• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.1
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• pp.51-62
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• 1994

The sagittal split osteotomy of the mandibular ramus is a common procedure which has been used in the correction of mandibular deformities for a few decades. Although the technical improvements have increased the reliability and stability of SSRO procedure, the postoperative relapse is imperative and clinically more significant than any other complication. One of the major causes of the relapse is due to the displacement of the proximal segment during SSRO procedure, which is well documented in the literature. Therefore it is important to preserve the original position of the proximal segment during SSRO proced and maxillofacial fixation period. In the case of mandibular asymmetry, if one side of mandible is advanced and the other side of mandible is setback during SSRO procedure, the proximal segment in the advancement site will rotate laterally and the proximal segment in the setback site will rotate medially. For the prevention of the lateral rotation or flaring of the proximal segment in the advancment site. we deliberately fracture the posterior protion of the distal segment in green-stick fashion during SSRO procedure, and there is no need to fix the fractured lingual segment. We fix the two osteotomized bony segments in the buccal cortex area rigidly with adjustable monocortical plates and screws. During SSRO procedure the lingual fracture technique was applied to nine patients with severe mandibular asymmetry who underwent orthognathic surgery in our hospital since march, 1992. These clinical experiencies enable us to find the lingual fracture technique has the following advantages. 1. The proximal segment is displaced minimally. 2. The osteotomized bony segments are contacted intimately. 3. The postoperative relapse and the healing period are decreased.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.45-59
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• 1989

This study was undertaken to analyze the displacement and stress distribution in the mandible according to the pulling directions during mandibular first molar cervical traction after mandibular second molar extraction. The 3-dimensional finite element method(FEM) was used for a mathematical model composed of 594 elements and 1019 nodes. An orthodontic force, 450 gm, was applied to the each mandibular first molar in parallel, and below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$ and meet the midsagittal plane by $40^{\circ}$ toward posterior direction. The results were as follows: 1. Mandibular teeth were displaced in more downward, posterior and lateral direction. Especially high stress was noted in case of parallel pull than in case of below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$. 2. Mandibular first molar was moved bodily. 3. Generally, alveolar bone, mandibular body, ascending ramus and mandibular angle portion were displaced in downward, posterior and lateral direction. But coronoid process was displaced in downward, forward and lateral direction, and anterior and inner middle portion of condyle head and neck were displaced in downward, forward and medial direction, and posterior and outer middle portion of condyle head and neck were displaced in upward, forward and medial direction. 4. Maximum stress was observed at the condyle head and neck portion. With steeper direction of force, condyle head and neck showed more stress than parallel relation to the occlusal plane.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.28 no.2
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• pp.64-73
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• 2019

Various techniques have been developed, and the development of piezo electric devices have made it possible to widen the alveolar ridge even if the residual bone is dense or if there is a lack of cancellous bone between the cortical bones. In the operation of the mandibular posterior area, the flap is easily accessible to the ramus bone, from which high quality autogenous bone can be obtained, compared to other parts. A small autologous bone block can be used with particulated bone graft material using one screw for bone regeneration instead of a large autologous bone with two screws. The tapered implant design can minimize buccal bone fracture, even in severely atrophic mandibular areas. We report a case of 4 years following implant placement with ridge splitting and small autogenous bone graft in severly atrophic mandible. This report demonstrates a case of functional and aesthetic restoration in a patient through a collaboration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.276-280
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• 2011

BSSRO (bilateral sagittal split ramus osteotomy) is an effective surgical method for maxillofacial deformities. Rigid fixation using a plate and screws can stabilize bony segments and induce early mouth opening. Though this procedure has a low complication rate, normal function and esthetic recovery is achieved through proper and early management of the complications. Complications consisting of temporomandibular disorders, sensory disturbances due to inferior alveolar nerve damage, open bite, malunion or nonunion, and facial nerve palsy occur, but these rarely develop. Facial nerve palsy causes the muscles involved in facial expression to depress, which results in ocular dryness or retinal damage. When facial nerve palsy develops, early management involving steroid medication and physical therapy is effective. In the case of severe damage, surgical intervention should be considered. A 20-year-male patient came to the oral and maxillofacial surgery department for orthognathic surgery. The mandible was set back by BSSRO under general anesthesia. Facial nerve palsy was observed on the left side of the face: steroid and vitamins were administered early and physical therapy was performed daily. These forms of management can aid in function and allow for gradual esthetic recovery. Presumed causes were excessive soft tissue retraction or soft tissue injury by the osteotome at the horizontal osteotomy of the ramus. Careful dissection, retraction and a precise osteotomy are needed for protection of the facial nerve. If nerve damage is observed, early management can help in the recovery of facial nerve function and esthetics.

• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.51-55
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• 2011

BACKGROUND. Mandibular displacement is a common complication of condylar fracture. In the mandibular displacement due to condylar fracture, it is difficult to restore both esthetics and function without using orthognathic surgery. CASE DESCRIPTION. This clinical report described a full mouth rehabilitation in the patient with bilateral condylar fractures and displaced mandible using bilateral sagittal split ramus osteotomy (BSSRO) and simultaneous dental implant surgery. Mandibular position was determined by model surgery through the diagnostic wax up and restoration of fractured teeth. The precise amount of the mandibular shift can be obtained from the ideal intercuspation of remaining teeth. CLINICAL IMPLICATION. Mandibular displacement by both condylar fractures can be successfully treated by orthognathic surgery. Determination of occlusal plane and visualization from diagnostic wax up are mandatory for mandibular repositioning of model surgery. Stable occlusion and regular recall check up are needed for long-term outcome.

