• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.289-301
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• 2004

It is the purpose of this study to characterize oral symptoms and to comprehend the cause and the relapse possibility of patients with open bite. This case study examines the orthodontic treatment of a group of female patients with open bite and Angle's Class I malocclusion. A cephalograph of the patient was taken and tracing of the radiograph was completed. In addition to Bjork and Ricketts analysis, additional measurements of specific areas were taken. The occlusal plane was determined by drawing a line connecting the mesiobuccal cusp tip of the maxillary first molar and the incisal edge of the maxillary central incisors. Patients were divided into two groups depending on the relationship between the marginal ridge of the maxillayy first premolar and the drawn line. Those patients with marginal ridges above the occlusal plane were placed into Group 1, while Group 2 subjects exhibited marginal ridges lower than the occlusal plane. The common characteristics within each group and the characteristic differences between each group both prior to and after orthodontic treatment were examined, and finally, the functional oral volume of each patient was analyzed. The results of the case study were as follows: 1. An examination of the skeletal relationship and anatomical form for both Group 1 and 2 showed that all subjects exhibited hyperdivergent skeletal forms, but Group 2 subjects generally demonstrated underdevelopment of the mandible and a smaller articular angle, resulting in an anterior positioning tendency of the mandible. 2. An analysis of the maxillary arches of Group 1 subjects prior to and after orthodontic treatment showed that the antero-inferior direction had changed to an antero-superior directional tendency, while the maxillary arches of the Group 2 patients showed a trend from an antero-superior direction to an antero-inferior relationship. The mandibular arches in both groups showed a change to an antero-superior direction. 3. Functional space analysis showed that Group 2 patients exhibited a greater tendency of haying palatal planes that drop in a postero-inferior direction, resulting in a more severe open bite than their Group 1 counterparts. The results of this case study show that although patients belonging to either Group 1 or 2 exhibited few external differences in the appearance of open bite, an examination of the dental and skeletal relationships by analyzing patient cephalographs showed that patients presenting with flat maxillary occlusal planes exhibited more severe open bite relationships than patients with curved occlusal planes.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.4 no.2
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• pp.82-87
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• 2008

Cleidocranial dysplasia (CCD) is an autosomal dominant skeletal dysplasia and is caused by mutation in the CBAFA1 gene of 6p21 chromosome band. Patients with CCD express skeletal dysplasia such as hypoplastic/aplastic clavicle, brachycephalic skull, midface hypoplasia and moderate short stature. In addition to skeletal dysplasia, specific symptoms may appear in respiratory organs, auditory area, and the more distinguished, dentition. Dental findings include: delayed eruption of permanent tooth, multiple supernumerary tooth more than five, malocclusion, etc. In Patients presenting excessive SNT, complications of SNT could be prevented and will be managed through pertinently timed treatment such as tooth extraction, using space maintainer, and orthodontic management after early diagnosis. This case is about the treatment of eruption disorders in permanent teeth owing to SNT in CCD patients, who are three family members in the $3^{rd}$ generation inherited from maternal grandfather through atavism. We performed the extraction of numerous SNT and orthodontic treatment on them in this case. On evaluating panoramic and cephalometric views, some classical signs of skeletal dysplasia due to CCD were recognized in a pool of three patients, the clavicle was distinctively displayed in all patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.649-656
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• 2005

The present study was designed to formulate cephalometric norms of normal occlusion for usage in orthodontic diagnosis of malocclusion in Korean children. Thirty two children, aged 4 to 6, with normal occlusion were chosen for this study, Sagittal and vertical relations were analyzed using lateral cephalogram and clinical photos and the measurements were compared with those of adults. On skeletal sagittal analysis, the mean values of the SNA and SNB angles were $83^{\circ}\;and\;78.72^{\circ}$. It showed that the mandible was retrognathic and retropositioned in comparison to those of adults. On skeletal vertical analysis, the mean values of the genial angle was $127^{\circ}$. This showed high angle pattern in children and reduction of genial angle due to counterclockwise rotation of the mandible is expected with growth. On soft tissue analysis, children showed convex pronto, obtuse nasolabial angle. On dental analysis, the mean values of the U1 to SN and IMPA were $91.04^{\circ}\;and\;86.57^{\circ}$. This showed retroclined upper and lower deciduous teeth in comparison to adults. For skeletal values, the liner values were generally greater in males than females.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.359-366
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• 2010

