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Craniomaxillofacial Reconstructive and Corrective Bone Surgery - part 7

Hình 42,4 (a) hình ảnh ba chiều mô mềm trước khi xây dựng lại một khiếm khuyết của ramus phải tăng dần cho thấy sự thay đổi bên phía bên trái cần thiết cho chiếu cằm đối xứng. (b, c) Trong khi phân khúc hàm dưới lớn đã được thay đổi vị trí theo chiều ngang sang bên trái, condyle có | Figure 42.2 Severe resorption of a nonvascularized iliac crest graft for reconstruction of the ascending ramus and condyle in a 50-year-old patient. Note the pencil-like shape of the severely atrophic bone graft with additional soft tissue shrinkage. a b c Figure 42.3 a b Twelve-year-old boy following reconstruction of the right condyle with a costochondral graft. Excessive growth overshoot 3 years after reconstruction with lateral deviation of the d mandible to the left. c d X-ray of the patient immediately and 3 years postoperatively demonstrating the massive mandibular shift. 42. Microvascular Reconstruction of the Condyle and the Ascending Ramus 465 b ward the condyle can be kept in its original position with the miniplate temporarily fixed to the maxilla. Then the length of the ascending ramus and the mandible can be estimated. Additional prosthetic devices fixed to the maxilla with screws in the midline may help to get an orientation for sagittal extension of bone grafts in patients with large mandibular reconstructions. d Figure 42.4 a Three-dimensional soft tissue imaging before reconstruction of a defect of the right ascending ramus demonstrates lateral shift to the left side necessary for symmetrical chin projection. b c Whereas the major mandibular segment has to be repositioned laterally to the left the condyle has to be repositioned posteriorly and laterally. d In cases with the condyle still in situ the condyle first is mobilized and the muscle process resected. After- After positioning of the remaining condyle plate fixation to the vascular graft should be performed at least with two or three screws at the condyle. Otherwise removal of the condyle with replacement by the vascularized bone graft must be considered. Alternatively the remaining condyle may be fixed to the proximal aspect of the vascularized graft according to Hidalgo.19 20 If a small condyle shows severe signs of osteoporosis with unsecure bone hold the condyle should also be removed .