Change of Craniofacial Deformity After Sternocleidomastoid Muscle Release in Pediatric Patients with Congenital Muscular Torticollis

BACKGROUND: Craniofacial deformity is one of the main features of congenital muscular torticollis. The purposes of this study were to quantify craniofacial deformity and its postsurgical change in patients with congenital muscular torticollis and to analyze this change with reference to the age at surgery. METHODS: Eighty patients with congenital muscular torticollis who had successful surgical release of the sternocleidomastoid muscle and had preoperative and follow-up cephalometric evaluation were studied. The craniofacial deformity was evaluated in two aspects: curvature and asymmetry. Postsurgical changes of craniofacial deformity were analyzed in all patients. Two groups of patients were identified: Group 1, which consisted of patients who had surgery before five years of age; and Group 2, which consisted of patients who had surgery at or after five years of age. Preoperative deformity parameters and the postsurgical changes were compared between Groups 1 and 2. Finally, postsurgical changes in the first and second year postoperatively were compared in forty-two patients for whom cephalometric radiographs were made at both the first and second-year follow-up visits. RESULTS: All of the cephalometric parameters improved significantly after surgical release of the sternocleidomastoid muscle (p <0.001). The preoperative craniofacial asymmetry parameters, such as transverse calvarial asymmetry and transverse skull-base asymmetry, were significantly more severe in Group 1 than in Group 2 (p = 0.018 in both), and these parameters improved significantly more in Group 1 than in Group 2 postoperatively (p = 0.029 and 0.003, respectively). No significant difference between Groups 1 and 2 was found in postsurgical changes of craniofacial curvature and mastoid-process length ratio. The improvements were significantly larger in the first year than they were in the second year in all parameters except mastoid-process length ratio. CONCLUSION: Cephalometry quantitatively showed improvement in the craniofacial deformity after surgical release of the sternocleidomastoid muscle. The results of this series were better when surgery was performed before the patient reached five years of age. More postsurgical change can be expected during the first year postoperatively than during the second year.