• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.69-81
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• 1990

Classification of facial asymmetry has not been yet well-organized because of their variety on etiologic factors, involved sites and clinical expressions. And surgical treatments are also variable and depend upon their causes and clinical abnormalities. This is a case report on surgical experiences of two patients who had severe facial asymmetry and could not treated pre-surgical orthodontics before surgery. One patient was belong to hemifacial microsomia and another was a very unusual complex type related to unilateral condylar hyperplasia, unilateral macrognathia and unilateral mandibular hypoplasia. The authors used a simultaneous two-jaw surgery, bone shaving and onlay-type bone graft in former case, and a simultaneous two-jaw surgery, condylectomy, bone shaving and only-type bone graft in latter case. In two cases, immediate post-operative results in function and esthetics were excellent, however, progressive resorption of onlay-type bone grafts have been noticed.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.20.1-20.7
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• 2019

Background: The purpose of this study was to evaluate the effects of botulinum toxin A (BTX) injection into the anterior belly of the digastric muscle on a growing rat. Methods: Ten Sprague Dawley rats were used in this study. When the rats were 13 days old, 0.5 units of BTX was injected into the anterior belly of the digastric muscle for the experimental group (n = 5). For the control, the same volume of normal saline was injected (n = 5). The rats were sacrificed at 60 days old, and the skulls were harvested for micro-computed tomography (μCT) analysis. Results: In anthropometric analysis, the zygomatic arch and mandibular bi-condylar width were significantly lower in the experimental group than those in the control group (P = 0.025 and 0.027, respectively). The maxillary point width was significantly higher in the experimental group than that in the control group (P = 0.020). Conclusion: BTX injection into the anterior belly of the digastric muscle had effects on the maxillofacial bony width in growing rats.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.21.1-21.3
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• 2019

Background: Treatment planning the correction of a transverse maxillary occlusal plane cant often involves a degree of qualitative "eyeballing", with the attendant possibility of error in the estimated judgement. A simple chair side technique permits quantification of the extent of asymmetry and thereby quantitative measurements for the correction of the occlusal plane cant. Methods: A measuring instrument may be constructed by soldering the edge of a stainless steel dental ruler at 90° to the flat surface of a similar ruler. With the patient either standing in natural head position, or alternatively seated upright in the dental chair, and a dental photographic retractor in situ, the flat under-surface of the horizontal part of this measuring instrument is placed on a unilateral segment of a bilateral structure, e.g. the higher maxillary canine orthodontic bracket hook. The vertical ruler is held next to the contralateral canine tooth, and the vertical distance measured directly from the canine bracket to the flat under-surface of the horizontal part of the measuring instrument. Results: This vertical distance quantifies the overall extent of movement required to level the maxillary occlusal plane. Conclusions: This measuring instrument and simple chair side technique helps to quantify the overall extent of surgical levelling required and may be a useful additional technique in our clinical diagnostic armamentarium.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.217-231
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• 1984

Many investigators have studied the growth changes of craniofacial complex to obtain important informations and standard values with which attempts at prediction of growth and treatment results have been under exploration. The author analyzed 360 cephalometric roentgenograms of 40 boys and 50 girls taken from the ages of 6 to 9 to assess the growth changes of craniofacial complex and to establish Korean norms by Ricketts' analysis method. 17 Landmarks, 10 planes and 8 angles were plotted and measured by linearly and angularly. The results were as follows: 1. The author made the tables of means, standard deviations from the measured values. 2. The item which showed significant difference between males and females in longitudinal study was facial axis length. 3. Items which show significant changes during 3 years were cranial base length, facial axis length, lower incisor to APO, Upper molar to PTV in males, and cranial base length, facial axis length, upper molar to PTV in females. 4. The correlations between cranial base length and facial axis length to body height and weight were higher in males than in females throughout the items.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.71-84
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• 1986

The purpose of this study was to analyze the effect of orthopedic forces on the craniofacial complex utilizing the three kinds of the head gear. (high pull head gear, straight pull head gear, cervical pull head gear) For this study, the teeth and alveolar bone and palate were reproduced from birefringent materials and other parts of craniofacial complex were coated with birefringent material on the model. The effect of orthopedic forces on the craniofacial complex was analyzed by photoelastic method using transmission polariscope and reflection polariscope. The results were as follows. 1. The cervical pull head gear had the greatest tipping effect on the maxillary molars and high pull head gear had the least tipping effect. 2. In areas stressed, the cervical pull head gear stressed the greatest degree. 3. Only cervical pull head gear produced stress at the zygomaticofrontal suture and the posterior region of palate. 4. The straight pull head gear and high pull head gear produced stress at just inferior to the anterior nasal spine. 5. The cervical pull head gear and straight pull head gear produced tensile stress at the fronto-maxillary suture. 6. The pterygoid plates of the sphenoid bone, the zygomatic arches, the junction of the maxilla with the lacrimal and ethmoid bone, and the maxillary molars were affected by three types of head gear.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.151-160
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• 1981

