• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.29-40
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• 2008

The purpose of this study was to evaluate the prevalence of symptoms and signs of temporomandibular joint dysfunction (TMD) and malocclusion in 10-12 year old children and to determine if a relationship exists between symptoms and signs of TMD and malocclusion. The subjects were composed of 465 school children (233 boys and 232 girls). Each subject was evaluated with simplified questionnaire and clinical examination to measure symptoms and signs of TMD and malocclusion. The results showed an elevated prevalence of headache (34.6%), which were more frequent in girls than boys. The most common cardinal sign of TMD was clicking (32.9%), which increased with age. TMJ lateral tenderness was present in 18.1% of the subjects and had a tendency to increase with age. Masseter muscle tenderness was found to be sensitive in 15.1%of the subjects and had a tendency to increase with age. Restriction of mandibular mobilitywas present in 30.3% of the subjects and had a tendency to increase with age. There was no significant difference in the prevalence of TMD signs between sex. The occlusal status showed Class I malocclusion in 73.3%, Class III in 12.9%,Class II division 1 in 11%, Class II division 2 in 2.8%. There was no significant difference in malocclusion traits between sex. There was statistically significant relationship between TMD signs and symptoms and class II division 1 and Class III malocclusion(p<0.05). The results indicate that the prevalence of TMD symptoms and signs in children is high, and the evaluation of TMD in children seems to be important.

• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.497-505
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• 2004

The purpose of this study was to evaluate the post-retention stability of the lower incisor axis in Class II division 2 malocclusions. The dental casts and lateral cephalograms from before (T1) and after (T2) orthodontic treatment and long-term post-retention (T3) in 62 Class II division 2 malocclusion cases were included in this study. After several linear and angular measurements at each time were taken, the significance in the amount of change of the lower incisor axis for each gender and extraction versus non-extraction was evaluated. The results showed that the lower incisors that inclined labially during treatment were unstable and relapsed to the original lingual position in Class II division 2 malocclusions (p<0.001). There was no significant difference between extraction and non-extraction groups for the amount of lingual relapse of the lower incisors (p>0.05). There was no significant difference between male and female groups for the axial change of the lower incisors (p>0.05). As a result of multiple regression analysis, the cephalometric measurement best predicting the lower incisor position to the A-Pog line post-retention was pre-treatment L1-Apog(mm) and pre-treatment SNGoMe$(^{\circ})$. Because of the instability of labially inclined lower incisors after orthodontic treatment, the treatment goal should be the pre-treatment incisor axial position.

• The korean journal of orthodontics
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• v.50 no.3
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• pp.216-226
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• 2020

Root resorption can be caused by several factors, including contact with the cortical bone. Here we report a case involving a 21-year-old female with Angle Class II, division 1 malocclusion who exhibited significant root resorption in the maxillary right central incisor after orthodontic treatment. The patient presented with significant left-sided deviation of the maxillary incisors due to lingual dislocation of the left lateral incisor and a Class II molar relationship. Cephalometric analysis demonstrated a Class I skeletal relationship (A point-nasion-B point, 2.5°) and proclined maxillary anterior teeth (upper incisor to sella-nasion plane angle, 113.4°). The primary treatment objectives were the achievement of stable occlusion with midline agreement between the maxillary and mandibular dentitions and appropriate maxillary anterior tooth axes and molar relationship. A panoramic radiograph obtained after active treatment showed significant root resorption in the maxillary right central incisor; therefore, we performed cone-beam computed tomography, which confirmed root resorption along the cortical bone around the incisive canal. The findings from this case, where different degrees of root resorption were observed despite comparable degrees of orthodontic movement in the bilateral maxillary central incisors, suggest that the incisive canal could be an inducing factor for root resorption. However, further investigation is necessary to confirm this assumption.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.247-257
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• 2003

Various methods have been used on patients with skeletal Class II division 1 malocclusion. The activator, Frankel appliance, headgear, Herbst appliance, and Twin-block appliance are some examples. The ideal treatment effect using these appliances would be to inhibit horizontal and vertical growth of the maxilla while promoting mandibular growth and obtaining optimum dentition. The Teuscher appliance has a simultaneous combined headgear effect with maxillary growth inhibition and an activator effect with mandibular growth promotion. The purpose of this study was to examine how well these effects were clinically obtained and the results are as follows. 1. The forward growth of the maxilla was effectively inhibited. 2. The downward-forward growth of the maxillary dentoalveolar complex was inhibited. 3. Growth promotion of the mandible was not observed. 4. The overjet, overbite, molar key were effectively improved. 5. The protruded upper lip and facial profile were unproved.

• The korean journal of orthodontics
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• v.13 no.2
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• pp.209-222
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• 1983

Three patients who had Angle's Class II Division 1 malocclusion were treated by Bioprogressive therapy. In spite of their occlusions, the 3 patients did not have any skeletal problems. Their skeletal patterns were within normal range. So headgear or functional appliance therapy were not considered. During the treatment procedure, the most noteworthy results of Bioprogressive therapy were the effect of the Utility arch to intrude 4 mandibular anterior teeth, the effect of the Cuspid retractor in cuspid retraction and the effect of the Double delta retraction arch in the retraction of 4 anterior teeth. The whole treatment results in these cases which were achieved by Bioprogressive therapy were very favorable and the efficiency of this therapy was very excellent.

