Edward B.Seldin, DMD, MD B . Seldin (original) (raw)
Papers by Edward B.Seldin, DMD, MD B . Seldin
Lecture Notes in Computer Science, 2000
Three-dimensional planning tools will enable the use of minimallyinvasive distraction osteogenesi... more Three-dimensional planning tools will enable the use of minimallyinvasive distraction osteogenesis for the correction of craniomaxillofacial deformities by simulating treatment, precisely quantifying movement vectors, and aiding pre and post-treatment evaluation. Current techniques extrapolate 3D surgical movements and outcomes based on standard 2D radiographs. Surgical planning and outcome evaluation would be greatly improved by an accurate, reproducible and reliable 3D treatment planning system. Building upon a software foundation that includes the 3D Slicer of the Brigham & Women's Hospital, and the Visualization Toolkit (VTK) of Schroeder, Martin & Lorensen, we add algorithms that support interactive cutting of large triangulated surface models, collision detection, landmark-based registration, and cephalometric analysis. The oriented bounding-box tree (OBB tree) structure is used throughout to enhance the interactivity of selection, collision detection, and cutting. The cutting tool is notable for its generality and preservation of topological closure in the resultant models. In a retrospective case study, the collision of the proximal fragment of the distracted mandible with the skull base is detected and the resulting 3D bone movements are quantified. The distracted bone volume is computed. In prospective cases, this system will be used to compute the placement and configuration of appropriate buried distractor(s).
Atlas of the Oral and Maxillofacial Surgery Clinics, 2005
Journal of Oral and Maxillofacial Surgery, 2012
The purpose of this study was to answer this clinical question: When a patient presents with a ra... more The purpose of this study was to answer this clinical question: When a patient presents with a radiolucent lesion of the mandible presumed to be an odontogenic cystic lesion, to what extent is the radiographic finding of multilocularity predictive of a final diagnosis of keratocystic odontogenic tumor (KCOT)? Materials and Methods: The study sample was derived from the population of patients who presented to the Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital for evaluation and management of suspected mandibular lesions from January 1991 through January 2009. Subjects were eligible for study inclusion if there was a final histologic diagnosis of KCOT or dentigerous cyst. The predictor variable was radiographic appearance of the lesion and was grouped into 2 categories (unilocular or multilocular). The outcome variable was lesion type (KCOT or dentigerous cyst). Appropriate univariate, bivariate, and multivariate statistics were computed. Statistical significance was defined as P Ͻ .05. Results: The study consisted of 130 subjects. Multilocular lesions were 1.7 times more likely to be KCOTs than unilocular lesions (P ϭ .0001). The sensitivity, specificity, and positive and negative predictive values were 0.48, 0.87, 0.86, and 0.49, respectively. In the multiple logistic regression model, a multilocular radiographic appearance was associated with a 12-fold (95% confidence interval, 3.7 to 38) increased risk of KCOT. Conclusion: The results of this study confirm the hypothesis that radiographic multilocularity is predictive of a KCOT because it is associated with a 12-fold increased risk for the diagnosis of KCOT.
Journal of Oral and Maxillofacial Surgery, 2013
The Journal of General Physiology, 1972
The spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow ... more The spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow fever mosquito Aedes aegypti L. (reared in darkness) was measured by means of the electroretinogram. The spectral sensitivity is maximal at about 520 nm, with a small secondary peak near 370 nm. When allowance is made for some screening and filtering by the eye tissues, the spectral sensitivity is in reasonable agreement with the absorption spectrum of ocellar rhodopsin (λmax = 515 nm).
Oral surgery, oral medicine, and oral pathology, 1981
A computer reporting system in radiology at the Massachusetts General Hospital (MGH) uses the dir... more A computer reporting system in radiology at the Massachusetts General Hospital (MGH) uses the direct transcription of dictated reports into the computer with the option of standard reports. This article describes a system in regular use at MGH for reporting dental radiographs in which both the clinical history and the radiographic findings are assembled from canned subunits of standard text. The system covers 80 to 90 percent of all dental radiographs and results in a clear report requiring far less production time than previously.
