Update on intraoperative analysis of mandibular margins

Purpose: Assessing the adequacy of the surgical resection during composite resection of carcinoma is limited by the ability to evaluate the bone margins. The standard pathologic evaluation of bone is by decalcification.Patients and Methods: A method of analysis was devised based on histologically proven methods of cortical invasion and subsequent spread. Frozen-section analysis of cancellous bone was investigated as a rapid method of evaluating adequacy of the mandibular resection. This report is an update of previously published results and includes an increase in the sample size as well as the analysis of additional pathology. Subjects consisted of 66 patients undergoing full thickness mandibular resection with 30 cases of histologically proven mandibular invasion qualifying for evaluation. Results on frozen section were then compared to the permanent section analysis on the cancellous bone and to the decalcified specimen.Results: Complete correlation was found between frozen and permanent section results. Frozen section analysis was able to correctly predict adequacy of resection in 60 of 61 margins.Conclusion: Based on these results, the oncologic surgeon can evaluate bone margins at the time of the resection and adjust the amount of excision required to eradicate the disease.     

Excision of ameloblastoma and reconstruction using a mandibular autologous graft

Three patients with mandibular ameloblastomas were treated by hemimandibulectomy followed by immediate reconstruction by a single-block mandibular homograft prepared at a distance from the operating field and taken from the bone section removed after visual and radiologic control of total tumoral separation. This procedure is simpler and more economic, rapid and reliable that conventional reconstruction using rib or iliac homografts. It is indicated for those limited cases of ameloblastoma or benign bone tumors which, even though possessing similar prognoses by their site (coronal...) or their tendency for recurrence and thus requiring interruptive resection, are sufficiently small to ensure total tumor excision and the recovery of a sufficiently thick bone piece for an ideal homograft. The procedure is of particular interest in the elderly and/or debilitated patients, and may be useful after abusive hemimandibulectomy.     

Mandibular reconstruction in 2004: an analysis of different techniques

PURPOSE OF REVIEW: The field of mandibular reconstruction has evolved dramatically over the past fifty years. Numerous advances in microsurgical technique, plating technology and instrumentation, and an understanding of donor site angiosomes have made consistent and reliable mandibular reconstruction possible. Refinements in technique continue to improve the functional and aesthetic outcomes of oromandibular reconstruction. This review discusses the current state-of-the-art techniques for mandibular reconstruction and highlights the latest innovations in technique. RECENT FINDINGS: The most common indication for oromandibular reconstruction remains ablative surgery for advanced neoplastic processes of the oral cavity and oropharynx. Reconstruction of these complex three-dimensional composite bony and soft-tissue defects is paramount for rehabilitation of form and function. Vascularized osseous free tissue transfer is the state-of-the-art for mandibular reconstruction. The long-term excellent functional and aesthetic outcomes of this technique have recently been reported. The most commonly used free flaps for mandibular reconstruction are the fibula, iliac crest, and scapula. Each of these typically accepts endosseous implants improving functional outcomes. The use of mandibular reconstruction plates and coverage with a soft-tissue flap remains a reconstructive option for selected patients. The latest refinements in technique include temporary intraoperative external fixation, the use of periosteal free flaps, distraction osteogenesis, and development of biodegradable biopolymer scaffolds for mandibular defects. SUMMARY: Oromandibular reconstruction, although a challenge for the head and neck reconstructive surgeon, is now reliable and highly successful with excellent long-term functional and aesthetic outcomes.     

Combining use of resin models with external fixation in mandibular reconstruction

OBJECTIVE: To obtain accurate occlusion in mandibular reconstruction when the tumor is exophytic, which makes prebending the plate impossible. DESIGN AND SETTING: Use of computed tomography-based resin models and external fixation devices is combined in a tertiary academic center. The exophytic part of the tumor on the model is burred off, and the reconstruction plate is bent on the model before surgery. Temporary external fixation is applied before resection, and a precontoured plate is applied following segmental resection before the release of external fixation. RESULTS: Six patients underwent mandibular reconstruction by using this technique, and all of the patients retained a class 1 occlusal relationship without need for additional intraoperative plate contouring. CONCLUSION: Computer-generated resin models of the mandible combined with intraoperative temporary external fixation allow the maintenance of preoperative occlusal status.     

