• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.553-564
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• 1990

The purpose of this study was to compare mandibular teeth development of Angle Class I malocclusion group with that of Angle Class III malocclusion group. The studied subjects consisted of 217 Angle Class I malocclusion patients and 235 Angle Class III malocclusion patients. Two study methods were used. One was to evaluate tooth development degree by means of Nolla stage method, the others was to measure tooth length on panoramic radiograph. The following results were obtained, in 7, 8 and 9 years, tooth development of Angle Class III malocclusion group was significantly faster than that of Angle Class I malocclusion group. in 6 year and 10, 11, 12, 13, 14 years, the difference of tooth development degree between Angle Class III malocclusion group was not significant.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.233-239
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• 1984

The author studied on the tongue position, tongue space and intermaxillary space at 4 groups; normal occlusion 30 cases, Angle's Class I bimaxillary protrusion 29 cases, Angle's Class II malocclusion 26 cases, Angle's Class III malocclusion 26 cases. This study used the data from cephalometric films of female subject aged from 16 to 23 years. Following results were obtained; 1. Dorsal height in Angle's Class III malocclusion was greater than normal occlusion. 2. Anterior Intermaxillary Height in Angle's Class I bimaxillary protrusion and Angle's Class III malocclusion was greater than normal occlusion. 3. Tongue space in Angle's Class I bimaxillary protrusion was greater than normal occlusion. 4. The ratio of the tongue space to the intermaxillary space (T.S./I.S.) in Angle's Class II malocclusion was greater and the ratio in Angle's Class III malocclusion is lesser than normal occlusion.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.827-839
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• 1994

This study was conducted to assess the positional changes of hyoid bone following the use of activator in Angles class III malocclusion patients with functional factors. For this study, 40 Angle's class I patients and 40 Angle's class III patients, totally 80 subjects were used. They are all in Hellman's dental age IIIB-IIIC ranges. In lateral cephalogram to compare Angle's class I group and Angle's class III group, and the positional changes of the hyoid bone before and after the use of activator in Angle's class III malocclusion group. The results were obtained as follows; 1. Comparison of Angle's class I group and Angle's class III group. In comparison to Angle's class I group, hyoid bone is more anteriorly and superiorly positioned in Angle's class III group. The hyoid bone showed reverse inclination to the mandibular plane in Angle's class III malocclusion group. 2. Comparison of the hyoid positional change before and after use of Activator in Angle's class III malocclusion group. The hyoid bone is displaced posteriorly and inferiorly in vertical relationship. The hyoid bone also showed counter-clockwise rotation. 3. No statistical difference was found between after Activator use data of Angle's class m malocclusion group and Angle's class I group. It is concluded that the hyoid bone in Angle's class III malocclusion group changed its position, similar to Angle's class I malocclusion group.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.151-157
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• 2017

Objective: The objective of this study was to investigate the differences in masticatory efficiency among patients with different Angle's classes of malocclusion and to assess the correlation between masticatory efficiency and the occlusal contact area. Methods: The mixing ability index (MAI) was calculated for measuring masticatory efficiency of 61 adult patients according to Angle's classifications of malocclusion. The study included 25, 15, and 21 patients with Angle's Class I, II, and III malocclusions, respectively. Silicone interocclusal recording material was used to measure the occlusal contact area. Results: Both the MAI and occlusal contact area showed the highest average values in the Class I malocclusion group, followed by the Class II and Class III malocclusion groups. No significant difference was observed in the MAI values between the Class I and Class II malocclusion groups (p > 0.05), whereas a significant difference was observed between the Class I and Class III malocclusion groups (p < 0.01) and between the Class II and Class III malocclusion groups (p < 0.05). A weak positive correlation was also observed between the MAI and occlusal contact area (p < 0.01, $r^2=0.13$). Conclusions: The results of this study indicated that masticatory efficiency was the highest in patients with Angle's Class I malocclusion, followed by those with Angle's Class II and Angle's Class III malocclusions. Moreover, a weak positive correlation was observed between masticatory efficiency and the occlusal contact area.

• The korean journal of orthodontics
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• v.4 no.1
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• pp.13-19
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• 1974

In orthodontic view points, there were a few attempts to describe on the mandibular rest position with roentgenocephalometric studies for the persons with malocclusion. The purpose of the present study was to evaluate and interpret the difference in each of the Angle's classification of the malocclusion. The author has selected 115 malocclusion patients of the both sexes as subjects, whose dental ages were from III A. Two lateral cephalometric head films were taken mandible at rest and with the teeth in occlusion utilizing the Broadbent-Bolton cephalometer. Their linear and angular measurements were made directly. The author obtained the following results: 1) The change in the incisal overbite was of $-2.32\~-3.36mm$, and the overjet decreased similiarly in each class of the malocclusion. 2) The range of free-way space was of $1.97\~3.56mm$, and showed prominent in the Angle's class III malocclusion. 3) In the rest position, the mandible showed backward displacement, and it was prominent in the Angle's class III malocclusion. 4) In the change of Ar-Gn, the class I and II showed more increase of distance-than the class III. 5) In the change of ${\angel}SNL_1L_1'$, the class III showed smaller angle than the class I and II. 6) There was no significant difference between the male and female in each class of the malocclusion.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.109-121
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• 1992

