• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.205-218
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• 2004

The aims of this study were to investigate the differences in the early craniofacial morphology of Class III malocclusions with good, fair and poor occlusal stability and to elucidate a key determinant for distinguishing the cases. Lateral cephalograms of 30 subjects with Class III malocclusion in the mixed dentition were analyzed at the start of treatment (mean age of $8.58\pm1.47$). All subjects were reevaluated after a mean period of $7.50\pm1.94$ years comprising active treatment and retention. At this time, the samples were divided into three groups: good (10 subjects), fair (10 subjects) and poor (10 subjects) occlusal stability groups. According to the results of ANOVA, there were significant morphological differences in the early stage among the good, fair and poor occlusat stability groups, especially in variables that represented the vertical skeletal relationships. As well, there were already more dental compensations in the poor occlusal stability group. Stepwise discriminant analysis on the measurements at the time of first observation identified only one predictive variable: AB to mandibular plane angle(AB-MP). With this discriminant function, $83.3\%$of the original grouped cases were correctly classified and the canonical correlation coefficient was 0.857. In conclusion, AB-MP can be a possible predictor for the eventual prognosis of early Class III treatment. If it is below 60, the prognosis of early Class III treatment is expected to be poor, while if it is above 65, a good prognosis is expected.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.108-113
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• 2009

The functional regulator(FR) appliances act to remove the restrictive forces that prevent the normal maturation of the maxilla and mandible. FR appliances are different from other functional jaw orthopedic appliances(e.g., the twin block, bionator, and activator). $Fr{\ddot{a}}nkel$ has based his treatment philosophy on the concept that the capacity to regulate growth residues in the soft tissue environment, and that adequate space must be available for the proper development of the hard tissue. In class II malocclusion with mandibular retrusion, FR-II treatment is not only the change in the postural position of mandible, but also expansion of the dental arches. By balancing the neuromuscular environment, not only can severe malocclusions be treated successfully, but also the tendency toward relapse is minimized because the neural and soft tissue factors associated with the skeletal malocclusion have been addressed as well. We report cases using by FR-II that is applicated in cases of Class II malocclusion without fixed appliance, only FR-II and space supervision.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.1
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• pp.60-69
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• 2005

Orthopedic rapid maxillary expansion(RME) has been a common treatment modality used to widen narrow maxillae in young children. However, since more skeletally matured adolescents or adults has closed midpalatal suture, the result of RME was undesirable because of dental tipping with little or no basal skeletal movement and resulted to many other complications. After such treatment, complications often occurred such as alveolar bending, compression of periodontal ligament, extrusion, buccal tipping, and severe relapse. Thus, surgically assisted rapid maxillary expansion(SA-RME) is required, especially for patients over 14 years old, to skeletally release maxillary expansion. We used two methods of maxillary expansion surgery. Surgically assisted rapid maxillary expansion(SA-RME) & surgically assisted posterior segmental expansion(SA-PSE) were used for narrow maxilla. The study was divided into two groups(SA-RME group and SA-PSE group). SA-RME group was consisted of 2 males and 4 females, and the ages of materials ranged from 15 years to 25 years with a mean of 20.2 years. SA-PSE group was consisted of 1 male and 5 females, and the ages ranged from 13 years to 23 years with a mean of 18.7 years. Dental study models were fabricated before starting the expansion and immediately after the expansion was completed. It was fabricated again 1 month later, 3 months later when the expansion device was removed, and 6 months later after the expansion was completed. A repeated measures analysis of variance(ANOVA) test was applied to assess changes between each groups over time. The amount of expansion and the amount of tipping movement each in both groups were compared by using paired t-test and it was also compared between each subjects within the group by using independent t-test. Both SA-RME and SA-PSE group showed stable results, but SA-PSE group showed statical significance in tipping movement of second premolar. We compared 6 patients who recieved SA-RME with 6 patients who received SA-PSE, and appraised the clinical usefulness.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.87-108
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• 1996

This study was intended to perform cephalometric analysis of the facial soft tissue profile after surgical correction of skeletal Class III malocclusion after SSRO in 29 patients (Males 12, females 17). Lateral cephalograms were taken in centric occlusion before and immediate, long term after surgeries. 1. Counter-clockwise rotation of mandible was observed after the surgery, average relapses of mandibular set back were 1.23-1.28mm. The net effects of the mandibular set-back after surgeries were 81.7-82.2%. Because these relapse tendencies may reduce the effects of the surgical outcomes, surgeon must consider these net before the surgical treatment planning. 2. The ratio of horizontal changes of hard tissue to soft tissue at lower lip, mentolabial sulcus, pogonion were 72.7-93.7%, 100.3%, 99.1-102.1% respectively. There were little changes at upper lip position anteroposteriorly. 3. The relationship of upper and lower lips were improved after surgery. Lower lip was posteriorly repostioned and upper lip was flattend and elongated in conjunction with deepening of inferior lobial sulcus. But profile of chin was still prominent after surgery. 4. Hard tissue horizontal changes and tissue vertical changes were significantly correlated with each other and there were reverse correlations with hard tissue vertical changes and soft tissue horizontal changes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.25-33
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• 2004

