Rodrigues Lucimar, Traina Andréia Aparecida, Nakamai Luiz Felipe, Luz João Gualberto de Cerqueira
Department of Maxillofacial Surgery, Prosthodontics and Traumatology, School of Dentistry, University of São Paulo, Brazil.
Braz Oral Res. 2009 Jan-Mar;23(1):89-95. doi: 10.1590/s1806-83242009000100015.
This study analyzed the effects of the unilateral removal and dissection of the masseter muscle on the facial growth of young rats. A total of 30 one-month-old Wistar rats were used. Unilateral complete removal of the masseter muscle was performed in the removal group, and detachment followed by repositioning of the masseter muscle was performed in the dissection group, while only surgical access was performed in the sham-operated group. The animals were sacrificed at three months of age. Axial radiographic projections of the skulls and lateral projections of the hemimandibles were taken. Cephalometric evaluations were made and the values obtained were submitted to statistical analyses. In the removal group, there were contour alterations of the angular process, and a significant homolateral difference in the length of the maxilla and a significant bilateral difference in the height of the mandibular body and the length of the mandible were observed. Comparison among groups revealed significance only in the removal group. It was concluded that the experimental removal of the masseter muscle during the growing period in rats induced atrophic changes in the angular process, as well as asymmetry of the maxilla and shortening of the whole mandible.
本研究分析了单侧切除和剥离咬肌对幼鼠面部生长的影响。共使用了30只1月龄的Wistar大鼠。切除组进行单侧咬肌完全切除，剥离组进行咬肌剥离后重新定位，而假手术组仅进行手术入路。动物在3月龄时处死。拍摄颅骨的轴向放射影像和半侧下颌骨的侧位影像。进行头影测量评估，并将获得的值进行统计分析。在切除组，观察到角突轮廓改变，上颌长度存在显著的同侧差异，下颌体高度和下颌长度存在显著的双侧差异。组间比较仅在切除组有显著差异。得出的结论是，在大鼠生长期间实验性切除咬肌会导致角突萎缩性改变，以及上颌不对称和整个下颌缩短。
