• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.266-275
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• 2008

Dental endosseous implants require sufficient alveolar bone volume and quality for complete bone coverage and initial stability. But, atrophy or resorption of alveolar bone height and width according to patient's age and period of tooth loss can prevent ideal implant placement. Bone graft procedure has been proposed before or simultaneously with the placement of dental implants in patients with insufficient alveolar bone volume. While allografts, xenografts, and alloplastic bone grafts have been proposed and studied for alveolar ridge augmentation, the use of autogenous bone grafts represents the 'gold standard' for bone augmentation procedures. Conventional bone grafts are usually harvested from distant sites such as the ilium or ribs. Recently there is a growing use of intraoral bone grafts from intraoral donor sites such as mandibular symphysis, mandibular ramus and maxillary tuberosity. We recommend that the mandibular ramus is a safe autogenous bone graft donor site for bone harvesting with low morbidity. We report various effective autogenous bone graft procedures from mandibular ramus for the implant placement on various atrophic alveolar ridges.

• The korean journal of orthodontics
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• v.47 no.1
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• pp.50-58
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• 2017

Introduction: Identifying menton (Me) on posteroanterior cephalograms and three-dimensional (3D) cone-beam computed tomography (CBCT) images is difficult, because the midpoint of the symphyseal area is not identifiable after the mandibular symphysis fuses at an early age. The aim of this study was to evaluate the reliability of the identification of the genial tubercle (GT) in patients with mandibular asymmetry and to compare it with that of the traditional landmark, Me. Methods: The samples comprised 20 CBCT images of adults with mandibular asymmetry. Two examiners performed the identifications and measurements. Me and GT were marked, and the anteroposterior, vertical, and transverse distances to the three reference planes were measured on 3D-reconstructed CBCT images. The intra- and inter-examiner reliability of landmark identification of Me and GT were assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Results: The Me and GT landmarks showed excellent reliability ($ICC{\geq}0.993$) three-dimensionally. In the transverse evaluation, the ICC values of the GT (range, 0.997-0.999) tended to be slightly higher than those of Me (range, 0.993-0.996). In the Bland-Altman plots for the two separate assessments, Me showed a maximum error of 1.76 mm in the transverse direction, whereas the GT showed a maximum error of 0.96 mm in the 95% limit. Conclusions: Our results suggest that both Me and GT are clinically reliable and equally useful landmarks for the evaluation of mandibular asymmetry on CBCT images.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.255-263
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• 2011

Introduction: Maxillomandibular fixation (MMF) is essential before surgery under general anesthesia in maxillofacial trauma patients. MMF is used basically to reconstruct the occlusion and occlusal stability to recover the facial shape and oral functions. The arch bar and wire is a traditional method for MMF, but it can not only bring pressure to the periodontal ligaments and teeth but also cause a penetrating injury to the surgeons. Materials and Methods: In this study, 198 patients with an open reduction using a manual reduction without MMF from September 2005 to May 2010 in Dankook University Dental Hospital were subjected to a follow-up evaluation during the postoperative 4 months periods. This study evaluated the incidence of complications according to the condition of the patient (gender, age), the state of bony union of the fracture sites and a numeric rating scale evaluation for postoperative pain scoring. Results: 1. The complications were classified into major and minor according to the seriousness, and the major complication rate was as low as 2.02%. Only 2 cases of re-operations (1.01%) were encountered. In the classification according to the fracture line, plate fracture was observed in both cases of mandibular symphysis fracture, and angle fractures and loosening of two screws were noted in the case of mandibular angle fracture. 2. The complication rate was similar regardless of gender and age. 3. The degree of bony union was satisfactory, and the complication rate was reduced as the bony union improved. 4. More patients complained of pain as the operation time was increased. Conclusion: The use of MMF is not always necessary if a skilled assistant is provided to help manually reduce the fracture site. Compared to other studies of mandibular fracture surgery using MMF, the complication rate was similar using only manual reduction and the patients' discomfort was reduced without MMF.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.3
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• pp.291-299
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• 1991

We retrospectively reviewed 334 inpatients who sustained a total of 518 mandibular fractures and who ewer treated in our department between l980-1990. This results were obtained as follows : 1. In respect of incidence, there were the highest frequency in July, and the lowest frequency in May. The number of patients has not been increased year after year due to competition with other department in our hospital. 2. The age frequency was the highest in the 2nd decade(38.9%) and the ratio of man to women was 4.9 : 1. 3. The most frequent cause of mandibular fracture was traffic accident(43.4%), and the next was fall down(24.3%), fist blow(71%), industrial accident(21%) and others in order. In the traffic accident, autobicycle accident was 14.1%. 4. The most common location of mandibular fracture was symphysis(38.8%), condyle(20.7% ), angle(19.9%) and body(15.1%) were next in order of frequency. The classification by location of fracture, the frequency of single fracture was 54.8%. 5. In 334 patients of mandibular fracture, the frequency of associated injuries was facial laceration(58.4%), teeth injuries(37.7%), extremity injuries(13.2%) were next in order of frequency. 6. The patients arrived in hospital immediately within 24 hours after accident wee 61.4% of all. In respect of treatment, open reduction was 68.7% of all. 7. Complications including infection were present 11.1% of patient. Other complications inclued delayed healing malocclusion, malocclusion and neurologic problem.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.5
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• pp.365-372
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• 2021

