• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.1
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• pp.63-67
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• 2022

Controversies exist regarding the need for prophylactic extraction of mandibular third molars in patients who plan to undergo orthognathic surgery. An 18-year-old male patient was diagnosed with mandibular prognathism and maxillary retrognathism with mild facial asymmetry. He had a severely damaged mandibular first molar and a horizontally impacted third molar. After extraction of the first molar, the second molar was protracted into the first molar space, and the third molar erupted into the posterior line of occlusion. The orthognathic surgery involved clockwise rotation of the maxillomandibular complex as well as angle shaving and chin border trimming. Patients who are missing or have damaged mandibular molars should be monitored for eruption of third molars to replace the missing posterior tooth regardless of the timing of orthognathic surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.71-75
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• 2005

This study evaluated retrospectively the treatment method and postoperative complications of communited mandibular fractures. We analyzed the clinical and radiologic data of 14 patients with the comminuted mandibular fractures who were admitted to Chosun University Dental Hospital from January 1998 to December 2003. We reviewed the cause of trauma, fracture sites, treatment methods, and postoperative complications. Thirteen patients (93%) had a successful treatment outcome without complications. Only one patient developed postoperative osteomyelitis requiring early plate removal and sequestrectomy. For the comminuted fractures of mandible, internal fixation using micro- or mini-plate was an effective treatment method with a low incidence of major complications.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.5
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• pp.214-218
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• 2014

Macroglossia can create dental and skeletal instability after orthodontic treatment or orthognathic surgery for mandibular prognathism. In relevant literature, partial glossectomy is suggested for a good post-treatment prognosis. Most of the published partial glossectomy cases are two-staged surgery, because of concern about postoperative airway obstruction. As orthognathic surgical techniques and fixation method develop, however, concerns about postoperative airway obstruction have lessened. In this case, mandibular setback surgery and partial glossectomy were performed simultaneously, leading to stable recovery without any postoperative respiratory problems. After surgical technique to preserve the tongue tip, we achieved good outcomes without postoperative side effects of lingual hypoesthesia, pronunciation disorder and dyskinesia. We report this case with a literature review.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.299-310
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• 1987

The purpose of this study was to examine soft tissue and hardtissue changes following orthognathic surgery in patients with mandibular prognathism lateral cephalometric films were obtained immediate before surgery, 48 hours following surgery, and 6 months following surgery. 18 patients were selected (10 men, and 6 women) for this study, who had received orthognathic surgery. Statistical analysis for the each time interval differences were performed with the SPSS package The results were as follows, *In the cases of mandibular sagittal split osteotomy 1 LI point was moved backward (average 7.55mm) 48 hours following surgery. 6 months later, it was returned forward (average 1.1mm) Relapse rate was 14.6% 2 Pog was moved backward (average 8.3mm) 48 hours following surgery The ratio of horizontal change of soft tissue to hard tissue at pog is 0.95 1 *In the cases of maxillary Le-Fort I osteotomy & mandibular sagittal split osteotomy. 3. A point was moved forward (average 3.31mm) 48 hours following surgery. 6 months later, it was returned backward (average 0.31) Relapse rate was 9 4% 4 6 months later, the ratio of facial convexity angle change of soft tissue to hard tissue is 0.63 1.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.51.1-51.8
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• 2019

Purpose: It has been reported before that the amount of pharyngeal airway space (PAS) significantly decreases following mandibular setback (MS) surgery in patients with mandibular prognathism (MP). Further, MP patients with an anterior open-bite (AOB) presentation may show a larger decrease in PAS compared with those without AOB. However, studies on postoperative PAS changes in MP patients with AOB remain rare. This study sought to evaluate changes in PAS and hyoid bone positioning following MS surgery in MP patients with and without AOB. Patients and methods: Twenty patients who underwent two jaw surgery involving MS movement were included. Patients were divided into a non-AOB group (n = 10; overbite > 2 mm) and an AOB group (n = 10; overbite < - 4 mm). Three-dimensional changes in PAS and hyoid bone positioning were compared and statistically evaluated pre- and postoperatively using computed tomography (CT). Results: The mean magnitude of MS was 6.0 ± 2.8 mm and 5.6 ± 3.2 mm in the non-AOB group and AOB group, respectively. The oropharyngeal volume and upper hypopharyngeal volume were significantly reduced after surgery in both the groups (p = 0.006 and p = 0.003), while the retroglossal cross-sectional area was significantly reduced only in the AOB group (p = 0.028). Although the AOB group showed a larger decrease in PAS, the difference was not statistically significant between the groups. The position of the hyoid bone showed significant posterior and inferior displacement only in the AOB group, while the vertical displacement of the hyoid bone showed a statistically significant difference between the two groups. Conclusion: PAS was significantly decreased after MS in both the groups, while only the AOB group presented a statistically significant reduction in the retroglossal cross-sectional area. Vertical displacement of the hyoid bone showed a statistically significant difference between the groups, while the PAS change was not. Surgeons should be aware of potential postoperative airway problems that may arise when performing MS surgeries.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.4
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• pp.161-167
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• 2014

