Stephen M. Parel

Osseointegration in maxillofacial prosthetics. Part I: Intraoral applications

Osseointegrated implants can provide anchorage and promote prosthesis stability in a variety of oral defect situations. The application of proven TIP fixture principles and techniques to these patients has allowed high level of function to be attained with great promise for longevity.

Diminishing dependence on adhesives for retention of facial prostheses

Attempts to augment or circumvent adhesives for retaining facial prostheses have been beneficial for many patients, particularly when a significant number of prostheses have failed because of insufficient retention. This approach is helpful in overcoming the problems created by the continued reluctance of surgeons to remove an entire facial organ in eradicating a relatively small disease process. There has been a positive response to suggestions that proposed surgery be planned to include the creation of sites which could be used for anatomic or mechanical retention.

Mandibular fractures through endosseous cylinder implants: Report of cases and review

These case reports and review focus on three mandibular fractures that occurred through endosseous cylinder implant sites. The first patient, and most likely the second, had osteoporotic changes that affected their already atrophic mandibles. The third patient probably had an area of deficient mineralization or poorly consolidated bone in the region where the fracture developed. These bony conditions increased the potential for fracture. Although the exact mechanism by which such fractures occur is not known, an examination of past research suggests that stress concentration at the mandibular defect prepared for implant placement is a probable explanation. The site of an implant that has not yet osseointegrated acts as a site of tensile stress concentration and ultimately an area of weakness. Consequently, this area of weakness in a mandible with decreased bone density or mineralization is more prone to applied functional forces. Repeated submaximal functional forces in an area of bony weakness, such as an endosseous implant site, may lead to a spontaneous fracture with no associated trauma. With these factors in mind, several extra precautions should be taken when implants are placed in thin or weak mandibles.

Single-visit hollow obturators for edentulous patients

A method of fabricating a simple hollow obturator for edentulous patients was described. This procedure can be accomplished in a single office visit using readily available materials. The use of a relatively long-lasting soft reline material for obturators allows stable, comfortable, and effective obturation for many edentulous patients with recently created maxillary defects (Fig. 6). The hollow prosthesis is lightweight and sufficiently flexible to allow relatively simple placement in retentive undercut regions. Direct finger placement of the material insures complete duplication of all desired tissue undercuts. The soft reline material may also serve as a final impression of the defect when fabrication of the definitive prosthesis is undertaken.

A risk assessment treatment planning protocol for the four implant immediately loaded maxilla: preliminary findings

STATEMENT OF PROBLEM There is debate as to the efficacy of maxillary complete arch reconstructions when only 4 implants are used. PURPOSE The purpose of this study was to determine what risk factors, if any, may increase the likelihood for implant failure in immediate function by using a tilted distal, 4-implant approach in the maxilla. MATERIAL AND METHODS A retrospective analysis of implant performance was conducted for patients treated with 4 implants placed in 285 maxillae (1140 implants) and 273 mandibles (992 implants) providing immediate function for complete arch implant-supported prostheses. The consecutively treated patient cohort consisted of those who provided consent between April 2008 and December 2010. A retrospective chart review was conducted to assess potential maxillary implant failure factors, including a history of smoking, gender, opposing occlusion, bone density, bone volume, insertion torque, parafunction, failed implant site, addiction, and systemic factors. Data were analyzed with descriptive statistics. A series of risk factors were postulated in an effort to establish guidelines for modification of treatment planning protocols in response to combined risks. RESULTS Several common primary factors in maxillary implant failure scenarios were identified through this process of patient profiling. Opposing natural dentition, male gender, lack of bone density, the distal implant site, and parafunction were sufficiently frequent occurrences in failure situations to suggest that either the use of additional implants or delayed loading and the provision of a complete denture as an interim prosthesis may be more appropriate in the management of patients identified as being high risk. Secondary factors such as bone availability (volume) and smoking were less common in failure situations. CONCLUSIONS A preliminary protocol is suggested for both treatment planning and profiling patients with respect to presenting characteristics that may contribute to implant failure. A decrease in failure occurrence has been noted anecdotally during the short term implementation of this protocol.

Modified topical steroid therapy for the treatment of oral mucous membrane pemphigoid

A modified approach to the treatment of two patients with oral mucous membrane pemphigoid, using an adaptation of a custom fluoride carrier, is described. The method provided for occlusive topical steroid therapy, overcoming many of the obstacles to such treatment for oral lesions. Response was excellent, with no adverse local or systemic effects. Further clinical trials to determine the applicability of this form of therapy in the treatment of patients with a number of infectious, ulcerative, and vesiculobullous oral diseases appear warranted.

The All-on-4 Shelf: Maxilla

All-on-4 treatment is facilitated by bone reduction to create prosthetic restorative space, establish maximum anterior posterior spread of implants, and to avoid pneumatized sites. Unlike a reduction alveloplasty for denture placement, the All-on-4 shelf enables optimal surgical prosthetic management of implant placement for the fixed hybrid prosthesis.

Fabrication of facial prostheses by applying the osseointegration concept for retention

Initial clinical studies applying the osseointegration concept for retention of facial prostheses have been encouraging. The results of these preliminary investigations indicate new treatment possibilities with facial prostheses anchored to the cranial skeleton by osseointegrated implants. Osseointegrated rehabilitation of the maxillofacial prosthetic patient presents the potential for overcoming many of the disadvantages associated with conventional retentive methods. Fabrication and support for facial prostheses by using osseointegrated implants for retention are described.

The prosthetic management of oral commissure burns

The complications of electrical burn to the oral cavity include microstomia and cosmetic deformity. Surgical burn excision and repair by primary closure, skin grafts, or tongue flaps have recognized disadvantages. The use of intraornl fixed or removable appliances, or the extraoral facemask prosthesis, serves to maintain adequate commissure spacing and allows normal skin and mucosal healing to occur. Secondary commissuroplasties may be required after prosthetic management of the burn.

Microwave techniques for fabrication of provisional facial prostheses

Timely rehabilitation of facial defects necessitates provisional prostheses during the period following surgery. The possibilities of using microwave radiation in the drying of gypsum casts, the preparation of stone molds, the curing of silicone elastomers, and the extrinsic coloring of silicone prostheses are presented. Microwave radiation has the potential for saving time, energy, and resources during the fabrication of provisional facial prostheses.