Microbiology and antibiotic therapy of oral and maxillofacial infections

Surgical Mini-Lectures careful techniques and knowledge of anatomy and are accepted risks of surgical treatment. However, peripheral sensory nerve injuries do not always heal spontaneously, and they may have lasting and unpleasant sequelae. If left untreated, numbness, pain, or other abnormal sensations, spontaneous or stimulus related, in the lips, cheeks, gingiva, tongue, jaws, teeth, or face may become permanent, bothersome, and interfere with normal daily orofacial motor functions that require appropriate sensory input, such as washing, shaving, toothbrushing, kissing, applying makeup or lipstick, eating, drinking, speaking, swallowing, or playing wind musical instruments. Reports in the literature and the author’s experience in laboratory animals and in microsurgical operations on patients with sensory and motor nerve injuries have established the efficacy of timely and skillful microneurosurgical operations. Results are technique-sensitive and time-dependent. In complete nerve severance, for example, recovery of useful sensory function (defined by the Medical Research Council as twopoint discrimination threshold of 15 mm or less and absence of pain or hyperesthesia) can be expected in 80% to 90% of patients operated on by an experienced surgeon within six months of injury. Improvement in lost sensation is more predictable than relief of pain. Although late surgical repair can be successful in selected patients, replacement of distal nerve tissue with scar may reach a critical mass making repair impossible after 12 to 18 months. Basic microanatomy, neurophysiology and surgical principles provide the foundation for successful microneurosurgery. Experience is gained in fellowship training, laboratory animal operations, and postgraduate courses. Methods for prevention of nerve injuries in everyday oral and maxillofacial surgery practice are emphasized. An efficacious method of evaluation and documentation of nerve injuries is utilized. Accepted guidelines determine indications, timing, and prognosis of microsurgical repair of nerve injuries. After sensation begins to return, patients practice a daily regimen of “sensory re-education” exercises for at least one year, which enhances the quality of sensory function of the surgically repaired or reconstructed nerve. Documented results from microsurgical operations on 594 injured nerves followed for at least twelve months in the author’s practice are discussed and analyzed. Overall, 523 (88.1%) nerves regained “useful sensory function.” Of the 71 nerves that showed “no improvement” of pain or numbness after microneurosurgery, 40 were operated on more than twelve months after injury and 48 had intractable pain rather than numbness as their chief complaint. Factors which impact favorably on microneurosurgery outcome include numbness rather than pain as primary complaint, operation done less than twelve months following nerve injury, patient age under thirty years, absence of serious chronic systemic illness (eg, diabetes mellitus, connective tissue disease), and surAAOMS • 2004

geon experience. Currently, microneurosurgery offers selected nerve-injured patients an effective method of treatment and is part of the standard of care for such injuries. Some patients, especially those with long-standing painful nerve injuries, may benefit from non-surgical management. References Meyer RA: Nerve harvesting procedures. Atlas Oral Maxillofac Surg Clin North Am 9:77, 2001 Meyer RA, Rath EM: Sensory rehabilitation after trigeminal nerve injury or nerve repair. Oral Maxillofac Surg Clin North Am 13:365, 2001 Meyer RA, Ruggiero SL: Guidelines for diagnosis and treatment of peripheral trigeminal nerve injuries. Oral Maxillofac Surg Clin North Am 13:383, 2001

M221 Esthetic Zone Reconstruction: Synergy of Hard and Soft Tissue Augmentation for Optimal Implant Placement Michael A. Pikos, DDS, Palm Harbor, FL The loss of alveolar ridge contour in the esthetic zone compromises both esthetics and function. This unique clinical course will focus on the application of both hard and soft tissue grafting in the esthetic zone for optimal implant reconstruction. Emphasis will be on indications, timing, and surgical protocol utilizing mandibular block autografts in conjunction with connective tissue grafts, acellular dermis matrix, and related soft tissue procedures to avoid functional and esthetic pitfalls. Both single and multiple tooth cases will be presented and will include the use of computer generated custom abutments for optimal esthetic results. The role of platelet rich plasma with associated growth factor technology will also be featured. References Pikos MA: Block autografts for localized ridge augmentation: Part I. The posterior maxilla. Implant Dent 8:279, 1999 Pikos MA: Block autografts for localized ridge augmentation: Part II. The posterior mandible. Implant Dent 9:67, 2000 Langer B, Calagna L: The subepithelial connective tissue graft: A new approach to the enhancement of anterior esthetics. Int J Periodont Restor Dent 2:23, 1982

M222 Microbiology and Antibiotic Therapy of Oral and Maxillofacial Infections Thomas R. Flynn, DMD, Boston, MA The changing microbiology of odontogenic deep space infections has been a topic of considerable interest in recent years. Improved culturing techniques have 77

