• The korean journal of orthodontics
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• v.15 no.1
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• pp.149-153
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• 1985

The purpose of this study was to pursue the morphology and position of mandibular symphysis and the positioning of lower incisors in 36 male and female adults with severe skeletal Class III malocclusion indicated for surgical orthodontic treatment. The following results were obtained. 1. Skeletal Class III malocclusion samples had thinner labio-lingual depth and more lingual inclination of mandibular symphysis than that of normal occlusion in both sexes. 2. Male and female with the skeletal Class III malocclusion showed marked lingual tipping of lower incisors. 3. In skeletal Class III malocclusion samples, lingual basal bone was thinner than that of normal occlusion in both sexes.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.19-29
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• 1995

This study was performed to compare the size of soft palate, tongue and airway according to the types of the malocclusion and evaluate the correlation between the size of soft palate, tongue, airway and dentofacial skeleton respectively. The sample of this study was 98 malocclusion female patients between the ages 12 and 17 years. The lateral cephalometric radiographs were taken and the distance, angle, ratio and area of the dentofacial skeleton, soft palate, tongue and airway were measured and evaluated statistically. The results obtained were as follows: 1. There was significant difference in SNB, ANB, facial angle, facial convexity, A-B plane angel, Y axis to FH, SN-MP, Wits appraisal, ODI and APDI according to the types of malocclusion. 2. The hyoid bone was more posteriorly positioned in Class II malocclusion group than other two groups and superio-inferior position of the hyoid bone was not different according to the malocclusion types. 3. The nasopharyngeal area of Class II and Class III malocclusion group was smaller than that of Class I malocclusion group, and the pharyngeal area of Class II malocclusion group was smaller than that of Class I and Class III maocclusion group. There was no difference of the area of the soft palate, tongue, oropharynx and hypopharynx according to malocclusion types. 4. The ramal height and mandibular body length(Go-Me) showed positive correlation with the area of tongue, nasopharynx, oropharynx, and pharynx. SNA did not correlated with the area of tongue and airway but SNB showed positive correlation with the area of hypopharynx and pharynx. The anterior, posterior facial height, upper and lower central incisor position to facial plane showed positive correlation with tongue area.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.395-403
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• 1994

To find out the antero-posterior morphology of the upper face in Angle's class III malocclusion patients, 90 patients, adults in Heilman's Dental age, were used as samples and following results were obtained after the relative comparision of antero-posterior relationship of upper facial structures between Angle's class I malocclusion patients and Angle's class III malocclusion patients and of antero-posterior size of upper facial structures to horizontal and vertical structures in each patients. 1. After comparison of the distance from PMV line to anterior margin of maxillary sinus and cheek, which determines the antero-posterior position of the upper face, upper face in Angle's class III patients are underdeveloped relative to Angle's class I patients. The distance between orbitale and anterior margin of maxillary sinus were greater in Angle's class I patients, whic implies thart the upper face in Angle's class III are depressed. 2. Antero-posterior dimension of anterior cranial base from PMV line and vertical dimension of upper face are statistically insignificant between two groups. After comparing antero-posterior position of upper face to anterior cranial base, the upper face in Angle's class Et patients are depressed antero-posteriorly in relation to anterior cranial base. Following the comparision of antero-posterior position of upper face in relation to vertical dimension of upper face, the upper face in Angle's class III patients seem to be narrow antero-posteriorly

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.89-104
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• 1988

This study was performed to investigate the relationships between the EMG activity of the masticatory muscles in Angle's Class II div. 1 malocclusion and normal occlusion. This study was ranged from age 12 to 14 year-old for 30 male subjects: 15 subjects were Angle's Class II div. 1 malocclusion, and 15 subjects were normal occlusion with acceptable profile. Their cephalometric measurement were analyzed, and the EMG recordings from the anterior temporal, posterior temporal, masseter, and orbicularis oris muscles were analyzed during rest position, mastication of peanuts, and swallowing. All data was recorded and statistically processed with the VAX-11/780 computer system. The results were as follows: 1. The activity of muscles at rest was highest in the posterior temporal muscle with normal occlusion, as well as in those with Class II div. 1 malocclusion, and the posterior temporal muscle activity of Class II div. 1 malocclusion was higher than that of normal occlusion. 2. During mastication, all muscle activities of Class II div. 1 malocclusion were recorded lower than those of normal occlusion, and the activity of the anterior temporal muscle was higher than that of the posterior temporal muscle in both types of occlusion. 3. As for the activity in orbicularis oris muscle, it was greater in opening phase than in closing phase during chewing cycle with both types of occlusion. 4. During swallowing, the activities of the anterior temporal, masseter, and orbicularis oris muscles of Class II div. 1 malocclusion were recorded lower than those of normal occlusion.

