• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.153-163
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• 1995

In this study, Receiver Operating Characteristic(ROC) analysis was used to evaluate the ability of cephalometric measurements to identify patients with Class III malocclusions. ROC analysis is the method for determining the validity of a diagnostic measure and for evaluating the relative value of diagnostic tests. The sample consisted of 496 patients with malocclusion. Class III malocclusion is defined as the dental relationship for which The mesiobuccal groove of the lower first molar is deviated mesially from the mesiobuccal cusp of the upper first molar. Of the total sample of 496 patients, 245 had Class III malocclusions. 16 cephalometric measurements were selected, each of which was treated as a diagnostic test. The ROC curves were generated for each cephalometric measurement with intervals of $1.0^{\circ}$ for angular measurements, 1.0mm for linear measurements. The area under the ROC curves was measured for direct comparison among different diagnostic tests. The results were as follows; 1. The 'Wits' appraisal was found to be a better diagnostic criterion for the presence of Class III malocclusion than any other commonly'used cephalometric measurement. 2. AB plane angle, ANB angle, App-Bpp distance, AF-BF distance, APDI, Distance of point A and Pog to N perpendicular, maxillomandibular differential had high diagnostic value. 3. Cephalometric measurements which evaluate the position of the mandible had moderate diagnostic value. 4. Cephalometric measurements related to the maxilla discriminated least between patients with and without Class III malocclusion.

• The Journal of the Korean dental association
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• v.34 no.3 s.322
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• pp.160-162
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• 1996

같은 급의 부정교합이라도 악골의 수직 수평관계, 악골과 치아의 크기에 따라서 여러 유형으로 분류된다. 여러 유형에 따라 치료방법에도 일률적일 수 없고 다양하게 된다. 진단과 치료계획 수립 시에 종종 어려움을 겪게 되는 경우가 있다. 진단의 어려움을 겪는 경우는 발치할 것인지 여부, 어떤 치아를 발치할 것인지, 악궁과 치아크기의 부조화를 어떻게 해소시킬 것인지 들의 결정을 내릴 때이다. 이런 경우 정확한 두부방사선분석 석고모형 분석, 성장과 발육분석에 의하여 판단하며 무엇보다 술자의 능력에 맞게 최선의 방법을 선택하는 것이 중요하다. 부정교합의 유형에 따라 다양한 발치 등 방법을 보고하고자 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.144-150
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• 2015

Early treatment is recommended for class III malocclusion in the primary dentition, though it is difficult to diagnose correctly. It was recommended dental maturation can possibly be used to make a differential diagnosis of skeletal class III malocclusion. This study aimed to compare dental maturation of first molars in children with skeletal or non-skeletal class III malocclusion in the primary dentition and to determine if dental maturation could be used to make a differential diagnosis of class III malocclusion. Among the children visiting the department of pediatric dentistry in Pusan National University Dental Hospital for anterior crossbite in the primary dentition, 18 were categorized into the non-skeletal class III malocclusion and 34 into the skeletal class III malocclusion. Panoramic radiographs were used to make comparative analysis of dental age and the eruption rate of the first molars. The following results were obtained. No difference was found between chronologic and dental age by the skeletal features or gender, with the latter being older than the former (p < 0.05). The discrepancies in eruption rate of first molars were significantly different between skeletal (18.91%) and non-skeletal groups (16.53%) (p < 0.05). This result implies that maturation of the first molars might be used to make a differential diagnosis of class III malocclusion.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.267-276
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• 1999

