Faculty Bibliography

PURPOSE: The purpose of this study was to evaluate the bone healing kinetics around commercially pure titanium implants following inferior alveolar nerve (IAN) lateralization in a rabbit model. MATERIALS AND METHODS: Inferior alveolar nerve lateralization was performed in 16 adult female rabbits (Oryctolagus cuniculus). During the nerve lateralization procedure, 1 implant was placed through the mandibular canal, and the IAN was replaced in direct contact with the implant. During the 8-week healing period, various bone labels were administered for fluorescent microscopy analysis. The animals were euthanized by anesthesia overdose, and the mandibular blocks were exposed by sharp dissection. Nondecalcified samples were prepared for optical light and scanning electron microscopy (SEM) evaluation. RESULTS: SEM evaluation showed bone modeling/remodeling between the IAN and implant surface. Fluorochrome area fraction labeling at different times during the healing period showed that bone apposition mainly occurred during the first 2 weeks after implantation. CONCLUSIONS: The results obtained showed that bone healing/deposition occurred between the alveolar nerves in contact with a commercially pure titanium implant. No interaction between the nerve and the implant was detected after the 8-week healing period. Appositional bone healing occurred around the nerve bundle structure, restoring the mandibular canal integrity and morphology.

Despite a growing consensus that seclusion or restraint should never be used with children or adolescents, there are a few patients who are resistant to treatment, and are persistently violent. The purpose of this study was to measure the efficacy of installing a padded seclusion room to decrease the use of mechanical restraints, a potentially more emotionally traumatic and dangerous intervention than seclusion. After padded room installation, the number of monthly mechanical restraint events per 1000 patient days decreased by 93.7%, from 21.2 to 1.3. A padded seclusion room may offer a safer, albeit a less than desirable alternative to mechanical restraint.

BACKGROUND: The purpose of this study was to investigate the relationship between soft-tissue and underlying skeletal structures before and after unilateral mandibular distraction osteogenesis. METHODS: The sample consisted of 11 patients (three girls and eight boys) with an average age of 4.6 years at the time of treatment. All patients had unilateral craniofacial microsomia (four right-sided and seven left-sided unilateral craniofacial microsomia) and all underwent unilateral mandibular distraction osteogenesis. Measurements were performed on frontal medical photographs and posteroanterior cephalograms at predistraction (time 1) and postdistraction (time 2) periods. Left and right ramus heights, skeletal midline deviation, and transverse occlusal plane were measured on the posteroanterior cephalograms and compared with the linear distances between the lip commissures and the orbital plane, the circumference of both sides of the faces, and the angulation of the oral commissure plane as recorded on the medical photographs, respectively. To reduce magnification error, ratios of affected to less affected sides of the mandibles and soft-tissue facial structures were selected and studied. RESULTS: A similar relationship was observed between soft-tissue and skeletal components. However, there was no 1:1 relationship between the changes in ramus height and improvement in parallelism of lip commissures to the orbital plane. CONCLUSIONS: A significant improvement in soft- and hard-tissue anatomy has been observed following unilateral distraction osteogenesis of the mandible. The relationship between the soft-tissue and skeletal correction was different for all patients because of the large range in severity of the craniofacial malformation. Greater skeletal deficiency requires more correction to achieve symmetry of both hard and soft tissue

Hyperbaric oxygen (HBO) therapy is used in the treatment of osteoradionecrosis. Although HBO is thought to improve radiation-induced hypocellularity and bone tissue hypoxia, the precise effects of HBO on bone cells such as osteoblasts have not been described. In this study, our goal was to assess the effect of HBO on irradiated and nonirradiated primary osteoblast cultures and assess for changes in growth, apoptosis, cell cycle profile, differentiation, and gene expression. We found that daily HBO treatments caused a 24% decrease in cell growth after 9 days in culture. Hyperbaric oxygen negatively affects growth by inducing osteoblast apoptosis and cell cycle arrest. Hyperbaric oxygen leads to G1/S cell cycle arrest in unirradiated osteoblasts where as it causes G2/M arrest in cells that were previously irradiated with either 7 or 12 Gy of ionizing radiation. Although radiation was shown to have a dose-dependent inhibitory effect on early osteoblast differentiation as measured by alkaline phosphatase activity, HBO did not have a significant effect on osteoblast differentiation. Microarray analysis revealed that exposure to HBO leads to a differential expression of a variety of gene families including stress response pathways. In summary, although successive daily HBO treatments resulted in growth delay, osteoblast function as measured by the ability to produce alkaline phosphatase was not significantly affected. These data suggest that HBO does not have any positive effects on either normal or radiation-damaged osteoblasts in vitro.