• The korean journal of orthodontics
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• v.10 no.1
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• pp.15-27
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• 1980

This study was undertaken to compare the craniofacial morphology of Class II, Division 1 malocclusion with that of normal occlusion in children, and to investigate the incidence of various Class II, Division 1 craniofacial skeletal patterns. The subjects consist of thirty seven boys and fifty three girls with Class II, Division 1 malocclusion, and forty six boys and eighty one girls 10-15 years with normal occlusion. Measurements were recorded, tabulated and analyzed on the lateral cephalograms by the degree of SNA, SNB and ANB. The following characteristics of the Class II, Division 1 skeletal pattern were observed. 1. The anteroposterior relationship of the maxilla to the cranium in the Class II, Division 1 was very similar to that of normal occlusion. 2, Mandible of the Class II, Division 1 malocclusion was in the posterior position in relation to the cranial anatomy when compared to normal. 3. The chin point as measured by SN Pog and NS Gn showed distal positioning in relation to normal occlusion. 4. SN to mandibular plane angle was large in Class II, Division 1 malocclusion. 5. Mandibular incisor inclination was not significantly different between Class II, Division 1 malocclusion and normal occlusion, but maxillary incisors inclined and positioned labially and consequently overjet was large in Class II, Division 1 malocclusion. 6. Class II, Division 1 malocclusion was divided into four types of craniofacial skeletal pattern. The most common Class II, Division 1 pattern was found to be type C in which SN-Mand. Pl. was above mean range of normal occlusion. The next frequent pattern was found to be type A in which maxilla and mandible were within normal range of protrusion while upper incisors were severly labially inclined.

• The Journal of the Korean dental association
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• v.52 no.10
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• pp.623-632
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• 2014

The facial asymmetries include maxillary, mandibular, and chin asymmetries, although the most common deformity is primarily in the mandible. Common causes of this type of asymmetry can include asymmetric growth of the condyle or the mandible. In these patients, the location of the Me would be deviated to the shorter side because of the asymmetric growth of the mandible, and, commonly, the maxillary occlusal plane would be tilted toward the deviated side because the maxilla likely grows asymmetrically according to the pattern of asymmetric mandibular growth. Three-dimensional CT images are ideal for evaluating the size and location of anatomic structures, and such reconstructed images allow the use of software that can show anatomic structures from numerous angles, allowing actual measurements of distances and angles without problems of magnification, distortion, or superimposition caused by 2-dimensional imaging. In the present study using 3D-CT imaging, the 8 parameters, including measurements of the upper midline deviation, maxillary canting in the canine and first molar regions, width of the upper arch, width of the mandible at the Go, vertical length of the ramus, inclination of the ramus, and deviation of the Me were easily measured. The dentition should be orthodontically decompensated and dental midline should ensure incisor midlines positioned in the midline of each jaw before surgical correction. Surgical correction could be considered such as canting or yawing correction in the frontal or horizontal aspect, respectively.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.637-645
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• 1996

In non-growing Class III malocclusion, the critical aspects which determine the need of orthognatic surgery are the severity of skeletal discrepancy, incisor inclination, overbile and soft tissue profile. Two-jaw surgery is more effective in correcting severe sagittal, vertical, transverse skeletal discrepancies and facial asymmetry. And more esthetic and stable profile can be achieved by two-jaw surgery Some midfacial deficiency Patients can be treated by Pyramidal Le Fort II osteotomy to maintain infraorbital rim and malar complex and to advance nasomaxillary complex. Others who require advancement of infraorbital rim and malar complex can be treated by quadrangular Le Fort II osteotomy. On the following cases, patients who had represented midfacial deficiency and mandibular prognathism were treated with combined orthodontic-surgical therapy by Le Fort II osteotomy and BSSRO.

• The korean journal of orthodontics
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• v.12 no.1
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• pp.21-26
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• 1982

