• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.255-259
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• 2005

We observed 469 cases (male 217 cases, female 252 cases) with dento-facial deformity for 10 years from Jan 1994 to Dec 2003. The ratio of male to female was 1:1.2 and the mean age was 23.3 years (male 24.0 years, female 22.6 years) ranged from 11 to 43 years. The most dominant group was related to mandibular prognathism (80.4%). A rate of 83.8% demonstrated mandibular protrusion according to Slavicek's classification (n=160), and 85.4% were classified as skeletal Class III type according to Sugawara's classification (n=151). Surgical method were divided into 355 cases of one jaw surgery (single method), 26 cases of one jaw surgery (combined method), and 77 cases of two jaw surgery. Sagittal split osteotomy were performed on 316 cases (69.0%). The average operation time and blood loss in SSRO were $4.1{\pm}2.2$ hrs. and $138.8{\pm}222.6$ ml (n=152).

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.795-804
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• 1997

Developmental dental morphological anomalies are fusion, gemination, twinning, concrescence and etc. They may cause many problems in conservative, periodontal and esthetic aspects. Fusion is a condition where two separate tooth buds unite at some stage in their development to form a bifid crown. If tooth contact occurs early, at least before the start of calcification, the two teeth may be completely unites to form a single large tooth. If tooth contact occurs after the time when a portion of the tooth crown has completed its formation, there may be union of the roots only. In fusion the dentin is always confluent. Fusion teeth is more common in the deciduous than in the permanent dentition. Fused teeth are relatively rare, and are mostly mandibular anterior teeth. Fusion of normal and supernumerary teeth or between normal teeth may occurs. The exact etiology factor of fusion is unknown, but genetic and environmental factors seems to be related. A variety of complications and subsequent treatments have been suggested on this teeth. Periodontal conditions may arise due to a groove formed at the line of fusion of the two teeth. Crowding or Protrusion with potential for malocclusion or delayed eruption of adjacent teeth. Fusion teeth appear in the anterior region, they usually cause esthetic problems. Treatments vary depending on the problem, the location, and the extent of fusion. Treatment of fused teeth has been reported from endodontic, orthodontic, periodontic, surgical and multidisciplinary. This report presents the esthetic improvements by separation of two clinical crowns. Bone reduction or endodontic treatments are not required.

• The korean journal of orthodontics
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• v.49 no.1
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• pp.59-69
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• 2019

In this report, we describe a case involving a 34-year-old woman who showed good treatment outcomes with long-term stability after multidisciplinary treatment for unilateral cleft lip and palate (CLP), maxillary hypoplasia, severe maxillary arch constriction, severe occlusal collapse, and gingival recession. A comprehensive treatment approach was developed with maximum consideration of strong scar constriction and gingival recession; it included minimum maxillary arch expansion, maxillary advancement by distraction osteogenesis using an internal distraction device, and mandibular setback using sagittal split ramus osteotomy. Her post-treatment records demonstrated a balanced facial profile and occlusion with improved facial symmetry. The patient's profile was dramatically improved, with reduced upper lip retrusion and lower lip protrusion as a result of the maxillary advancement and mandibular setback, respectively. Although gingival recession showed a slight increase, tooth mobility was within the normal physiological range. No tooth hyperesthesia was observed after treatment. There was negligible osseous relapse, and the occlusion remained stable after 5 years of post-treatment retention. Our findings suggest that such multidisciplinary approaches for the treatment of CLP with gingival recession and occlusal collapse help in improving occlusion and facial esthetics without the need for prostheses such as dental implants or bridges; in addition, the results show long-term post-treatment stability.

• The korean journal of orthodontics
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• v.49 no.4
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• pp.254-264
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• 2019

Objective: To evaluate the short-term changes in masticatory muscle activity and mandibular movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry. Methods: Twenty-seven skeletal Class III adult patients were divided into two groups based on the degree of facial asymmetry: the experimental group (n = 17 [11 male and 6 female]; menton deviation ${\geq}4mm$) and control group (n = 10 [4 male and 6 female]; menton deviation < 1.6 mm). Cephalography, electromyography (EMG) for the anterior temporalis (TA) and masseter muscles (MM), and mandibular movement (range of motion [ROM] and average chewing pattern [ACP]) were evaluated before (T0) and 7 to 8 months (T1) after the surgery. Results: There were no significant postoperative changes in the EMG potentials of the TA and MM in both groups, except in the anterior cotton roll biting test, in which the masticatory muscle activity had changed into an MM-dominant pattern postoperatively in both groups. In the experimental group, the amount of maximum opening, protrusion, and lateral excursion to the non-deviated side were significantly decreased. The turning point tended to be shorter and significantly moved medially during chewing in the non-deviated side in the experimental group. Conclusions: In skeletal Class III patients with facial asymmetry, the EMG activity characteristics recovered to presurgical levels within 7 to 8 months after the surgery. Correction of the asymmetry caused limitation in jaw movement in terms of both ROM and ACP on the non-deviated side.

