Steinbacher Derek M, Bartlett Scott P
Plastic and Reconstructive Surgery, Yale University, New Haven, Connecticut, USA.
J Craniofac Surg. 2011 Jan;22(1):302-5. doi: 10.1097/SCS.0b013e3181f7df87.
Treacher Collins syndrome is associated with a clockwise mandibular deformity (Plast Reconstr Surg 2008;121:77e-84e). We hypothesize that the Treacher Collins mandible exhibits a more obtuse relation between the body and the ramus compared with unaffected subjects. The purpose of this study was to objectively analyze the body-ramus relation in Treacher Collins compared with control subjects and to investigate the effect of age.
This was a retrospective analysis involving three-dimensional computed tomography (CT) scans. Demographic and CT scan information was obtained for Treacher Collins and control subjects. Measurements were performed on the IDXrad platform. The ramus body angle (RBA) was defined as the intersection of the anterior ramus with the tangent from the alveolar process of the mandible. The mandibular plane angle (MPA) was measured in standard fashion. Left and right hemimandibles were analyzed. Statistical analysis involved the paired t-test (P < 0.005 significance). Subgroups based on age, younger than 3 years and older than 12 years, were then compared, within and between groups.
Three-dimensional CT scans were identified in 18 Treacher Collins (36 sides) and 24 control (48 sides) subjects. The MPA was excluded in 6 Treacher Collins and 2 control hemimandibles for absent centric occlusion. The Treacher Collins group consisted of 7 females and 11 males, ranging in age from 0.66 to 204 months (mean, 91.6 months). The control cohort included 13 females and 11 males, aged 0.26 to 204 months (mean, 111.5 months). The mean RBAs for the Treacher Collins and comparison groups were 150.28 and 114.2 degrees (P < 0.0001). The mean MPAs were 38.25 and 31.9 degrees for the Treacher Collins group and control subjects, respectively (P < 0.0001). In children younger than 3 years, the RBAs were 154.40 and 119.36 degrees, and for patients older than 12 years, the RBAs were 148.40 and 111.75 degrees for the Treacher Collins group and control subjects (both P < 0.0001). Comparing Treacher Collins younger than 3 years with those older than 12 years, the mean RBAs were not statistically different at 154.40 and 148.40 degrees (P = 0.1869). Among control subjects younger than 3 years compared with older than 12 years, the RBAs approached significance, but not statistically at 119.36 and 111.75 degrees (P = 0.0122). Notably, among control subjects, the MPA did statistically flatten with increasing age, showing 37.36 and 29.50 degrees (P = 0.0011).
The clockwise relation of the mandibular body relative to the ramus is objectively documented in Treacher Collins subjects. This relation persists despite increasing age, in distinction to control subjects where the mandibular plane flattens in adolescence.
特雷彻·柯林斯综合征与下颌骨顺时针畸形相关（《整形与重建外科》2008年；121:77e - 84e）。我们假设与未受影响的受试者相比，特雷彻·柯林斯综合征患者的下颌骨体与升支之间的关系更为钝角。本研究的目的是客观分析特雷彻·柯林斯综合征患者与对照受试者的下颌骨体 - 升支关系，并研究年龄的影响。
这是一项涉及三维计算机断层扫描（CT）的回顾性分析。获取了特雷彻·柯林斯综合征患者和对照受试者的人口统计学及CT扫描信息。在IDXrad平台上进行测量。升支体角（RBA）定义为下颌升支前缘与下颌牙槽突切线的交点。以标准方式测量下颌平面角（MPA）。对左右半侧下颌骨进行分析。统计分析采用配对t检验（P < 0.005为有统计学意义）。然后比较基于年龄的亚组，即3岁以下和12岁以上的患者，在组内和组间进行比较。
确定了18例特雷彻·柯林斯综合征患者（36侧）和24例对照受试者（48侧）的三维CT扫描。6例特雷彻·柯林斯综合征患者和2例对照半侧下颌骨因无正中咬合而排除MPA测量。特雷彻·柯林斯综合征组包括7名女性和11名男性，年龄范围为0.66至204个月（平均91.6个月）。对照队列包括13名女性和11名男性，年龄为0.26至204个月（平均111.5个月）。特雷彻·柯林斯综合征组和对照组的平均RBA分别为150.28度和114.2度（P < 0.0001）。特雷彻·柯林斯综合征组和对照受试者的平均MPA分别为38.25度和31.9度（P < 0.0001）。在3岁以下儿童中，特雷彻·柯林斯综合征组和对照组的RBA分别为154.40度和119.36度，对于12岁以上患者，RBA分别为148.40度和111.75度（均P < 0.0001）。比较3岁以下与12岁以上的特雷彻·柯林斯综合征患者，平均RBA在154.40度和148.40度时无统计学差异（P = 0.1869）。在3岁以下与12岁以上的对照受试者中，RBA接近有统计学意义，但在119.36度和111.75度时无统计学差异（P = 0.0122）。值得注意的是，在对照受试者中，MPA确实随着年龄增长在统计学上变平，分别为37.36度和29.50度（P = 0.0011）。
在特雷彻·柯林斯综合征患者中客观记录了下颌骨体相对于升支的顺时针关系。与对照受试者不同，对照受试者的下颌平面在青春期变平，而这种关系在特雷彻·柯林斯综合征患者中尽管年龄增长仍持续存在。