Objectives: Mandibular fractures vary significantly with respect to epidemiological and demographic parameters among populations. To date, no study has evaluated these aspects of mandibular fractures in Nuh, Mewat, Haryana, India. To retrospectively analyze the incidence, age and sex distributions, etiology, anatomic distribution, occlusal status, treatment modality provided, and their correlation in patients who suffered isolated mandibular fractures. Materials and Methods: The records of maxillofacial injury patients who reported to the Department of Dentistry, SHKM Government Medical College from January 2013 to December 2019, were retrieved from our database, and necessary information was collected. The data collected were analyzed statistically using IBM SPSS ver. 21. Results: Totals of 146 patients and 211 fractures were analyzed. There were 127 males and 19 females with an age range of 3-70 years (mean age, 26 years). Road traffic accident (RTA) was the most common cause of fracture (64.4%), followed by fall (19.9%), assault (15.1%), and sports injury (0.7%). Of all patients, 42.5% had bilateral fractures, 31.5% had left side fracture, 21.2% had right side fracture, 3.4% sustained midline symphyseal fracture, and 1.4% had symphyseal fracture along one side of the mandible. Site distribution was as follows: parasymphysis (34.6%), angle (23.7%), condyle (20.4%), body (12.8%), symphysis (4.3%), ramus 2.4%, and dentoalveolar 1.9%. The most common facture combination was angle with parasymphysis (17.8%). Occlusion was disrupted in 69.2% patients. Closed reduction was the predominant treatment modality. Conclusion: The data obtained from retrospective analyses of maxillofacial trauma increase the understanding of variables and their outcomes among populations. The results of the present study are comparable to those of the literature in some aspects and different in others.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.220-230
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• 2007

Objective: The purpose of this study was to determine the changes of mandibular anterior alveolar bone thickness with age. Methods: Cephalometric radiographs of 160 skeletal class I patients (male 80, female 80) with normal vertical growth pattern was investigated by measuring the buccolingual thickness of mandibular alveolar bone on the basis of root axis. Results: As the age increases, both male and female showed a significant decrease in buccolingual width of the mandibular anterior alveolar bone and in the width of mandibular anterior lingual alveolar bone except the CEJ area of females. However, there was no significant difference in the thickness of mandibular anterior buccal alveolar bone and in the width of maximum prominence of mandibular symphysis with age. Conclusion: From the above results, it is concluded that Korean children whose growth pattern is sagittally skeletal class l with a vertical normal growth pattern have a greater mandibular anterior lingual alveolar bone width than Korean adults; therefore, lingual movement of mandibular incisors, which is usually accompanied in extraction treatment, is considered to be more preferable in younger patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.476-483
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• 2021

Traumatic bone cyst (TBC) is an asymptomatic lesion seen most in adolescents. TBC is found incidentally on routine panoramic examinations and appears as a relatively well-demarcated unilocular radiolucency with scalloped margins. Histological examination reveals a vacant cavity of cancellous bone usually unlined or very occasionally lined with a thin connective tissue layer. The lack of lining epithelial membrane is common histological feature. The most affected site is between the mandibular canine and third molar. The involvement of the mandibular symphysis is rare. The etiopathogenesis of the TBC is unclear. TBC is treated with surgical exploration and curettage; new bone is formed in place of the lesion within 6 - 12 months of surgery. Diagnosis of TBC prior to surgical intervention has limitations in most of the cases. Both of our patients were diagnosed through radiological examination and biopsy. Neither patient had a history of trauma. After surgery, the panoramic radiograph and CBCT were used to confirm bone healing.

• Korean Journal of Head & Neck Oncology
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• v.21 no.2
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• pp.190-195
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• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• The korean journal of orthodontics
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• v.49 no.2
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• pp.97-105
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• 2019

Objective: This study was performed to evaluate the accuracy and reliability of a newly designed method to achieve mandibular dental model superimposition, using voxel-based cone-beam computed tomography (CBCT) registration. Methods: Fourteen dry cadaveric mandibles and six teeth extracted from patients with severe periodontitis were used to establish 14 orthodontic tooth-movement models. The protocol consisted of two steps: in the first step, voxel-based CBCT mandible superimposition was performed; the reference comprised the external portion of the symphysis, extending to the first molar. The laser-scanned dental model image was then integrated with the CBCT image to achieve mandibular dental model superimposition. The entire process required approximately 10 minutes. Six landmarks were assigned to the teeth to measure tooth displacement, using tooth displacement on the superimposed laser-scanned mandibles as the reference standard. Accuracy was evaluated by comparing differences in tooth displacement based on the method and the reference standard. Two observers performed superimposition to evaluate reliability. Results: For three-dimensional tooth displacements, the differences between the method and the reference standard were not significant in the molar, premolar, or incisor groups (p > 0.05). The intraclass correlation coefficients for the inter- and intra-observer reliabilities of all measurements were > 0.92. Conclusions: Our method of mandibular dental model superimposition based on voxel registration is accurate, reliable, and can be performed within a reasonable period of time in vitro, demonstrating a potential for use in orthodontic patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.41-49
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• 1989

This is a retrospective study on facial bone fractures of Koreans. This study was based on a series of 110 patients who had been treated for facial bone fractures as in-patient at Guro Hospital, School of Medicine, Korea University for the period of September, 1984. to August, 1988. The results were obtained as follows : 1. 2nd decade(42.7%) was the highest age group in incidence, and age range was 2 years to 72 years, and the ration of Male/Female was 3.7 : 1. 2. Falling was most frequent cause of facial bone fractures(40.9%) 3. The frequent location of facial bone fractures were mandibule(67.1%), zygoma & zygomatic arch(11.7%), maxilla(10.9%), and others in order. 4. In mandibular fractures, one site fractures showed 30.1% and two site fractures showed 58.8% and triple site fractures showed 11.1%. The most frequent site of mandibular fracture was symphysis(32.7%) 5. The most frequent month of facial bone fracture was September.