Ellis E, McNamara J A, Lawrence T M
J Oral Maxillofac Surg. 1985 Feb;43(2):92-105. doi: 10.1016/0278-2391(85)90055-2.
In an effort to identify the frequency and distribution of the dental and skeletal components of adult Class II malocclusion with and without open-bite, 124 adults, half of whom had an anterior open-bite, were evaluated. Significant differences (P less than 0.05) between the open-bite and non-open-bite groups were found for the following measurements: the posterior maxilla exhibited vertical excess in the open-bite group; the maxillary occlusal plane was less steep in the open-bite group; the mandibular occlusal plane was more steep in the open-bite group; the gonial angle was higher in the open-bite group; the mandibular plane angle was higher in the open-bite group; the mandibular ramus was positioned in a more downward and backward (clockwise) location in the open-bite group; the total and lower anterior facial height were increased in the open-bite group; and the mandible was less protrusive in the open-bite group. No significant intergroup differences were noted in the cranial base, the anteroposterior position of the maxilla or of the upper and lower incisors, the palatal plane, posterior facial height, mandibular ramus height, or mandibular body length. The results of this analysis indicate that the average Class II open-bite malocclusion is characterized by aberrations in both the maxilla and the mandible. Therapy, therefore, may frequently require surgical intervention in both jaws to successfully correct this deformity.
为了确定伴有和不伴有开牙合的成人安氏II类错牙合的牙齿和骨骼组成部分的频率及分布情况，对124名成年人进行了评估，其中一半患有前牙开牙合。在开牙合组和非开牙合组之间，以下测量结果存在显著差异（P小于0.05）：开牙合组上颌后部表现出垂直过度；开牙合组上颌牙合平面较平缓；开牙合组下颌牙合平面较陡峭；开牙合组下颌角更大；开牙合组下颌平面角更大；开牙合组下颌升支位于更向下和向后（顺时针）的位置；开牙合组面部总高度和下部前牙高度增加；开牙合组下颌前突较小。在颅底、上颌或上下切牙的前后位置、腭平面、后牙高度、下颌升支高度或下颌体长方面，未发现组间有显著差异。该分析结果表明，平均安氏II类开牙合错牙合的特征是上颌和下颌均有异常。因此，治疗可能经常需要对上颌和下颌进行手术干预，以成功矫正这种畸形。
