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will continue to undergo modifications and change in an effort to improve the quality of patient care and outcome. This program will present newer treatment approaches and technical modifications, as well as the clinical and research results substantiating the efficacy of these surgical methods. The following modifications will be discussed: 1. Genioplasty A. Porous block HA and HTR augmentations B. Tenon and mortise osseous genioplasty 2. Anterior mandibular subapical osteotomy 3. Mandibular body osteotomy A. Anterior B. Posterior 4. Mandibular ramus sagittal split modifications A. Ramus and inferior border osteotomy B. Rigid fixation 5. Maxillary osteotomy modification A. Maxillary step osteotomy and rigid fixation B. Porous block HA grafting 6. Double jaw surgery A. Selective alteration of the occlusal plane B. Surgical sequencing of the maxilla and mandible C. Model surgery modifications 7. Simultaneous orthognathic surgery and rhinoplasty A. Surgical sequencing B. Rhinoplasty techniques Implementation of these techniques by the experienced, skilled surgeon, coupled with accurate diagnosis and treatment planning, should provide optimal functional and esthetic outcomes for our patients.

This study reports 4-year experiences with placement of hydroxylapatite-coated dental implants into extraction sites immediately after tooth extraction. Small defects present after implant placement were treated with dense, nonresorbable hydroxylapatite. Larger defects present after implant placement were treated with demineralized bone. Indications and contraindications for placement, as well as surgical techniques, are discussed.

This study evaluates the healing of the rabbit temporomandibular joint (TMJ) following discectomy in animals fed coarse or ground diets. Twenty New Zealand rabbits were divided into four groups with two unoperated groups serving as controls. A unilateral discectomy was performed and the animals were placed on either a regular (coarse) or a ground diet immediately following surgery. After 3 months, histologic evaluation demonstrated that fibrocartilage thickness was greatest in the discectomy-coarse diet operated joint, less in the discectomy-ground diet operated joint, still less in the discectomy-coarse diet unoperated joint, and unaffected in the control animals. The results of this study demonstrate that diet texture can affect TMJ healing following discectomy. The adverse responses of the coarse diet affected not only the operated joint but also the unoperated contralateral joint.

The endosseous implant design and surgical technique of Branemark et al. have resulted in longterm success of prosthetic rehabilitations.’ When titanium implants are submerged in bone for three to four months before loaded, close proximity of bone to the implant surface develops. Although absence of an intervening fibrous tissue seam is observed,’ direct chemical bonding of bone to titanium has not been shown.* However, it has been shown that dense, nonresorbable. nonporous hydroxylapatite (HA) can bond directly to bone.3 This study compares the histologic response to a HAcoated titanium implant with that of two types of uncoated titanium endosseous dental implants in dogs.

A comparison of solid root forms and particulate hydroxylapatite implanted into dog tooth extraction sites showed both types of implants to be well tolerated. Neither prevented postextraction bone resorption, but the particles were better able physically to maintain ridge height and width than the root forms.

This study investigates the tissue response in dogs to mandibular augmentation with hydroxylapatite (HA) combined with demineralized bone. Thirty mongrel dogs underwent ridge augmentation with 3 ml of HA alone (HAO), HA combined with autogenous bone (HAB), or HA combined with demineralized bone (HAD). Bone was not found in the HAO augmented ridges through 52 weeks; bone was found in the HAB augmented ridges by 12 weeks, and the HAD augmented ridges had bone formation after 26 weeks. This study demonstrates that demineralized bone can induce osteogenesis within the HA augmented dog ridge, but it is delayed when compared to HAB augmentations.

Patients with midfacial deficiency and exorbitism may pose a difficult challenge for orbital decompression. This article presents a review of the literature and discusses patient assessment, treatment planning, and surgical approaches to correction. Two cases are reported, demonstrating orbital decompression by midfacial advancement via the classic LeFort III osteotomy and a modified LeFort III osteotomy.

Publisher Summary This chapter discusses the vertical height stability of hydroxylapatite augmented mandibular atrophic alveolar ridges, comparing patients augmented with hydroxylapatite (HA) alone or HA combined with autogenous bone marrow. Patients with mandibular alveolar ridge deficiency augmented with HA alone and HA combined with autogenous cancellous bone were followed up to four years, less than average of 4% reduction in measurable vertical ridge height was seen in ridges augmented with hydroxylapatite alone. Less than an average of 10% reduction in measurable vertical ridge height was seen in ridges augmented with HA combined with the autogenous cancellous bone. No statistically significant differences were demonstrated between Durapatite or Calcitite. Denture use did not seem to affect vertical augmented heights after four years of function.

