• The korean journal of orthodontics
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• v.27 no.1
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• pp.35-44
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• 1997

mastication is basically regulated by central pattern regulalor(CPG) of brain system, target organ output from CPG is modulated by oral sensory feedback, anterior cross bite pattern infuluence the feedback mechanism and change muscle activity and jaw movement. The purpose of this study was to investigate differnce anterior cross bite group from normal group, the selected sample groups were 30 normal patient, 30 anterior cross bite patient. EMG and EGN of Biopak system were used for this study The following results were obtained 1 In resting slate of mandible, anterior cross-bite showed the higher muscle activities in all the muscle.(exception:left digastric muscle) than normal group. 2. In clenching state, No significant difference in muscle activities of normal group and anterior cross bite group was noticed 3. In swallowing state Normal group showed the higher muscle activities in left and right masseter muscle, right posterior temporal muscle. 4. In maximum opening and closing velocity, normal group showed the higher value than anterior cross-bite. 5. In the mean value of the maximum opening,the maximum anterior posterior movemenl from centric-occlusion, the lateral deviation from centric occclusion, normal group showed the higher value than anterior cross-bite group.

• The korean journal of orthodontics
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• v.26 no.4
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• pp.373-387
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• 1996

The purpose of this study was to evaluate the growth pattern of nasopharyx and adenoid and to obtain useful measurements for evaluating the fuction of the nasal breathing. The biennial serial cephalometric radiographs of 33 samples(19 male, 14 female) with normal occlusion from 8.5 years to 18.5 years of age were used in this study. The distances, areas and ratios on nasopharynx and adenoid were measured and analyzed in each age and sex. The results of this study might be summarized as follows ; 1. The mean value and standard deviation of each measurement was obtained in each age and sex. 2. The nasopharyngeal height and the nasopharyngeal depth increased significantly by 14.5 years of age in male and 12.5 years of age in female(p<0,05), 3. The relative nasal airway area showed the minimal value at 8.5 years of age and showed significant increase from 10.5 years to 12.5 years of age in male and from 12.5 years to 14,5 years of age in female(p<0.05). 4. In the correlation analysis between the measurements on the nasal airway and the measurement of relative nasal airway area, the measurements of Ad2-PNS, Ad2-PNS/Ho'-PNS and Upper pharynx appeared singnificant correlation with the measurement of relative nasal airway area(p<0.01).

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.407-418
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• 2003

The purpose of this study is to analyze dentoalveolar compensation in normal occlusion samples previously classified into 9 skeletal types, and to provide clinically applicable diagnostic criteria for individual malocclusion patients. Cephalometric measurements of the 294 normal occlusion samples previously divided into 9 types were analyzed. The descriptive features of dentoalveolar variables were compared for the 9 types using analysis of variance, followed by post hoc multiple comparisons. In addition, the correlation between skeletal and dentoalveolar variables were analyzed. Discriminant analysis with a stepwise entry of variables was designed to find out several potential variables for use in skeletal typing. The dentoalveolar compensation pattern of the skeletal types varied, especially with regards to the variables that indicated the inclination of incisors and the occlusal plane. Stepwise variable selection identified four variables: AB-MP, SN-AB, PMA and ANB. Discriminant analysis assigned a classification accuracy of $87.8\%$ to the predictive model. On the basis of these results, this study could provide rudimentary information for the development of diagnostic criteria and treatment guidelines for individual skeletal types.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.355-373
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• 1995