• Journal of Oral Medicine and Pain
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• v.14 no.1
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• pp.67-80
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• 1989

The author studied the changes of muscle activity with Bioelectric processor Model EM2(Myotronics Corp., USA) before and after occlusal stabilization splint therapy. For this study, 15 temporomandibular disorders patients and 15 students without any temporomandibular disorders symptoms were selected, for experimental group and control group, respectively. Experimental group were treated with occlusal stabilization splint and checked about electromyographic activity before and after therapy. Electromyographic levels were measured in both groups at the following mandibular position, i.e., physiologic rest, tapping, light biting, hard open without pain, open with pain, right excursion and ipsilateral biting, left excursion and ipsilateral biting, protrusion, protrusive biting, edge biting and physiologic rest after movement. The obtained results were as follows : 1. In experimental group, post-treatment mean values of muscle activity were lower than pretreatment values. 2. In general, the pre-treatment mean values of muscle activity in experimental group were higher than those of control group. 3. In experimental group, no statistically significant difference appeared between affected and unaffected side. 4. The mean value of muscle activity in physiologic rest position after each movement check was lower than that before each movement check.

• Journal of Oral Medicine and Pain
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• v.13 no.1
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• pp.5-12
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• 1988

The purpose of this study was to evaluate the therapeutic effect of occlusal stabilization splint on the clinical symptoms and the condylar movement in patients with Temporomandibular Disorders(TMD). For the study, 15 TMD patients treated with stabilization splint and followed up were selected. The age of them was from 18 to 65 years and the mean period of treatment was 2.9 months. The author examined signs and symptoms of TMD according to Dr. Friction's evaluation from and recorded the condylar paths with Denar pantronic before and after splint therapy. The obtained results were as follows : 1. On the first visit, 11 patients(73.3%) showed muscle tenderness on palpation and the frequency was lateral pterygoid, masseter, medial pterygoid, temporalis, sternocleidomastoideus in the order named. 2. Occlusal stabilization splint was more effective in pain relief(100%) than in other dysfunction improvement(85.7%) 3. The amount of maximum opening increased from 37.1㎜ to 42.2㎜, but those of protrusion and laterotrusion changed little. 4. Pan. PRI scores decreased from 32.9 to 21.8, which meant improved reproducibility of mandibular border movements, and the group with sever dysfunction category showed more decrease in score than the group with moderate or slight dysfunction category.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.168-174
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• 2005

Reconstruction of the lower lip requires consideration of several factors. There should be retained sensation, maintenance of oral sphincter function, and a large enough opening for the mouth. In addition, it is important to achieve an aesthetically acceptable appearance. Webster's modification of Bernard operation is one of good methods which satisfy above mentioned goals. The purpose of this article is to present the results and review the perioperative problems after reconstruction of the lower lip by this operation. We reviewed seven patients after surgical reconstruction by the same method between January of 1996 and December of 2003. Five patients were male and two were female. The mean follow-up period was 15 months. We obtained functionally and cosmetically acceptable appearance after reconstruction. Most of the reconstructed lower lips were large enough for full mouth opening, but one patient required additional commissuroplasty, and one other patient was treated with wound revision for dehiscence resulting from protrusion of mandibular lateral incisor tooth. All other patients accepted their facial appearance. In conclusion, careful planning and consideration for dental problems and proper closure tension may ensure satisfactory outcome & lower lip competence, when using this modified operative method for lower lip reconstruction.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.735-742
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• 1997

Class II malocclusion can be treated via early orthopedic, orthodontic treatment or orthognathic surgery with orthodontic treatment. In the mixed dentition, early orthopedic treatment can be used. Especially, in the case of mandibular retrognathism, the functional appliances can be used, and in the case of maxillary protrusion is combined, they can be used together with headgear. After using activator and activator combined with headgear to the class II malocclusion paitent in the mixed dentition, the results were as follows: 1. Lateral profile was improved, and lower face height was increaed. 2. Overjet was decreased, and molar relationship was changed to class I molar relationship. 3. Growth can be undisturbed, and the aggravation of malocclusion can be prevented to make the 2nd phase orthodontic treatment be much easier.

• Journal of Oral Medicine and Pain
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• v.7 no.1
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• pp.86-94
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• 1982

Maximal active movements of the mandible in the vertical and the horizontal plane were measured in 147 boys and 155 girls. with an age of 13, 15, 17 years respectively. The studied persons had no pain or severe symptoms of dysfunction of the masticatory system and the method used in this paper was devised by Agerberg, and the numerical calculations were performed at the Dept. of Medical Engineering of Seoul National University Hospital. The obtained results were as follows : 1. The mean values of maximal opening in 13 year-old boys and girls were 58.5 mm,58.9 mm respectively, and the mean values of boys were increased with age. 2. The mean values of maximal lateral movement to the right in 13-year-old boys and girls were 9.1 mm, 8.3 mm respectively, and the mean values to the left were 9.3 mm, 8.7 mm resprctively. The mean values were not increased with age in both. 3. The mean values of maximal protrusion in 13-year-old boys and girls were 8.7 mm, 8.1 mm respectivly, and in all ages the mean values of boys were larger than those of girls. 4. The range of maximal mandibular movements in teen-agers with 95% probability prediction ellipses were presented.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.