家兔之咀嚼機能與顱顏部形態的關係

The Relationship between Masticatory Function and Craniofacial Morphology

莊森源(Sheng-Yen Chuang)

《The Kaohsiung Journal of Medical Sciences》 11卷8期 (1995/08) Pp. 458-469

https://doi.org/10.6452/KJMS.199508.0458

摘要

1960年Moss提出功能性基質理論（functional matrix theory）之後，學者認為顱顏部的生長發育並非全由遺傳基因所決定，功能上的需求在顱顏部形態的成長，佔重要的地位，為了了解咀嚼功能需求對顱顏部生長發育的影響，作者將動物飼料的物理性質改變，降低咀嚼肌的活動力，觀察其對顱顏部的生長發育有何影響。
使用70隻雄性紐西蘭白兔（Oryctolagus cuniculus），分成兩組，每組各35隻，第一組為實驗群，餵食磨成粉末的正常固體飼料，第二組餵食未經磨碎處理的正常固體飼料，稱為對照群。兩組皆由出生後一個月離乳起開始飼養，直到兔齡七個月為止。於實驗前，及每個月各秤體重，並照射測顱規格化X光片。取得之X光片資料經放大二倍後拷貝成照片，然後描繪出解剖構造，再用數位板（Summergraphy digitizeer），輸入電腦測量分析頭顱顏面的形態及角度，比較實驗群與對照群之間的差異，得到以下的結論：
一、 體重變化而言：
兩群的體重隨時日的增加而增加，實驗群比對照群增加較慢，但兩群間皆無有意義差，最終體重，兩群間亦無有意義差。
二、測顱分析的結果顯示頭顱整體的形狀，兩群間無差異，但軟食群的上顎有向前上方回旋生長的現象，而對照群則不明顯。此外，軟食群動物的頭顱處於較直立上方位置，此亦說明軟食群動物的頭顱生長形式有改變。
三、下顎骨形態的差異而言，軟食群動物的下顎骨形態顯得較為尖細平坦且向順時針旋轉的方向生長。

並列摘要

In 1960, the functional matrix hypothesis was first articulated by Moss. Although many investigators agreed that there were genetic influences on craniofacial growth, the functional demands of matrices are more significant in determining craniofacial morphology during growth. Therefore, during postnatal growth, an intimate functional relationship exits between the jaw muscles and the bones to which they are attached. The most recent findings suggest that the morphological changes can be observed not only in areas adjacent to muscle insertion but also in growth sites affecting the rotational growth pattern of the cranium.
If this is true, the reduced functional demands on the masticatory muscles may cause some changes of craniofacial growth. To test this hypothesis, a longitudinal study by means of cephalometric analysis ot observe the changed masticatory function induced by a diet of physically soft food on the craniofacial morphology in the growing rabbits was conducted.
One group of rabbits was fed with a soft diet, while another group received a standard laboratory diet and served as the control group. These animals had been weaned at the start of the experiment (1 month of age), and the experimental period last for 6 months. During that time, all rabbits were weighed every month, and lateral cephalograms were taken with the skull fixed in a specially constructed cephalostat. The procedure of taking a cephalogram entails the sacrifice of the subject. Thus five rabbits in each group were sacrificed each experimental period. The radiographic images were copied on photographic paper, magnified by two and the cephalometric analyses were performed.
The results are as follows:
1.There were no statistical differences between groups in any of the test periods for body weights.
2.The results of cephalometric analysis showed that no difference in overall skull shape could be found between the two groups, but a more anterior superior growth rotation of the upper jaw occurred in the rabbits fed with soft diet compared to the rabbits fed with a standard laboratory diet. Thus, the skull became more erect position in the soft diet group.
3.In the soft diet group, the angular process of the mandible was less convex. That was a clockwise growth pattern. In addition, there was a thin and flat shape of mandibular body in compared to control group.

並列關鍵字

masticatory function ； craniofacial growth