Craniofacial region is a musculodentoskeletal system that consists of many anatomical structures ; cranioskeletal structures, dental arches, and formation and functions of masticatory muscles have close correlations. Growth and development of craniofacial region are influenced by not only hereditory factors, but also environmental factors such as craniofacial muscles and surrounding tissues. On the contrary, however, study on changes in functions or adaptations of craniofacial muscles following changes of craniofacial skeletal structures has been somewhat insufficient. The author's purpose was to observe correlations between masticatory muscular functions and change patterns according to cranial skeletal structures and occlusion patterns, for this, comparative study of muscle activity changes of preand post- orthognathic surgery states in skeletal Cl III malocclusion patients was peformed. The selected sample groups were 15 normal male patients, 15 skeletal Cl III pre-orthognatic surgery patients and 15 skeletal Cl III post-orthognatic surgery patients. For each sample groups, cephalometric x-ray taking, masticatory efficiency test and measurements of muscle activities in anterior temporal muscle, masseter and upper lip in rest, clenching, chewing and swallowing were carried out. The following results were obtained : 1. In resting state of mandible, pre-surgery malocclusion group showed higher m. activities in ant. temporalis, masseter and upper lip than post-surgery group. Post-surg. malocc. group showed significantly high m. activity only in upper lip compared to the normal group. 2. In clenching state, post-surg. malocc. group showed higher m. activities in ut. temporalis, masseter and upper lip than pre-surg. malocc. group. 3. In chewing state, post-surg. malocc. group showed higher m. activities in ant. temporalis and masseter than pre-surg. malocc. group, on the other hand, decreased upper lip activity was noticed. 4. In swallowing state, post-surg. malocc. group showed lower upper lip activity than pre-surg. malocc. group but higher than that of the normal group. No significant difference in m. activities of ant, temporalis and masseter was noticed among the three groups. 5. Masticatory efficiency was lower in pre-surg. malocc. group than normal group, masticatory efficiency showed an increase in post-surg. malocc. group compared to the pre-surg. malocc. group. However, both groups showed significant differences compared to the normal group.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.557-568
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• 1996

The purpose of this study was to analyze the growth changes of ODI and APDI with age on the three facial growth patterns. The biennial serial cephalometric radiographs of 19 male and 14 famale samples with normal occlusion during 10 years were used in this study. The samples were divided into three groups - drop type, neutral type, forward type - by the total change of the Y-axis during the periods of the study. The findings in this investigation indicated the following: 1. The mean values and standard deviations of each age group in each facial type of male and famale were obtained. 2. The difference of ODI and APDI among the 3 facial types was not significant through all observed ages(P)0.05). The size of ODI appeared large consistently in order of the drop, neutral, and forward type in both male and female through all observed ages. 3. The ODI and APDI were maintained without any charges with age during the periods of the study(p>0.05). 4. In correlation analysis between the total change of the Y-axis and 6 measurements, the AB plane angle and facial angle showed correlation in both male and female(p<0.05), the APDl in only female(p<0.001), but the ODI not appeared correlation in either male or female(p>0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.269-280
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• 1995

저작은 교합과 악운동 뿐만 아리라 근신경계, 고위 중추까지 복합적으로 관여하는 기능적 행위이다. 교합 양상은 다양하게 저작 형태에 영향을 끼치며 저작 효율에도 관여한다. 저작 형태는 다양한 모양을 가지나 두가지 전형적인 군 즉, 전방에서 관찰시 그 양상이 수직적이며 chopping운동을 닮은 군과 저작 형태가 주로 측방으로 이루어지며 grinding을 하는 군으로 나눌 수 있다. 본 연구의 목적은 저작 형태의 치아가 교합접촉 및 저작 효율에 미치는 영향을 고찰해 보고자 하는 것이다. 하악운동궤적기록기를 이용하여 정상교합을 가진 치과대학생중 전형적인 2가지 저작형태를 보이는 각 10명씩을 피검자로 선택하였다. 3가지 하악위 즉, 중심위, 작업측 비작업측에서의 교합접촉을 고무형 교합인기재로 기록하여 천공부의 직경이 1mm이하면 1점, 1-2mm또는 직선상이면 2점, 2mm이상이면 3점으로 평가하여 각 점수의 합으로 좌우 소구치 및 대구치의 접촉 지수를 측정하였다. 저작 효율을 평가하기 위해 땅콩 3g(${\pm}0.01g$)을 20회 저작하게 한 후 3회 입을 헹구어 뱉게 하였다. 체눈 크기가 각 0.425, 0.60, 0.85, 2.0, 4.0인 체에 거른 후 $65^{\circ}C$로 오븐에서 세시간 말려 무게를 측정하고 중심 크기$(M_{50})$과 저작효율치(R)를 계산 비교하여 다음과 같은 결론을 얻었다. 1. Chopping형은 grinding형에 비해 중심위에서 더 넓은 교합접촉을 보였다(P<0.01). 2. Grinding형은 chopping형에 비해 측방위에서 더 넓은 교합접촉을 보였다(P<0.01). 3. Chopping형은 중심크기($(M_{50})$)과 저작효율치(R)로 비교하였을 때 더 좋은 저작 효율을 보였다(P<0.01).

