Fabrication and use of a simple implant placement guide

Proper placement and orientation of dental implants is a requirement for optimum function and esthetics to be obtained with the definitive restoration. This article describes an acrylic resin implant placement guide which is simple to fabricate and easy to use. This device guides the surgeon in the precise position and angulation planned for the implant, yet allows for some flexibility in the event slight adjustments are necessary during surgery.     

Postoperative maxillary cyst following sinus bone graft: report of a case

Sinus bone grafting with autogenous bone is routinely performed to allow placement of endosseous dental implants. Although numerous maxillary sinuses have been successfully grafted, some complications of this procedure have been reported. These include maxillary sinusitis, resorption, infection and possible failure of grafts, loss of implants after 1-stage surgery, and oroantral fistulae. Only one case of postoperative maxillary cyst developing in the graft has been reported in the literature. Here, the authors report a similar case that necessitated grafting of the cyst with autologous iliac bone.     

Factors affecting neurosensory disturbance after mandibular bilateral sagittal split osteotomy.

PURPOSE: The current study evaluated the incidence of subjective neurosensory disturbances after bilateral sagittal split osteotomy (BSSO) in relation to gender, age, indication for osteotomy, magnitude of mandibular movement, degree of manipulation of the inferior alveolar nerve at operation, side of the mandible operated, and complications during and after surgery. PATIENTS AND METHODS: Thirty patients (60 sides) who had undergone a BSSO were followed up for 1 year after operation. The patients were classified into different groups according to gender, age, indication for osteotomy, magnitude of mandibular movement, degree of manipulation of the nerve, and complications during or after surgery. A self-administered questionnaire was used at every follow-up to evaluate the sensations in the mental region. RESULTS: A statistically significant positive correlation was found between subjective neurosensory loss and the patient's age (P = .039), magnitude of mandibular movement (P = .044), and degree of manipulation of the nerve (P = .0007). However, no significant correlation was found between disturbances of sensation and gender, indication for osteotomy, side of the operated mandible, or intraoperative and postoperative complications. Even if all patients evaluated their sensation as "normal" 1 year postoperatively, 31% of them reported slightly altered sensation in the mental region. CONCLUSIONS: After BSSO, a prolonged neurosensory deficit is strongly related to age, the intraoperative magnitude of mandibular movement, and the degree of manipulation of the inferior alveolar nerve. However, a long-term sensory loss is very rare, and patients seem to adapt to a mild neurosensory deficit and report sensory function as "normal" despite slightly altered sensation.     

Histologic analysis of implant sites after grafting with demineralized bone matrix putty and sheets

Grafting to restore lost alveolar bone is frequently used to enable placement of endosseous implants and improve cosmesis. Conflicting reports concerning the osteoinductivity of demineralized bone matrix (DBM) and historical use of synthetic bone graft substitutes has limited the use of DBM in oral and maxillofacial applications. Implant placement after bone grafting provides the unique opportunity to biopsy and histologically evaluate new bone formation. Bone grafting of the mandible or maxilla was performed to fill extraction sockets and restore ridge structures in a consecutive series of eight patients. DBM prepared as malleable putty (Grafton DBM Putty) or flexible sheets (Grafton DBM Flex) was used. Biopsies were taken at reentry, and histologic analysis determined the amount and quality of regenerated bone. Extensive new bone formation and minimal residual bone graft matrix were observed at an average of 5 months postoperative. The pattern of new bone maturity and remodeling varied by patient and the time in situ. Putty and Flex regenerated excellent bone height and width for the placement of dental implants, were easy to handle intraoperatively, and readily conformed to bony defects.     

Treatment of a large periapical lesion with loss of labial cortical plate using GTR: a case report

Following endodontic treatment, a large periapical lesion (9.0 mm x 9.0 mm) at a maxillary central incisor was treated with demineralized freeze-dried bone allograft (DFDBA) using the principles of guided tissue regeneration. The physical barrier was removed 6 months postsurgical. The cortical alveolar plate was observed to be completely reconstructed. Histologic evaluation demonstrated lamellar bone surrounding DFDBA particles. Radiographic follow-up 1 year posttreatment demonstrated complete resolution of the periapical radiolucency.     

Clinical and histologic evaluation of the demineralized freeze-dried bone membrane used for ridge augmentation

The biologic principle of guided bone regeneration has been successfully used to regenerate alveolar ridges. The objective of this pilot study was to clinically and histologically evaluate the demineralized freeze-dried bone membrane. Four premolar teeth were extracted from two dogs, and the remaining alveolar bone was surgically reduced in width and height to produce Class III ridge defects. After a 2-month healing period, mucoperiosteal flaps were elevated, and demineralized freeze-dried cortical columns were used as space maintainers. Bone membranes were used as barriers. The animals were sacrificed at 3 months and the surgical areas were recovered and processed for histologic evaluation. Results showed ridge augmentation in all sites. Clinically, the augmented areas appeared to have the same hardness as the surrounding bone on the periphery of the experimental site. After elevation of a mucoperiosteal flap, the bone membrane could be seen. Histologically, the bone membrane acted as an efficient barrier, excluding the nonosteogenic tissues. New bone formation underneath the membrane was found in all specimens. This study suggests that a bone membrane in combination with a space maintainer can guide new bone formation to regenerate localized chronic alveolar ridge defects.     

Advances in subperiosteal implant reconstruction

Recent advances in subperiosteal implant surgery of the mandible and maxilla are described in terms of changes in implant design, use of particulate autogenous marrow cancellous bone in conjunction with subperiosteal implant to structurally rebuild marked deficient mandibles at the time the implant is placed, and the of computerized tomography to develop a three-dimensional model for the construction of implant framework, eliminating the direct bone impression surgery. The latter procedure has revolutionized the use of subperiosteal implants. These techniques are outlined, and areas of future research in use of implants in structurally deficient areas are described.     

An in utero model of craniosynostosis.

To define better the pathophysiology of craniosynostosis, we developed an in utero model in rabbits. Premature fusion of the sutures was achieved by osteoinduction using demineralized bone matrix (DBM). Thirty-six fetuses from 18 time-dated pregnant rabbits underwent coronal strip craniectomies and implantation of DBM at 25 days of gestation (term = 31 days). Seventeen (47%) survived vaginal delivery and 10 (28%) survived for long-term follow-up. Surviving, operated animals demonstrated bony fusion across the coronal sutures presumably due to osteoinduction by the DBM. Coronal computed tomographic scans with sagittal reconstructions revealed that experimental animals had taller and wider skulls than nonoperated control animals. We conclude that employing DBM to create craniosynostosis in the fetal rabbit is technically feasible. Such a model may be used to more clearly define the pathophysiology of craniosynostosis and to evaluate methods of treatment.