Disclaimer: The information contained within the Grand Rounds Archive is intended for use by doctors and other health care professionals. These documents were prepared by resident physicians for presentation and discussion at a conference held at Baylor College of Medicine in Houston, Texas. No guarantees are made with respect to accuracy or timeliness of this material. This material should not be used as a basis for treatment decisions, and is not a substitute for professional consultation and/or peer-reviewed medical literature. Mandibular Reconstruction Mandibular reconstruction continues to provide one of the most difficult challenges to the head and neck reconstruction surgeon. The mandible is both functionally and cosmetically one of the most important structures of the head and neck, contributing to facial contour, chewing, speech and swallowing. The goals of mandibular reconstruction are: 1) establishment of mandibular continuity; 2) establishment of an osseous-alveolar base; and 3) correction of soft-tissue defects. A distinction should be made between the etiology and location of mandibular defects. In general, mandibular loss due to benign processes results in preservation of soft-tissue and is more likely to heal. In contrast, mandibulectomy for carcinoma more frequently results in large bone and soft-tissue defects in elderly patients who often have additional health problems and compromised nutritional status. Lateral mandibular defects are generally well tolerated and do not require reconstruction. In contrast, anterior mandibular defects result in severe functional and cosmetic deformities. The timing of mandibular reconstruction continues to be debated. Primary reconstruction offers the theoretical advantage of rapid return of form and function in a single operation procedure. Secondary reconstruction via an external approach prevents salivary contamination and avoids infection, resulting in higher success rates. The literature describes a multitude of methods to restore mandibular defects. These can be classified into three basic categories: 1) alloplastic material, 2) alloplast with bone, and 3) autogenous bone. Alloplasts have been widely used in mandibular reconstruction in the form of metallic wires and plates, organic materials (calcium aluminate, calcium apatite, calcium sulfate), and synthetic material (methylmethacrylate, proplast, teflon). Of these, mandibular reconstruction plates constructed of stainless steel (AO plates), vitallium, and titanium (titorp plates) are used most often. Mandibular reconstruction plates have the advantage of: 1) no donor site morbidity, 2) expediency, 3) ease of contour, and 4) ability to reconstruct the condyle. Major complications include plate extrusion, loosening of screws, and plate fracture. Additional soft-tissue coverage is frequently required in the form of a myocutaneous flap. Alloplastic implants may be combined with autogenous bone, either cortical or cancellous. Implants are in the form of trays made of vitallium, titanium, or dacron. This method can only be used for secondary reconstruction. Successful reconstruction is reported in 80% to 90% of patients with traumatic defects, compared to 50% of patients with resection for carcinoma. Major disadvantages include extrusion and difficulty with postoperative radiotherapy. Autogenous bone grafts can be in the form of free bone transfer, pedicled osteomyocutaneous grafts or microvascular free flaps. Reconstruction using free bone grafts has a high failure rate due to the lack of vascularization. Pedicled osteomyocutaneous flaps overcome the major problems associated with free bone grafts by supplying their own vascularity and soft-tissue. These flaps, however, require an additional operation site, longer surgical time and provide a limited amount of bone. These osteomyocutaneous flaps include the sternomastoid-clavicular, pectoralis major - 5th rib and trapezius grafts. Microvascular free flaps have found wide application in mandibular reconstruction. Advantages include: 1) wide selection of donor site, 2) non-irradiated tissue, 3) own vascular supply, and 4) soft-tissue for closure. Major disadvantages include: 1) donor site morbidity, 2) longer operation time, 3) need for special surgical and nursing skills, and 4) longer hospitalization. Case Presentation A 60-year-old man was diagnosed with a T1N2aM0 squamous cell carcinoma of the floor of the mouth in November 1990. He refused surgery and received 5914 Gy of external beam radiation followed up by iridium 192 intersticial implants in February 1991. He had a complete response. However, in July 1992 he was found to have a 2 cm by 3 cm ulceration of the midline floor of the mouth which was fixed to the lingual surface of the mandible without evidence of recurrent neck disease. Radiological examination