• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.627-646
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• 1992

The purpose of this study was to investigate the relationship among the activity of the craniofacial muscle and craniofacial form and occlusal state. In this study, subjects were consisted of 23 male adults with skeletal Class III malocclusion and 30 male adults with normal occlusion. The measurements in oral exam, lateral ceghalogram, and E.M.G. recordings of anterior temporal, masseter, and upper lip muscles at rest position, clenching in centric occlusion, chewing of gum, swallowing of juice, were analyzed with SPSS system. The results were as follows: 1. At rest position upper lip muscle activity of skeletal Class III group was significantly higher than that of normal group. 2. Both clenching and chewing masseter and temporal muscle activity of normal group were significantly higher than that of skeletal Class III group. 3. During swallowing of juice, upper lip muscle activity of skeletal Class III group were significantly higher than that of normal group. 4. The activities of masseter and anterior temporal muscle during clenching and chewing were significantly correlated with hypodivergent facial form and number of occluded teeth. 5. The activity of upper lip during swallowing had positive correlation with mandibular prognathism.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.235-242
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• 2008

The purpose of this study was to investigate the relationship of the skeletal maturity of hand-wrist and the development of mandibular third molar in subjects with class I and class III malocclusion. The subjects used in this study were 304 children(149 boys, 155 girls) with class I malocclusions and 308 children( 153 boys, 155 girls) with class III malocclusions, ranged from 8 to 15 years of age. Hand-wrist radiographs and panoramic radiographs were used to evaluate the stage of skeletal maturity and teeth development. Fishman's method for the skeletal maturity stages of the hand-wrist and new six-developmental-stage method for the calcification stages of mandibular third molars were analyzed. The results were as follows : 1. In subjects with class I and class III malocclusion, skeletal maturity of the hand-wrist occured earlier in females than in males(p<0.05), while the calcification stages of mandibular third molars were no significant gender differences. 2. There were no significant differences between the groups, when comparing the skeletal maturity stages of the hand-wrist and the calcification stages of mandibular third molars between subjects with the class I and the class III malocclusion. 3. The correlation coefficients between the calcification stages of mandibular third molars and the skeletal maturity stages of the hand-wrist in subjects with class I and class III malocclusion showed a high interrelationship(p<0.01). 4. The correlation coefficients between the calcification stages of mandibular third molars and chronological age in subjects with class I and class III malocclusion showed a high interrelationship (p<0.01). As a result, there were no significant differences between class I and class III malocclusion group for skeletal maturity of the hand-wrist and third molar development.

• Korean Journal of Cleft Lip And Palate
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• v.14 no.1_2
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• pp.1-18
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• 2011

Skeletal malocclusion is the result of abnormal dimension and alignment of each skeletal component. Understanding on these mechanisms may help to elucidate the etiology of skeletal malocclusion and to establish population-oriented treatment plans. Attempts to subdivide the Angle's classification have been performed for Class III malocclusion, while few studies have been conducted for Class II malocclusion despite recent growing interests in Class II malocclusion. 200 adults (88 male, 112 female) with skeletal Class II malocclusion were collected and subdivided using cluster analysis, using the measurements representing the dimension and the alignment of each facial skeletal component. The properties of each cluster was grouped within the subjects and a comparison between the subjects and the control group (38 male, 35 female) with normal occlusion was performed. Six clusters were finally recognized in each male and female groups. The clusters in both genders were mainly characterized by the cranial base alignment, dimension of the posterior cranial base, dimension of the mandibular ramus and the degree of mandibular rotation. The results implicate that active treatment of mandible rather than the nasomaxillary complex may be primarily considered for the correction of Korean Class II skeletal pattern.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.420-426
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• 2009

The purpose of this study was to evaluate skeletal and soft tissue changes that occur after using a facemask for treatment of skeletal class III malocclusion, and to assess the relapse pattern when no retention appliance was used. Fifteen skeletal class III malocclusion patients were treated with a facemask for an average of 12 months. No retention appliance was used during the 1 year follow-up period. Cephalograms were taken during pretreatment, posttreatment, and the 1 year follow-up. Cephalograms were traced, analyzed, and the results were compared between cephalograms. All patients showed significant sagittal skeletal changes after treatment, but they also showed a significant relapse during the 1 year follow-up period when no retention appliance was used. Despite the relapse, the sagittal skeletal changes that remained were still significant. Vertical skeletal change was also significant after treatment, but the total change was not significant after a 1 year follow-up due to relapse. In soft tissue changes, facial convexity and upper lip position improved after treatment and this change remained significant after the 1 year follow-up period. Facemask therapy is therefore an effective method for treatment of skeletal class III malocclusion, however, retention is imperative to maintain the treatment effect.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.457-468
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• 1991

This investigation was designed to categorize Angle's class III malocclusion groups through analyzing horizontal and vertical components of craniofacial skeleton in Angle's class III malocclusion. The material selected for this study consisted in standard lateral cephalogram of one hundred and fifty five children, seventy four boys and eighty one girls, aged 6 through 15 years, having Angle's class III malocclusion. On the basis of findings of this study, the following results were obtained. 1. In horizontal skeletal classifications,16 groups were classified FMN-A-B, SE-FMN-A according to the Ba-SE-Me, Ba-SE/R. 2. The sequences that have relatively high frequency are as follow; a) Horizontal Group l b) Horizontal Group 3 c) Horizontal Group 5 d) Horizontal Group 9 e) Horizontal Group 4 3. In vertical skeletal classification, 8 groups were classified according to the PMV/PP, PMV/OP, PMV/MP. 4. The sequences that relatively high are as follows; a) Vertical Group 1 b) Vertical Group 3 c) Vertical Group 4 d) Vertical Group 8.