• The korean journal of orthodontics
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• v.36 no.5
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• pp.369-379
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• 2006

Objective: The purpose of this study was to find changes in the occlusal plane related to different vertical facial patterns and suggest treatment goals and conduct possible treatment mechanisms. Methods: 60 adult patients (28 males, 32 females) who had been diagnosed as Class 1 skeletal malocclusion and treated without extraction were selected. Patients were divided into three groups; short face type (group 1), average face type (group 2) and long face type (group 3), using the data on normal occlusion of Korean adults. Results: The results were achieved by analyzing cephalometric tracings of each group at pre-treatment, end-treatment and post-treatment (about 1 year recall check). The inclination of the occlusion plane tends to gradually increase as the face becomes longer In group 1, COP-X, FOP-X, L6/L1, MP-L6 were significantly decreased, and L1-FOP was significantly increased during the retention period (T3-T2). Group 2 showed no significant change, In group 3, FOP-X was significantly increased during the retention period (T3-T2). During the retention period, FOP-X showed significant change among each group, especially between group 1 and group 3. Conclusion: These results suggest that changes of occlusal plane inclination according to facial vertical pattern need to be considered during the retention period for intrusion, extrusion, and incisor overbite.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.419-435
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• 2003

The purpose of this study was to evaluate growth changes and skeletal characteristics of Korean children with Class III malocclusions from 10 to 14 years of skeletal age. Radiographs of 60 children with Class III malocclusion and 60 normal controls were assessed. Both groups were subdivided into 6 samples according to sex and skeletal age. Skeletal age was assessed using handwrist X-rays using the Greulich and Pyle norms. The Krogman-Walker plane (occipitale-maxillon) through Sella was used as a reference plane in this study with x-axis perpendicular to the x-axis. Sir Student t-tests were conducted to compare the control group with the Class III group according to each gender a:nd age. The characteristics of Class III malocclusion group compared to the control group included shorter anterior and posterior cranial base, shorter and retrusive maxilla, forger mandible, increased molar-incisor distance, retroclined lower incisors, labially proclined upper incisors, and anteriorly located mandibular molar, smaller upper and middle facial depth, and larger lower facial depth. Landmarks representing facial depth, size of maxilla and mandible, and their AP relationship including anterior facial height indicate that growth characteristic was determined early in life. But growth Pattern of cranial base and some of the dental landmarks showed progressive divergence between Control and Class III groups with age. The position of the posterior border of the mandible was found to be significantly forward in both females and males by the age of 14 and at the anterior border in males and females at all ages. Hyperdivergent mandibular plane, changes in anterior segment of mandible, small anterior cranial base, and decrease in cranial base flexure was also noted.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.95-106
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• 1989

This study was designed to investigate dental arch shapes buccally and lingually at Bracket Level of Koreans. This involved studying 63 inviduals (37 males, 26 females) with normal occlusion ranging in age from 17 to 24 years old. The landmarks were digitized and measurements and statistical analysis were performed by NEC 9801 V-M computer. The Results were as Follows: Bicanine width, Bipremolar width and Bimolar width were larger in males than in females. Buccal and lingual arch form and coordination form were obtained by NEC 9801 V-M computer. The parabolic equations which represents buccal and lingual arch form were obtained.

• The korean journal of orthodontics
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• v.35 no.2 s.109
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• pp.91-105
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• 2005

For af accurate diagnosis and treatment planning of facial asymmetry, the use of 3-dimensional (3-D) image is indispensable. The purpose of this study was to get standard data for the 3-D analysis of facial asymmetry Computerized tomography (CT) was taken in the 60 normal occlusion individuals (30 male. 30 female) who did not have any apparent facial asymmetry. The acquired 2D CT DICOM data were input on a computer, and the reformatted 3-D images were created using a 3-D image software. Twenty three measurements were established in order to evaluate asymmetry; 15 ;omear measurements (6 for ramus length. 1 for condylar neck length, and 8 for mandibular body length) and 8 angular measurements (4 for gonial angle. 2 for frontal ramal inclination. and 2 for lateral ramal inclination) The right aid left difference of each measurement was calculated and analyzed. It is suggested that the right and left differences of the measurements obtained from the study could be used as references for the diagnosis of facial asymmetric patients.