It was easy to find that children of a skeletal anterior crossbite in the early mixed dentition period showed a stark difference in the dental maturity between their maxillary and mandibular teeth, if they have stronger physical characteristics. If the difference of dental age between maxillary and mandibular teeth which can be identified via panoramic radiographs may serve as an early sign of class III malocclusion, this is considered valuable as a tool of early detection diagnosis. We obtained lateral cephalometric radiographs, panoramic radiographs, working model and clinical images of patients of Hellman dental age IIA and IIC who visited the department of pediatric dentistry, Pusan National University Dental Hospital and examined them to select 50 patents for normal occlusion group and skeletal anterior crossbite group, respectively. Their panoramic radiographs were used for the Demirjian's method to figure out dental ages of maxillary and mandibular teeth of each group and the eruption rate of the first molars. Their differences are as follows: 1. In both groups, the dental ages from Demirjian's method were advanced than the chronological ages. No sexual dimorphism was detected for the chronological or dental age in either group (p>0.05). 2. The difference of dental age of maxillary and mandibular teeth between the normal occlusion group and crossbite group was 0.22 and 0.69 years, respectively, with a higher difference in crossbite group(p<0.05). 3. Compared to the normal occlusion group, the crossbite group showed a higher difference in the eruption rate between maxillary and mandibular first molar(p<0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.1
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• pp.70-79
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• 2016

Patients who lost posterior teeth due to periodontitis or dental caries have collapsed vertical dimension, unstable occlusion and change of the mandibular position. In particular, patients in orthognathic surgery, clinician should re-establish the pre-operative stable position of mandibular condyle in articular fossa and favorable vertical dimension for high post-operative stability of mandible. Therefore, interdisciplinary approach and co-operation, including prosthetics, orthodontics, oral and maxillofacial surgeon, from diagnosis and treatment plan is important to get a good outcome. This case report was patients who had collapsed occlusal plane due to severe dental caries on maxillary molars with skeletal Class III malocclusion. Before orthognathic surgery, resetting of maxillary occlusal plane with temporary removable denture was performed. Then successful multidisciplinary approach was done and lead to acceptable clinical outcome.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.13-21
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• 2004

Recently several techniques have been reported for the treatment of anterior open bite in adults characterized by molar intrusion with skeletal anchorage. In this study, five adult patients who had anterior open bite malocclusion were selected to undergo upper molar intrusion with midpalatal miniscrew to close the open bite. The aim of this study is (1) to validate true intrusion of molars in adults (2) to test the usefullness of midpalatal miniscrews as anchorage for intruding upper molars (3) to evaluate the skeletal and dental changes of open bite closure. The results are as follows. (1) All had true intrusion of the maxillary molars. Mean amount of molar intrusion was 3.4mm(range 1.5-5mm). (2) No movement of midpalatal miniscrew occurred during their use. (3) Open bite closure was achieved for all 5 patients. The mandible closed and B-point rotated anteriorly and upward. The mandibular plane angle and the occlusal plane angle decreased.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.473-479
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• 1997

This author tried to find if the size of the frontal sinus can be used as a diagnostic aid to predict the manldibular growth pattern in growing Patients in lateral cephalogram utilizing the fact the the frontal sinus completes its growth in earlier stage but the mandible continues to grow until later. At this study, the 228 samples were divided into 3 groups as skeletal Class I, II, III malocclusions and three indicies(ANB, APDI, Wits) were measured which indicate the mandibular body length and the antero-posterior relationship of maxilla and mandible to evaluate their relations with frontal sinus. And results were obtained as followings 1. The size of frontal sinus is highly related to ANB, APDI, Wits and mandilar body length.(p<0.001) 2. the size of the frontal sinus of the Cl III malocclusion group was on the lateral cephalogram larger than Cl I and Cl II group.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.172-184
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• 1999

