• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.509-522
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• 1996

By studying the relationship between the morphology of mandibular symphysis and craniofacial morphology in classIII malocclusion, this study aims at deciding whether the morphogy of mandibular symphysis can be used as a predictor on the growth of mandible. The materials used for this study were the cephalometric radiographs of male class III malocclusion. The subjected age groups were 10-12(G1 group) and 20 and above(G2 group): 50 were selected from each group. Each group was again divided, according to the ratio of symphysis, into Large(L), Average(A), and Small(S). The results of this study were summarized as follows: 1. In average the ratio of symphysis, G2 group showed significantly bigger than G1 group(p<0.05) 2. In both G1 and G2 groups, the ratio of symphysis had no relationship with the measurements on the cranial base and the maxilla(p>0.05). 3. In both G1 and G2 groups, there was not distinct difference in the antero-posterior positions among L, A, S subgroups. 4. L and A subgroups showed significantly larger than S subgroup in lower gonial angle and chin angle in G1 group (p<0.05). 5. In the measurements on the vortical relation of the face, anterior total face height(ATFH) and anterior lower face height(ALFH) of L subgroup were significantly larger than that of S subgroup in G1 group(p<0.05) and also mandible showed a tendency to grow downward vertically. 6. In the measurements on the tooth position and inclination, L subgroup showed as compared with S subgroup a tendency of extrusion of maxillary and mandibular teeth in G1 group, but G2 group showed such tendency only in mandibular teeth. 7. In the measurements on the abnormal growth prediction by Schulhof, in G1, there was no significant difference among L, A, S sugroups. 8. In the correlative analysis of the ratio of symphysis and other measurements, G1 group showed significant correlationships in chin angle, PP/MP angie, ANS-Me and other, while G2 group showed the same only in MP-LIT and MP-LMMC(p<0.05, p<0.01). In summarizing the above, in the G1 group, consisting of young males, no difference was noted in horizontal relation between L and S subgroups; in vertical relation, L subgroup showed a stronger tendency of downward growth of mandible than S subgroup. In adult male G2 group, however, no distinct morphological difference of craniofacial complex by the ratio of symphysis.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.799-817
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• 1994

The purpose of this study was to evaluate the initial skeletal pattern and growth change of whom had responsed well to chincap therapy. 93 patients seleted for this study were in mixed dentition and treated with chincap for more than 2 years. And 54 subjects were selected from these total samples and classified into two groups by the improvement of four measurements : ANB difference, APDI, Wits appraisal, and AF-BF. One was good response group which consisted of 26 children and the other was poor response group with 19 patients. Various measures of the craniofacial structure in the initial lateral cephalograms and the annual increments were calculated and analyzed by comparing two groups with t-test. The results were as follows : 1. Good response group had more horizontal growth pattern in initial stage of treatment than poor response group, and the contributing factors of this result were anterior posterior facial height ratio, gonial angle, lower genial angle and SN-mandibular plane angle. 2. The maxilla was positioned more anteriorly in good response group. 3. The amounts of vertical growth of maxilla was smaller but the horizontal growth of maxilla was larger in good response group. 4. The mandible rotated more infero-posteriorly in good response group. 5. The good response group had more vertical growth pattern of mandibular condyle.

• The korean journal of orthodontics
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• v.20 no.1
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• pp.123-133
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• 1990

The work was undertaken to evaluate the calcification of the second and the third molars in skeletal Class II and III malocclusions. The differences in the calcification stages between skeletal Class II and III malocclusion were evaluated and statistically analysed from panoramic radiographs of 202 males and females ranging in age from 11 to 15 years old. The results were as follows, 1. The calcification stages of the second and the third molars were not different between the skeletal Class II and III malocclusions in each age groups of both sexes. 2. The calcification stages of lower second and third molars of the skeletal Class III malocclusion are more advanced than those of the skeletal Class II malocclusion in male. 3. The clacification stages of upper second and third molars are more advanced than those of lower second and third molars in skeletal Class II malocclusion. 4. The calcification stages of lower second and third molars are more advanced than those of upper second and third molars in skeletal Class III malocclusion.