Mandibular aggressive fibromatosis

INTRODUCTION: Aggressive fibromatosis is a rare histologically benign fibrous tumor with a potential for locoregional aggression. Treatment is not well defined and several therapeutic approaches have been proposed. Surgical treatment is the reference, chemotherapy, radiotherapy and homonotherapy being proposed as complementary treatment or for inoperable tumors. CASE REPORT: A three-year-old patient underwent surgery for removal of a mandibular tumor. Pathology reported aggressive fibromatosis. The patient was given conservative treatment and was free of recurrence nine years after resection. DISCUSSION: Conservative surgery for aggressive mandibular fibromatosis appears to be preferable to radical mutilating surgery which would have a major impact on facial growth in children.     

Use of the Kirschner wire for mandibular reconstruction

An adaptation of the Kirschner wire, using tie wires for fixation of the Kirschner wire in primary mandibular reconstruction following ablative surgery, is described. Eighteen patients with a Kirschner wire serving as a prosthesis following mandibular resection were followed up. Except for three patients, who had extensive resection of the tongue, all patients were judged as having satisfactory mastication and deglutition. Only two patients required another operation for wire-related complications. The Kirschner wire, when modified as presented, proved a dependable and stable prosthesis for mandibular reconstruction.     

Mandibular invasion in carcinoma of the lower alveolus.

PURPOSE: Efforts to conserve the mandible in resection for oral cancer tend to bring the resection margin progressively closer to the tumor front. This study of the manner of mandibular invasion by carcinoma of the lower alveolus provides added information regarding the behavior of the cancer within the bone. MATERIALS AND METHODS: Twenty-four resected specimens of squamous carcinoma of the lower alveolus were studied with x-rays and step-serial whole-organ histological sections. RESULTS: In 19 of the 21 specimens showing bone invasion, the spread was in the form of a broad front. Insinuation of tumor beyond the tumor front was extensive in 9 of 13 tumors showing deep mandibular invasion. Horizontal subcortical spread took place in 5 of 18 specimens for a distance of up to 1 cm. Perineural spread along the inferior alveolar nerve was found in 4 of 13 specimens in which the tumor extended to the canal; tumor spread along the canal, without neural involvement, was never seen. Preoperative orthopantomogram correctly estimated the extent of mandibular invasion in 16 of 24 patients. CONCLUSIONS: The tumor front of mandibular invasion by carcinoma of the lower alveolus is usually broad. In the absence of deep invasion, which is defined by invasion reaching the alveolar canal, there is little or no insinuation of cancer cells beyond the tumor front, and no spread along the alveolar canal. Marginal mandibulectomy can be applied more widely, taking a margin of 1 cm in all directions.     

Rapid analysis of mandibular margins

Evaluating surgical margins during composite resection of carcinoma is limited by analysis of the bone margins. The standard pathologic evaluation of bone is by decalcification. A method of analysis was devised based on histologically proven methods of cortical invasion and subsequent spread. Frozen section analysis (FSA) of the cancellous bone was investigated as a rapid method of evaluating adequacy of the mandibular resection. Subjects consisted of 29 patients undergoing full-thickness mandibular resection, with 16 cases of histologically proven mandibular invasion qualifying for evaluation. Results of FSA were then compared to the permanent section analysis of the cancellous bone and to the decalcified specimen. Complete correlation was found between frozen and permanent section results. Frozen section analysis was able to correctly predict adequacy of resection in 32 (97%) of 33 margins.     

Alloplastic and Microvascular Restoration of the Mandible

The evolution of mandibular reconstruction following composite resection is advanced by improved alloplastic prosthesis and reliable microvascular free tissue transfers. A 42-case, 6-year experience is presented using both methods at the University of California, San Francisco. The advantages and complications of both are discussed. The authors conclude that the success rate for lateral defect restoration is equivalent with either technique, and that the anterior defects are more reliably reconstructed with free tissue transfer. The advantage of microvascular flaps in the anterior defect must be gauged against the physical status of the patient, disease extent, and likelihood of dental rehabilitation by interosseous fixation.     

