;肌肉活动整合：咬肌活动整合时间短，颏舌骨肌活动整合时间短，咬肌活动整合时间短，颏舌骨肌活动整合时间短，咬肌活动整合时间短。 ...更多信息 母乳喂养的二腹肌比奶瓶喂养的高，而母乳喂养的二腹肌比奶瓶喂养的低。2）舌、颌运动：母乳喂养组下颌运动的垂直距离大于奶瓶喂养组。2.咀嚼功能发育程度的差异1）肌肉活动：（1）肌肉活动周期长，奶瓶喂养组比母乳喂养组长。（2）肌肉活动整合：母乳喂养组咬肌活动整合率高于奶瓶喂养组。二腹肌、咬肌、茎突舌肌、双舌肌肌活动的相互作用在奶瓶喂养中低于正常喂养。2）颌舌运动：正常喂养组的摄食期较奶瓶喂养组短，下颌运动量小，正常喂养组咀嚼期较长，下颌运动量较大，这可能是由于正常喂养组咀嚼期发育程度的差异，兔的咀嚼功能和依赖于吮吸方式的下颌运动已经存在，这表明在瓶饲条件下兔的咀嚼器官功能发育不足。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