• Korean Journal of Cleft Lip And Palate
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• v.6 no.2
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• pp.59-67
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• 2003

A cephalometric study was performed to reveal differences between skeletal Class III malocclusion patients and cleft lip and palate patients, The material for this study consisted of 16 males (mean age 19.8, range 17-29) and 9 females(mean age 19.4, range 16-27) with cleft lip and palate, and 222 Skeletal Class III malocclusion patients(males 106, females 116), Cephalometric tracing and measurements were done by one investigator. Results were followed: 1. Cleft lip and palate group had more retrusive maxilla than the skeletal Class III malocclusion group. 2, Cleft lip and palate group had smaller effective maxillary and mandibular length than skeletal Class III malocclusion group, and the difference was more prominent in the mandible than in the maxilla. 3. Dental compensation was not observed in the upper incisors of cleft lip and palate group and in the lower incisors it was smaller than skeletal Class III group. 4, In the Gonial angle and lower anterior facial height values, there was no significant difference between cleft lip and palate and skeletal Class III malocclusion group. These results can be used in orthodontic treatment planning and orthognathic surgery for the cleft lip and palate patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.2
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• pp.119-128
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• 2011

In the process of assessing the children with anterior crossbite in early mixed dentition, it has frequently been detected that the stronger the skeletal pattern of the malocclusion is, the more markedly delayed the development and eruption of maxillary teeth are. If the anteroposterior characteristics of craniofacial skeleton has any relationship with dental maturation, the evaluation of dental development and eruption was thought to be able to contribute to early diagnosis of crossbite in children. This study was performed for the purpose of elucidating the relationship between dental maturation of maxillary teeth and some cephalometric values in children with anterior crossbite of maxillary undergrowth type in early mixed dentition. Among the children in Hellman dental age IIA and IIC who attended the Pediatric Dental Clinic of Pusan National University Hospital with orthodontic problems, cases with Class III malocclusion were classified and 50 cases of maxillary undergrowth type and type with normal maxilla respectively were randomly selected and studied as subjects. From their lateral cephalographs and panoramic radiographs, their anteroposterior skeletal features, the dental maturity and eruption rate were obtained of each group and data were analyzed to yield the results as follows: 1. Comparing the maturity of maxillary teeth of both groups, only the first molars of maxillary undergrowth group showed significantly slower development and eruption (p<0.05). 2. There was high correlation between maturation of maxillary 1st molar and chronological age(p<0.05). 3. Among the parameters of anteroposterior relationship of skeletal pattern in maxilla and mandible. Wits was revealed as a useful index to predict both the calcification and eruption rate of the 1st molars whereas SNA was to eruption rate(p<0.05).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.397-403
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• 2001

Purpose: The purpose of this study was to evaluate the postoperative stability of LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion and to help the establishment of treatment planning in patients with a skeletal class III malocclusion in the future. Materials and Methods: The lateral cephalograms of 14 patients who had been underwent two-jaw surgery via one-piece LeFort I osteotomy were traced and the landmarks were identified. Repeated tracings and construction of reference planes were done. Comparisons were made from the immediate postoperative to late postoperative results of each landmarks on the horizontal and vertical directions. Conclusions: 1. The horizontal changes of landmark ANS, point A, PNS and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 2. The vertical changes of landmark ANS, point A, PNS, Mx6Cr and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 3. The horizontal change of landmark Mx6Cr between immediate postoperative to late postoperative data was statistically significant(p<0.05). 4. Results showed that it was stable that one-piece LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.297-313
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• 1997

The purposes of this study were to compare the soft tissue changes following hard tissue change after surgery between the one jaw and two-jaw surgery in skeletal class III patients and to get the reference of the incisal inclination at presurgical orthodontics. For this study 24 patients for the two-jaw surgery group and 18 patients for one jaw surgery group were selected. Lateral cephalograms were taken at pretreatment, after presurgical orthodontic treatment, immediately after surgical treatment and at least 6 months after surgery. They were traced and analyzed on skeletodental structure and soft tissue. The results were as follows: 1. After surgery, maxilla, maxillary incisors and upper lip were moved anteriorly and superiorly in two-jaw surgery group. Mandible and mandibular incisors were moved posteriorly and superiorly, and thickness of lower lip was increased in both group but there were no statistically significant difference. Anterior facial height was more decreased in two-jaw surgery group (p<0.05). At least 6 months after surgery, by the postorthodontic treatment, maxillary incisors were moved labially 1.44mm, mandible and mandiibular incisors were moved lingually 1.43mrn, 1.26mm respectively in one jaw surgery group. But there was no statistically significant changes of hard tissue in two :jaw surgery group. 2. The correlation coefficients of maxillary hard and soft tissue horizontal changes were high in two jaw surgery group and the ratios for soft tissue to A point were 19% at Sri, 80% at SLS, 82% at LS. The ratios for soft tissue to B point were 92% at LI, 104% at ILS in one jaw surgery group, 89% at LI, 101% at ILS in two-jaw surgery group. 3. The correlation coefficients and change ratios of mandibular incisors and LL HS on lower lip horizontal changes were 0 0.89 and 75%, 85% in one jaw surgery group, 0.93, 0.90 and 76%, 87% in two-jaw surgery group. The correlation coefficients of maxillary incisors and Sn, SLS and LS on upper lip horizontal changes were 072, 0.76 and 0.75 in two jaw surgery group and ratios of changes were 57%, 58% and 59%. 4. The regression equations between skeletal horizontal discrepancy and incisal inclinaton were taken in one jaw surgery group. Those were FMIA=57.48-2.17ANB, U1-SN=-75.02+2.17SNB and $R^2$ were 0.63, 063 respectively. So if there is skeletal horizontal discrepancy by mandibular prognathism in one jaw surgery case, we consider attaining more labial inclination of maxillary incisors than normal and more lingual inclination of mandibular incisors than normal. But correlation coefficient of the regression equations in two jaw surgery group was low, so, that equation was not reliable.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.343-355
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• 2000