Condylar prostheses in head and neck cancer reconstruction.

OBJECTIVE: To discuss the use of condylar prostheses after mandibular resection for tumor. DESIGN: Case series and literature review. SETTING: Tertiary referral center. PATIENTS: Four patients underwent condylar reconstruction with metallic condylar prostheses after hemimandibulectomy for either squamous cell cancer or Ewing sarcoma. MAIN OUTCOME MEASURE: Complications related to the condylar prostheses. RESULTS: Clinical and radiological follow-up in these patients revealed several complications, including exposure or extrusion of the prosthesis and migration of the prosthesis into the epitympanum, resulting in profound sensorineural hearing loss owing to bony destruction of the cochlea. Two of our patients required removal of the mandibular hardware because of the seriousness of the complications, and 1 of the 2 underwent reconstruction of the condyle with a fibular free flap. CONCLUSIONS: Metallic condylar prostheses in the setting of tumor resection and reconstruction involve significant risks. Autogenous materials, such as vascularized bone grafts, should be used whenever possible.     

非血管化肋、髂骨移植在下颌骨节段截除术后Ⅰ期重建中的应用

目的 探讨非血管化肋、髂骨移植在下颌骨节段截除术后Ⅰ期重建中的效果。方法 2004-2012年为16例因骨良性病变导致下颌骨严重破坏者行下颌骨节段截除术后缺损,取自体肋、髂骨游离移植Ⅰ期重建。结果 手术切口均Ⅰ期愈合,随访1~24个月,远期并发瘘道及植骨坏死各1例,颌面下份外观及咬合咀嚼功能基本满意,对半侧下颌骨缺损修复病例相对略差但能维持颜面轮廓及进食。结论 非血管化肋、髂骨游离移植在下颌骨节段截除术后Ⅰ期重建中手术操作简单,无需血管吻合技术,只要选择好病例适应证、注意手术技巧即能获得较为满意的疗效,在条件相对较差的基层医院仍是修复下颌骨缺损的一种理想方法。在外观及咬合恢复方面,髂骨移植优于肋骨,骨缺损范围大者略差。     

Transcervical resection of the styloid process in Eagle syndrome

We conducted a retrospective study to determine the treatment outcomes of 6 patients who had either unilateral or bilateral elongated styloid processes and symptoms consistent with Eagle syndrome. Five of these patients had undergone transcervical resection of the styloid process, with relief of symptoms over the follow-up period (mean: 8 mo). Two of the 5 patients experienced a transient weakness in the marginal mandibular nerve, and both recovered completely. The transcervical surgical approach to resection in patients with elongated styloid processes and Eagle syndrome appears to be safe and effective, although the risk for transient marginal mandibular nerve weakness is notable.     

Bone reconstruction after resection of the mandible for osteoradionecrosis (author's transl)]

Resection of the sections of the mandibular affected by osteoradionecrosis has completely modified the progression and prognosis of this affection by ensuring that the patient does not have to suffer long periods of pain and suppuration, constantly observed when medical treatment is used alone. Unfortunately, these resections are usually extensive and are themselves responsible for functional and esthetic sequelae supported with difficulty by some patients, especially in the case of bilateral or mandibular arch resections. All efforts must be made, therefore, to limit the consequences, and with this in mind it is possible: -- to perform an uninterrupted resection limited to the alveolar area involved, in early cases of mandibular osteoradionecrosis; -- to reconstitute mandibular continuity with a bone graft in more advanced stages; -- to improve the esthetic appearance with skin and subcutaneous grafts whenever this is necessary. Good results can only be obtained if certain anatomical conditions exist and if surgical precautions are adapted to each case.     