• The Journal of the Korean dental association
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• v.50 no.2
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• pp.64-71
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• 2012

Recently, the presurgical orthodontic duration tends to be shortened by virtue of the advancement of surgical and orthodontic techniques in class III orthognathic surgery cases. But the predictability of the surgical results should be secured by removing several uncertain factors in presurgical orthodontic treatment. The purpose of this study is to investigate the influence of immediate postsurgical occlusal stability on postsurgical mandibular change. The study includes 40 patients who underwent orthognathic surgery to correct skeletal class III malocclusion. The patients were divided into two groups based on the numbers of occlusal contact in surgical setup occlusion: group 1 (stable surgical occlusion, n=24) and group 2(unstable surgical occlusion, n=16). Changes of horizontal and vertical mandibular measurements during postsurgical follow up period(from 1 week postsurgery to 12month after debonding) were compared to examine the differences between two groups. The stability of surgical occlusion is one of the factors influencing postsurgical mandibular changes in class III malocclusion. The various class III malocclusion cases have specific prerequisites for the orthognathic surgery according to the skeletal patterns. The prerequisites should be obtained by minimum presurgical orthodontics to increase the predictability of the surgical results.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.537-548
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• 1996

To investigate the relationship between the calcification stages of mandibular canines and the skeletal maturity stage of the hand-wrist in subjects with normal occlusion and Class III malocclusion, hand-wrist radiographs and panoramic radiographs were taken from subjects of normal occlusions(94 males, 88 females) and Class III malocclusions(75 males, 76 females) who had no systemic diseases and no history of orthodontic or prosthodontic treatment. Fishman's method for the skeletal maturity stages of the hand-wrist and Demirijian's method for the calcification stages of mandibular canines were used and analyzed. The results were as follows : 1. In subjects with normal occlusion and Class III malocclusion, skeletal maturity of the hand-wrist and calcification of mandibular canines at various ages occured earlier in females than in males(p<0.05). 2. Comparing the skeletal maturity stages of the hand-wrist and the calcification stages of mandibular canines between subjects with normal occlusion and Class III malocclusion, there were no significant differences between the groups. 3. The correlation coefficient between the calcification stages of mandibular canines and the skeletal maturity stages of the hand-wrist. in subjects with normal occlusion and Class III malocclusion showed a high association(p<0.01). 4. In stage 4 of the skeletal maturity of the hand-wrist, the frequency distribution of calcification G stage among the various calcification stages was highest both in normal occlusion and in subjects with Class III malocclusion. However, there was no significant difference in the frequency distribution of calcification stages between the groups.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.144-150
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• 2015

Early treatment is recommended for class III malocclusion in the primary dentition, though it is difficult to diagnose correctly. It was recommended dental maturation can possibly be used to make a differential diagnosis of skeletal class III malocclusion. This study aimed to compare dental maturation of first molars in children with skeletal or non-skeletal class III malocclusion in the primary dentition and to determine if dental maturation could be used to make a differential diagnosis of class III malocclusion. Among the children visiting the department of pediatric dentistry in Pusan National University Dental Hospital for anterior crossbite in the primary dentition, 18 were categorized into the non-skeletal class III malocclusion and 34 into the skeletal class III malocclusion. Panoramic radiographs were used to make comparative analysis of dental age and the eruption rate of the first molars. The following results were obtained. No difference was found between chronologic and dental age by the skeletal features or gender, with the latter being older than the former (p < 0.05). The discrepancies in eruption rate of first molars were significantly different between skeletal (18.91%) and non-skeletal groups (16.53%) (p < 0.05). This result implies that maturation of the first molars might be used to make a differential diagnosis of class III malocclusion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.152-161
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• 2007

