Padwa B L, Kaiser M O, Kaban L B
Department of Oral & Maxillofacial Surgery, Harvard School of Dental Medicine, Children's Hospital, Boston, MA 02115, USA.
J Oral Maxillofac Surg. 1997 Aug;55(8):811-6; discussion 817. doi: 10.1016/s0278-2391(97)90338-4.
The purpose of this study was to compare subjective evaluation of occlusal canting in frontal photographs with objective radiographic measurements to determine the threshold at which a cant is recognized as abnormal.
Standardized frontal photographs (at rest and smiling) of two groups of orthognathic surgery patients were evaluated. Group 1 consisted of patients with a documented occlusal cant (n = 21), and group 2 consisted of patients with no cant (n = 22). Four untrained and five trained observers independently, and blind to the diagnoses, assessed patient photographs to judge the presence or absence of canting. These subjective results were compared with objective measurements of the angle of the occlusal plane to the true horizontal on each patient's posteroanterior (PA) cephalogram.
The mean occlusal cant was 5.0 degrees +/- 1.6 degrees for group 1 and 1.4 degrees +/- 0.9 degree for group 2. The difference between groups was statistically significant (P < .01). Cants greater than 4 degrees were detected clinically with greater than 90% frequency by both untrained and trained observers.
The results of this study indicate that 4 degrees is the threshold for recognition of an occlusal cant by 90% of observers. This information has significant implications for three-dimensional planning and outcome assessment in orthognathic and craniofacial surgery.
本研究旨在比较正面照片中咬合偏斜的主观评估与客观影像学测量结果，以确定偏斜被视为异常的阈值。
对两组正颌外科手术患者的标准化正面照片（休息时和微笑时）进行评估。第1组由记录有咬合偏斜的患者组成（n = 21），第2组由无偏斜的患者组成（n = 22）。四名未经培训和五名经过培训的观察者独立且在不知诊断结果的情况下评估患者照片，以判断是否存在偏斜。将这些主观结果与每位患者后前位（PA）头颅侧位片中咬合平面与真正水平方向夹角的客观测量结果进行比较。
第1组的平均咬合偏斜为5.0度±1.6度，第2组为1.4度±0.9度。两组之间的差异具有统计学意义（P <.01）。未经培训和经过培训的观察者在临床上检测到大于4度的偏斜的频率均超过90%。
本研究结果表明，4度是90%的观察者识别咬合偏斜的阈值。该信息对正颌和颅面外科的三维规划和结果评估具有重要意义。