The purpose of this study was to compare the retentive values of various dental cements used for cementing the orthodontic bands on the teeth. Sound freshly extracted human premolar teeth were selected for the study. Eleven commercial dental cements (Zinc phosphate, reinforced Zinc-oxide eugenol, Carboxylate and Glass ionomer cements) were handled under standardized conditions. All cemented speciments were then kept in a thermostatic humidor cabinet regulated at $23{\pm}2^{\circ}C$ and more than $95\%$ relative humidity and tested after 24 hours and 1 week each. The force required to remove the cemented orthodontic bands from the teeth was determined on an Instron Universal Testing Machine using a modified specimen holding device with a cross-head speed of 0.20mm/min. The results obtained were as follows: 1, The retentive values of the band cemented with zinc phosphate cements and carboxylate cements were considerably higher than those of the reinforced zinc oxide-eugenol and glass ionomer cements. 2. There was no significant difference between the retentive value of carboxylate cements as compared with zinc phosphate cements. 3. The retentive value of the reinforced zinc oxide eugenol cements was lowest all of the coements. The retentive values expressed for all cements up to at least one week were highly but no significant difference was found between the 24-hour and 7 day time intervals.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.161-168
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• 1981

This study was undertaken to observe the histologic changes of surrounding maxillary sutures to the widening of midpalatal suture, using two adult dogs, weighing about 10 kg, for experimental, and one for control group. After widening of the midpalatal suture with expansion screw for ten days was performed, and followed by sacrifice of experimental animals. Tissues were excised from 5 surrounding maxillary suture portions such as, internasal, interfrontal, midsagittal, zygomatrco-temporal, and midpalatal sutures. After that, the specimens were fixed and decalcified in $10\%$ formalin sol. and $5\%$ nitric acid. Embedding in paraffin and serial sections at a thickness of 5 micron was done, After Hematoxylin-Eosin staining and light microscopic examination, Following results were obtained: 1. In midpalatal suture area, which showed most prominent histologic change, High degree of fibronlastic and osteoblastic proliferation lining the bony trabeculae with osteoid tissue projection into the fibrous connective tissue were observed. 2. In interfrontal suture area, moderate degree of fibroblastic and osteoblastic proliferation was observed. 3. In internasal suture area, active osteoblastic and osteoclastic proliferation lining the bony trabeculae was observed, and separation of fibrous connective tissue was also observed. 4. In midsagittal and zygomatico-temporal suture areas, no histologic changes can be observed.

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.101-113
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• 1993

For the purpose of interpretation of positional changes of craniofacial structures in Class III malocclusion between mixed and permanent dentition, 73 normal samples and 103 Class III samples of mixed dentition and 125 normal samples and 168 Class III samples of permanent dentition were selected. Comparative cephalometric analysis was undertaken between them respectively by mesh diagram method to evaluate the positional changes of maxilla and mandible in anteroposterior direction and vertical direction and also the inclination changes of maxillary and mandibular incisors in labio-lingual direction. The following results were obtained : 1. The antero-posterior positional changes of the maxilla and mandible were posterior direction of maxilla and anterior direction of mandible. 2. The vertical positional changes of the maxilla and mandible were superior direction of both maxilla and mandible. 3. The labio-lingual inclination changes of the maxillary and mandibular incisors were lingual direction of both maxillary and mandibular incisors.

• The korean journal of orthodontics
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• v.4 no.1
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• pp.57-61
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• 1974

The patient, a girl of 19 years in good health, had a class I malocclusion. The maxillary left centra1 incisors and both lateral incisors had already erupted. But the space for the right central incisor was partially closed by the mesial drifting of the neighboring teeth. The caused a shift in the midline and a cross-bite relation on the incisors. X-ray examination revealed the presence of the right central incisor in the alveolar bone and odontoma just above the crown of the right central incisor. After enough space for the impacted incisor was created in the dental arch with a open-coil spring the rectangular incision was made. Removing the odontoma uncovered the flat surface of the labial aspect of the incisor. During the tooth had erupted of its own accord, any unnecessary force had been imposed on the tooth. When it was decided that the tooth should be brought out by the mechanical device, the gold cast onlay with hook was used and run a light elastic between this hook and the main arch wire. Finally the tooth was brought down to the arch level. The result was excellent. Fortunately the esthetic problem and any detrimental effects on the psychological make-up could be avoided.

• The korean journal of orthodontics
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• v.42 no.3
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• pp.144-154
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• 2012

This article reports the orthodontic treatment of a patient with skeletal mandibular retrusion and an anterior open bite due to temporomandibular joint osteoarthritis (TMJ-OA) using miniscrew anchorage. A 46-year-old woman had a Class II malocclusion with a retropositioned mandible. Her overjet and overbite were 7.0 mm and -1.6 mm, respectively. She had limited mouth opening, TMJ sounds, and pain. Condylar resorption was observed in both TMJs. Her TMJ pain was reduced by splint therapy, and then orthodontic treatment was initiated. Titanium miniscrews were placed at the posterior maxilla to intrude the molars. After 2 years and 7 months of orthodontic treatment, an acceptable occlusion was achieved without any recurrence of TMJ symptoms. The retropositioned mandible was considerably improved, and the lips showed less tension upon lip closure. The maxillary molars were intruded by 1.5 mm, and the mandible was subsequently rotated counterclockwise. Magnetic resonance imaging of both condyles after treatment showed avascular necrosis-like structures. During a 2-year retention period, an acceptable occlusion was maintained without recurrence of the open bite. In conclusion, correction of open bite and clockwise-rotated mandible through molar intrusion using titanium miniscrews is effective for the management of TMJ-OA with jaw deformity.