The purpose of this study was to evaluate the amount and interrelationship of hard and soft tissue changes after mandibular setback osteotomy and reduction genioplasty in mandibular prognathism with long anterior facial height. The control group (Group A) consisted of 20 patients who had severe horizontal discrepancy. They experienced Presurgical orthodontic treatment and orthognathic surgery via mandibular setback. The experimental group (Group B) consisted of 20 patients who had severe horizontal and vertical discrepancy. They experienced presurgical orthodontic treatment and orthognathic surgery via mandibular setback and reduction genioplasty. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was tarried on with EXCEL 97 program. The results were as follows : 1. The correlation of hard and soft tissue horizontal changes in lower 2/3 of lower anterior facial height were high for both groups. The correlation coefficients of hard tissue changes and Ls, Stm, Li changes in Group B were moderately higher than Group A. 2. The correlation of hard and soft tissue vortical changes in Group B were lower than Group A. (except for pointB-Ils, Me-Me') 3. The ratio for soft tissue to Pog in Group B was lower than Group A. The ratios of hard and soft tissue vertical changes were 32% at Ils, 54% at Pog', and 60% at Me'. 4. The ratio of lower anterior facial height to total anterior facial height was reduced for both groups. But ratio of upper 1/3 of lower anterior facial height to total anterior facial height did not changed significantly in Group B. 5. Reduction genioplasty combined with mandibular setback procedure showed no change in upper one third(Sn-Stm) and significant decrease(Stm-Me') in the lower two thirds of the soft-tissue anterior lower facial height

• The korean journal of orthodontics
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• v.22 no.4 s.39
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• pp.837-853
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• 1992

The purpose of this study was to investigate the positional changes of the mandibular condyles after orthognathic surgery In patients with severe skeletal Class III malocclusion. This study was based on 21 patients who had received bilateral sagittal split osteotomy for mandibular setback. Among them 14 were fixated non - rigidly (W group), and 7 were fixated rigidly (R group). After submental vertex view analysis, each subject was given the T.M.J. Tomogram in both centric occlusion and centric relation immediate before, $4\~6$ weeks after and more than 6 months after surgery. The anteroposterior and vertical changes between each time interval were measured and analyzed statistically. Following results were obtained. 1. There was no significant difference between right and left condyles in their anteroposterior and vertical changes of the condylar position. 2. In anteroposterior changes of condylar position of the wire fixation group, the condyles were moved anteriorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, there was no significant difference in any observation periods of centric occlusion and centric relation. 3. In vertical changes of condylar position of the wire fixation group. the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery in centric occlusion only.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.1
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• pp.24-30
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• 2002

The facial patterns were expressed by the interrelation of variable factors such as heredity, function and environment. Such variable factors have an effect on the growth and development of maxillofacial bones. The malocclusions with skeletal discrepancies are caused by abnormal forms, sizes and positions of cranial base, maxilla and mandible. For the proper diagnosis and treatment planning, the analysis of such structures is necessary. Lateral cephalograms of 54 adults with class III malocclusion patients (test group) and 61 adults with normal occlusion (control group) were analyzed. Anteroposterior relations and sizes of cranial base, maxilla, mandible were estimated to compare with those of normal ones. In test group, the anterior cranial base length was within normal range, but posterior cranial base, maxilla and mandibular body were longer than those in control group, significantly. Based on the cranial base, the location of maxilla in test group was normal, but the location of mandible was more anterior than that in control. Based on the maxilla, the location of mandible was more anterior in test group than that in control. Both mandibular body and ramus anteroposterior lengths in test group were larger than those in control. Both mandibular plane angle and upper gonial angle were within normal range, but lower gonial angle was significantly high in test group.