Temporary intraoperative external fixation in mandibular reconstruction

OBJECTIVES: To describe the use of a temporary intraoperative external fixation device to assist in the optimal bony reconstruction of the mandible in the setting of vascularized bone grafts. STUDY DESIGN: A retrospective review of six patients who underwent composite resection of the mandible and subsequent reconstruction with osteocutaneous free tissue transfer in a tertiary care center. METHODS: Six cases of mandibular reconstruction using an intraoperative external fixation system to assist the positioning of vascularized bone grafts are presented. All patients had composite resection of the mandible and subsequent reconstruction with either a scapula or fibula osteocutaneous flap. Follow-up ranged from 2 to 16 months. RESULTS: Successful reconstruction as defined by acceptable contour, occlusion, and condylar position was achieved in all cases. Complications were limited to a postoperative cerebrovascular accident requiring anticoagulation and subsequent neck hematoma. CONCLUSIONS: Use of intraoperative external fixation maintains the proper alignment of mandibular segments without the use of a bridging reconstruction plate. This technique is particularly valuable with tumors involving the outer cortex of the mandible.     

Long term results of reconstruction plates in lateral mandibular defects. Revision of nine cases

OBJECTIVE: Although microsurgical bone transplant is still the gold standard, mandibular reconstruction plates (MRP) were for several years considered a fast and safe way to restore mandibular continuity without using a bone graft. New plate designs with locking screws have been recently introduced, and these may overcome some of the complications related to previous designs. We review the results of mandibular reconstruction plates in our institution from 1991 to 1995. METHODS: The records of nine cancer patients who underwent lateral mandibular resections (with preservation of both condyle and symphysis) followed by reconstruction with a mandibular reconstruction plate, were retrospectively reviewed. Patients were treated between 1991 and 1995 with regular Synthes and Leibinger plates (without locking screws). Immediately after tumour resection, the bone defect was reconstructed with an MRP without bone grafting. Three cases required soft tissue coverage: two flaps and one buccal fat pad flap. RESULTS: There was immediate orocervical fistula in six cases, one of which required surgical closure; and late complications were common. One patient died due to distant metastasis 13 months after surgery without symptoms related to the plate. The remaining eight patients had their plates removed at between 9 and 52 months after reconstruction, due to screw loosening (four cases), plate exposure (one case), or both (three cases). CONCLUSION: Lateral mandibular reconstruction with non-locking screws and regular profile plates is no longer recommended. New plates with improved designs are currently available. Their low profile and locking screws are the usual characteristics of these new plates. More clinical experience is necessary before plate reconstruction can be recommended over microvascular bone transfer.     

Review of segmental and marginal resection of the mandible in patients with oral cancer

This paper reviews the medical literature of the last decade to ascertain the criteria used to assess mandibular invasion by cancer of the oral cavity and to suggest how best to evaluate the mandible with a view to surgical management. It is generally agreed that patients with mandibular invasion should be treated surgically, but the extent of mandibular resection required remains a controversial matter and the accurate preoperative determination of neoplastic invasion of the mandible remains a challenge for head and neck surgeons. The relative reliability of preoperative orthopantomography, (OPG) bone scanning, computed tomography (CT) and magnetic resonance imaging (MRI), and of peroperative periosteal stripping and direct inspection in clinical assessment for mandibular surgery, is discussed. The histological patterns of tumor invasion and the most common routes of tumor entry in the mandible are described and the influence of variables such as prior radiotherapy and an edentulous vs a dentate state in relation to perineural invasion are also discussed. Finally, a comparison is drawn between the reported outcome of marginal vs segmental resection procedures and a decision-making algorithm is proposed. In selected cases, marginal mandibulectomy can ensure satisfactory tumor control, with a favorable effect on the morbidity associated with mandibular surgery.     

