• Journal of Korean society of Dental Hygiene
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• v.14 no.3
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• pp.303-310
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• 2014

Objectives : The purpose of the study is to investigate the effects of bite force by gender and physical features. Methods : A self-reported questionnaire was filled out by 212 college students in Chungnam province from October to December, 2013. The questionnaire consisted of oral health condition. The bite force of the first molar teeth was measured. Results : Males showed the greater bite force than females(p<0.001). Those who had temporomandibular joint(TMJ) disorder suffered from mouth opening difficulty and weaker bite force than those who had not(p<0.05). Those who had malocclusion showed weaker bite force (p<0.01). Those who had a habit of chewing gums tended to have greater bite force than those who had not(p<0.05). The bite force was correlated with height(r=0.309), weight(r=0.345), and BMI(r=0.249)(p<0.01). Conclusions : Males showed greater bite force than females. The temporomandibular joint (TMJ) disorder, subjective malocclusion, and eating habit also affected the bite force.

• The korean journal of orthodontics
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• v.19 no.2
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• pp.145-153
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• 1989

The causes of the missing teeth are classified as congenital missing, trauma and extraction due to dental caries, variable problems are occured clinically by the missing teeth. The missing of the upper incisors especially would assume a serious aspect, and could be treated by three methods of orthodontic treatment, prosthodontic treatment and autotransplantation of the premolar teeth. The patient of this report had the skeletal class II malocclusion with the left upper central incisor missing, and have been treated with the fixed appliance after extraction of the right upper central incisor and both lower second premolars. The results were obtained as follows: 1. Treatment was done for 1 year 6 months. 2. Normal overbite and overjet were achieved. 3. Cuspal interdigitation was obtained normally. 4. Space problem was resolved with resin restoration of the upper lateral incisors. 5. The upper canines were used as the upper laterals after cuspal contouring. 6. Retention would be required with adequate retainers for a long time to prevent relapsing after treatment.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.167-177
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• 1986

This study was undertaken to compare the main differences and its effects of the 4 first bicuspid extraction on the face and dental arch of the class II div 1 malocclusion. The subjects consisted of twenty two class II div 1 malocclusion, four males, eighteen females, were 14 Years 2 Months old at the stan of the treatment 16 Year 3 Months old at the end of the treatment. (mean age) Twenty one variables were observed by comparing the statistical data of the pretreatment records with postteratment records, which were consited of eight varibles on the study model digitation, thirteen variables on the tracing of the lateral cephalogram. The following results were obtained. 1. No significant change was observed in the intercanine width. 2. Intercuspal widths of the 1st. premolar and 2nd. premolar were decreased. 3. Change of the overjet was dependant upon upper anterior rather than lower anterior. 4. No significant changes were observed in facial plane angle and ANB angle. 5. Uprighting of the lower 1st. molar had an effect on the increase of the facial height.

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.101-113
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• 1993

For the purpose of interpretation of positional changes of craniofacial structures in Class III malocclusion between mixed and permanent dentition, 73 normal samples and 103 Class III samples of mixed dentition and 125 normal samples and 168 Class III samples of permanent dentition were selected. Comparative cephalometric analysis was undertaken between them respectively by mesh diagram method to evaluate the positional changes of maxilla and mandible in anteroposterior direction and vertical direction and also the inclination changes of maxillary and mandibular incisors in labio-lingual direction. The following results were obtained : 1. The antero-posterior positional changes of the maxilla and mandible were posterior direction of maxilla and anterior direction of mandible. 2. The vertical positional changes of the maxilla and mandible were superior direction of both maxilla and mandible. 3. The labio-lingual inclination changes of the maxillary and mandibular incisors were lingual direction of both maxillary and mandibular incisors.

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.669-679
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• 1998

During diagnostic process of the orthodontic patients, it is not unusual to find canine impaction. Generally, the chief complaint of the patients is crowding or antetior crossbite which is not related with canine impaction, but sometimes they complainted delayed eruption of the canine or deviation of the adjacent teeth caused by canine impaction. Orthodondists have to make the proper treatment plan according to final treatment goals. On the following cases, two patients were diagnosed as a malocclusion with canine impaction, and were treated by different accesses, one by extraction, and the other by non-extraction each.