New England Journal of Medicine, 1996
Journal of Oral and Maxillofacial Surgery, 2003
The study objective was to identify the types, frequency, and risk factors for complications afte... more 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 Ϯ 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.
Journal of Oral and Maxillofacial Surgery, 1999
This study evaluated a new small, buried distractor, capable of curvilinear movement while follow... more This study evaluated a new small, buried distractor, capable of curvilinear movement while following a fixed trajectory. The geometrical basis for such devices and the 3-dimensional treatment planning system required to make buried distractors practical are discussed. A curved rack and worm-gear device, based on the design of a hose clamp, was constructed to produce a curved distraction path, and this distractor was tested in 2 minipigs using a protocol with zero latency and 1 mm/d x 7 days of distraction. Serial standardized lateral cephalograms were used to verify distractor function and path. Curvilinear distraction was documented by clinical examination and serial cephalometric analysis in the 2 minipigs. Observed angulation of the margins of the wedge-shaped distraction gap conformed to the calculated angulation based on the fixed radius of curvature of the distractor. Distraction along a curved trajectory using a small, semiburied, curvilinear device of novel design is feasible in the minipig mandible.
Journal of Oral and Maxillofacial Surgery, 2007
This study was conducted to objectively evaluate the effect of feedback and instructional materia... more This study was conducted to objectively evaluate the effect of feedback and instructional material on the acquisition of surgical psychomotor skills for a model system based on mandibular fracture repair. This study was a prospective cohort study comprised of students in the preclinical years of dental or medical education. The students were divided into 4 groups and exposed to different levels of feedback/written instructions (including none) in the testing environment. Each subject was given a pair of aluminum bars, representing a fractured human mandible, and a standardized set of tools, including a fixed length of stainless steel wire to fix the bars together. The strength of fixation was measured, using a calibrated testing apparatus, as the amount of load that the fixed sample could tolerate to the point of failure. All subjects completed 5 successive trials under the same conditions. Descriptive statistics were recorded to provide comparisons between groups. Bivariate statistics were computed to compare the different study groups; multiple-comparison testing was used to evaluate differences among the groups. A P value <or= .05 was considered statistically significant. The sample was comprised of 61 students, divided into 4 groups. The students who received neither instructions nor feedback had the lowest average performance scores. Those who received both feedback and instructions had the highest average performance scores. The students who received instructions only fared better than those who received feedback only, but only immediately after receiving instructions. Differences between the groups tended to dissipate after a few trials. Written instructions and performance feedback can enhance the acquisition of psychomotor skills related to the performance of a complex task.
Journal of Oral and Maxillofacial Surgery, 2006
To evaluate outcomes associated with choice of wound management, ie, primary closure or healing b... more 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. 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. 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. 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.
Journal of Oral and Maxillofacial Surgery, 1985
Twenty-five cases in which a lower border threaded rod was used for fracture fixation and mandibu... more Twenty-five cases in which a lower border threaded rod was used for fracture fixation and mandibular reconstruction were reviewed. These cases were performed during the last 11 years and have been followed for periods of up to five years and ten months. The fixation technique, originally reported in 1978, is well tolerated and provides excellent mechanical stability when enhanced security of fixation is indicated. Three unusual cases are reported in detail.
