• Archives of Plastic Surgery
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• v.40 no.5
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• pp.546-552
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• 2013

Background The zygoma is a major portion of the midfacial contour. When deformity occurs in this area, a reduction should be conducted to correct it. If a sagittal fracture at the temporal root of the zygomatic arch occurs, this also requires reduction, but it is difficult to approach due to its anatomical location, and the possibility of fixation is also limited. Thus, the authors attempted the reduction of sagittal fracture by two- or three-point fixation and the Gillies approach without direct manipulation. The preoperative and postoperative results of the patients were evaluated. Follow-up was performed to establish a treatment guideline. Methods A retrospective study was done with 40 patients who had sagittal fractures at the temporal root of the zygomatic arch from March 2009 to June 2012. Only two- or three-point fixation was performed for the accompanying zygomatic-orbital-maxillary fracture. The Gillies approach was used for complex fractures of the zygomatic arch, while the temporal root of the zygomatic arch was only observed without reduction. Preoperative and postoperative computed tomography and X-ray scans were performed to examine the results. Results The result of the paired t-test on preoperative and postoperative bone gap differences, the depression level, and the degree of temporal protrusion showed a marked decrease in the mean difference at a 95% confidence interval. The results were acceptable. Conclusions In the treatment of sagittal fractures at the temporal root of the zygomatic arch, it is acceptable to use indirect reduction and non-fixation methods. This leads to a satisfactory aesthetic and functional outcome.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.4
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• pp.313-326
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• 2007

With rising prevalency of mouth breathing children caused by developing civilization and increasing pollution, there are many maxillary transverse discrepancy patients with undergrowth of maxilla. For improving this, maxillary mid-palatal suture splitting was often performed. The purpose of this study was to analyse the stress distribution on the craniofacial suture and cranium after rapid maxillary expansion by finite element model. The boy(13Y6M) was chosen for taking computed-tomography for finite element model. Three-dimensional model of maxilla, first premolar, first molar, buccal and lingual part of rapid maxillary expansion were constructed. 1. The alveolar bone adjacent to the first molar and the first premolar that was affected directly by rapid maxillary expansion was displaced laterally approximately 4.04mm at maximum. The force decreased toward anterior region and frontal alveolar bone displaced laterally about 3.18mm. 2. A forward maximum displacement was exhibited at zygomatic process middle region. 3. At maximum, maxillary median part experienced 0.973mm downward repositioning and 0.65mm upward repositioning at lateral alveolar bone. 4. Von mises stress was observed the largest stress distribution around teeth and zygomatic buttress. 5. The largest tensile force was observed around alveolar bone of teeth, while compression force was observed at zygomatic buttress.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.367-385
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• 1988

In case of skeletal Class III malocclusion with underdeveloped maxilla, the extraoral orthopedic force for the stimulation of maxillary growth or anterior reposition of the maxilla has been used clinically for the improvement of facial skeletal relationship. The purpose of this investigation was to examine the initial reaction of maxillofacial complex to the maxillary protraction by using extraoral orthopedic force. The dried human skull was used and this investigation was done by means of double exposure holographic interferometry. The protraction forces placed on the canine or the first molar were parallel, $10^{\circ}$ downward, $20^{\circ}$ downward to the occlusal plane. Fringe pattern of each protraction condition was compared and analized. The results were as follows: 1. Each maxillofacial bone displaced saparately. 2. More displacement was shown at the area of the teeth and the alveolar bone. 3. A counterclockwise rotation of the maxilla wa decreased by downward protraction and especially 20 degree downward protraction from the canine showed least rotation. 4. On the zygomatic arch, outward bend was observed and this effect was decreased by downward protraction. 5. On the zygomatic bone, the counter clockwise rotation was increased by the downward protraction. 6. When maxillary expansion was applied at the same time, outward and upward displacement with counterclockwise rotation was observed on the maxilla. 7. The lateral pterygoid plate of sphenoid bone was affected by maxillary protraction.

• Archives of Plastic Surgery
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• v.38 no.3
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• pp.287-294
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• 2011

Purpose: Reduction malarplasty is one of the common aesthetic procedures performed in the Orient. We have analyzed effective operative methods according to the pivot point for the osteotomy and reposition of the zygoma for reduction malarplasty after confirming the shapes of the individual zygomas. Methods: Thirty-six patients had been received malarplasty over the last 10 years. The average follow-up period was 16 months. We categorized the patients into three groups according to their prominent appearance features. Group I had a prominently protruded zygomatic body, group II had a prominently protruded zygomatic arch, and group III had a prominently protruded body and zygomatic arch. In the group I, two parallel oblique osteotomies on the body, the middle portion was removed, and with the zygomatic arch as the pivot point, the body was repositioned inwards. In the group II, the zygomatic body and arch osteotomy is performed, with the body as the pivot point, and the arch is depressed medially. In the group III, using the two aforementioned methods, the zygoma was repositioned medially. In each case, postoperative complications and patients satisfaction over the surgery were surveyed. Results: Each group had 25, 5 and 12 patients respectively. No significant complications were found except for one patient who experienced a non-union of zygomatic bone. In the case of group I, four patients underwent a secondary operation. Conclusion: Reduction malarplasty is popular as an effective facial contouring surgery. In order to obtain more effective results,however, the zygomatic shape should be identified, and appropriately repositioned by different operative technique according to pivot points.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.1.1-1.6
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• 2015

The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

• Archives of Craniofacial Surgery
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• v.17 no.4
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• pp.206-210
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• 2016