The present study was performed to identify morphologic sub-groupings in Korean children with Class I malocclusions, and to find out anatomic differences between the sub-groups. Standardized lateral cephalometric radiographs of 152 Korean children, aged between 6 and 12 years, with Class I malocclusions were analyzed by the Counterpart Analysis. A statistical method, Ward's Minimum Variance Cluster Analysis, was employed to divide the sample into sub-groups those with similar morphologic characteristics. The results were as follows; 1. There appeared two facial types, Type I and Type II, in Korean children with Class I malocclusions, 48.7% and 51.3%, respectively. 2. In both sub-groups, there existed strong Class III skeletal patterns due to a counterclockwise rotation of the Middle Cranial Fossa alignment, and strong Class II skeletal patterns due to the long Posterior Maxillary vertical dimension and a clockwise rotation of the Ramus alignment. 3. There were no significant differences in Upper Anterior Facial Height between Type I and Type II, $52.6{\pm}2.92mm\;and\;52.8{\pm}3.23mm$, respectively. 4. The Lower Anterior Facial Height in Type II was longer ($66.0{\pm}4.03mm$) due to the long Posterior Maxillary vertical dimension, the clockwise rotation of the Ramus alignment, and a clockwise rotation of the Mandibular plane alignment than that of Type I ($64.2{\pm}4.15mm$).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.218-224
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• 2011

Purpose: The purpose of this study is to evaluate the post-operative skeletal stability after surgical correction of patients with mandibular prognathism by bilateral sagittal split ramus osteotomy (BSSRO) and to evaluate the horizontal relapse tendency after the surgery. Methods: Twenty-six patients with Class III dental and skeletal malocclusion were selected for this retrospective study. Fifteen of them underwent BSSRO for mandibular setback and eleven of them underwent two-jaw surgery (Lefort I and BSSRO). In each patient, lateral cephalometric radiographs were taken pre-operatively, post-operatively within 1 week, and post-operatively after eight months. After tracing of the cephalometric radiographs, various parameters were measured. The analyses were done by linear measurement to evaluate the change in position of hard tissue B point, pogonion and mandibular plan angle by examination on lateral cephalograms. Results: The horizontal relapse rate was 27.1% at B point and 31.6% at pogonion in patients who underwent BSSRO. The horizontal relapse rate of the group where the amount of correction exceeded 10 mm was 25.69% at B point. Conclusion: There were no statistical differences on the magnitude of setback and direction of rotation of the mandible in mandibular stability. There were also no statistical differences between single mandibular surgery and two-jaw surgery for mandibular stability.

• The korean journal of orthodontics
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• v.47 no.1
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• pp.39-49
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• 2017

Objective: This retrospective, cross-sectional study aimed to establish reference data for normal crown and root lengths and the root-crown ratios (R/C ratios) for the mature maxillary and mandibular incisors in a Korean population by using cone-beam computed tomography (CBCT). Methods: We included 672 Korean patients (141 men and 531 women; mean age, $27.2{\pm}7.7years$) who underwent CBCT examinations during various dental treatments. Crown and root lengths and the R/C ratios of the maxillary and mandibular incisors were measured using CBCT data, which were analyzed to detect significant differences between demographic factors as well as sagittal and vertical skeletal or occlusal relationships. Results: Teeth of the same type in each half-arch were symmetrical. The mean R/C ratios varied from 1.1 to 1.2 for the maxillary incisors and from 1.3 to 1.4 for the mandibular incisors. Crown and root lengths were greater in men than in women, regardless of tooth type. Root lengths and R/C ratios for the mandibular incisors were significantly greater in patients with skeletal Class II malocclusion or an excessive overjet than in the other patients. The R/C ratios for the mandibular incisors were lower in patients with an open bite than in those with a normal or deep bite. Moreover, the R/C ratios for the mandibular incisors increased with age. Conclusions: The data obtained in our study can serve as reference values for crown and root lengths and the R/C ratios for the maxillary and mandibular incisors in the Korean population.