demonstrated invasion of the anterior mandible. Metastatic work-up, including liver-spleen scan, bone scan, and CT scanning of the chest were negative. Past medical history was significant for severe peripheral vascular disease and lower extremity claudication. Arteriograms demonstrated significant aortoiliac atherosclerotic disease which precludes the use of a vascularized iliac osteocutaneous graft. The patient underwent composite resection of his anterior mandible and floor of mouth with bilateral supraomohyoid neck dissections. The mandible was reconstructed using the THORP plating system. A right rectus abdominis free flap was harvested to provide soft-tissue coverage. The patient did well perioperatively; however, on post-operative day number two, he developed a hematoma of his abdominal donor site that required evacuation. His postoperative course was marked by respiratory failure and by dehiscence of his abdominal wound, requiring dressing changes. He is currently doing well and remains free of recurrent disease. Bibliography Albert TW, Smith JD, Everts EC, Cook RA. Dacron mesh tray and cancellous bone in reconstruction of mandibular defects. Arch Otolaryngol Head Neck Surg 1986:112:53-59. Baker S, Sullivan M. Osteocutaneous free scapular flap for one-stage mandibular reconstruction. Arch Otolaryngol Head Neck Surg 1988;114:267-277. Cohen M, Schultz RC. Mandibular reconstruction. Clin Plast Surg 1985;12:411-422. Conley J. Use of composite flaps containing bone for major repairs in the head and neck. Plast Reconstr Surg 1971;49:522-526. Duncan M, Mankteelow R, Zuker R, Rosen I. Mandibular reconstruction in the radiated patient: the role of osteocutaneous free tissue transfers. Plast Reconstr Surg 1985;76:829-840. Gullane PJ, Holmes H. Mandibular reconstruction. New concepts. Arch Otolaryngol Head Neck Surg 1986;112:714-719. Hidalgo DA. Fibula free flap: a new method of mandible reconstruction. Plast Reconstr Surg 1989;84:71-79. Kellman RM, Gullane PJ. Use of the AO mandibular reconstruction plate for bridging of mandibular defects. Otolaryngol Clin North Am 1987;20:519-533. Komisar A. The functional result of mandibular reconstruction. Laryngoscope 1990;100:364-374. Kotch DW, Prein J. Mandibular reconstruction using A-O plates. Am J Surg 1987;154:384-388. Lawson W, Baek S-M, Loscalzo LJ, Biller HF, Krespi YP. Experience with immediate and delayed mandibular reconstruction. Laryngoscope 1982:92:5-10. Maisel RH, Hilger PA, Adams GL. Reconstruction of the mandible. Laryngoscope 1983;93:1122-1126. Riediger D. Restoration of masticatory function by microsurgically revascularized iliac crest bone grafts using onosseous implants. Plast Reconstr Surg 1988;81:861-876. Schlenker J, Robson M, Parsons R. Methods and results of reconstruction with free flaps following resection of squamous cell carcinoma of the head and neck. Ann Plast Surg 1981;6:362-373. Schusterman MA, Reece GP, Kroll SS, Weldon ME. Use of the AO plate for immediate mandibular reconstruction in cancer patients. Plast Reconstr Surg 1991;88:588-593. Shenaq SM. Refinements in mandibular reconstruction. Clin Plast Surg 1992;19:809-817. Shockley WW, Weissler MC, Pillsbury HC. Immediate mandibular replacement using reconstruction plates. Arch Otolaryngol Head Neck Surg 1991;117:745-749. Urker ML. Composite free flaps in oromandibular reconstruction. Review of the literature. Arch Otolaryngol Head Neck Surg 1991;117:724-732. Urken ML, Buchbinder D, Weinburg H, Vickery C, Sheiner A, Biller HF. Primary placement of osseointegrated implants in microvascular mandibular reconstruction. Otolaryngol Head Neck Surg 1989;101:56-73. Urken ML, Buchbinder D, Weinberg H, Vickery C, Sheiner A, Parker R, et al. Functional evaluation following microvascular oromandibular reconstruction of the oral cancer patient: a comparative study of reconstructed and nonreconstructed patients. Laryngoscope 1991;101:935-950. Urken ML, Weinberg H, Vickery C, Buchbinder D, Lawson W, Biller HF. The internal oblique-iliac crest free flap in composite defects of the oral cavity involving bone, skin and mucosa. Laryngoscope 1991;101:257-270. Urken ML, Weinberg H, Vickery C, Buchbinder D, Lawson W, Biller HF. Oromandibular reconstruction using microvascular composite free flaps. Arch Otolaryngol Head Neck Surg 1991;117:733-744. Vuillemin T, Raveh J, Sutter F. Mandibular reconstruction with the titanium hollow screw reconstruction plate (THORP) system: evaluation of 62 cases. Plast Reconstr Surg 1988;82:804-814. Wenig BL, Keller AJ. Microvascular free-tissue transfer with rigid internal fixation for reconstruction of the mandible following tumor resection. Otolaryngol Clin North Am 1987;20:621-632. Grand Rounds Archive | Department Home page BCM Public | BCM Intranet | Privacy Notices | Contact BCM | BCM Site Map | ©2001-2006 Baylor College of Medicine
|