Three-dimensional planning and reconstruction of the mandible in children with craniofacial microsomia type iii using costo chondral grafts

摘要

Background: In craniofacial microsomia (CFM) Type III patients, autogenous costochondral grafts (CCG) are conventionally used for the reconstruction of the ramus and condyle. The aim of this study was to describe the use of CCG in children with CFM in terms of outcomes, growth patterns, and complications. Materials and Methods: This is a retrospective study of nine, aged 4–12 years, patients with CFM Type III, who underwent reconstruction of the mandibular ramus condyle unit by CCG. Seven patients had right-sided CFM and two had left-sided CFM. The rationale for this choice was to utilize the potential growth of the CCG, providing length to the ramus, and the joint by acting as a growth center; to control the repositioning of the chin center; and to improve child compliance by undergoing only one operation. The surgical treatment plan was determined preoperatively, based on measurements of mandibular vertical and horizontal deficiency and analysis of the mandibular posterior and anterior angulation. The mandibular planes and axis were defined by a three-dimensional simulation software program to perform a “mock surgery”, by creating a prototype model. Clinical follow-up included measurements of the maximal opening, observation of the facial symmetry, and recording of complications, such as reankylosis. Results: There were no serious postoperative complications, infections, or graft rejections. Successful postoperative occlusal cants were noted and measured in five patients and acceptable results were obtained in three patients. In one case, the CCG underwent distraction osteogenesis to improve the facial symmetry. In one patient, the graft continued to grow and the chin started to deviate into the opposite side. Measuring and calculating the ratio of the ramus height on the panoramic X-ray revealed a good relation between the healthy contralateral and the reconstructed ipsilateral ramus. Postoperative mean mouth opening was 34.3 mm, with minimal midline deviation of 2.6 mm in occlusion. Mean follow-up was 51.7 months. The mean postoperative occlusal cant analysis for eight patients was 3.66°. Conclusion: CCG is useful in treating CFM Type III. The growth potential of the CCG makes it the ideal choice for children. The advantages of this graft are its biological compatibility, workability, functional adaptability, and minimal additional detriment to the patient. The use of a stereolithographic model preoperatively improved intraoperative precision by clearly displaying detailed anatomy of the patient undergoing craniofacial surgery. The surgeon can plan the length of the CCG before surgery and use the printed template while harvesting without waiting for the exact measurements to be provided by the facial surgical team.