Surgical Mini-Lectures helped to identify the synergistic roles that anaerobes and streptococci play in these infections. Molecular methods for identifying unculturable pathogens have shown that over 60% of the species found in these infections cannot be cultured in the laboratory. The implications of this new understanding of oral microbiology in culturing and antibiotic therapy are discussed. Antibiotic resistance is a growing problem in the head and neck region. The effect of antibiotic therapy on antibiotic resistance within individuals and communities is explored, along with the mechanisms of antibiotic resistance. Strategies for treatment of highly resistant organisms are also described. Recent data on the antibiotic sensitivity of the commonly isolated pathogens of odontogenic infections indicate that penicillin is still the empiric drug of choice, at least for outpatients. The effectiveness of erythromycin and the new macrolides is weak against the oral streptococci and anaerobes, yet concentration of azithromycin into phagocytes may make this macrolide useful. Clindamycin retains its effectiveness in serious (hospitalized) and chronic cases. One can estimate also from these data the usefulness of some newer antibiotics, including new fluoroquinolones and cephalosporins, in odontogenic infections, and that certain older antibiotics are now obsolete. A cost-effectiveness comparison is made among the various available antibiotics and their combinations both by the oral and intravenous routes. Salient pharmacology and antibiotic drug interactions are discussed. References Sakamoto H, Kato H, Sato T, et al: Bull Tokyo Dent Coll 39:103, 1998 Flynn TR: Oral and Maxillofacial Surgery Knowledge Update 2002. Rosemont, IL, American Association of Oral and Maxillofacial Surgeons, 2002 Flynn TR, Halpern LR: Oral Maxillofac Surg Clin North Am 15:17, 2003

M223 Tibial Bone Graft Technique: In the OR and in the Office George M. Kushner, DMD, MD, Louisville, KY Brian Alpert, DDS, Louisville, KY The oral and maxillofacial surgeon faces many reconstructive challenges in contemporary practice. Reconstruction of the bony maxillofacial skeleton is frequently required for trauma, pathology, implant site preparation and a host of other clinical scenarios. The “gold standard” in bony reconstruction is autogenous grafting. Several sites, including the calvarium, iliac crest, tibia, and the mandible itself, are currently popular in clinicians’ hands. Each site has its own advantage, and disadvantages or limitations must be evaluated for each patient. 78

We feel the tibia bone graft site is very versatile and technically easy to perform and has a low complication rate. The amount of bone that can be harvested is usually more than adequate. Additionally, this procedure can easily be adapted to use in the office. We will present the technical aspects of this surgical procedure and show its use in a variety of surgical cases. Lastly, we will discuss the University of Louisville experience and our complications with the tibia bone graft. References Catone GA, Reimer BL, McNeir D, et al: Tibial autogenous cancellous bone as an alternative donor site in maxillofacial surgery: A preliminary report. J Oral Maxillofac Surg 50:1258, 1992 Alt V, Nawab A, Seligson D: Bone grafting from the proximal tibia. J Trauma 47:555, 1999 Besly W, Ward Booth P: Technique for harvesting tibial cancellous bone modified for use in children. Br J Oral Maxillofac Surg 37:129, 1999

M224 Distraction Osteogenesis for Dental Implants Suzanne U. Stucki-McCormick, MS, DDS, Encinitas, CA Louis F. Clarizio, DDS, Portsmouth, NH Distraction osteogenesis (DO) is a useful technique for the reconstruction of deficient alveolar ridges. In addition to recreating bone, soft tissues including keratinized gingiva are created. DO affords the clinician the opportunity to “overgrow” the bone, thus allowing osseous recontouring at the time of device removal and implant placement. The technique of DO can easily be mastered, yet the technique does require attention to detail, especially in device trajectory. Yet pitfalls and complications can be encountered. Mastery of these complications as well as the basic DO technique will be discussed in this course. Additionally, special case presentations such as anterior maxillary DO for esthetic implant reconstruction for patients status post avulsion of anterior teeth and bone, treatment of distal saddle deformities using DO and a posterior hinge, monocortical DO for knife edge ridges, evolving technology including the use of smaller, multi-vector distraction devices, DO for treatment of alveolar clefts as well as the use of DO-PRP sandwich technique and “immediate” DO for special cases will be offered. References Chin M: Distraction osteogenesis for dental implants. Atlas Oral Maxillofac Surg Clin North Am 7: 1999 Jensen OT, Cockrell R, Kuhike L, et al: Anterior maxillary alveolar distraction osteogenesis: A prospective 5-year clinical study. Int J Oral Maxillofac Implants 17: 2002 Gaggi A, Schultes G, Rainer H, et al: The transgingival approach for placement of distraction implants. J Oral Maxillofac Surg 60: 2002

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