Purpose: The reconstruction of mandibular defects poses many difficulties due to the unique, complex shape of the mandible and the temporomandibular joints. With development of microvascular anastomosis, free tissue transplantation techniques, such as deep circumflex iliac artery (DCIA) flap and fibular free flap (FFF), were developed. The DCIA offers good quality and quantity of bone tissue for mandibular segmental defect and implant for dental rehabilitation. Virtual surgical planning (VSP) and stereolithography-guided osteotomy are currently successfully applied in three-dimensional mandibular reconstruction, but most use FFF. There are only a few articles on reconstruction with the DCIA that assess the postoperative results. Methods: Three patients admitted during a five month period (April of 2013 to August of 2013) underwent resection of mandible and DCIA musculo-osseous reconstruction using a VSP and stereolithographic modeling and assessment of outcomes included technical accuracy, esthetic contour, and functional outcomes. Results: This technique yielded iliac bone segment with excellent apposition and duplication of the preoperative plan. Flap survival was 100 percent and all patients maintained preoperative occlusion and contour. Conclusion: Based on our experience, we offer considerations and logically consistent protocols by classification of mandibular defects, and demonstrate the benefits in VSP and stereolithographic modeling of mandibular reconstructive surgery with DCIA flap.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.3
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• pp.217-226
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• 2007

Purpose: Distraction osteogenesis is considered to take favorable effect on the TMJ and be beneficial to prevent the relapse after the mandibular advancement of Class II malocclusion patient. This is the report with literature review on the mandibular advancement in the patients showing preoperative condylar resorption and who need larger amount of advancement. Patients and method: Distraction osteogenesis using intraoral device was performed for three mandibular hypoplasia patients (one male and two females). All patients were adult over 18 years old. The patients showed condylar bony resorption preoperatively. The distraction was performed intraorally with modified SSRO. After 7 days of latency period, activation was performed at the rate of 1.0 mm/day with twice turn. The devices were removed after 4-8 month consolidation period. Results: Total advancement of mandible was average 13 mm. One patient showed openbite immediately after removal of distraction device. It took long time to guide the openbite with elastics. The comparison between cephalometries immediately after device removal and postoperative six month revealed average 3.4 mm relapse. This means that mandibular advancement with distraction osteogenesis needs overcorrection and elastic rehabilitation even after enough consolidation periods. Conclusion: Larger amount of mandibular advancement could be achieved with distraction osteogenesis in severe mandibular hypoplasia with condylar resorption. However, some relapse was found during the follow-up period and the over correction is considered to be needed. The effect of distraction osteogenesis seems to be investigated with long-term follow-up.

• The korean journal of orthodontics
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• v.47 no.6
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• pp.344-352
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• 2017

Objective: The purpose of this study was to compare the changes induced in the pharyngeal airway space by orthodontic treatment with bodily retraction of the mandibular incisors and mandibular setback surgery without extraction. Methods: This retrospective study included 63 adult patients (32 men and 31 women). Thirty-three patients who had been treated via four-bicuspid extraction and bodily retraction of the mandibular incisors (incisor retraction, IR group) were compared with 30 patients who had been treated via mandibular setback surgery (MS group) without extraction. Lateral cephalograms were acquired and analyzed before (T1) and after treatment (T2). Results: The superior pharyngeal airway space did not change significantly in either group during treatment. The middle pharyngeal airway space decreased by $1.15{\pm}1.17mm$ and $1.25{\pm}1.35mm$ after treatment in the IR and MS groups, respectively, and the decrease was comparable between the two groups. In the MS group, the inferior pharyngeal airway space (E-IPW) decreased by $0.88{\pm}1.67mm$ after treatment (p < 0.01). The E-IPW was larger in the MS group than in IR group at T1, but it did not differ significantly between the two groups at T2. No significant correlation was observed between changes in the pharyngeal airway space and the skeletal and dental variables in each group. Conclusions: The middle pharyngeal airway space decreased because of the posterior displacement of the mandibular incisors and/or the mandibular body. The E-IPW decreased only in the MS group because of the posterior displacement of only the mandibular body.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• 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.