• The korean journal of orthodontics
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• v.30 no.6 s.83
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• pp.687-698
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• 2000

The purpose of this study was to evaluate the changes of skeletodental patterns during Class II treatment and its retention period. Forty two patients of Class II malocclusion, which was treated with nonextraction or first premolar-extraction were selected and their lateral cephalograms were examined in this study. Various skeletodental changes in lateral cephalograms of pre-treatment, post-treatment and retention were measured by superimposition in reference to the cranial base for jaws, the palatal plane for maxillary teeth, and mandibular plane for mandibular teeth. The data were analyzed by paired t-test. In this study, occlusal plane showed the significant anterior downward steepening after active treatment, and remained during retention period. In the nonextraction group, maxillary incisors were retracted and extruded during treatment. Maxillary molars were extended, and mandibular molar were uprighted, with no mesial movement. In the extraction group, both maxillary and mandibular incisors were retracted and extruded. Maxillary molars were extruded and moved mesially, and mandibular molars were extruded and moved mesially with no mesial tilting. During retention period in both groups, there were tendencies of labial tipping of maxillary incisor, and mesial tipping of maxillary and mandibular molar. But the changes were not significant and most of teeth showed no change in vortical and horizontal direction.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.45-54
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• 1997

The purpose of this study was to evaluate the indications of bionator in Class II division 1 malocclusion, The 48 subjects were classified into good result group(group1) and poor result group(group2) in reference to posttreatment molar relation, posttreatment overbite and overjet, posttreatment profile, and relapse. Pretreatment lateral cephalograms were calculated and evaluated by t-test stepwise discriminant analysis. The results were as follows ; 1. In jaw bone relationship, ANB, facial convexity angle, AB to facial plane angle were significantly different between two treatment groups. In denture pattern, L1 to facial plane, L1 to A-Pog, FMIA, and U1 to facial plane were significantly different and m soft tissue profile, protuberance of lower lip and upper lip were significantly different between tw o treatment groups. 2. The results in according to discriminant analysis stated that L1 to facial plane, ANB, FMIA and protuberance of lower lip help prediction of treatment result of bionator. 3. 3 major influential variables were obtained by stepwise discriminant analysis - L1 to facial plane, articular angle and ANB difference. And Fisher discriminant function was made by these three major variables.

• The korean journal of orthodontics
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• v.42 no.6
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• pp.280-290
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• 2012

Objective: This study aimed to compare the effects of conventional and orthodontic mini-implant (OMI) anchorage on tooth movement and arch-dimension changes in the maxillary dentition in Class II division 1 (CII div.1) patients. Methods: CII div.1 patients treated with extraction of the maxillary first and mandibular second premolars and sliding mechanics were allotted to conventional anchorage group (CA, n = 12) or OMI anchorage group (OA, n = 12). Pre- and post-treatment three-dimensional virtual maxillary models were superimposed using the best-fit method. Linear, angular, and arch-dimension variables were measured with software program. Mann-Whitney U-test and Wilcoxon signed-rank test were performed for statistical analysis. Results: Compared to the CA group, the OMI group showed more backward movement of the maxillary central and lateral incisors and canine (MXCI, MXLI, MXC, respectively; 1.6 mm, p < 0.001; 0.9 mm, p < 0.05; 1.2 mm, p < 0.001); more intrusion of the MXCI and MXC (1.3 mm, 0.5 mm, all p < 0.01); less forward movement of the maxillary second premolar, first, and second molars (MXP2, MXM1, MXM2, respectively; all 1.0 mm, all p < 0.05); less contraction of the MXP2 and MXM1 (0.7 mm, p < 0.05; 0.9 mm, p < 0.001); less mesial-in rotation of the MXM1 and MXM2 ($2.6^{\circ}$, $2.5^{\circ}$, all p < 0.05); and less decrease of the inter-MXP2, MXM1, and MXM2 widths (1.8 mm, 1.5 mm, 2.0 mm, all p < 0.05). Conclusions: In treatment of CII div.1 malocclusion, OA provided better anchorage and less arch-dimension change in the maxillary posterior teeth than CA during en-masse retraction of the maxillary anterior teeth.

• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.447-454
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• 1993

Patient with skeletal class II relationship was treated with L-ARS. L-ARS is fixed functional appliance that could be effective in children and adolescent patient who don't wear activator. The following results were obtained ; 1) Growth of Mandible was stimulated and overjet was decreased, therefore coupling of anterior teeth was established with L-ARS which is fixed functional appliance. 2) These changes were accomplished with Mandibular skeletal growth with no effect on the Maxilla. 3) L-ARS was especially effective on patient who deny to wear the removable functional appliance.

• The korean journal of orthodontics
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• v.13 no.2
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• pp.193-199
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• 1983

The purpose of orthodontic treatment is to produce functional occlusion and to create or maintain facial esthetic harmony. The soft-tissue covering of the face also plays an important role in facial esthetics, speech and other physiologic functions. The study of the soft-tissue profile is important for the planning of orthodontic treatment. The author studied cephalometric X-ray films on 49 patients (23boys, 26 girls) with Angle's class II division 1 malocclusion, ranged from 9 to 13 years of age. Roentgenocephalmetric X-ray films were taken pre and post orthodontic care. Tracings were made in usual manner. The obtained results were as follow. 1. There was no significant sexual difference on mean changes. 2. In the comparison of the soft-tissue thickness changes, Ls-Ls' and Si-Si' in male subjects were remarkable. 9. There were significant correlations between osseous (Ss') change and soft-tissue (Ss) chang, of maxilla in male and female subjects subsequent to orthodontic treatment. 4. The ratios between the protraction of the Ss' and that of the Ss were 1:1.5 in all sexes, the ratios between the Si' and that of the Si were 1:1.4 in male and 1:1.2 in female. 5. There were significant correlations between maxillary central incise. angulation change $({\angle}A)$ and upper lip inclination change $({\angle}B)$ in all sexes. 6. There were little correlations between change in distance difference of Is and Ii and change in distance difference of Ls and Li in all sexes in all sexes.