Glenoid fossa prostheses, alone or in combination with metallic condyles, were placed in 192 joints (127 patients) for temporomandibular joint reconstruction. Anatomic requirements, material characteristics, indications, and surgical technique are presented.

From six months to four years after alveolar ridge augmentation was performed, the vertical ridge heights of 74 Class III and Class IV alveolar ridge deficiency patients, who had undergone augmentation with hydroxylapatite with or without autogenous cancellous bone, were measured using panoramic radiographs adjusted for magnification errors. No statistically significant decreases in vertical ridge heights were seen when only hydroxylapatite was used, nor were there significant differences between the two types of hydroxylapatite particles used. Unlike other bone onlay procedures, the use of autogenous bone and HA together did not result in significant decreases in vertical ridge height.

The response of bone to surface-textured dense hydroxylapatite (HA) was evaluated in interpositional and onlay grafts to the dog mandible. For surfaced-waffled HA blocks, bonding of bone to the HA stabilized the interpositional grafts within 4 weeks and the onlay grafts at 6 weeks. Bone conformed intimately to the textured HA surface. This study demonstrates the early bone response to surface-textured HA blocks in the dog.

Summary This case report demonstrates the difficulty involved in establishing a diagnosis of malignant fibrous histiocytoma. The histologic characteristics of this tumor as well as the important contributions of electron microscopy and special staining techniques in making the diagnosis, have been discussed. Review of 16 cases of MFH revealed the typical presentation of maxillary sinus malignancy. Treatment modalities vary, depending on the size of the tumor and the preference of the surgeon.

Dog mandibles were augmented with either hydroxylapatite (HA) alone or HA combined with autogenous bone. Within the limited time frame of this experiment (16 weeks) the group which received HA alone did not demonstrate the induction of bony ingrowth further than 1-2 mm into the augmented ridge. However, the animals augmented with HA combined with autogenous bone demonstrated an active, lamellar-type bony ingrowth, maturing bony haversian systems, and vascular elements forming throughout the entire area, extending to the overlying soft tissue interface. The clinical assessment of both types of augmented ridges (HA and HA and bone) were similar; both formed hard, firm ridges at approximately the same rate. This observation is consistent with human clinical experience with HA or HA mixed with bone. 5 However, for patients who have severe mandibular atrophy and for whom increased mandibular bony bulk is crucial, a combination of HA and bone should be advantageous because of the increased extent of bony ingrowth.

Publisher Summary Glenoid fossa prostheses have been constructed from cast stainless steel, chrome cobalt, and silicone rubber. The metalic glenoid fossas have been limited in usage because of lack of adaptability during surgery. This chapter presents the brief history, indications, and results of materials used as glenoid fossa prosthesis alone or combined with metallic condyles for total joint replacement in major TM joint dysfunction. These materials are not recommended for temporomandibular joint surgery when more conservative medical and surgical therapy can solve the problem. In major joint dysfunction in which there has been a significant loss of vertical dimension, a new glenoid fossa prosthesis made of Proplast-FEP polymer fabricated from the patient's radiographic measurements has been used in 38 joints on 23 patients, since early in 1981. The chapter presents anatomical requirements, material characteristics, indications, operative technique, and results of complications.

A new technique for treating diffuse sclerosing osteomyelitis is described. The entire lesion is eliminated and the ridge bulk and form are immediately reconstructed by implantation of hydroxylapatite. Three cases are described.

Summary A case is reported in which a modified rhytidectomy incision is used to access both the TMJ and the lateral ramus for total TMJ reconstruction. This approach hides the incision in the neck hairline and eliminates the retromandibular incision scar.

Facial deformities following fractures of the zygomatic complex are common. Included in this article are the indications, work-up, and surgical technique for placement of Proplast implant material to correct the deformity of the malunited zygomatic complex. Three cases are presented to illustrate this approach.

Compressive creep and stress relaxation tests were performed on human temporomandibular joint discs and implanted and unimplnated Teflon-Proplast II laminates. The standard linear solid model for viscoelasticity was used to described the observed creep and stress relaxation behavior of the tested materials. The results from testing can be summarized as follows: (1) human and implanted Teflon-Proplast II laminates are viscoelastic; (2) the unimplanted Teflon-Proplast II laminate are elastic; (3) when Teflon-Proplast II laminates are implanted, sissue grows into the porous Proplast II structure, changing the intrinsic mechanical properties of the implant from an elastic to a viscoelastic material.