Complications of orthognathic surgery. Apropos of a series of 84 patients

BACKGROUND: Patients demand satisfactory functional and esthetic results from orthognatic surgery. The aim of this study as to assess adverse outcomes after orthognatic surgery. PATIENTS AND METHODS: We retrospectively reviewed 84 patients who underwent maxillary (22.6%), mandibular (29.8%) or bimaxillary (38.1%) osteotomy in 1997. We re-examined 76 of these patients at a mean 21 months follow-up. Data were recorded for the preoperative, early postoperative, secondary postoperative and late postoperative periods. RESULTS: Infectious complications occurred in 2% of the cases of maxillary surgery. For mandibular surgery there were 10.5% infectious complications including 83% that resolved spontaneously, 3.5% neurological complications and 1.7% temporomandibular joint complications. DISCUSSION: Maxillary osteotomy has proven reliable. Major adverse outcome is infrequent but serious. Adverse outcomes in mandibular surgery are more common but less problematic.     

Review of Segmental and Marginal Resection of the Mandible in Patients with Oral Cancer

This paper reviews the medical literature of the last decade to ascertain the criteria used to assess mandibular invasion by cancer of the oral cavity and to suggest how best to evaluate the mandible with a view to surgical management. It is generally agreed that patients with mandibular invasion should be treated surgically, but the extent of mandibular resection required remains a controversial matter and the accurate preoperative determination of neoplastic invasion of the mandible remains a challenge for head and neck surgeons. The relative reliability of preoperative orthopantomography, (OPG) bone scanning, computed tomography (CT) and magnetic resonance imaging (MRI), and of peroperative periosteal stripping and direct inspection in clinical assessment for mandibular surgery, is discussed. The histological patterns of tumor invasion and the most common routes of tumor entry in the mandible are described and the influence of variables such as prior radiotherapy and an edentulous vs a dentate state in relation to perineural invasion are also discussed. Finally, a comparison is drawn between the reported outcome of marginal vs segmental resection procedures and a decision-making algorithm is proposed. In selected cases, marginal mandibulectomy can ensure satisfactory tumor control, with a favorable effect on the morbidity associated with mandibular surgery.     

The functional result of mandibular reconstruction

A study was performed to determine if patients who underwent mandibular reconstruction were functionally rehabilitated. Five parameters were evaluated: deglutition, mastication, cosmesis, diet, and the use of dentures. Deglutition was not improved in patients who had mandibular continuity restored. Problems with deglutition were related to soft tissue resection. Mastication was poorer in the reconstructed group due to scarring, loss of the muscles of mastication, and inhibition of compensatory mandibular motion. Cosmesis was improved in patients who had immediate restoration of mandibular continuity. Cosmesis was not improved in patients with delayed mandibular reconstruction due to previous scarring. Prosthetic rehabilitation was poor in both groups of patients. Reconstructed patients had a greater number of hospitalizations due to management of, or complications from reconstructive surgical procedures. The results of this study suggests that restoration of mandibular continuity does not enhance the functional rehabilitation of the majority of patients with oral-pharyngeal malignancy.     

Latissimus-serratus-rib free flap for oromandibular and maxillary reconstruction

OBJECTIVE: To review complications and outcomes associated with latissimus-serratus-rib free flap oromandibular and midface reconstruction. DESIGN: Retrospective medical record review. SETTING: Two academic tertiary care medical centers. PATIENTS: Twenty-eight patients with segmental resection of the mandible and 1 patient with combined resection of the mandible and maxilla after excision of neoplasms of the oral cavity, who were believed to be poor candidates for fibula free flap reconstruction, were identified. INTERVENTIONS: Twenty-seven latissimus-serratus-rib osteomusculocutaneous free flap reconstructions and 2 serratus-rib osteomuscular free flap reconstructions were performed. MAIN OUTCOME MEASURES: The outcome of microvascular free tissue transfer as well as short- and long-term complications were recorded. RESULTS: There were no perioperative free flap failures. Delayed partial rib graft resorption occurred in 1 patient 33 months after free flap transfer for maxillary reconstruction. Among 28 cases of mandibular reconstruction, 1 case of bone graft nonunion was noted after a postoperative period of 57 months. All other cases achieved successful restoration of mandibular continuity. Donor site morbidity was well-tolerated in all patients. CONCLUSION: Latissimus-serratus-rib osteomusculocutaneous free flaps are effective for reconstruction of composite defects of the mandible in patients who are not candidates for more commonly used vascularized bone-containing free flaps.