Lisiecki Jeffrey, Wan Derrick C, Wang Lu, Zhang Peng, Enchakalody Binu, Zhang Xu, Kasten Steven J, Wang Stewart C, Buchman Steven R, Levi Benjamin
Department of Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, Michigan, USA.
J Craniofac Surg. 2013 Jan;24(1):158-62. doi: 10.1097/SCS.0b013e3182646411.
Pierre Robin sequence (PR) and Treacher Collins syndrome (TC) are congenital disorders associated with multiple craniofacial abnormalities. The mandibular malformations linked with these maladies are closely associated with the form and function of the temporalis muscle. Despite these associations, a paucity of research has been directed at quantifying how these malformations affect the tissues of the temporal region. In this paper, we seek to quantify differences in the temporalis muscle and the temporal fat pad using a novel CT-derived analytic program to examine craniofacial morphomic indices within these patient groups in comparison to normal age-matched controls. We posit that the temporalis muscle and temporal fat pad, like other derivatives of the first branchial arch, are hypoplastic in patients with TC and PR compared to age-matched controls.
High-throughput image analysis was used to reconstruct the 3-dimensional (3D) anatomy and quantify morphomic measures of the temporalis muscle and temporal fat pad in children with PR, TC, and age-matched controls. These steps were completed in a semi-automated method using algorithms programmed in MATLAB v13.0. The 3D reconstructions were analyzed in 3 children with PR (6 temporal regions), 3 children with TC (6 temporal regions), and a control group of 19 children (38 temporal regions). We also quantified the same measurements in a localized "core" sample in the area of greatest thickness, providing a more consistent sample of the tissue position. Relationships between the temporal muscle and fat pad values and craniofacial abnormality type were assessed using Wilcoxon nonparametric test using exact distribution, with a P value of less than 0.05 being deemed significant.
The mean age of our patients was 6.0 years in PR and 4.5 years in TC cohorts. We were able to establish an automated methodology to quantify the temporalis muscle and temporal fat pad based on CT characteristics. Localized temporalis volume and localized temporalis area were significantly smaller in children with PR than in the control group. Total temporalis fat volume and localized temporalis area were significantly less in children with TC than in the control group. When compared to each other, the PR group had small morphomic values compared to TC group.
There are significant morphomic differences in the temporalis muscle and the temporal fat pad in children with either PR or TC when compared to age-matched control group which can be measured from pre-existing CT scans. Specifically, both of these test groups show decreases in the morphomic measures of the temporalis region. The quantification of these changes corroborates and objectifies the clinical findings associated with these congenital deformities while simultaneously allowing for preoperative planning. Furthermore, this finding confirms that the hypoplasia seen in these patient populations is not only hypoplasia of the mandible but also of the surrounding functional matrix, which includes the temporalis muscle and temporal fat pad.
皮埃尔·罗宾序列征（PR）和特雷彻·柯林斯综合征（TC）是与多种颅面畸形相关的先天性疾病。与这些疾病相关的下颌骨畸形与颞肌的形态和功能密切相关。尽管存在这些关联，但针对量化这些畸形如何影响颞区组织的研究却很少。在本文中，我们试图使用一种新的CT衍生分析程序来量化颞肌和颞脂肪垫的差异，以检查这些患者组与年龄匹配的正常对照组相比的颅面形态计量指标。我们假设，与年龄匹配的对照组相比，TC和PR患者的颞肌和颞脂肪垫与第一鳃弓的其他衍生物一样发育不全。
采用高通量图像分析重建三维（3D）解剖结构，并量化PR、TC患儿及年龄匹配对照组颞肌和颞脂肪垫的形态计量指标。这些步骤使用MATLAB v13.0编程的算法以半自动方法完成。对3例PR患儿（6个颞区）、3例TC患儿（6个颞区）和19例儿童的对照组（38个颞区）进行了3D重建分析。我们还在最厚区域的局部“核心”样本中量化了相同的测量值，以提供更一致的组织位置样本。使用威尔科克森非参数检验（精确分布）评估颞肌和脂肪垫值与颅面异常类型之间的关系，P值小于0.05被认为具有统计学意义。
PR组患者的平均年龄为6.0岁，TC组为4.5岁。我们能够建立一种基于CT特征量化颞肌和颞脂肪垫的自动化方法。PR患儿的局部颞肌体积和局部颞肌面积明显小于对照组。TC患儿的颞肌总脂肪体积和局部颞肌面积明显小于对照组。与彼此相比，PR组的形态计量值比TC组小。
与年龄匹配的对照组相比，PR或TC患儿的颞肌和颞脂肪垫存在显著的形态计量差异，这些差异可以通过现有的CT扫描测量。具体而言，这两个测试组的颞区形态计量指标均降低。这些变化的量化证实并客观化了与这些先天性畸形相关的临床发现，同时有助于术前规划。此外，这一发现证实，在这些患者群体中观察到的发育不全不仅是下颌骨的发育不全，还包括周围功能基质的发育不全，其中包括颞肌和颞脂肪垫。