American Journal of Orthodontics and Dentofacial Orthopedics, 2009
Introduction: The purpose of this study was to investigate the efficiency of copper-nickel-titani... more Introduction: The purpose of this study was to investigate the efficiency of copper-nickel-titanium (CuNiTi) vs nickel-titanium (NiTi) archwires in resolving crowding of the anterior mandibular dentition. Methods: Sixty patients were included in this single-center, single-operator, double-blind randomized trial. All patients were bonded with the In Ovation-R self-ligating bracket (GAC, Central Islip, NY) with a 0.022-in slot, and the amount of crowding of the mandibular anterior dentition was assessed by using the irregularity index. The patients were randomly allocated into 2 groups of 30 patients, each receiving a 0.016-in CuNiTi 35 C (Ormco, Glendora, Calif) or a 0.016-in NiTi (ModernArch, Wyomissing, Pa) wire. The type of wire selected for each patient was not disclosed to the provider or the patient. The date that each patient received a wire was recorded, and all patients were followed monthly for a maximum of 6 months. Demographic and clinical characteristics between the 2 wire groups were compared with the t test or the chi-square test and the Fisher exact test. Time to resolve crowding was explored with statistical methods for survival analysis, and alignment rate ratios for wire type and crowding level were calculated with Cox proportional hazards multivariate modeling. Results: The type of wire (CuNiTi vs NiTi) had no significant effect on crowding alleviation (129.4 vs 121.4 days; hazard ratio, 1.3; P .0.05). Severe crowding (.5 on the irregularity index) showed a significantly higher probability of crowding alleviation duration relative to dental arches with a score of \5 (138.5 vs 113.1 days; hazard ratio, 2.2; P50.02). Conclusions: The difference of the loading pattern of wires in laboratory and clinical conditions might effectively eliminate the laboratory-derived advantage of CuNiTi wires. (Am J Orthod Dentofacial Orthop 2009;136:152.e1-152.e7)
The purpose of this study was to use geometric parameters of movement, calculated from 3-dimensio... more 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. 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. 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. 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.
To report the use of a semiburied curvilinear distraction device, with a 3-dimensional (3D) compu... more To report the use of a semiburied curvilinear distraction device, with a 3-dimensional (3D) computed tomography treatment planning system, for correction of mandibular deformities. This was a retrospective evaluation of 13 consecutive patients, with syndromic and nonsyndromic micrognathia, who underwent correction by curvilinear distraction osteogenesis. A 3D computed tomography scan was obtained for each patient and imported into a 3D treatment planning system (Slicer/Osteoplan). Surgical guides were constructed to localize the osteotomy and to drill holes to secure the distractor's proximal and distal footplates to the mandible. Postoperatively, patients were followed by clinical examination and plain radiographs to ensure the desired vector of movement. At end distraction, when possible, a 3D computed tomography scan was obtained to document the final mandibular position. Of the 13 patients, 8 were females and 5 were males, with a mean age of 11.9 years (range 15 months to 39 years). All 13 underwent bilateral mandibular curvilinear distraction. Of the 13 patients, 8 were 16 years old or younger and 5 were younger than 6 years of age. The diagnoses included Treacher Collins syndrome (n = 3), Nager syndrome (n = 3), craniofacial microsomia (n = 2), post-traumatic ankylosis (n = 1), and micrognathia (syndromic, n = 3; nonsyndromic, n = 1). The correct distractor placement, vector of movement, and final mandibular position were achieved in 10 of 13 patients. In the other 3 patients, the desired jaw position was achieved by "molding" the regenerate. The use of a semiburied curvilinear distraction device, with 3D treatment planning, is a potentially powerful tool to correct complex mandibular deformities.
Current surgical treatment planning systems predict three-dimensional (3D) corrections from two-d... more Current surgical treatment planning systems predict three-dimensional (3D) corrections from two-dimensional (2D) data and are inadequate for complex movements. In this paper, we present a 3D planning system based on computed tomographic (CT) data. A three-dimensional CT scan of the craniofacial skeleton forms the database. Software developed in the Harvard Surgical Planning Laboratory was modified for the craniofacial skeleton. Reproducible skeletal landmarks are identified for superimposition. A 'cutting tool' is used to segment the mandible and segments are moved to their predicted positions. A 'collision tool', alerts the operator of skeletal interferences. An analysis of selected scans is used to demonstrate the system. Three-dimensional visualization of the facial skeleton, selection of landmarks, measurement of angles and distances, simulation of osteotomies, repositioning of bones, detection of collisions and super-imposition of scans were accomplished. In an illustrative case of Hemifacial Microsomia, predicted and actual 3D corrective movements of the entire mandible were documented. Analysis of scans indicated that 3D planning can prevent insufficient jaw lengthening or other surgical inaccuracies which occur with standard 2D methods. Software demonstrated here will allow the surgeon to accurately plan treatment and evaluate craniomaxillofacial surgery outcomes. Future applications may include surgical navigation.
