Wood Benjamin C, Mendoza Carlos S, Oh Albert K, Myers Emmarie, Safdar Nabile, Linguraru Marius G, Rogers Gary F
Washington, D.C. From the Division of Plastic and Reconstructive Surgery, Children's National Health System; the Division of Plastic Surgery, George Washington University School of Medicine and Health Sciences; Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System; and the Departments of Radiology and Pediatrics, School of Medicine and Health Sciences, George Washington University.
Plast Reconstr Surg. 2016 Jan;137(1):205-213. doi: 10.1097/PRS.0000000000001938.
The metopic suture is unlike other cranial sutures in that it normally closes in infancy. Consequently, the diagnosis of metopic synostosis depends primarily on a subjective assessment of cranial shape. The purpose of this study was to create a simple, reproducible radiographic method to quantify forehead shape and distinguish trigonocephaly from normal cranial shape variation.
Computed tomography scans were acquired for 92 control patients (mean age, 4.2 ± 3.3 months) and 18 patients (mean age, 6.2 ± 3.3 months) with a diagnosis of metopic synostosis. A statistical model of the normal cranial shape was constructed, and deformation fields were calculated for patients with metopic synostosis. Optimal and divergence (simplified) interfrontal angles (IFA) were defined based on the three points of maximum average deformation on the frontal bones and metopic suture, respectively. Statistical analysis was performed to assess the accuracy and reliability of the diagnostic procedure.
The optimal interfrontal angle was found to be significantly different between the synostosis (116.5 ± 5.8 degrees; minimum, 106.8 degrees; maximum, 126.6 degrees) and control (136.7 ± 6.2 degrees; minimum, 123.8 degrees; maximum, 169.3 degrees) groups (p < 0.001). Divergence interfrontal angles were also significantly different between groups. Accuracy, in terms of available clinical diagnosis, for the optimal and divergent angles, was 0.981 and 0.954, respectively.
Cranial shape analysis provides an objective and extremely accurate measure by which to diagnose abnormal interfrontal narrowing, the hallmark of metopic synostosis. The simple planar angle measurement proposed is reproducible and accurate, and can eliminate diagnostic subjectivity in this disorder.
CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, IV.
额缝与其他颅骨缝不同，它通常在婴儿期闭合。因此，额缝早闭的诊断主要依赖于对颅骨形状的主观评估。本研究的目的是创建一种简单、可重复的影像学方法，以量化前额形状，并区分三角头畸形与正常颅骨形状变异。
对92例对照患者（平均年龄4.2±3.3个月）和18例诊断为额缝早闭的患者（平均年龄6.2±3.3个月）进行计算机断层扫描。构建正常颅骨形状的统计模型，并计算额缝早闭患者的变形场。分别根据额骨和额缝上最大平均变形的三个点定义最佳和发散（简化）额间角（IFA）。进行统计分析以评估诊断程序的准确性和可靠性。
发现早闭组（116.5±5.8度；最小值106.8度；最大值126.6度）和对照组（136.7±6.2度；最小值123.8度；最大值169.3度）的最佳额间角有显著差异（p<0.001）。两组间发散额间角也有显著差异。就现有临床诊断而言，最佳角和发散角的准确性分别为0.981和0.954。
颅骨形状分析提供了一种客观且极其准确的测量方法，用于诊断额缝早闭的标志性异常额间狭窄。所提出的简单平面角测量方法可重复且准确，能够消除该疾病诊断中的主观性。
临床问题/证据级别：诊断性，IV级。