The purpose of this study was to evaluate the postoperative stability of the severe open bite or mandibular prognathic patients after mandibular set back surgery by Obwegeser II method. There were 19 patients who had been undergone Obwegeser II method. The horizontal and vertical position of the cephalometric points were measured preoperation and immediate postoperation, postoperative 1 month, postoperative 6 months ; were analyzed by linear measurement to evaluate changes in skeletal landmark and the relapse was compared between open bite group and prognathism group. By the operation, horizontal change of B was $6.84{\pm}4.35mm$ and vertical change of B was $6.28{\pm}3.25mm$ in open bite group and horizontal change of B was $14.20{\pm}4.81mm$ and vertical change of B was $1.99{\pm}2.66mm$ in prognathism group, horizontal change of Pog was $3.82{\pm}5.71mm$ and vertical change of Pog was $5.38{\pm}2.11mm$ in open bite group and horizontal change of Pog was $13.24{\pm}5.99mm$ and vertical change of Pog was $1.91{\pm}0.94mm$ in prognathism group. Between immediate postoperation and postoperative 1 month, all skeletal landmarks change was no statistical difference (p>0.05) and there were no statistical difference between open bite group and prognathism group except x-Me landmark (p>0.05). Between postoperative 1 month and 6 months, horizontal change of B was $0.12{\pm}1.35mm$ and vertical change of B was $1.47{\pm}1.48mm$ in open bite group and horizontal change of B was $1.43{\pm}1.35mm$ and vertical change of B was $0.82{\pm}1.99mm$ in prognathism group, horizontal change of Pog was $0.13{\pm}1.40mm$ and vertical change of Pog was $0.88{\pm}1.71mm$ in open bite group and horizontal change of Pog was $1.08{\pm}1.74mm$ and vertical change of Pog was $0.47{\pm}1.57mm$ in prognathism group (p>0.05) and there were no statistical difference between open bite group and prognathism group (p>0.05). Between immediate postoperation and postoperative 6months, horizontal change of B was $0.24{\pm}1.17mm$ and vertical change of B was $1.87{\pm}1.63mm$ in open bite group and horizontal change of B was $1.54{\pm}1.55mm$ and vertical change of B was $1.04{\pm}1.96mm$ in prognathism group, horizontal change of Pog was $0.91{\pm}1.46mm$ and vertical change of Pog was $1.18{\pm}2.05mm$ in open bite group and horizontal change of Pog was $0.96{\pm}1.62mm$ and vertical change of Pog was $1.23{\pm}2.35mm$ in prognathism group (p>0.05) and there were statistical difference between open bite group and prognathism group in x-B, x-Pog, x-Gn, x-Me (p<0.05). Obwegeser II method is considered as one of the best operation when surgical correction of severe open bite or severe mandibular prognathism is needed.

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.261-272
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• 2000

Severe skeletal anteroposterior and vertical discrepancy is difficult to obtain satisfactory result by only orthodontic treatment, and much anteroposterior movement and treatment stability require orthodontic treatment with orthognathic surgery. The treatment goal of mandibular prognathic patients is to promote the function of stomatognathic system including mastication and phonetics, to improve the esthetics of facial profile and to maintain stability. Positional changes of hyoid bone, pharynx and tongue were seen with mandibular movement after orthognathic surgery. This study was performed to observe the changes of perimandibular tissues of orthodontic patients with skeletal mandibular prognathism who treated with orthodontic treatment, and the changes of hyoid bone, pharyx and tongue by relapse or recurrance after before and after orthognathic surgery and retention. The 22 patients who had mandibular prognathism were selected. They treated with orthodontic treatment with sagittal split ramus osteotomy as orthognathic surgery. And lateral cephalometric radiographs were taken 3 times : pre-surgery (T1), immediate post-surgery (T2) and 2 years alter retention (T3). The results were as follows : 1. The hyoid bone returned back after clockwise rotation to maxilla and occlusal plane during retention (P<0.01). 2. The hyoid bone moved posterior-inferiorly by mandibular surgery and returned back anterior-superior after retention. (P<0.01) 3. The changes of pharyngeal depth showed a little decrease at upper area in post- surgery, but it was not a significant difference generally through before, after and retention. 4. In relating to tongue base, the angle of tongue base was decreased and the dorsal area of tongue base moved to inferior-posterior direction and to superior direction again after retention (P<0.01). 5. Related to the thickness of upper and lower lip, the thickness of upper lip decreased after surgery, and the soft tissues below lower lip increased after surgery and decreased after retention.