Distributions trends were examined in 9159 malocclusion patients who had been examined and diagnosed at Department of Orthodontics, College of Dentistry Yonsei University over a 6 year-period from 1992 to 1997. The results were as follows ; 1. The total number of orthodontic patients in 1997 increased in comparing with that of 1992(86%) and after 1995, the number of annual patients showed an increase. 2. Age distribution had shown over-19 year-old group being the largest(39.9%) but percentages of pre-adolescent patients had been decreasing while that of adult patient had gradually increased. 3. Distributions in the types of malocclusion, the Angle's Classification had shown : 33.3% for Class I, 28.6% for Class II and the largest 38.1% for Class III. 4. Among Class I patients, crowding showed the largest(32.6%) and protrusion group had gradually increased to 33.9% in 1996. Otherwise openbite and crossbite groups tend to decrease, annually. 5. Geographic distribution showed a majority of patients from Seoul(above 70%). Among the patients from Seoul, group within the distance 3-6Km from Yonsei dental hospital was the largest(32.3%) and group within 9Km showed 69% of total patients.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.283-300
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• 2001

With socioeconomic development and change of esthetic recognition, the demand for orthodontic treatment and number of orthodontic patients has been increasing so rapidly. And frequency of malocclusion was changed. So this study was done in an attempt to provide an epidemiologic study so that we can accomodate their orthodontic needs adequately and to obtain the reliable quantitative information regarding the characteristics of orthodontic patients. Distribution and trends were examined in 3,070 malocclusion patients who had been examined and diagnosed at Department of Orthodontics, Dental Hospital, Chosun University over 10 year-period from 1990 to 1999. The results were as follows : 1. The number of patients per year was increasing trend and higher visiting rate in female(56.5%) than in male(43.5%). 2. Age distribution had shown 7${\sim}$ 12 year-old group being the largest(37.9%) and each percentage of 13${\sim}$18, 19${\sim}$24, above-19, 0${\sim}$6 year${\sim}$old group was 32.0%, 19.6%, 7.1%, 3.4%. 3. Hellman dental age IVa which is completion of the permanent dentition showed the highest percentage in male and female. 4. Geographic distribution showed a majority of patients in Kwang Ju(71.0%). Group within the distance 10km from Chosun Dental Hospital was 56.3% and group within 20km was 14.7%. 5. Anterior cross bite showed the highest percentage in chief complaints and percentage of Mn. prognathism and protrusion of Mx. teeth was 12.6%, 12.2%. 6. Distribution in the types of malocclusion according to the Angle's classification had shown; 38.9% for Class I, 20.7% for Class II division 1, 2.0% for Class III division 2, 38.4% for Class III. 7. In the dental vertical dysplasia according to the Angle's classification, deep bite was the most frequent in Class II div.1 and div. 2(24.3%, 56.7%) and open bite in Class III(21.4%). 8. In the skeletal sagittal dysplasia, 39.3% of skeletal Class II was due to the undergrowth of the mandible and 46.3% of skeletal Class III was due to the overgrowth of the mandible. 9. Distribution in orthodontic treatment acceding to the extraction and nonextraction had shown 66.9% for nonextraction case, 33.1% for extraction case, and four first bicuspids have been extracted in the highest percentage(38.6%). 10. Patients who had orthognathic surgery comprised 7.9%, with an increasing trend.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.121-128
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• 2007

If patients complain about sudden ill-fitting occlusal sensation(acute malocclusion), a dentist has to consider many possible causes about that. Acute malocclusion is characterized its sudden onset and mainly can be caused by teeth and its related structure problem. But we always keep on mind that acute malocclusion also can be caused by temporomandibular disorders In this 3 cases of acute malocclusion, evaluating by patient history, clinical and radiographic findings, we diagnosed them as 1. Lateral pterygoid muscle spasm, 2.. Retrodiscitis, 3. Osteoarthritis. Through this non-odontogenic acute malocclusion cases, we emphasize the key of diagnosis is on comprehensive and careful patient history taking and clinical examination.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.694-699
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• 2001