• The korean journal of orthodontics
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• v.17 no.1
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• pp.107-117
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• 1987

The study was designed to examinate the discrimination rate of 4 antero-posterior cephalometric measurements from Angle's malocclusion groups. The material was 246 cephalometric radiographs taken from 42 Normal occlusions, 83 Class I malocclusions, 64Class II Division I malocclusions, 57Class III malocclusions. ANB angle, APDI, AB/OP angle, and Wits appraisal as measurements of antero-posterior skeletal relationship were measured on the cephalometric radiographs and statistically analyzed by the Canonical Discriminant Function. The results of this study were as follows: 1. ANB angle, APDI, AB/OP angle, and Wits appraisal were clinically useful measurements for the evaluation of the antero-posterior skeletal relationship. 2. The rates that discriminate actual malocclusion groups were $77.45\%$ in Wits appraisal, $74.02\%$ in AB/OP angle, $71.08\%$ in ANB angle, and $70.59\%$ in APDI. 3. The discrimination rate of actual Class III malocclusion show above $93\%$, but actual Class I and Class II division I malocclusions were relatively low.

• The korean journal of orthodontics
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• v.42 no.1
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• pp.11-16
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• 2012

Objective: This study aimed to evaluate the mean age of menarche, its secular trend in Korean women, and the relationship between malocclusion and the rate of skeletal maturation, as defined by menarcheal age. Methods: We retrospectively collected data on menarcheal age from 931 Korean women born during 1961 - 1997. Subjects were divided by the malocclusion type and birth-year decade into 3 and 4 groups, respectively. The mean menarcheal age for each group was determined, and one-way ANOVA was performed for intergroup comparison (p = 0.05). Two-way ANOVA was also performed to compare all the 12 subgroups (p = 0.05). Results: The mean age of menarche was 12.82 years for Korean women born during 1961 - 1997. A distinct downward secular trend of menarcheal age was noticed (p < 0.05). For the birth-year decade 1961 - 1970, the Class III malocclusion group showed earlier onset of menarche than the other malocclusion groups (p < 0.05), but the other birth-year groups did not show any significant difference in the type of malocclusion (p > 0.05). Conclusions: A positive secular trend towards earlier menarche exists among Korean women. Malocclusion does not show any significant relationship with the rate of skeletal maturation, as defined by menarcheal age.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.407-412
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• 2011

Purpose: The purpose of the present study was to evaluate the postoperative skeletal stability of two-jaw surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) via surgery first orthodontic treatment (SFOT) in class III malocclusion. Methods: Thirty-two patients who had two-jaw surgery via SFOT were included in this study. Serial lateral cephalograms were obtained before (T0), immediately after (T1), and six months after (T2) surgery. Twelve variables were measured for horizontal and vertical skeletal stability as well as for dental change. All measurements were evaluated statistically by a paired t-test ($P$ <0.05). Results: The mean skeletal changes were $0.1{\pm}2.5$ mm at point A and $-12.0{\pm}7.4$ mm at the pogonion. The mean horizontal relapse was 11.6% at the pogonion, and the mean vertical surgical changes included an upward displacement of $2.1{\pm}7.1$ mm and a forward displacement of $1.4{\pm}4.6$ mm at the pogonion. Upper incisor inclination decreased after surgery and was maintained at T2, and lower incisors were proclined from T1 to T2 by postsurgical orthodontic treatment. Conclusion: Postoperative skeletal stability of two-jaw surgery via surgery first orthodontic treatment in class III malocclusion was clinically acceptable.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.349-357
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• 2010

Physical factors and intra- and extra-oral factors of a patient have to be considered in order to decide a treatment plan for the skeletal class III malocclusion patient. Most of cases, the pre-prosthodontic treatment requires the orthodontic approaches and maxillofacial surgery. However, in some cases, patients' economic or medical condition makes impracticable situation for the orthodontic or surgical intervention. For those cases, the compromised prosthetic treatment which provides more stable and persistent occlusal stabilization is recommended. In this case report, a woman patient has a skeletal class III maxillomandibular relationship and misses multiple teeth. The prosthetic treatment without orthodontic and surgical intervention is performed due to her physical problem. The functional and esthetic results are achieved by the fixed prosthesis.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.208-214
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• 2001

Background: When we make treatment plan of class III malocclusion children, it is difficult to determine whether we treat it with orthognathic surgery or without orthognathic surgery. To determine that, we must consider many factors, such as cephalometric analysis, growth pattern, family history, and skeletal age. A Harvold cephalometric analysis is useful in determining the amount of discrepancy by comparing the maxillary unit length with mandibular, unit length. We tried this study to help the decision of treatment planning in class ill malocclusion children by comparison in class III malocclusion and normal occlusion children using a Harvold analysis. Materials and Methods: The materials for this study consisted of 20 class III malocclusion children. Cephalometric tracing and measurements were performed by one investigator. The control group consisted of 18 normal occlusion children and lateral cephalograms were obtained from 8.5 to 14.5 years old children biannually. The relationships between class III malocclusion group and normal occlusion group were evaluated statistically. Results: The lower anterior facial heights between two groups were not significantly different, although the lower anterior facial heights of class III malocclusion group was higher than those of normal occlusion group in all age groups. The Maxillary-mandibular unit length differences of class III malocclusion group were significantly higher than those of normal occlusion group(p<0.05). Conclusion: A Harvold analysis was useful to make treatment planning for class III malocclusion children.