• The korean journal of orthodontics
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• v.13 no.1
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• pp.95-103
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• 1983

By observing the lateral cephalometric radiograms of the Naso-pharynx of the mouth breatheres with adenoid hyperplasia, orthodontists could use the 'discriminant function' as the supplementary diagnotic aid for the malocclusion cases with mouth bloating. The purpose of this study was to ustilize the 'discriminant function' as the indicator to remove the etiologic factor producing the relapse. The author used the 19 boys and 20 girls, who were the nasal-breathers with normal occlusion as the control group, and 16 boys and 20 girls, who were the mouth breathers with adenoid hypaplasia and malocclusion. The age of the both groups was ranged from 12ys to 15ys. Results were as following; 1. There was the difference in the bony structure of Naso-pharynx between the mouth-breathers nasal-breathers. 2. IMRA of the mouth breathers was smaller than the nasal breathers'. 3. The mouth-breathers had the skeletal open bite tendency. 4. Discriminant function: $$D_i=9.85374+ax_2+bx_4+cx_6+dx_7+ex_8$$ a = -0.1211273 b = 0.5908992 c = -1.508446 d = -1.541869 e = 1.404478.

• The korean journal of orthodontics
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• v.45 no.4
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• pp.209-214
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• 2015

Maxillary protraction is the conventional treatment for growing Class III patients with maxillary deficiency, but it has undesirable dental effects. The purpose of this report is to introduce an alternative modality of maxillary protraction in patients with dentoskeletal Class III malocclusion using a modified C-palatal plate connected with elastics to a face mask. This method improved skeletal measurements, corrected overjet, and slightly improved the profile. The patients may require definitive treatment in adolescence or adulthood. The modified C-palatal plate enables nonsurgical maxillary advancement with maximal skeletal effects and minimal dental side effects.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.1
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• pp.8-15
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• 2001

The Class III malocclusion classified in two types of Skeletal Class III and Pseudo Class III. In the case of the maxillary deficiency, the protraction H-G(facemask) with Bonded RPE can be used. For children with A-P and vertical maxillary deficiency, the preferred treatment is to move the maxilla into a more anterior and inferior position, which also increases its size as bone is added at the posterior and superior sutures. Successful forward repositioning of the maxilla can be accomplished before age 8. To resist tooth movement as much as possible, the maxillary teeth should be splinted together as a single unit. The maxillary appliance must have hooks for attachment to the facemask that are located in the canine-primary molar area above the occlusal plane. The facemask usually worn until a positive overjet of 2-5mm is achieved interincisally. Occipital chin cup is successful in those patients who can bring their incisors close to an edge-to-edge position when in centric relation. This treatment is particularly useful in patients who begin treatment with a short lower anterior facial height, as this type of treatment can lead to an increase in lower anterior facial height. If the pull of the chin cup is directed below the condyle, the force of the appliance may lead to a downward and backward rotation of the mandible.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.2
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• pp.131-135
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• 2004

The purpose of this study was to evaluate the resistant force of medial pterygoid muscles against the mandibular advancement and distraction to anterior, and inquire into the relationship between medial pterygoid muscles and cephalometric variables. Sixty six patients with class III malocclusion underwent bilateral sagittal splitting of ramus with intraoralvertico-sagittal ramus osteotomy for mandibular set-back. The spring scale was used to measure the resistance of medial pterygoid muscles after splitting of ramus. Skeletaldental cephalometric analysis was made and statistic package was used for correlation between resistance and cephalometric variables. The resistant force of the right medial pterygoid muscle was greater than the left one in Koreans with class III malocclusion, and the force had a linear regression relationship with facial depth. The results suggested that facial depth has significant correlation with the resistance of medial pterygoid muscle, which can be acquired from patient's cephalometric analysis.