Kumari Nita, Fida Mubassar, Shaikh Attiya
Section of Dentistry, Department of Surgery, The Aga Khan University Hospital Karachi, Pakistan.
J Ayub Med Coll Abbottabad. 2016 Oct-Dec;28(4):766-772.
The position and arrangement of teeth as well as the entire scheme of occlusion differs from one individual to the other .The purpose of this study was to examine differences in position and inclination of incisors, overjet, overbite and lower arch crowding in subjects with different depths of curve of Spee and to determine correlations between depth of curve of Spee and these variables.
The sample comprised of 114 patients (55 females and 59 males) with fully erupted permanent second molars (age 12-25 years), having no history of previous orthodontic treatment, no craniofacial anomalies, and no missing permanent teeth. Study parameters were assessed by using pretreatment lateral cephalograms and dental casts of orthodontic patients. The entire sample was divided into three groups according to depth of curve of Spee (mild Spee=38, moderate Spee=38, severe Spee=38). Descriptive statistics were calculated. Differences between the Spee groups were assessed by analysis of variance. In addition, correlation coefficients were calculated between curve of Spee and other parameters.
Statistically significant differences were found in upper incisor inclination (p=0.000), lower incisor inclination (p=0.003), Steiner's mandibular plane angle (p=0.000), overjet (p=0.001), overbite (p=0.000) and irregularity index (p=0.008) among the Spee groups. Moreover, statistically significant positive correlations were found between curve of Spee and overjet, overbite and irregularity index. Upper and lower incisor inclinations as well as mandibular plane angle were found to have statistically significant but negative correlations with curve of Spee.
Overjet and overbite in severe Spee group are larger than in mild and moderate Spee groups. There is negative correlation between curve of Spee depth and inclinations of upper and lower incisors. There is positive correlation between curve of Spee depth and severity of lower anterior crowding and Steiner's mandibular plane angle.
牙齿的位置和排列以及整个咬合方案因人而异。本研究的目的是检查不同斯皮曲线深度的受试者中切牙的位置和倾斜度、覆盖、覆合及下牙弓拥挤情况的差异，并确定斯皮曲线深度与这些变量之间的相关性。
样本包括114例患者（55名女性和59名男性），恒牙第二磨牙完全萌出（年龄12 - 25岁），无正畸治疗史，无颅面异常，无恒牙缺失。通过正畸患者的治疗前侧位头影测量片和石膏模型评估研究参数。根据斯皮曲线深度将整个样本分为三组（轻度斯皮曲线组 = 38例，中度斯皮曲线组 = 38例，重度斯皮曲线组 = 38例）。计算描述性统计量。通过方差分析评估斯皮曲线组之间的差异。此外，计算斯皮曲线与其他参数之间的相关系数。
斯皮曲线组之间在上颌切牙倾斜度（p = 0.000）、下颌切牙倾斜度（p = 0.003）、斯坦纳下颌平面角（p = 0.000）、覆盖（p = 0.001）、覆合（p = 0.000）和不整齐指数（p = 0.008）方面存在统计学显著差异。此外，在斯皮曲线与覆盖、覆合和不整齐指数之间发现统计学显著的正相关。发现上颌和下颌切牙倾斜度以及下颌平面角与斯皮曲线存在统计学显著但为负的相关性。
重度斯皮曲线组的覆盖和覆合大于轻度和中度斯皮曲线组。斯皮曲线深度与上下颌切牙倾斜度之间存在负相关。斯皮曲线深度与下前牙拥挤程度和斯坦纳下颌平面角的严重程度之间存在正相关。
