• The korean journal of orthodontics
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• v.41 no.3
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• pp.211-218
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• 2011

Objective: This case report describes orthodontic treatment of contracted mandibular arch using a trombone appliance. Methods: A 14-year-old girl with Class II division 2 malocclusion, retroclined maxillary incisors, and buccally displaced maxillary canines required dental expansion in 3 spatial directions to correct the contracted maxillary and mandibular arches. In the initial phase of treatment, the maxillary arch was expanded and distalized using a quad-helix appliance and cervical headgear. Following the expansion and leveling of the maxillary arch, a trombone appliance was used to expand the mandibular arch. On correction of the mandibular arch and provision of sufficient space to level the mandibular teeth, fixed orthodontic treatment phase was initiated. Results: A trombone appliance proved effective in correcting the contracted mandibular arch. Because of labiolingual and transversal expansion, the mandibular dental arch perimeter was increased by 7.4 mm; the misalignment of the mandibular teeth was corrected successfully. Conclusions: A trombone appliance may serve as an appropriate clinical alternative for treating moderate mandibular arch crowding caused by the contraction of the dental arch.

• Journal of Korean Dental Science
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• v.16 no.1
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• pp.87-98
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• 2023

This report presents a case of successful treatment of skeletal Class III malocclusion with transverse discrepancy in adult by surgery-first approach. Traditionally dental decompensation is necessary prior to surgery in 2-jaw surgery to correct transverse and rotational discrepancy. However, the hyrax-type palatal expansion appliance was used to improve maxillary expansion accuracy and postoperative stability in this surgery-first approach (segmental Le Fort I osteotomy and mandibular setback surgery). It was established to be an effective means of precisely predicting postoperative occlusion and achieving stable retention after surgery of skeletal Class III malocclusion with maxillary transverse discrepancy.

• The korean journal of orthodontics
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• v.49 no.2
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• pp.89-96
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• 2019

Objective: The purpose of this study was to assess the long-term stability of rapid palatal expansion (RPE) followed by full fixed edgewise appliances. Methods: This study included 67 patients treated using Haas-type RPE and non-extraction edgewise appliance therapy at a single orthodontic practice. Serial dental casts were obtained at three different time points: pretreatment ($T_1$), after expansion and fixed appliance therapy ($T_2$), and at long-term recall ($T_3$). The mean duration of the $T_1-T_2$ and $T_2-T_3$ periods was $4.8{\pm}3.5years$ and $11.0{\pm}5.4years$, respectively. The dental casts were digitized, and the computed measurements were compared with untreated reference data. Results: The majority of treatment-related increases in the maxillary and mandibular arch measurements were statistically significant (p < 0.05) and greater than expected for the untreated controls. Although many measurements decreased postretention ($T_2-T_3$), the net gains persisted for all of the measurements evaluated. Conclusions: The use of RPE therapy followed by full fixed edgewise appliances is an effective method for increasing maxillary and mandibular arch width dimensions in growing patients.

• Imaging Science in Dentistry
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• v.32 no.3
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• pp.167-173
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• 2002

Purpose : To evaluate clinical and radiographic differential diagnosis between ameloblastoma and odontogenic keratocyst (OKC) using clinical data, plain radiographs, and CT. Materials and Methods: 25 cases of ameloblastoma and 44 cases of OKC diagnosed in biopsy, were selected from the files stored in Department of Oral and Maxillofacial Radiology, Seoul National University Dental Hospital from 1999 to 2001, and evaluated using following criteria: sex and age, location, shape, border to normal bone tissue, effect to adjacent tissues, homogeneity in the lumen of the lesion, response of the cortical bone, long-to-short length (LIS) ratio of the lesion, and expansion angle of the cortex. Results: Ameloblastoma and OKC were seen most frequently in third decades and no statistical significance was noted between both sexes. Ameloblastoma occurred most frequently in mandibular angle and ramus area (68%) and OKC at the maxillary molar (34.1 %), and mandibular angle and ramus area (43.2%). The root resorption of the adjacent teeth, mandibular canal displacement, and the impaction of teeth were seen more frequently in ameloblastoma than in OKC. The LIS ratio measured in CT was largest in maxillary OKC cases, followed by mandibular ameloblastoma, and mandibular OKC (1.2, 1.8 and 2.4 respectively). The expansion angle of the cortex shows a statistically significant difference between ameloblastoma (48.8°) and OKC (31.5°). Conclusion : The numeric morphology (LIS ratio) and expansion angle of the cortical bone of the lesion measured in computed tomography can be used to differentiate the ameloblastoma and odontogenic keratocyst.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.82-89
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• 2005

Mandibular widening is one method of mandibular distraction osteogenesis, which has anatomic limitations such as curved surface, mandibular condyle and narrow arch. The purpose of this study was to understand the biomechanics of various mandibular widening procedures Experimental models consisted of 6 groups according to different osteotomy hues and distractor positions. The results of this study showed different expansion patterns. which meant the feed for proper approaches in mandibular widening.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.357-365
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• 1999

Desmoplastic fibroma is a rare. benign intraosseous fibroblastic tumor. which is locally aggressive. It is osseous counterpart of soft tissue fibromatosis. The authors experienced the patient who complained persistent mouth opening limitation with mild swelling on the left mandibular angle area. After careful analysis of clinical. radiological and histopathological findings. we diagnosed as desmoplastic fibroma of the mandible. The results were as follows: 1. Main clinical symptoms were mouth opening limitation which had been persistent for 9 months and mild swelling on the left mandibular angle area. 2. Radiographs showed the radiolucent lesion and expansion of lingual cortex. CT finding is homogeneous soft tissue mass with expansion of left mandibular ramus. Destruction of medial wall of ramus and invasion to adjacent soft tissue is also seen. 3. Histopathologically, plump spindle shaped fibroblasts arranged in bundles or fascicles are observed. The cells of tumor are infiltrating into muscle fiber with destruction of bony trabeculae and merged with surrounding salivary gland.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.516-525
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• 2004