Atlas of The Oral and Maxillofacial Surgery Clinics, 2005
Lecture Notes in Computer Science, 2000
Three-dimensional planning tools will enable the use of minimallyinvasive distraction osteogenesi... more Three-dimensional planning tools will enable the use of minimallyinvasive distraction osteogenesis for the correction of craniomaxillofacial deformities by simulating treatment, precisely quantifying movement vectors, and aiding pre and post-treatment evaluation. Current techniques extrapolate 3D surgical movements and outcomes based on standard 2D radiographs. Surgical planning and outcome evaluation would be greatly improved by an accurate, reproducible and reliable 3D treatment planning system. Building upon a software foundation that includes the 3D Slicer of the Brigham & Women's Hospital, and the Visualization Toolkit (VTK) of Schroeder, Martin & Lorensen, we add algorithms that support interactive cutting of large triangulated surface models, collision detection, landmark-based registration, and cephalometric analysis. The oriented bounding-box tree (OBB tree) structure is used throughout to enhance the interactivity of selection, collision detection, and cutting. The cutting tool is notable for its generality and preservation of topological closure in the resultant models. In a retrospective case study, the collision of the proximal fragment of the distracted mandible with the skull base is detected and the resulting 3D bone movements are quantified. The distracted bone volume is computed. In prospective cases, this system will be used to compute the placement and configuration of appropriate buried distractor(s).
Atlas of the Oral and Maxillofacial Surgery Clinics, 2005
Journal of Oral and Maxillofacial Surgery, 2012
The purpose of this study was to answer this clinical question: When a patient presents with a ra... more The purpose of this study was to answer this clinical question: When a patient presents with a radiolucent lesion of the mandible presumed to be an odontogenic cystic lesion, to what extent is the radiographic finding of multilocularity predictive of a final diagnosis of keratocystic odontogenic tumor (KCOT)? Materials and Methods: The study sample was derived from the population of patients who presented to the Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital for evaluation and management of suspected mandibular lesions from January 1991 through January 2009. Subjects were eligible for study inclusion if there was a final histologic diagnosis of KCOT or dentigerous cyst. The predictor variable was radiographic appearance of the lesion and was grouped into 2 categories (unilocular or multilocular). The outcome variable was lesion type (KCOT or dentigerous cyst). Appropriate univariate, bivariate, and multivariate statistics were computed. Statistical significance was defined as P Ͻ .05. Results: The study consisted of 130 subjects. Multilocular lesions were 1.7 times more likely to be KCOTs than unilocular lesions (P ϭ .0001). The sensitivity, specificity, and positive and negative predictive values were 0.48, 0.87, 0.86, and 0.49, respectively. In the multiple logistic regression model, a multilocular radiographic appearance was associated with a 12-fold (95% confidence interval, 3.7 to 38) increased risk of KCOT. Conclusion: The results of this study confirm the hypothesis that radiographic multilocularity is predictive of a KCOT because it is associated with a 12-fold increased risk for the diagnosis of KCOT.
Journal of Oral and Maxillofacial Surgery, 2013
The Journal of General Physiology, 1972
The spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow ... more The spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow fever mosquito Aedes aegypti L. (reared in darkness) was measured by means of the electroretinogram. The spectral sensitivity is maximal at about 520 nm, with a small secondary peak near 370 nm. When allowance is made for some screening and filtering by the eye tissues, the spectral sensitivity is in reasonable agreement with the absorption spectrum of ocellar rhodopsin (λmax = 515 nm).
Oral surgery, oral medicine, and oral pathology, 1981
A computer reporting system in radiology at the Massachusetts General Hospital (MGH) uses the dir... more A computer reporting system in radiology at the Massachusetts General Hospital (MGH) uses the direct transcription of dictated reports into the computer with the option of standard reports. This article describes a system in regular use at MGH for reporting dental radiographs in which both the clinical history and the radiographic findings are assembled from canned subunits of standard text. The system covers 80 to 90 percent of all dental radiographs and results in a clear report requiring far less production time than previously.