Background: Zygoma is a major buttress of the midfacial skeleton, which is frequently injured because of its prominent location. Zygoma fractures are classified according to Knight and North based on the direction of anatomic displacement and the pattern created by the fracture. In zygomaticomaxillary complex (ZMC) fracture many incisions (lateral eyebrow, lateral upper blepharoplasty, transconjunctival, subciliary, subtarsal, intraoral, direct percutaneous approach) are useful. We reviewed various approaches for the treatment of ZMC fractures and discussed about incisions and fixation methods. Methods: A retrospective review was conducted of patients with ZMC fracture at a single institution from January 2005 to December 2014. Patients with single zygomatic arch fracture were excluded. Results: The identified 694 patients who were admitted for zygomatic fractures from which 192 patients with simple arch fractures were excluded. The remaining 502 patients consisted of 439 males and 63 females, and total 532 zygomatic bone was operated. Orbital fracture was the most common associated fracture. According to the Knight and North classification the most frequent fracture was Group IV. Most fractures were fixated at two points (73%). Conclusion: We reviewed our cases over 10 years according to fracture type and fixation methods. In conclusion, minimal incision, familiar approach and fixation methods of the surgeon are recommended.

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.493-499
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• 2014

Background Maintaining stability and restoring the aesthetic appearance are the fundamental goals when managing zygomatic fractures. We aimed to evaluate the stability and anthropometric outcomes of zygomatic fracture patients who underwent two-point fixation involving the infraorbital rim and zygomaticomaxillary buttress via the transconjunctival and gingivobuccal approaches without any skin incisions. Methods We examined 15 zygomatic fracture patients who underwent two-point fixation during a 3-year period. Stability was evaluated using three-dimensional facial bone computed tomography. Superoinferior and anteroposterior displacement of the zygoma was quantified. The aesthetic appearance of the periorbital region was evaluated using indirect anthropometry with standardized clinical photographs. The ratios between the eye fissure height and width, and lower iris coverage ratio were used to evaluate aesthetical changes. The bony displacement and aesthetic ratios were analyzed using Wilcoxon or Friedman tests. The correlation between the preoperative zygoma position and anthropometric values was analyzed. Results The positions of the zygoma were similar to those on the contralateral side at the long-term follow-up. The preoperative anthropometric measurements on the fractured side differed from those on the contralateral side, although these values were close to the normal values at the long-term follow-up. Furthermore, we noted that the anteroposterior displacement strongly positively correlated with the lower iris coverage rate (Spearman's coefficient=0.678, P=0.005). Conclusions Two-point fixation of zygomatic fractures achieved stable outcomes on long-term follow-up, and also appeared to be reliable in restoring the aesthetic appearance of the periorbital region.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.14 no.3
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• pp.207-216
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• 1992

The congenital condition referred as hemifacial microsomia is characterized by underdevelopment, malformation or abscence of certain soft and hard tissue derivatives of the first and second branchial arches and open also of structures which are not derived from the branchial arches, such as the zygoma, temporal bone. This is a report about a 14 years old male patient with the chief complaint of severe facial asymmetry, who was diagnosed as hemifacial microsomia having agenesis of the right mandibular condyle and zygomatic arch. Deformities and rib bone graft on the affected mandibular condyle and body, and LeFort I osteotomy in the maxilla. To correct contour-deficient chin, we performed the genioplasty, and the zygomatic arch was reconstructed with rib bone graft.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.1
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• pp.103-113
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• 1990

The study was based on a series of 252 patient with facial bone fractures who visited to Chun Cheon Sacred Heart Hospital, College of Medicine, Hallym University during the period of Dec., 1984 trough Nov., 1989. The results obtained are as follows; 1. The most frequent etiologic factor was traffic accident(45.2%). 2. The ratio of male to female was 5.5 : 1 and 2nd decade(44%) was the highest age group in incidence. 3. Monthly incidence was the highest in Aug(14.3%). 4. The most common site of fracture was mandible(55.3%) and zygoma complex(24.2%), nasal bone(11.6%), maxilla(8.9%) were next in order of frequeny. 5. In mandible fractures, the most frequent site was symphyseal area(36.9%) and 142 cases(85%) had fractures only in mandible. 6. In maxillary fractures, fracture with other facial bones(85.2%) was more frequent than fracture on maxilla only. The major fracture type on maxilla was Le Fort II type. 7. In fracture of zygoma complex, zygoma & zygomatic arch was the most frequent site(52.0%) and zygomatic arch(24.7%), zygoma(23.3%) were next in order. 8. Open reduction was major method of treatment in facial bone fractures except nasal bone ; mandible(62.9%), maxilla(77.8%), zygoma complex(65.8%). 9. Maxillofacial fractures were most frequently combined with head & neck injury(43.1%), and upp. & low. extremities(29.4%), chest and abdomen(11.9%) were in order of frequency.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.399-402
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• 2003

A female unknown aged Yorkshire terrier, weighing 3.5 kg with nasal discharge, left facial swelling and severe inflammation was referred to Veterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were lytic change and soft tissue swelling of left zygomatic process and increased radiopacity of nasal cavity. In computed tomography, turbinate bone destruction was observed as well as lytic change of left zygomatic process and left maxilla indicating aggressive lesion. Then 3-dimensional reconstruction was also performed. Biopsy of tissue mass revealed it as squamous cell carcinoma. For this patient, euthanasia was performed guarded prognosis. Generally, tumors of the nasal cavity in dogs account for approximately 1 % to 2% of all neoplasms. The prevalence of these tumors increased with age and exposure to the ultraviolet. About two thirds of all nasal tumors are malignant tumors such as squamous cell carcinoma and adenocarcinoma. As these tumors of nasal cavity are locally invasive, and external beam radiotherapy is the current treatment of choice. Unfortunately, diagnosis of these tumors often occurs late in the course of disease, resulting in a poor prognosis for outcome in many patients. It is considered that computed tomography could be used as an aid modality for the exact evaluation of extend and degree of bone lysis of nasal cavity and metastasis.