• Imaging Science in Dentistry
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• v.49 no.3
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• pp.241-249
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• 2019

Ameloblastoma is a benign locally invasive tumor with a high tendency to recur. It is considered rare in the pediatric population, with most cases diagnosed in the third to fifth decades of life. Approximately 80% of ameloblastomas occur in the molar and ramus region of the mandible, while 20% of cases occur in the maxillary posterior region. This report presents a case of plexiform ameloblastoma in an uncommon location in an 8-year-old child. The lesion was initially thought to be a dentigerous cyst, based on its location and radiographic appearance. The clinical and radiographic features, histopathology, and treatment of solid, plexiform, maxillary ameloblastoma are reviewed, with an added emphasis on a literature review of ameloblastoma in children. This report emphasize the importance of long-term follow-up, since recurrence may occur many years after initial tumor removal.

• The korean journal of orthodontics
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• v.47 no.5
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• pp.289-297
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• 2017

Objective: The objective of this study was to analyze the patterns of tooth movements when distalization of mandibular molars using a mini-plate took place. A finite element analysis was applied to analyze patterns of tooth movements. Methods: The model of the mandible and teeth were used to build a finite element analysis model, and a mini-plate was inserted in the mandibular ramus. Two different orthodontic forces were established for displacement of mandibular molars. Orthodontic forces were applied at the level of the bracket and at the level of the cemento-enamel junction in the mandibular canine respectively. Results: Applying orthodontic forces at the level of the cemento-enamel junction resulted in a greater biomechanical bodily movement in distalization of the mandibular molars compared to when the orthodontic forces were applied at the level of the bracket. Applying orthodontic forces to the cemento-enamel junction also resulted in unwanted greater extrusive movements in distalization of the mandibular molars compared to the bracket level. Conclusions: With considering the mode of orthodontic teeth movement, applying different vertical orthodontic forces for distalization of mandibular molars can lead to more effective distalization of teeth.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.165-176
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• 1982

A cephalometric radiographic cross sectional comparative study was undertaken to investigate craniofacial growth in cleft lip and palate individuals. The material for this study consisted of 43 subjects with operated cleft lip and palate.(29 males, 14 females). The range of age was from 6 years to 12 years. The roentgenocephalometric values of cleft individuals were compared with values of normal individuals reported by Lee. The following conclusions were obtained; 1) The pattern of cranial base of the cleft subjects was almost the same as that previously reported for the normal individuals. 2) Anterio-posterior length of the mandible did not show any significant difference but in the cleft subjects, that of the males was larger than that of the females. 3) The maxilla of the cleft subjects was very retruded and showed very concave profile. 4) Gonial angle of the cleft subjects was very high, especially in the female clefts. 5) The height of ramus was very poor in the cleft subjects. 6) The facial length was almost the same, but the facial depth of the cleft subjects was smaller than that of the normal individuals. 7) Maxillary and mandibular incisors were severely retroclined. 8) The range of values in the cleft subjects was very variable and the female clefts showed more distured growth than the male clefts.

• Archives of Plastic Surgery
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• v.34 no.6
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• pp.799-802
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• 2007

Purpose: The masserteric space is an important tissue compartment of the face, but a disease in it is difficult to diagnose and treat. The submasseteric abscess is located between the masseter muscle and mandibular ramus with different appearances such as sepsis, infection, or tumor. Especially the common misdiagnosis of submasseteric abscess is acute or chronic parotitis. The purpose of this report is to pay special attention to the possible diagnosis of submasseteric abscess for the symptoms of unilateral cheek swelling and tenderness that accompany marked trismus. Methods: A 11-year-old boy came to our hospital because of facial swelling, tenderness, and trismus in a history of left cheek swelling and toothache. We diagnosed his case as submasseteric abscess by CT scan and surgical intervention was performed. Under general anesthesia, the abscess was opened by the intraoral incision and considerably massive pus was drained. Results: Swelling, tenderness, and trismus became to subside during postoperative 10 days and general condition and vital signs became stable. After 6 months, CT scan showed that both masseteric muscles were symmetric and there was no periosteal reaction of the mandible. Conclusion: In conclusion, submasseteric abscess is a rare infection with the symptoms of cheek tenderness and marked trismus. A detailed medical history and clinical examination of a patient as well as computed tomography(CT) are important tools in the accurate diagnosis and efficient treatment of the submasseteric abscess. Adequate drainage, removal of cause, and antibiotic infusion are the management of choice.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.214-216
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• 2010

An osteochondroma is an osseous protuberance with cartilaginous growth potential, usually arising in skeletal bone and relatively uncommon in the craniofacial bone. Osteochondroma of the craniofacial region usually occurs at the condyle or the tip of the coronoid process, and rarely arises in the mandibular body, symphysis, ramus, and similar areas. Excision of the lesion including the periosteum is curative, and recurrence or malignant change (usually to a chondrosarcoma) after treatment is rare. We present an atypical case of osteochondroma in the left mandibular inferior border with review of literature.