• Maxillofacial Plastic and Reconstructive Surgery
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• 제15권2호
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• pp.123-128
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• 1993

For the purpose of studying postsurgical stability of mandibular prognathism, 18 patients(8 men and 10 women) were selected who underwent sagittal split ramus osteotomy and lateral cephalograms taken preoperatively, immediate postoperatively, and over 6-month follow-up were traced and analysed. The following results were obtained. 1. Average magnitude of setback vas 11.0mm, and aberage relapse was 3.0mm, so the rate of relapse was 27%. 2. Magnitude of mandibular setback contributed to relapse. 3. The patients of less than 10mm setback showed average 10% of relapse rate, and it was of little clinical significance. 4. Proper detachment of pterygomasseteric sling prevention of clockwise rotation of proximal segment and rigid fixation are recommended for the better postoperative stability.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권2호
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• pp.126-131
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• 2010

Objectives: This study is aimed to determine any differences in the postoperative stability between absorbable and titanium plate systems for fixation in orthognathic surgery with simultaneous maxillomandibular procedures especially including maxillary posterior impaction and advancement. Study Design: Forty patients with dentofacial deformities were randomly assigned into titanium (4 males and 6 females) and absorbable (17 males and 13 females) fixation group. All patients had undergone surgical alterations of maxilla with posterior impaction and advancement. A comparison study of the change in the maxillary position after the simultaneous surgery was performed with 1-day, 6-months postoperative lateral cephalograms compared to preoperative lateral cephalogram by tracing. Wilcoxon rank sum test was used for statistical analysis. Result: The position of the maxilla was stable after surgery and was not changed significantly from 1 day to 6 month after the simultaneous maxillomandibular surgery both in the experimental (absorbable plates) and control (titanium plates). Conclusion: This study suggests that application of absorable plating system in the fixation of maxillary segment in the simultaneous maxillomandibular procedures, leads to a predictable short-term postoperative skeletal stability comparable to the titanium plating system. Long term follow-up and further studies will be needed.

• 대한치과교정학회지
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• 제25권6호
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• pp.655-664
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• 1995

Sixty male patients with polysomnographically documented OSA were included in this study. A pair of cephalograms were obtained in the upright and supine positions. In the supine position, the ANB angle, lower facial height and the cross-sectional area of soft palate increased and there was a decrease in the vertical airway length and oropharynx cross-sectional area. Positional changes did not affect the cross-sectional area of tongue, but the cross-sectional area of the oropharynx decreased in the supine position. The obese group had higher AI and RDI. Maxillary unit length, C3-H, the cross-sectional areas of tongue, soft palate and oropharynx were significantly greater in the group Obese than in non-obese group. No correlation was noted between the mandibular unit length and OSA severity, The group of small mandibular unit length showed shorter lower facial height and maxillary unit length, and smaller cross-sectional area of tongue than the long mandibular unit length group. Hyold bone positioned more inferiorly and cross-sectional area of nasopharynx decreased as the OSA severity increased.

• 대한치과교정학회지
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• 제19권1호
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• pp.77-93
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• 1989

The purpose of the present study were to disclose whether the depth of the mandibular antegonial notch can be used as an indicator of mandibular growth potential. The patients composed of 76 samples and were classified following 3 groups, based on the depth of mandibular antegonial notch : Deep notch group (more than 3mm), Neutral notch group (1-3mm), Shallow notch group (less than 1mm). For each case, the first lateral cephalograms were taken prior to the start of treatment and the second films 3-4 years after. The results were as follows; 1. Deep notch group had a shorter corpus, less ramus height and greater genial angle than did Shallow notch group. 2. Deep notch group had a more retrusive mandibular position than Shallow notch group. 3. Deep notch group had longer total anterior facial height and longer anterior lower facial height group. 4. Deep notch group grow vertical clockwise growth pattern, while Shallow notch group grow horizontal counterclockwise growth pattern. 5. Deep notch group had less mandibular growth than Shallow notch group during observation period.

• 대한치과교정학회지
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• 제46권1호
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• pp.55-61
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• 2016

Skeletal anchorage-assisted upper molar distalization has become one of the standard treatment modalities for the correction of Class II malocclusion. The purpose of this study was to analyze maxillary molar movement patterns according to appliance design, with the simultaneous use of buccal fixed orthodontic appliances. The authors devised two distinct types of midpalatal miniscrew-assisted maxillary molar distalizers, a lingual arch type and a pendulum type. Fourteen patients treated with one of the two types of distalizers were enrolled in the study, and the patterns of tooth movement associated with each type were compared. Pre- and post-treatment lateral cephalograms were analyzed. The lingual arch type was associated with relatively bodily upper molar distalization, while the pendulum type was associated with distal tipping with intrusion of the upper molar. Clinicians should be aware of the expected tooth movement associated with each appliance design. Further well designed studies with larger sample sizes are required.