This study was undertaken to document relations between facial skeletal pattern and dental occlusion. The data in .this study were collected from pretreatment cephalometric radiographs and study models of patients' records present in the files of Orthodontic Department, Seoul National University Hospital. Patients were selected on the basis of a mandibular plane-sella nasion angle equal to or greater than $38^{\circ}$ (high SN-MP angle) or equal to or less than $26^{\circ}$ (low SN-MP angle). Patients in the mixed dentition and with missing permanent teeth were excluded for ease of assessing tooth size / arch circumference relationships and then 30 high SN-MP and 11 low SN-MP patients were selected among them. The mean age of these two groups of patients was high SN-MP, $12.8{\pm}1.23$ years and low SN-MP, $13.0{\pm}1.48$ years. The following conclusions were obtained. 1. In the maxilla and mandible the mean tooth size of high SN-MP patients was nearlly identical to the low SN-MP patients. 2. The mean maxillary arch circumference was increased in low SN-MP group compared with high SN-MP group and a smilar, but smaller, mean increase was present in mandible. 3. The difference between the mean maxillary circumference required and the mean maillary circumference present ranged from -4.8mm in the high SN-MP group to -1.3mm in the low SN-MP group. A small range of means occurred in the mandible (high SN-MP: -4.0mm to low SN-MP: -1.8mm). 4. In the maxilla and mandible the mean arch length was nearly identical in the high and low SN-MP groups. 5. The mean incisor inclination was increased as the SN-MP angle decreased in the maxilla and mandible. 6. The men distance of the maxillary first molar from anterior border of the pterygomaxillary fissure was nearly similar between high and low groups. 7. The mean mandibular intermolar width was increased from high SN-MP to low SN-MP patients.

• The korean journal of orthodontics
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• v.45 no.3
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• pp.121-129
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• 2015

Objective: This study aimed to assess three-dimensional changes in the temporomandibular joint positions and mandibular dimensions after correction of dental factors restricting mandibular growth in patients with Class II division 1 or division 2 malocclusion in the pubertal growth period. Methods: This prospective clinical study included 14 patients each with Class II division 1 (group I) and Class II division 2 (group II) malocclusions. The quad-helix was used for maxillary expansion, while utility arches were used for intrusion (group I) or protrusion and intrusion (group II) of the maxillary incisors. After approximately 2 months of treatment, an adequate maxillary arch width and acceptable maxillary incisor inclination were obtained. The patients were followed for an average of 6 months. Intraoral and extraoral photographs, plaster models, and cone-beam computed tomography (CBCT) images were obtained before and after treatment. Lateral cephalometric and temporomandibular joint measurements were made from the CBCT images. Results: The mandibular dimensions increased in both groups, although mandibular positional changes were also found in group II. There were no differences in the condylar position within the mandibular fossa or the condylar dimensions. The mandibular fossa depth and condylar positions were symmetrical at treatment initiation and completion. Conclusions: Class II malocclusion can be partially corrected by achieving an ideal maxillary arch form, particularly in patients with Class II division 2 malocclusion. Restrictions of the mandible in the transverse or sagittal plane do not affect the temporomandibular joint positions in these patients because of the high adaptability of this joint.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.381-392
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• 2019

Objective: The objective of this two-arm parallel trial was to compare the type of tooth movement during en masse retraction of the maxillary anterior teeth using labial versus lingual biocreative therapy. Methods: Twenty-eight subjects were randomized in a 1 : 1 ratio to either the labial or lingual group. En masse anterior retraction was performed using labial biocreative therapy in group A and lingual biocreative therapy in group B. Cone beam computed tomography scans were taken before and after retraction and the primary outcome was the type of tooth movement during anterior retraction. Data were analyzed using paired t-tests for comparisons within each group and independent-sample t-test for comparison of the mean treatment changes between the two groups. Results: Significant differences were found between the two groups in relation to the type of tooth movement (labiolingual inclination of the central incisor; mean difference, $5.85{\pm}1.85^{\circ}$). The canine showed significant distal tipping in the lingual group (mean difference, $6.98{\pm}1.25^{\circ}$). The canine was significantly more intruded in the lingual group (mean difference, $1.67{\pm}0.49mm$). Good anchorage control and significant soft tissue changes occurred in both groups. No serious adverse effects were detected. Conclusions: With a 10-mm retraction hook, the labial biocreative technique with the reverse curve overlay provided anterior retraction with good torque control, while in the lingual group, anterior retraction occurred with controlled tipping movement with significant distal tipping and intrusion of the canine (trial registration: The trial was registered at ClinicalTrials.gov [NCT03239275]).

• Journal of dental hygiene science
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• v.23 no.4
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• pp.245-254
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• 2023

