Particulated Coronoid Process Grafts in Marginal Mandibulectomy

Purpose: Depending on the residual bone height after marginal mandibulectomy, fracture may occur postoperatively. While, in certain morphology of cancer the coronoid process of the affected side can be easily collected during marginal mandibulectomy. Utilizing morphological features of the coronoid process, the coronoid process is reportedly used as a block bone graft for reconstruction of the orbital floor, temporomandibular joint, or alveolar ridge defect and for correction of midfacial concavity. However, there is no report of the coronoid process being particulated for bone grafting. Here we report three cases of bone grafting in the jaw defect after marginal mandibulectomy of the mandibular molar region, using the particulated coronoid process of the affected side.

Methods: Three patients with squamous cell carcinoma of the mandibular molar region underwent marginal mandibulectomy between January 2007 and November 2008. The mandibular canal was included in all the marginal mandibulectomies. The coronoid process was resected with the tumor, and a bone graft was harvested with bone-cutting forceps from a site at least 10 mm from the soft-tissue resection margin and the mandibular foramen. The harvested coronoid process of the affected side was placed as a bone graft in the jaw defect. Then, the area was carefully sutured to avoid any dead space.

Result: One of the three cases needed additional mandibulectomy based on postoperative pathological examination revealing suspected residual cancer in the marginal zone of the bone. Pathological examination of the tissue obtained from the additional mandibulectomy showed new bone formation around the grafted bone. In the other two cases, the vertical dimension of the mandible at the thinnest portion was approximately 7 mm, but improved to approximately to 15 mm on computed tomography performed 3 years or more after the surgery.

Conclusion: After bone grafting using the particulated coronoid process of the affected side in the jaw defect after marginal mandibulectomy of the mandibular molar region, the new bone formation was relatively good. This bone graft technique is effective in some carefully chosen patients depending on their cancer progression.

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2) Giacomo DR, Mario SM, et al: Mandibular coronoid process grafting for alveolar ridge defects. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 114:430-436, 2012.