1/34. Accuracy of integration of dental casts in three-dimensional models.PURPOSE: This study investigated errors occurring in three-dimensional (3D) models when plaster dental casts are integrated into them. MATERIALS AND methods: Three-dimensional milling models of three patients with a jaw deformity were fabricated using the Endoplan system (SPARC International Inc, Santa Clara, CA). After this, plaster dental casts were integrated into the 3D models using a face-bow transfer system. Two cephalograms were then compared, one obtained from the patient and the other obtained from the 3D model painted with contrast medium. RESULTS: In two cases, the reproducibility of the dental position as determined by angle analysis was within 2 degrees, and that determined by distance analysis was within 2 mm. However, errors over 4 degrees and 4.2 mm, respectively, were observed in one case. CONCLUSION: It is clinically important to confirm the accuracy of the 3D model by cephalometric analysis, and it may be necessary to reposition the dental model based on the results.- - - - - - - - - - ranking = 1keywords = jaw (Clic here for more details about this article) |
2/34. Efficacy of high condylectomy for management of condylar hyperplasia.The purpose of this study was to compare the treatment outcome and long-term stability of 2 groups of young adult patients diagnosed with active condylar hyperplasia and treated with 2 different surgical methods. Thirty-seven patients (19 females and 18 males) met the criteria for inclusion in the study. Group 1 (n = 12; average age at surgery, 17.5 years) was treated with orthognathic surgery only, while group 2 (n = 25; average age at surgery, 16.7 years) had high condylectomy, articular disc repositioning, and orthognathic surgery. All patients underwent standardized clinical and radiographic examination at initial consultation, immediately before surgery, immediately after surgery, and at longest follow-up. Objective evaluation of temporomandibular joint (TMJ) function included maximum incisal opening and lateral excursions. Subjective evaluations were performed in group 2 for TMJ pain, jaw function, and diet. Lateral cephalometric radiographs were evaluated for presurgical and postsurgical mandibular growth. There were no statistically significant differences (P >.05) between the 2 groups for maximal incisal opening, lateral excursions, or subjective jaw function before surgery. Presurgical growth differed significantly (P <.05), with group 2 showing more active growth. At the long-term follow-up, no differences were found in lateral excursions or subjective jaw function. There was a statistically significant difference in maximum incisal opening (P <.01), with a greater increase in group 2, as well as a statistically significant difference (P <.05) in cephalometric stability, with group 2 being much more stable at long-term follow-up. All patients in group 1 grew back into skeletal and occlusal Class III relationships and required secondary intervention. Only 1 patient in group 2 required secondary surgery, involving maxillary surgery to correct postsurgical transverse maxillary relapse; the mandible was stable at long-term follow-up. The results of this study showed that patients with active condylar hyperplasia treated with high condylectomy, articular disc repositioning, and orthognathic surgery have stable, predictable outcomes compared with those treated with orthognathic surgery alone.- - - - - - - - - - ranking = 14.774659352546keywords = mandible, jaw (Clic here for more details about this article) |
3/34. Thin-plate spline (TPS) graphical analysis of the mandible on cephalometric radiographs.We describe two cases of Class III malocclusion with and without orthodontic treatment. A thin-plate spline (TPS) analysis of lateral cephalometric radiographs was used to visualize transformations of the mandible. The actual sites of mandibular skeletal change are not detectable with conventional cephalometric analysis. These case analyses indicate that specific patterns of mandibular transformation are associated with Class III malocclusion with or without orthopaedic therapy, and visualization of these deformations is feasible using TPS graphical analysis.- - - - - - - - - - ranking = 58.87329676273keywords = mandible (Clic here for more details about this article) |
4/34. Maxillary expansion and protraction in correction of midface retrusion in a complete unilateral cleft lip and palate patient.A 7-year-old girl with a cleft lip and palate had a midface retrusion due to growth inhibition of the maxillary complex. She presented for correction of a severe total crossbite with a Class III skeletal pattern. Initially, maxillary expansion was provided to widen the maxilla and then maxillary protraction headgear was worn to improve the sagittal skeletal relation. Fixed orthodontic appliances were placed to align the dentition and Class III elastics were used to establish intercuspation and stability. The maxillary expansion and protraction usually provide effective improvement in skeletal Class III patients with repaired cleft lip and palate patients. The success of the orthopedic procedure essentially depends on the individual growth of the maxilla and the mandible. This case report shows the significant growth of the mandible after maxillary expansion and protraction in late adolescence.- - - - - - - - - - ranking = 23.549318705092keywords = mandible (Clic here for more details about this article) |
5/34. Thin-plate spline graphical analysis of the mandible in mandibular prognathism.The chin cup has been used to treat skeletal mandibular prognathism in growing patients for 200 years. The pull on the orthopedic-force chin cup is oriented along a line from the mandibular symphysis to the mandibular condyle. Various levels of success have been reported with this restraining device. The vertical chin cup produces strong vertical compression stress on the maxillary molar regions when the direction of traction is 20 degrees more vertical than the chin-condyle line. This treatment strategy may prevent relapse due to counter-clockwise rotation of the mandible. In this report, we describe a new strategy for using chin-cup therapy involving thin-plate spline (TPS) analysis of lateral cephalometric roentgenograms to visualize transformation of the mandible. The actual sites of mandibular skeletal change are not detectable with conventional cephalometric analysis. A case of mandibular prognathism treated with a chin cup and a case of dental Class III malocclusion without orthodontic treatment are described. The case analysis illustrates that specific patterns of mandibular transformation are associated with Class III malocclusion with or without orthopedic therapy, and that visualization of these deformations is feasible using TPS graphical analysis.- - - - - - - - - - ranking = 70.647956115276keywords = mandible (Clic here for more details about this article) |