Background: This study aimed to determine the skeletal and dental effects in pediatric and adolescent Korean patients with Class II Division 1 malocclusion treated using the Invisalign Mandibular Advancement (MA^®) appliance. Methods: The study included patients aged 6 to 18 years who received orthodontic treatment with the MA^® appliance for Class II Division 1 malocclusion at the Department of Pediatric Dentistry, Wonkwnag University Daejeon Dental Hospital, between July 1, 2018, and December 31, 2021. The treatment group consisted of 20 patients, 10 boys and 10 girls. The control participants were also 10 boys and 10 girls. Lateral cephalometric radiographs were taken before and after treatment, and 41 measurements of skeletal and dental changes were measured and analyzed using the V-Ceph^TM 8.0 (Osstem Implant). All analyses were performed using SPSS software (IBM SPSS for Windows, ver 26.0; IBM Corp.), and statistical significance was tested using paired and independent samples t-tests for within-group and between-group comparisons, respectively. Results: The patients in the treatment group showed significant decreases in ANB (A point, Nasion, B point), maxillary protrusion, maxillary anterior incisor labial inclination, and maxillary protrusion after treatment. However, when compared with the growth changes observed in the control group, only ANB and maxillary protrusion decreased, with no significant differences in SNA, SNB, and mandibular length. Conclusion: Collectively, the results of this study confirm that the use of MA^® appliance in pediatric and adolescent Korean patients with Class II Division 1 malocclusion results in a reduction of anteroposterior skeletal and dental disharmony.

• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.51-72
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• 1999

In orthodontic field, it is very important to understand the normal growth. Such an understanding can be derived from observation of normal growth in various samples from childhood to adulthood, and this builds a foundation from which growth abnormality or variation can be defined. Thus, a broad data collection of normal children, as well as basic study reviewing such data become necessary. The relationship between the mean values of cephalometric measurements in Growth and Development was studied among the groups(boys and girls) of Korean chidren from the ages 6-years to 16-years. 220 boys 170 girls were chosen as subjects : Cephalometric X-ray were taken for 3 years and hard tissue analysis on McNamara and Ricketts Analysis which was divided into measurements of 5 parts(Cranial base, Cranial base and Maxilla & Mandible, Maxilla and Mandible, Mandible, Dental measurements). The relationship of craniofacial growth was studied. The following conclusions were obtained: 1. There were statistically significant differences in anterior cranial base between the two sexes of 14 and 15-year grouips. 2. In comparison of growth amounts among different age groups, statistically singnificant difference in Posterior facial height exhisted among $10\~11,\;12\~13\;and\;14\~15$ year-old interval groups. This pattern increased with aging. 3. Na perpendicular to A showed earlier growth peak in females(11-12years) than males(12-13years). When horizontal measurements of point A and Pogonion are compared, mandibular growth appeared to be greater. 4. Maximum growth peak of cranial base and mandible was earlier in females (11-12years) than males(13-14 years). 5. Upper central incisor flared out with aging, and there were increases in lower incisor to A-Pg, and lower incisor inclination There was significant difference between the two sexes in 10-year-old group.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.521-533
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• 2000

This study was investigated to evaluate the morphologic characteristics of openbite and deep bite in Class I malocclusion patients and to find skeletodental factors which contributed to vertical discrepancy in Class I malocclusion. The subjects were consisted of 40 control subjects (male 20, female 20) and 40 Class I openbite patients and 40 Class I deep bite patients. Lateral cephalograms in centric occlusion were taken, traced and digitized lot each subjects. The computerized statistical analysis were carried out with SPSS program. The results were as follows. 1. The pattern of vortical discrepancy in Class I malocclusion is mainly influenced by the skeletodental factors under palatal plane. 2. In openbite group, vortical discrepancy is prominent on anterior lower face and is closely related with skeletal factors such as mandibular form and inclination. 3. In deep bite group, dental factors such as ewe of Spee, vertical height of maxillary molar and skeletal factor such as articular angle were contributed to the vertical discrepancy. 4. The multiple regression analysis showed that overbite in Class I molar relationship was determined mainly by dental factors such as lower incisor to occlusal plane angle, curve of Spee, interincisal angle, and ODI.

• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.33-42
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• 2002

This study was performed to compare the pattern of dentoalveolar characteristics in different vertical and anteroposterior skeletal types in skeletal Class III malocclusion. The samples selected for this study were consisted of 60 subjects(29 males and 31 females, mean age; 19.7 years) in Class III group, 43 subjects(14males and 29 females, mean age : 20.5 years) in normal group. The findings of this study were as follows : 1. The IMPA of the Class III group was smaller than that of the Class I group(p<0.01). 2. In the Class III groups, SNB and NtoPog had negative correlation with IMPA(p<0.01). The SNB and NtoPog had correlations with SNU1, FHU1 and PalU1(p<0.01) in the male samples, and in the female samples, the SNB and NtoPog had correlations with SNU1(p<0.01). 3. In the Class III male samples, SNMP, FMA, PalMP had negative correlation with IMPA(p<0.01). SNMP, FMA, PalMP had not significant correlation with SNU1, FHU1, PalU1. In the Class III female samples, FMA, PalMP had negative correlation with IMPA(p<0.01). 4. In the high angle group of Class III samples, SNU1, IMPA is smaller than that of low angle group of Class III samples(p<0.05).