New England Journal of Medicine, 1996
Journal of Oral and Maxillofacial Surgery, 2003
The study objective was to identify the types, frequency, and risk factors for complications afte... more 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 Ϯ 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.
Journal of Oral and Maxillofacial Surgery, 1999
This study evaluated a new small, buried distractor, capable of curvilinear movement while follow... more This study evaluated a new small, buried distractor, capable of curvilinear movement while following a fixed trajectory. The geometrical basis for such devices and the 3-dimensional treatment planning system required to make buried distractors practical are discussed. A curved rack and worm-gear device, based on the design of a hose clamp, was constructed to produce a curved distraction path, and this distractor was tested in 2 minipigs using a protocol with zero latency and 1 mm/d x 7 days of distraction. Serial standardized lateral cephalograms were used to verify distractor function and path. Curvilinear distraction was documented by clinical examination and serial cephalometric analysis in the 2 minipigs. Observed angulation of the margins of the wedge-shaped distraction gap conformed to the calculated angulation based on the fixed radius of curvature of the distractor. Distraction along a curved trajectory using a small, semiburied, curvilinear device of novel design is feasible in the minipig mandible.
Journal of Oral and Maxillofacial Surgery, 2007
This study was conducted to objectively evaluate the effect of feedback and instructional materia... more This study was conducted to objectively evaluate the effect of feedback and instructional material on the acquisition of surgical psychomotor skills for a model system based on mandibular fracture repair. This study was a prospective cohort study comprised of students in the preclinical years of dental or medical education. The students were divided into 4 groups and exposed to different levels of feedback/written instructions (including none) in the testing environment. Each subject was given a pair of aluminum bars, representing a fractured human mandible, and a standardized set of tools, including a fixed length of stainless steel wire to fix the bars together. The strength of fixation was measured, using a calibrated testing apparatus, as the amount of load that the fixed sample could tolerate to the point of failure. All subjects completed 5 successive trials under the same conditions. Descriptive statistics were recorded to provide comparisons between groups. Bivariate statistics were computed to compare the different study groups; multiple-comparison testing was used to evaluate differences among the groups. A P value <or= .05 was considered statistically significant. The sample was comprised of 61 students, divided into 4 groups. The students who received neither instructions nor feedback had the lowest average performance scores. Those who received both feedback and instructions had the highest average performance scores. The students who received instructions only fared better than those who received feedback only, but only immediately after receiving instructions. Differences between the groups tended to dissipate after a few trials. Written instructions and performance feedback can enhance the acquisition of psychomotor skills related to the performance of a complex task.
Journal of Oral and Maxillofacial Surgery, 2006
To evaluate outcomes associated with choice of wound management, ie, primary closure or healing b... more 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. 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. 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. 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.
Journal of Oral and Maxillofacial Surgery, 1985
Twenty-five cases in which a lower border threaded rod was used for fracture fixation and mandibu... more Twenty-five cases in which a lower border threaded rod was used for fracture fixation and mandibular reconstruction were reviewed. These cases were performed during the last 11 years and have been followed for periods of up to five years and ten months. The fixation technique, originally reported in 1978, is well tolerated and provides excellent mechanical stability when enhanced security of fixation is indicated. Three unusual cases are reported in detail.