6/34. Indications and procedures for segmental dentoalveolar osteotomy: a review of 13 patients.The authors evaluated the surgical area, indications, and procedures for segmental dentoalveolar osteotomy carried out on 16 jaws in 13 patients treated at the Department of Oral and Maxillofacial Surgery, Kobe University Graduate School of medicine, between 1990 and 2001. osteotomy was indicated mainly in cases where tooth repositioning by orthodontic treatment was limited, where social conditions (e.g., age, time, finances) precluded orthodontic treatment, or where revision of orthodontic or surgical treatment was required. In cases of maxillary anterior segmental dentoalveolar osteotomy, the modified Wunderer method was used, where after an incision was made in the palatal mucosa, a mucoperiosteal flap was abraded as much as possible until the area of the osteotomy on the palatal side could be visualized. In maxillary posterior segmental dentoalveolar osteotomy, the operation was carried out in 2 stages because of the risk of necrosis of the bone fragments. In the first stage, an osteotomy was carried out on the vestibular side, since the vestibular gingival pedicle was intact. In the second stage, 3 weeks later, another osteotomy was performed after the palatal mucoperiosteal flap was abraded to visualize the area of the osteotomy as well as that of the maxillary anterior segmental dentoalveolar osteotomy.- - - - - - - - - - ranking = 1keywords = jaw (Clic here for more details about this article) |
7/34. Mandibular symphyseal contouring in mild mandibular prognathism.Kolle's mandibular segmental osteotomy, with extraction of the bilateral first bicuspids, is often used in cases of mild mandibular prognathism. While mandibular prognathism is usually corrected by mandibular ramus osteotomy and the mandible is set back en bloc, the premolar region alone is set back by segmental osteotomy, retaining the protruding mental area. In Asians, particularly, the protruding chin is not preferred by our concepts of beauty. In mandibular segmental osteotomy, the entire mandibular symphyseal shape should be considered. Mandibular symphyseal contouring constitutes setting back the premolar region by segmental osteotomy, recession genioplasty, and chiseling out the protruding middle portion of the protruding chin. In 18 series of mild manibular prognathism in Asians patients, this procedure was used and satisfactory aesthetic results were obtained.- - - - - - - - - - ranking = 11.774659352546keywords = mandible (Clic here for more details about this article) |
8/34. A case of acromegaly.A fifty years old woman hailing from Purbadhala of Netrokona district complaining of gradual enlargement of hands, feet, nose and other acral parts of the body for about last eight years. She noticed coarsening of the skin and gradual protrusion of her lower jaw. She complained of headache, vertigo, frequent passage of urine, increased thirst, weight loss and fatiguability. She was found hypertensive having blood pressure 200/110 mm of Hg. Her appearance was coarse with rough skin. There were enlargement of hands, feet, nose, lower jaw with prognathism and enlargement of other acral parts. Investigations revealed high plasma glucose level, both fasting and 2 hrs. after glucose, high level of growth hormone, failure of suppression of growth hormone during OGTT. thyroid function tests of the patient were found normal with increased heel pad size and enlarged sella turcica in all diameters. She was diagnosed as a case of acromegaly due to growth hormone hypersecretion.- - - - - - - - - - ranking = 2keywords = jaw (Clic here for more details about this article) |
9/34. New oral findings in Cohen syndrome.Cohen syndrome is a hereditary disorder transmitted as an autosomal-recessive trait. Approximately 100 cases have been reported in the genetic and pediatric literature. Despite the fact that oral alterations are often observed in these cases, only 1 work has been published addressing this specific topic, and it tended to concentrate on periodontal abnormalities. The present study details 2 new patients, 2 brothers (8 and 11 years old), and mainly consists of an analysis of the dentomaxillary anomalies that until now have not been studied in depth. In this study, the mandible, characterized as hypoplastic in Cohen syndrome, appears to be in a normal position; what really exists is a maxillary hyperplasia of genetic origin. We also put forward an observation hitherto undescribed in the literature: dental agenesis.- - - - - - - - - - ranking = 11.774659352546keywords = mandible (Clic here for more details about this article) |
10/34. Post-operative optimization of gum-chewing kinematics in a prognathic patient.Smooth jaw movements during gum chewing, which are defined as those driven by optimally smooth patterns of temporal change in acceleration/deceleration, have been quantified in subjects with acceptable occlusions. This paper reports a case in which significant improvement of the smoothness of masticatory jaw movement was observed following surgical-orthodontic treatment. A patient, who demonstrated a mandibular prognathism, underwent the treatment. The irregularity in acceleration/deceleration of jaw closing movement during gum chewing was quantified by the movement jerk-cost, where the jerk is rate of change in movement acceleration/deceleration. The normalized jerk-costs and results of maximum-smoothness model simulation were compared between jaw movements at pre- and post-treatment stages. The correction of mandibular prognathism and crossbite allowed the patient to close the jaw with wider lateral excursion. Furthermore, smoothness of the jaw closing movements increased significantly and the velocity profile was characterized as similar to that predicted by the kinematic model after treatment. These findings for achievement of 'functional occlusion' that allows the patient to perform smooth and economical jaw closing movements during chewing demonstrate necessity of orthodontic treatment of mandibular prognathism to improve jaw motor function.- - - - - - - - - - ranking = 8keywords = jaw (Clic here for more details about this article) |
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