Ellis E, McNamara J A
Am J Orthod. 1984 Oct;86(4):277-90. doi: 10.1016/0002-9416(84)90138-6.
In an effort to identify the frequency and differences in the dental and skeletal components of a large sample of adults with Class III malocclusion, with and without open bite, 176 subjects, one half of whom had an anterior open bite, were evaluated. These subjects were chosen by looking at the lateral cephalometric radiographs that were taken of 302 adults (128 men and 174 women) who exhibited at least an end-to-end Class III molar and canine relationship. The dental overbite was calculated for all subjects, and those with a negative overbite were placed in the open-bite (OB) group. Those with a positive overbite were placed in the non-open-bite (non-OB) group. The dental overbite was the only criterion used to define the open-bite and non-open-bite groups. The open-bite subjects were paired with a non-open-bite subject by sex, presence of presurgical orthodontic treatment, and anterior cranial base length. Eighty-eight subjects in each group (43 men and 45 women) were obtained. Various measures of craniofacial structure were calculated and analyzed by comparing the OB and non-OB groups with the paired t test. The areas that showed significant differences (p less than 0.05) between the OB and non-OB groups were as follows: the posterior maxilla exhibited vertical excess in the OB group; the maxillary occlusal plane was less steep in the OB group; the mandibular occlusal plane was more steep in the OB group; the gonial angle was higher in the OB group; the mandibular plane angle was higher in the OB group; the mandibular ramus was positioned in a more downward and backward location in the OB group; the total anterior facial height and lower facial height were increased in the OB group; the vertical height of the anterior maxilla was increased in the OB group; and the mandible was less protrusive in the OB group. No significant intergroup differences were noted in the cranial base, the anteroposterior position of the maxilla or the upper and lower incisors, the palatal plane, posterior facial height, mandibular ramus height, or mandibular body height. The results of this analysis indicate that the average Class III open-bite malocclusion is characterized by aberrations in both the maxilla and the mandible. Surgical therapy may, therefore, require intervention in both jaws to correct this deformity successfully.
为了确定大量伴有或不伴有开牙合的III类错牙合成年样本中牙齿和骨骼成分的频率及差异，对176名受试者进行了评估，其中一半有前牙开牙合。这些受试者是从302名成年人（128名男性和174名女性）拍摄的头颅侧位片中挑选出来的，这些人至少呈现III类磨牙和尖牙的近远中关系。计算了所有受试者的覆牙合，覆牙合为负的受试者被归入开牙合（OB）组。覆牙合为正的受试者被归入非开牙合（non-OB）组。覆牙合是用于定义开牙合组和非开牙合组的唯一标准。开牙合受试者与非开牙合受试者按性别、术前正畸治疗情况和前颅底长度进行配对。每组获得88名受试者（43名男性和45名女性）。通过配对t检验比较OB组和non-OB组，计算并分析了各种颅面结构测量值。OB组和non-OB组之间显示出显著差异（p小于0.05）的区域如下：OB组上颌后部表现出垂直过度生长；OB组上颌牙合平面较平缓；OB组下颌牙合平面更陡峭；OB组下颌角更大；OB组下颌平面角更大；OB组下颌升支位置更向下和向后；OB组前面部总高度和下部面部高度增加；OB组上颌前部垂直高度增加；OB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、后部面部高度、下颌升支高度或下颌体高度方面，未观察到显著的组间差异。该分析结果表明，平均III类开牙合错牙合的特征是上颌和下颌均有异常。因此，手术治疗可能需要对上颌和下颌都进行干预，才能成功矫正这种畸形。