American Journal of Orthodontics and Dentofacial Orthopedics, 2009
Introduction: The purpose of this study was to investigate the efficiency of copper-nickel-titani... more Introduction: The purpose of this study was to investigate the efficiency of copper-nickel-titanium (CuNiTi) vs nickel-titanium (NiTi) archwires in resolving crowding of the anterior mandibular dentition. Methods: Sixty patients were included in this single-center, single-operator, double-blind randomized trial. All patients were bonded with the In Ovation-R self-ligating bracket (GAC, Central Islip, NY) with a 0.022-in slot, and the amount of crowding of the mandibular anterior dentition was assessed by using the irregularity index. The patients were randomly allocated into 2 groups of 30 patients, each receiving a 0.016-in CuNiTi 35 C (Ormco, Glendora, Calif) or a 0.016-in NiTi (ModernArch, Wyomissing, Pa) wire. The type of wire selected for each patient was not disclosed to the provider or the patient. The date that each patient received a wire was recorded, and all patients were followed monthly for a maximum of 6 months. Demographic and clinical characteristics between the 2 wire groups were compared with the t test or the chi-square test and the Fisher exact test. Time to resolve crowding was explored with statistical methods for survival analysis, and alignment rate ratios for wire type and crowding level were calculated with Cox proportional hazards multivariate modeling. Results: The type of wire (CuNiTi vs NiTi) had no significant effect on crowding alleviation (129.4 vs 121.4 days; hazard ratio, 1.3; P .0.05). Severe crowding (.5 on the irregularity index) showed a significantly higher probability of crowding alleviation duration relative to dental arches with a score of \5 (138.5 vs 113.1 days; hazard ratio, 2.2; P50.02). Conclusions: The difference of the loading pattern of wires in laboratory and clinical conditions might effectively eliminate the laboratory-derived advantage of CuNiTi wires. (Am J Orthod Dentofacial Orthop 2009;136:152.e1-152.e7)
The purpose of this study was to use geometric parameters of movement, calculated from 3-dimensio... more 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. 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. 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. 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.
To report the use of a semiburied curvilinear distraction device, with a 3-dimensional (3D) compu... more To report the use of a semiburied curvilinear distraction device, with a 3-dimensional (3D) computed tomography treatment planning system, for correction of mandibular deformities. This was a retrospective evaluation of 13 consecutive patients, with syndromic and nonsyndromic micrognathia, who underwent correction by curvilinear distraction osteogenesis. A 3D computed tomography scan was obtained for each patient and imported into a 3D treatment planning system (Slicer/Osteoplan). Surgical guides were constructed to localize the osteotomy and to drill holes to secure the distractor's proximal and distal footplates to the mandible. Postoperatively, patients were followed by clinical examination and plain radiographs to ensure the desired vector of movement. At end distraction, when possible, a 3D computed tomography scan was obtained to document the final mandibular position. Of the 13 patients, 8 were females and 5 were males, with a mean age of 11.9 years (range 15 months to 39 years). All 13 underwent bilateral mandibular curvilinear distraction. Of the 13 patients, 8 were 16 years old or younger and 5 were younger than 6 years of age. The diagnoses included Treacher Collins syndrome (n = 3), Nager syndrome (n = 3), craniofacial microsomia (n = 2), post-traumatic ankylosis (n = 1), and micrognathia (syndromic, n = 3; nonsyndromic, n = 1). The correct distractor placement, vector of movement, and final mandibular position were achieved in 10 of 13 patients. In the other 3 patients, the desired jaw position was achieved by "molding" the regenerate. The use of a semiburied curvilinear distraction device, with 3D treatment planning, is a potentially powerful tool to correct complex mandibular deformities.
Current surgical treatment planning systems predict three-dimensional (3D) corrections from two-d... more Current surgical treatment planning systems predict three-dimensional (3D) corrections from two-dimensional (2D) data and are inadequate for complex movements. In this paper, we present a 3D planning system based on computed tomographic (CT) data. A three-dimensional CT scan of the craniofacial skeleton forms the database. Software developed in the Harvard Surgical Planning Laboratory was modified for the craniofacial skeleton. Reproducible skeletal landmarks are identified for superimposition. A 'cutting tool' is used to segment the mandible and segments are moved to their predicted positions. A 'collision tool', alerts the operator of skeletal interferences. An analysis of selected scans is used to demonstrate the system. Three-dimensional visualization of the facial skeleton, selection of landmarks, measurement of angles and distances, simulation of osteotomies, repositioning of bones, detection of collisions and super-imposition of scans were accomplished. In an illustrative case of Hemifacial Microsomia, predicted and actual 3D corrective movements of the entire mandible were documented. Analysis of scans indicated that 3D planning can prevent insufficient jaw lengthening or other surgical inaccuracies which occur with standard 2D methods. Software demonstrated here will allow the surgeon to accurately plan treatment and evaluate craniomaxillofacial surgery outcomes. Future applications may include surgical navigation.
Atlas of The Oral and Maxillofacial Surgery Clinics, 2005