Mandibular symphyseal distraction osteogenesis is an alternative approach for correcting mandibular transverse deficiencies and dental crowding. The traditional approaches for these are extraction of teeth and arch expansion with traditional orthodontic treatment. Also extractions are usually unavoidable in patients with severe crowding. The purpose of this study is to evaluate the effect of mandibular symphyseal distraction osteogenesis by use of tooth-borne expansion appliance. All of 12 patients had been performed distraction osteogenesis. The surgical procedures were accomplished under local anesthesia and intravenous sedation in an ambulatory surgical setting using a routine distraction protocol. The latency period was 5 days or 7 days after symphyseal osteotomies. The rate & rhyth is a intermittent, 0.75mm or 1.0 mm per day and stabilized for 6, 8 weeks after distraction. The time of orthodontic tooth movement after distraction was variable from 2 weeks to 8 weeks (mean 3 weeks). All patients had been evaluated with study casts, plain periapical films, panorama radiograms before & after surgery. Mandibular symphyseal distraction osteogenesis increased mandibular arch width and corrected dental crowding, with paralleling tooth-borne movement, without proclination of the mandibular incisors.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.390-398
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• 2005

Purpose: The aim of this study was to evaluate the skeletal and dentoalveolar dimensional changes following surgically-assisted rapid maxillary expansion (SARME). Patients & methods: Thirteen adults who had been treated by SARME for transverse maxillary deficiency from May 2000 to December 2003 were evaluated. The SARME procedure was the subtotal Le Fort I osteotomy combined with pterygomaxillary separation and anterior midpalatal osteotomy. Dental study casts and posteroanterior cephalometric radiographs were taken before operation, after removal of expansion device, and follow up period. Nasal cavity width, skeletal and dentoalveolar parameters were measured pre- and post-operatively. Results: 1. Mean nasal cavity width was increased 12%$(0{\sim}21%)$ of total expansion after retention. 2. Mean maxillary interdental width was increased 70%$(47{\sim}99%)$, 95%$(84{\sim}115%)$, and 77%$(57{\sim}94%)$ of total expansion in the canine, the first premolar, and the first molar region, respectively after retention. 3. Mean maxillary alveolar bone width was increased 66%$(42{\sim}84%)$, 74%$(42{\sim}94%)$, and 57%$(31{\sim}78%)$ of total expansion in the canine, the first premolar, and the first molar region, respectively after retention. 4. Mean palatal vault depth was decreased 1.3 mm ($0.5{\sim}2.0$ mm) after retention. 5. Mean interdental and alveolar bone width of the mandibular canine and intermolar width of mandible were slight increased as maxilla was expanded after retention. 6. There were statistical differences between preoperative and postoperative values of nasal cavity, all maxillary interdental and interalveolar widths, palatal vault depth, mandibular interdental and interalveolar width of canine(paired t-test, p<0.05). 7. The maxillary interdental and alveolar bone width were decreased approximately 25% of total expansion by relapse at follow up period. Conclusion: In conclusion, most amounts of maxillary interdental expansions were acquired with the expansion of the maxilla by SARME. For preventing the relapse, approximately 25% of the overexpansion was needed.

• The Journal of the Korean dental association
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• v.55 no.6
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• pp.400-410
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• 2017

Approximately 30% of adult patients who want orthodontic treatment have transverse discrepancy with insufficient width of the maxilla. Particularly, in Class III patients requiring orthognathic surgery, the frequency of insufficient width of the maxillary arch related to respiratory problems is high. We report a case of non-surgical maxillary expansion using a Hyrax type expander with an orthognathic surgery, based on the reports that the ratio of non-fused midpalatal suture is not high in adults. A 30 years and 2 months old woman with a long face showed an Angle Class III with a vertical growth pattern. Class III molar and canine relation, anterior edge bite, and mandibular incisor compensatory lingual inclination were observed. The posterior buccal overjet seemed to be appropriate, but I diagnosed that there was a transverse discrepancy, for the following reasons. The inter-canine and inter-molar widths were sufficient but excessive lingual inclination of the mandibular molars was observed when assessing the bucco-lingual inclination based on the center of resistance of the maxillary and mandibular first molar. For this reason, it was expected that intercuspal interference would occur during orthodontic decompensation. Therefore, slow maxillary expansion using Hyrax type expander was performed and 2-jaw rotation surgery was performed to improve aesthetic and occlusion. Adults can also improve width discrepancy by non-surgical methods, which can avoid SARPE requiring additional surgery or segmental surgery lacking stability and predictability.

• Imaging Science in Dentistry
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• v.41 no.2
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• pp.89-93
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• 2011

Intraosseous ameloblastoma is the most common and simple type of ameloblastoma prevalent among odontogenic tumors. Clinico-radiographically intraosseous ameloblastoma presents as slow, painless swelling or expansion of the jaws and described as multilocular expansile radiolucency that occurs most frequently in mandibular molar/ramus area. This article describes a case of follicular ameloblastoma involving 45 year old male which is different from the usual presentation, which includes-exophytic growth, different location and without expansion of the cortex.