The prognosis for class III patients in growing child can be made in mixed dentition and the severity of the symptom is often amenable to early intervention. Class III malocclusion can be classified as functional class lit and skeletal origin. Skeletal Class III malocclusion is usually characterized by overdeveloped mandible, underdeveloped maxilla, but the cause of pseudo class III is most dentoalveolar or functional shift of mandible. The primary goal of early intervention of malocclusion is to supply an environment that is conducive to the development of favorable occlusal relationships and avoiding of worsening of the problems. Inverted labial bow appliance is introduced as an appliance to combine the advantage of active plate and activator. It is undemanding with this appliance to initiate not only dentoalveolar expansion of upper dentition but also to orient the functional retrusion of mandible. With simple design the compliance for patients such as mouth breathing problem can be improved. For successful use of this appliance it is utmost important to make accurate and early diagnosis between pseudo- and skeletal class III malocclusion. This article will demonstrate the use of an Inverted labial bow appliance for early treatment of a functional Class III malocclusion. After 4 month treatment, anterior crossbite was treated and the results were achieved mainly dentoalveolar change of upper and lower anterior teeth.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.453-463
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• 1995

Most commonly used axis for central incisors in lateral cephalometric radiographs is the line connecting root apex and incisor edge. However, crown axis and root axis do not always coincide in cases of malocclusion patients. The angle created by these axis are called the collum angle, which should be considered in orthodontic diagnosis and treatment. In this study, 31 Class I malocclusion, 30 Class II division 1 malocclusion, 31 Class II division 2 malocclusion, and 31 Class m malocclusion patients were selected and their collum angles were measured. Correlation between these angles and malocclusions was investigated, and the correlation analysis with other parameters in cephalometrics was done. The results were as follows ; 1. The mean collum angles according to the types of malocclusions are ; $3.11^{\circ}{\pm}3.54^{\circ}$ for Class I, $1.23^{\circ}{\pm}2.41^{\circ}$ for Class II division 1, $3.77^{\circ}{\pm}4.39^{\circ}$ for Class II division 2, and $3.90^{\circ}{\pm}4.08^{\circ}$ for Class III malocclusion. 2. Statistically significant differences in collum angles were noted between Class II division 1 group and Class II division 2 and Class III group. 3. Significant correlations were found between collum angles and other parameters used in cephalometrics, namely IMPA for Class I, Wits for Class II division 1, Overbite for Class II division 2 and for ClassIII.

• Journal of Korea Multimedia Society
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• v.12 no.1
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• pp.147-155
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• 2009

Occlusion force measuring and analysis is a diagnostic method of tooth dynamics through the related force analysis. In this paper, we design and implement a series of occlusion force measuring software and evaluate its utility as a base system for a new occlusion force measure and analysis system development. For the reason, we developed a group of tools to measure the normal and abnormal occlusion force. Firstly, we have visualized the occlusion force distribution with quantitative figures. The center of force (COF) variation was visualized the path of marker according to teeth dynamics and the distribution of occlusion forces in 14 tooth regions. Secondly, we have implemented a left and right tooth force balance measurement ratio tool to estimate a specific tooth region force. Furthermore, the measured occlusion force variation recorded in the software each 0.5 second. As the result of the physical examination by the accessed hardware of sensor sheet method, we confirmed the distribution and balance of forces effectively.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.71-81
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• 2006

Background: This study was done to better understand patterns, trends and local distribution patterns of malocclusion so that we can provide adequate information to patients, to help make the appropriate diagnosis and therapeutic plans, and to assess the future directions of malocclusion treatment. Materials and Methods: Malocclusion patterns, distribution and trends of visiting patients were examined in 993 malocclusion patients who had been evaluated and diagnosed at the Department of Dentistry, Yeungnam University Hospital over a 10-year period from 1995 to 2004. Results: The number of visiting patients per year showed an increasing trend and the visit rate was 1.28 time-higher in females(56.1%) than in males(43.9%). 1) Age distribution showed that the 7-12 year-old group was the largest (36.7%). Geographic distribution showed the majority of patients were from the Dalseo district(28.2%). Angle's malocclusion classification revealed that class III was the largest(38.4%). Crowding was the chief complaint in the highest percentage of patients(33.9%). The therapeutic method used was the fixed appliance in 61% of cases and a combination with extraction in 30.8%. Conclusions: The availability of dental services can accommodate orthodontic needs adequately as well as obtain reliable quantitative information regarding the characteristics of orthodontic patients.