This study was conducted to patients visited oral maxillo-facial surgery, KNUH and the purpose of the study was to assess skeletal and dento-alveolar stability after surgical-orthodontic correction treated by skeletal Class III malocclusion patients with open bite versus non-open bite. This retrospective study was based on the examination of 40 patient, 19 males and 21 females, with a mean age 22.3 years. The patients were divided into two groups based on open bite and non-open bite skeletal Class III malocclusion patients. The cephalometric records of 40 skeletal Class III malocclusion patients (open bite: n = 18, non-open bite: n = 22) were examined at different time point, i.e. before surgery(T1), immediately after surgery(T2), one year after surgery(T3). Bilateral sagittal split ramus osteotomy was performed in 40 patients. Rigid internal fixation was standard method used in all patient. Through analysis and evaluation of the cephalometric records, we were able to achieve following results of post-surgical stability and relapse. 1. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in maxillary occlusal plane angle of pre-operative stage(p>0.05). 2. Mean vertical relapses of skeletal Class III malocclusion patients with open bite were $0.02{\pm}1.43mm$ at B point and $0.42{\pm}1.56mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.12{\pm}1.55mm$ at B point and $0.08{\pm}1.57mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in vertical relapse(p>0.05). 3. Mean horizontal relapses of skeletal Class III malocclusion patients with open bite were $1.22{\pm}2.21mm$ at B point and $0.74{\pm}2.25mm$ at Pogonion point. In skeletal Class III malocclusion patients with non-open bite, $0.92{\pm}1.81mm$ at B point and $0.83{\pm}2.11mm$ at Pogonion point. There was no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in horizontal relapse(p>0.05). 4. There were no significant statistical differences between open bite and non-open bite with skeletal Class III malocclusion patients in post-surgical mandibular stability(p>0.05). and we believe this is due to minimized mandibular condylar positional change using mandibular condylar positioning system and also rigid fixation using miniplate 5. Although there was no significant relapse tendency observed at chin points, according to the Pearson correlation analysis, the mandibular relapse was influenced by the amount of vertical and horizontal movement of mandibular set-back(p=0.05, r>0.304).

• The korean journal of orthodontics
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• v.24 no.2
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• pp.319-329
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• 1994

This study was carried out to research the adaptation patterns of head posture after activator therapy in functional class III malocclusion patients. For this purpose, 29 functional class III malocclusion patients, from the ages of 8 to 13 years old, were used. 1, Increse in capacity of oral cavity capacity were found in all the samples, but craniocervical angulation were varied into incresed group and decreased group after activator therapy. 2. Head posture exhibited the compensatory adaptation in the relative growth increments of the vertical dimension, ALFH and PLFH. 1) A group with more PLFH and less sagittal angle showed relatively small growth increment in PLFH during the treatment period, thus craniocervical angulation was increased. 2) A group with less PLFH and more sagittal angle showed relatively great growth incrmenet in PLFH during the treatment period, thus craniocervical angulation was decreased.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.235-246
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• 1987

The purpose of this study was to detect out the changes occured during orthodontic treatment. The sample was consisted of 77 orthodontic patients. For this study 13 linear lengths and arch area were measured in maxilla, mandible respectively and were analyzed statistically. The results were as follows 1 The sequence of changes in the form and dimensions of dental arches following orthodontic treatment was as follows Class I malocclusion, Class III malocclusion, Class II malocclusion. 2 Changes in the form and dimensions of dental arches were greater in extraction cases than those of non-extraction cases 3 In comparison with maxilla and mandible on the amount of changes following orthodontic treatment in each malocclusion group, significant differences were greatest in class III malocclusion 4 In comparison with maxilla and mandible on the amount of changes following orthodontic treatment in extraction and non-extraction cases, significant differences were greater in extraction cases than those of non-extraction cases 5. The amount of changes during orthodontic treatment in extraction and non-extraction cases in male was not different from female's.