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Biomedical subjects

Edward B Seldin

Publications and source records attributed to Edward B Seldin.

8 recordsLinked to original sources

Range of curvilinear distraction devices required for treatment of mandibular deformities.

PURPOSE: The purpose of this study was to determine the range of fixed trajectory curvilinear distraction devices required to correct a variety of severe mandibular deformities. MATERIALS AND METHODS: Preoperative computed tomography (CT) scans from 18 patients with mandibular deformities were imported into a CT-based software program (Osteoplan). Three-dimensional virtual models of the individual skulls were made with landmarks to track movements. An ideal treatment plan was created for each patient. Upper and lower boundaries for the dimensions of curvilinear distractors were established based on manufacturing and geometric constraints. Then, anatomically acceptable distractor attachment points were identified on the models using proximal and distal grids. Treatment plans were simulated for a series of distractors with varying radii of curvature, elongations (arc-length of device), and placements along the grids. The outcomes using these distractors were compared with the ideal treatment plans. Discrepancies were quantified in millimeters by comparing landmarks in the simulated versus ideal movements. RESULTS: Approximately 400,000 simulated 3-dimensional movements, based on the distractor parameters and variations in placement were computationally evaluated for the 18 cases. It was determined that, by varying distractor placement, a family of 5 distractors, with 3, 5, 7, and 10 cm radii of curvature and a straight-line device, could be used to treat all 18 cases to within 1.8 mm of error. CONCLUSIONS: The results of this study indicate that a family of 5 curvilinear distractors may suffice to treat a broad range of mandibular deformities.

Computer Simulation↗

Comparison of wound management methods after removal of maxillofacial osseous lesions.

PURPOSE: To evaluate outcomes associated with choice of wound management, ie, primary closure or healing by secondary intention, of osseous defects after excision of maxillofacial bone lesions as a guide to clinical practice. PATIENTS AND METHODS: Using a retrospective cohort study design, we enrolled a sample composed of subjects treated for jaw lesions between 1995 and 2003. The primary predictor variable was the wound management choice of the residual jaw defect, classified as primary closure or healing by secondary intention. The primary outcome variable was postoperative inflammatory complications. Other study variables were grouped as demographic, medical/dental history, lesion information, preoperative complications, operative treatment, and follow-up information. Appropriate uni-, bi-, and multivariate statistics were computed. RESULTS: The sample was composed of 93 subjects with 126 jaw lesions, of which 90 (71.4%) were managed by primary closure. In the bivariate analyses, tobacco use was statistically associated (P < .05) with wound management and near statistically associated (P = .06) with complications. In the multivariate model, after adjusting for the presence of multiple cysts and tobacco use, there was not a statistically significant difference between the 2 wound management choices in terms of postoperative complications. CONCLUSIONS: Our results suggest that the choice of managing the osseous wound, ie, primary closure versus secondary intention, was not associated with increased risk of postoperative inflammatory complications. The implications of these findings are discussed below.

Adult↗

Analysis of skeletal movements in mandibular distraction osteogenesis.

PURPOSE: The purpose of this study was to use geometric parameters of movement, calculated from 3-dimensional computed tomography (CT) data, to determine the curvilinear distractor dimensions required to correct mandibular deformities in a series of patients. MATERIALS AND METHODS: Preoperative CT scans from 15 patients with symmetric (n = 5) and asymmetric (n = 10) deformities were imported into a CT-based software program (Osteoplan; an open-source visualization application developed by Gering et al at the Surgical Planning Laboratory [SPL, Brigham and Womens Hospital, Boston, MA]). The software was used to reconstruct virtual 3-dimensional models from these scans. Two experienced surgeons, working with a computer scientist, then used Osteoplan to create an ideal treatment plan for each patient. In each case, the 3-dimensional curvilinear movement was quantified using 4 "parameters of movement" (POMs). These parameters were then used to prescribe a distraction device capable of executing the planned skeletal correction. Curvilinear distractor dimensions calculated by Osteoplan included the radius of curvature of the prescribed device, and the distractor elongation, pitch, and handedness. RESULTS: Treatment plans including POMs were developed for each patient. The radii of curvature for the prescribed distractors ranged from 2.3 to 14.1 cm, the distractor elongation dimensions ranged from 0.7 to 3.2 cm, and the pitch (horizontal plane) dimensions ranged from 0.005 to 0.8 cm. Handedness was either a left (n = 12) or right (n = 8) turning helix. CONCLUSION: The results of this study indicate that, using geometric parameters of movement calculated from 3-dimensional CT scans, curvilinear devices could be prescribed for correction of the range of skeletal deformities in this group of patients.

Computer Simulation↗

Types, frequencies, and risk factors for complications after third molar extraction.

OBJECTIVES: The study objective was to identify the types, frequency, and risk factors for complications after third molar (M3) extractions. STUDY DESIGN: This retrospective cohort study consisted of patients who had 1 or more M3s removed between 1996 and 2001. Risk factors were grouped into demographic, general health, anatomic, and operative. Outcome variables were operative or inflammatory complications. Data were analyzed using descriptive, bivariate, and multivariate statistics. RESULTS: The study sample was composed of 583 patients (57.0% male) with a mean age of 26.4 +/- 8.4 years. The overall complication rate was 4.6%. Increasing age, a positive medical history, and the position of the M3 relative to the inferior alveolar nerve were associated with an increased risk for complications. CONCLUSION: While age, medical history, and M3 anatomy cannot be altered directly, these factors may be modified indirectly, resulting in a potential decrease for postoperative complications.

Adolescent↗