• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.420-432
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• 2005

Bolton analysis is widely used to predict tooth size discrepancy. but its accuracy has been challenged. The purpose of this study was to describe true anterior tooth size discrepancies among orthodontic patients and to evaluate the factors that affect true anterior tooth size discrepancies. The subjects consisted of 80 patients with varying malocclusions (Class I. Class II. Class III. and Class III surgery) who were treated orthodontically. Pre-treatment models. set-up models from post-treatment models. and lateral cephalometric radiographs were analyzed The results were as follows. The means. the standard deviations. and ranges of anterior Bolton ratio in the present study were somewhat higher than those of Bolton's samples and Korean normal samples. The number of patients showing maxillary deficiency was larger than that of patients showing maxillary excess in view of true anterior discrepancies. There was a significant difference between anterior Bolton discrepancy from pre-treatment models and true anterior discrepancy from set-up models (p < 0.05) There was no significant difference in true anterior discrepancies among malocclusion groups (p > 0.05). And there was also no significant difference between the male and female groups (p> 0.05). Overbite and the incisal edge thickness of maxillary anterior teeth have little relationship with true anterior discrepancies. Multiple regression analysis showed that true anterior discrepancy was mainly determined by anterior Bolton ratio, upper incisor to occlusal plane angle after treatment. interincisal angle after treatment. and upper right lateral incisor width.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.1-11
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• 2004

Predicting the arch length discrepancy by simply comparing the available arch perimeter with tooth materials is merely a 2-dimensional analysis of the teeth movement. However, the real teeth movement takes place 3-dimensionally and is affected by various factors such as, the arch fen the curve of Spee and the axis of the incisors. The purpose of this study is to clarify the relationship between the decrease in the arch perimeter and the horizontal positional change of the incisors after extraction of the 1st bicuspids, for more analytic evaluation of the arch length discrepancy at pre-treatment model analysis stage. In addition to that to evaluate the effect of the curve of Spee, teeth axis to the basal plane, and the incisional crowding to the treatment outcome. All patients were treated at the department of orthodontics, dental hospital, Yonsei university. Inclusion criteria for patients selection were as follows. $\cdot$ Angle classification I malocclusion with bialveolar protrusion $\cdot$ Extraction of 4 1st bicuspids $\cdot$ No tooth anomaly or prosthesis $\cdot$ No abnormal attrition $\cdot$ No ectopically erupted teeth $\cdot$ Angle classification I canine and molar relationship $\cdot$ Less than 3mm of crowding Model analysis of the above patients was performed and the following conclusions were obtained. 1. When the intercanine distance was maintained, the available space for the distal movement of the mandibular incisors after the extraction of the 4 1st bicuspids was larger than the space provided by the extraction of the 4 1st bicuspids. However the difference was less than 1mm. The more tapered the anterior arch form, the larger the difference. 2. Compared to the situation in which the intercanine distance was maintained, when the intercanine distance was expanded to meet the width of the Posterior teeth, the incisors could move about 3mm more distally. 3. The positional difference of the incisal tip was insignificant whether the central incisors were moved by tipping or bodily movement. 4. When the anterior crowding was solved without changing the intercanine distance, the larger the anterior arch length was, the more the anterior movement of the incisors. 5. When the curve of Spee was levelled, the increase in the arch perimeter was less than half of the deepest curve of Spee.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.433-446
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• 2005

The purpose of this study was to investigate the sociopsychological factors which might influence the course of the temporomandibular disorders and to develop models for prediction of treatment outcome related to pain, dysfunction and sound. For this study, 268 patients with temporomandibular disorders were selected from the patients presented to department of Oral Medicine, Wonkwang university dental hospital. Chief complaints of these subjects were largely grouped into three categories such as pain, dysfunction and sound, and 10 cm visual analogue scale(VAS) was used to record the state of the three complaints every visit and Treatment Index(VAS TI) was calculated from VAS. All the forty-two items obtained from clinical examination or questionnaire were statistically processed with $SPSS^{(R)}$ windows. The results of this study were as follows: 1. The items showed a difference between male and female subjects were maximum mouth opening, palpation score, jaw jerk during mandibular movement, and sleep disturbance. Among questionnaires such as SRRS, HAD scale and PSQI, the HAD scales showed the most highly significant correlation with the each scale item of the SCL-90R. 2. Among the groups classified by VAS TI, the group with the lowest VAS TI showed the highest VAS score in the start of treatment but showed the lowest score in the end of treatment, without respect to the type of chief complaint. From these results, it is assumed that the active treatment duration for the subjects with lower VAS score in the first visit would be longer than the subjects with higher score with the somewhat poor treatment outcome. 3. With regard to all the three complaints, the items showing significant effect in the model for prediction of treatment outcome were from questionnaire, except one item, maximum mouth opening, which suggest that the sociopsychological factors would be strongly related to development and progress of the symptoms.