• Journal of Oral Medicine and Pain
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• 제23권1호
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• pp.75-84
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• 1998

The Purpose of this Study was to examine the anatomic differences in the upper airway according to severity of respiratory disturbance index of habitual snorers. Forty-three male habitual snorers, aged 28-68, were examined by polysomnography and divided into 4 groups according to severity determined by polysomnography. Anatomic differences in the upper airway were assessed by lateral cephalograms in upright position, and epidemiological surveys were done by using questionnaires. The obtained results were as follows : 1. All subjects were habitual snorers and 35 patients (81.4%) complained the loudness of snoring as severe as be heard outside of the room. 2. According to the results of polysomnography, the number of the primary snoring patients was 7(16.3%), mild obtrusive sleep apnea 7(16.3%), moderate 7(16.3%), and severe 22(51.2%). 3. The respiratory disturbance index (RDI) of subjects was 39.5$\pm$24.4 and the body mass index(BMI) was 26.2$\pm$2. 4. More inferiorly positioned hyoid bone according to the degree of respiratory disturbace index (RDI) was observed. (p<0.001) 5. The width of superior oropharyngeal airway space was according to the degree of RDI. (p<0.001)

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권2호
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• pp.94-99
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• 2010

The purpose of this study was to examine the soft tissue changes in skeletal class II patients after mandibular advancement by bilateral sagittal split ramus osteotomy (BSSRO). In Asian population, the incidence of skeletal class II malocclusion is lower than that of skeletal class III malocclusion unlike the caucasians. This study was conducted to figure out the ratio at which hard tissue and soft tissue changes after mandibular advancement by analyzing cephalograms of 13 patients that have undergone the mandibular advancement surgery. As a result, change ratios of Li, B', Pog' according to the movement of li, B, Pog were found to be 0.59, 1.06, 0.82. Also, vertical height of vermilion zone (Si-Vb) and lower lip and chin (Si-Me') were measured to evaluate vertical changes. Vermilion zone showed tendency to decrease by 1.02 mm on the average postoperatively, whereas vertical length of lower lip and chin showed tendency to increase by 3.57 mm on the average.

• Imaging Science in Dentistry
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• 제47권1호
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• pp.1-9
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• 2017

Purpose: This retrospective study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of individuals with skeletal class II, division 1 and division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group. Materials and Methods: Totally 124 lateral cephalograms (47 for skeletal class I; 45 for skeletal class II, division 1; and 32 for skeletal class II, division 2) in pre-peak, peak, and post-peak growth periods were selected from the department archives. Thirteen landmarks, 4 angular and 4 linear measurements, and 4 proportional calculations were obtained. The ANOVA and Duncan test were applied to compare the differences among the study groups during the growth periods. Results: Statistically significant differences were found between the skeletal class II, division 2 group and other groups for the gonion-gnathion/sella-nasion angle. The sella-nasion-B-point angle was different among the groups, while the A-point-nasion-B-point angle was significantly different for all 3 groups. The nasopharyngeal airway space showed a statistically significant difference among the groups throughout the growth periods. The interaction among the growth periods and study groups was statistically significant regarding the upper oropharyngeal airway space measurement. The lower oropharyngeal airway space measurement showed a statistically significant difference among the groups, with the smallest dimension observed in the skeletal class II, division 2 group. Conclusion: The naso-oropharyngeal airway dimensions showed a statistically significant difference among the class II, division 1; class II, division 2; and class I groups during different growth periods.

• 대한치과의사협회지
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• 제25권9호통권220호
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• pp.861-872
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• 1987

The Purpose of this study was to know the differences between the occlusal plane angles formed by F-H plane on cephalograms and the occlusal plane angles by the upper margin of the articulator, and to ind the contributing factors to the difference of occlusal angles. for this study, 39 young adults (20 men, 19 women) were selected who had normal occlusion, no severe attrition, no missing tooth, not been under orthodontic treatment and occlusal equilibration and no temporomandibular disorders. The maxillary casts were mounted with Hanau 159-1 ear piece type face-bow and measured the occlusal plane angle with prototype occlusal plane projector. The following results were obtained; 1. The mean value of the ear rod F-H plane occlusal angle was 14.75˚, articulator occlusal angle was 9.26˚ and strong positive correlation between these angles, 2. It was almost same angle between the ear rod F-H plane angle (14.75˚) and the beyron point to infraorbital rim-6mm. occlusal angle (14.46˚) 3. The mean distance from the ear rod porion to the Byron point was 5.67mm. 4. It was no significant correlation between the distances Po-Beyron point, Or-infraorbital rim and articulator occlusal angle.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권1호
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• pp.59-69
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• 2001

Purpose : The purpose of the present study was to evaluate postoperative stability and soft-tissue osseous relations of the long face syndrome patients. Methods : Twenty-five patients who had undergone bimaxillary surgery to correct long face syndrome at the Pusan National University Hospital were evaluated. The lateral cephalograms of preoperative, 1 week postoperative and at least 1 year postoperative were examined. Results : 1. The facial height of the long face syndrome patients were longer than normal Korean adults. 2. The most common malocclusion type of the long face syndrome patients in Korea was class III. 3. Horizontal postoperative skeletal relapses were $-0.64{\sim}0.80mm$ in the maxilla, and $-0.56{\sim}0.48mm$ in the mandible. 4. Vertical postoperative skeletal relapses were $0.20{\sim}0.56mm$ in the maxilla, and $-0.80{\sim}0.20mm$ in the mandible. 5. Postoperative soft tissue changes in long face syndrome patients were correlated with postoperative skeletal changes. So prediction schemes for postoperative soft-tissue changes were obtainable. Conclusion : It is hard to predict the exact direction and quantity of the postoperative skeletal relapse in long face syndrome patient's orthognathic surgery because of large standard deviation. But soft tissue change is predictable via prediction scheme.