Mandibular reconstruction with osseointegrated implants into the free vascularized radius.

Complete oral rehabilitation after oromandibular resection is a goal that is frequently difficult to attain. Poor speech, inability to eat a solid diet, and cosmetic deformity are all potential problems. The introduction of osseointegrated implants and free vascularized bone grafting are two techniques that have permitted improved results of oromandibular reconstruction. When used together they provide the best possibility for providing oral continence, a stable denture, and minimal cosmetic deformity. The free vascularized iliac crest has been used widely to reconstruct mandibular defects with the placement of enosseus implants. However, the radius provides a good alternative to reconstruct the mandible. We report four cases of mandibular reconstruction with the use of the free vascularized radius with subsequent placement of osseointegrated implants. The results of these cases suggest that enosseus implants can be used successfully in the radius. The radius is ideal to reconstruct small to moderate-sized defects of the lateral mandible with loss of oral mucosa.

First brachial cleft sinuses: an analysis of current management strategies and treatment outcomes.

First branchial cleft sinuses account for less than 1% of all branchial cleft anomalies. A thorough understanding of the embryology and developmental anatomy is essential for successful management. Nine cases of first branchial cleft sinuses treated at The Hospital for Sick Children by the Department of Otolaryngology between 1984 and 1990 were reviewed. A large proportion of these lesions were initially misdiagnosed despite significant symptomatology. This resulted in a high rate of infectious complications. Early diagnosis, prompt control of infection, and early surgical excision are recommended. Current methods of diagnosis and treatment are discussed along with techniques for facial nerve preservation.

Role of hyperbaric oxygen therapy in the management of mandibular osteoradionecrosis.

Hyperbaric oxygen (HBO) has been used as a tool in the management of osteoradionecrosis (ORN). However, it has not been conclusively proven to be of benefit. The precise role and guidelines for its use also have not been clearly defined. This report retrospectively analyzes 41 patients treated at the Hyperbaric Chamber Unit at the Toronto Hospital (Toronto General Division) with proven mandibular ORN from 1980 to 1985. The results show that 83% of the patients had a significant improvement with HBO therapy, judged by at least a 50% decrease in the size of the exposed bone, closing of the fistulous tract, or complete relief of symptoms. Within the group of patients who were significantly improved, 15% showed complete resolution of ORN. Seven (17%) of the patients did not benefit from the HBO. All seven patients had radiological evidence of dead bone. Based on these observations, the following conclusions can be made: 1. HBO is of benefit in the management of ORN. 2. Patients with ORN may be divided into two groups: mild and severe. 3. Cases of mild ORN will heal with HBO alone, but, in severe ORN, surgery is necessary to remove dead bone. 4. All patients with ORN should receive dental evaluation, local wound care, and a strict oral hygiene regimen. Diseased teeth should be removed prior to radiotherapy. Subsequently, any teeth that became abscessed should be extracted in conjunction with prophylactic HBO. Antibiotics play an ancillary role in the management of ORN. For patients who have received radiation to the mandible, the authors propose regular follow-up in order to detect ORN at a time when HBO can arrest the disease.

Preconditioning: a new technique for improved muscle flap survival.

Musculocutaneous regional and distal flaps have become an important tool available to the head and neck surgeon. Vascularized autogenous muscle transplants allow single-stage reconstruction of complex defects. Ischemic muscle necrosis is a well-recognized complication with serious potential morbidity. It has been shown that myocardial muscle is protected from ischemic damage by brief periods of coronary artery occlusion and reperfusion subsequent to prolonged ischemia. This is called preconditioning. To our knowledge, this technique has never been extrapolated to skeletal muscle. This article presents a discussion of preconditioning and the potential benefits of this new technique as a means to enhance skeletal muscle survival to sustained normothermic global ischemia. Theories behind ischemic muscle injury are presented. A review of the development of preconditioning in myocardial muscle is discussed. Experimental models used to investigate this phenomenon are also presented. In addition, results of our laboratory investigations using the latissimus dorsi porcine model are discussed. Preconditioning is a new, nonpharmacologic means to improve muscle flap survival. This simple technique may have great clinical application in reducing ischemic muscle necrosis in regional and distal muscle transplantation.

Augmentation of skeletal muscle survival in the latissimus dorsi porcine model using acute ischemic preconditioning.

Reconstruction of head and neck defects commonly involve local and distal muscle transplants. Ischemic flap necrosis is a well recognized complication of autogenous muscle transplants. Research in the field of myocardial survival has recently shown that repeated brief periods of ischemia followed by reperfusion result in improve muscle survival when the cardiac muscle is subsequently subjected to prolonged ischemia. This is called preconditioning and the mechanism is unknown. The concept is discussed in this paper and presented as a potential new, non-pharmacological strategy to reduce skeletal muscle ischemic necrosis. A review of the development and application of preconditioning in myocardial muscle survival is presented, and causes of ischemic muscle necrosis are discussed. Potential mechanisms of preconditioning in muscle are also presented. The extrapolation of the concept of preconditioning is discussed with an examination of a potential experimental model to test this concept: the latissimus dorsi flap in the pig. The results of our investigations into the effect of preconditioning on skeletal muscle and its possible mechanism are discussed. Preconditioning may prove to be a useful method to improve skeletal muscle tolerance to sustained normothermic global ischemia. This may have important clinical benefits in muscle transplantation. To our knowledge, this is the first publication to discuss the application of preconditioning in skeletal muscle.