Temporomandibular joint is a major structure to play an important role in the function & stability of the occlusion as well as the stomatognathic system. Therefore, the TMJ is the structure that requires the complete analysis for diagnosing and planning treatment of pathologic changes by TMJ dysfunction and malocclusion. So, in this study, to evaluate TMJ situation in Korean malocclusion, based on the previous accomplishments, students of the dental college of Won-Kwang Univ. are surveyed and selected in terms of Angle's classification of malocclusion, whose TMJ radiographs were taken in the centric occlusion and centric relation. In each maiocclusion groups, the mean and standard deviation of anterior, posterior and superior joint space of the right, left and both side in CO & CR are evaluated and also those of the fossa height and the articular eminence angle of the right, left and both sides are evaluated. The obtained results were as follows: 1. In the correlation coefficient between the malocclusion groups, no other items except the posterior joint space of the right side in CR between in class I and class III are significant. 2. In the correlation coefficient between the right and left side, the each joint space in class I malocclusion group and class II malocclusion group are significant. 3. In the change of each joint space during the transmit from CO to CR, there is a tendency of increasing anterior joint space and decreasing posterior, superior joint spaces in class I, II malocclusion and increasing superior joint space and decreasing anterior, posterior joint space in class III malocclusion, which is significant in the correlation coefficient, but not significant in the T-test. 4. In each malocclusion group, the correlation coefficient between the posterior joint space and the superior joint space in C.R is highly significant. 5. The fossa height of class II malocclusion group is lesser than that of class I or class III, which is not significant in T-test. 6. In the correlation coefficient between Rt. and Lt. side in the fossa height, it is not significant in class I and class III group, but significant in class II malocclusion group. 7. The articular eminence angle of class II malocclusion group is larger then that of class I or class III groups, which is fairly significant. 8. In the correlation coefficient between Rt. and Lt. side in the articular eminence angle, it is significant in each malocclusion group.

• The korean journal of orthodontics
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• v.17 no.1
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• pp.107-117
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• 1987

The study was designed to examinate the discrimination rate of 4 antero-posterior cephalometric measurements from Angle's malocclusion groups. The material was 246 cephalometric radiographs taken from 42 Normal occlusions, 83 Class I malocclusions, 64Class II Division I malocclusions, 57Class III malocclusions. ANB angle, APDI, AB/OP angle, and Wits appraisal as measurements of antero-posterior skeletal relationship were measured on the cephalometric radiographs and statistically analyzed by the Canonical Discriminant Function. The results of this study were as follows: 1. ANB angle, APDI, AB/OP angle, and Wits appraisal were clinically useful measurements for the evaluation of the antero-posterior skeletal relationship. 2. The rates that discriminate actual malocclusion groups were $77.45\%$ in Wits appraisal, $74.02\%$ in AB/OP angle, $71.08\%$ in ANB angle, and $70.59\%$ in APDI. 3. The discrimination rate of actual Class III malocclusion show above $93\%$, but actual Class I and Class II division I malocclusions were relatively low.

• The korean journal of orthodontics
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• v.16 no.1
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• pp.107-118
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• 1986

This study was designed to investigate the variation of mandibular pattern and cranial base and their association in the craniofacial malocclusion. The material was the 165 cephalometric radiographs taken from craniofacial malocclusion. The sample was devided into two groups by age child group aged from 10 to 13 years and adult group aged over 18 years, and each group was devided into 3 types of malocclusion; class I, Class II div. 1 and Class III malocclusion. Child group consist of 35 samples and adult group consist of 20 samples in each malocclusion type. Various angular and linear measurements on the cephalometric radiographs were recorded and statistically analyzed. The results of the study were as follows; 1. The cranial base angle was largest in Class II div. 1 malocclusion and smallest in Class III malocclusion 2. The anterior cranial base length was largest in Class II div. 1 malocclusion but posterior cranial base length did not show statistical difference. 3. The mandibular body length of Class III malocclusion was larger than those of Class I and Class II div. 1 malocclusion in the adult group but did not shown difference in the child group. The ramus height of Class III malocclusion was larger than those of Class I and Class II div. 1 malocclusion in the child and adult group, but there were no difference between Class I and Class II div. 1 malocclusion. 4. The mandibular position was showed low correlation with the cranial base angele.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.395-403
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• 1994

To find out the antero-posterior morphology of the upper face in Angle's class III malocclusion patients, 90 patients, adults in Heilman's Dental age, were used as samples and following results were obtained after the relative comparision of antero-posterior relationship of upper facial structures between Angle's class I malocclusion patients and Angle's class III malocclusion patients and of antero-posterior size of upper facial structures to horizontal and vertical structures in each patients. 1. After comparison of the distance from PMV line to anterior margin of maxillary sinus and cheek, which determines the antero-posterior position of the upper face, upper face in Angle's class III patients are underdeveloped relative to Angle's class I patients. The distance between orbitale and anterior margin of maxillary sinus were greater in Angle's class I patients, whic implies thart the upper face in Angle's class III are depressed. 2. Antero-posterior dimension of anterior cranial base from PMV line and vertical dimension of upper face are statistically insignificant between two groups. After comparing antero-posterior position of upper face to anterior cranial base, the upper face in Angle's class Et patients are depressed antero-posteriorly in relation to anterior cranial base. Following the comparision of antero-posterior position of upper face in relation to vertical dimension of upper face, the upper face in Angle's class III patients seem to be narrow antero-posteriorly

• The korean journal of orthodontics
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• v.13 no.1
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• pp.63-72
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• 1983

The author was to study the types and distribution of malocclusion in the 1217 patients with diagnostic charts, cephalograms and study models, who have been treated from March, 1973 to August, 1982 in the Department of orthodontics, Infirmary of Dental College, Yon Sei University. The results were as follows; 1. In the Angle's classification of malocclusion, it was presented that class I malocclusion was 671 persons $(55.1\%)$, class II division 1 malocclusion was 241 persons $(19.8\%)$, class II division 2 malocclusion was 30 persons $(2.5\%)$ and class III malocclusion was 275 persons $(22.6\%)$. 2. In the Angle's class I malocclusion, the crowding was most remarkable $(39\%)$ 3. In the Angle's class II malocclusion, 88 persons $(32.5\%)$ were due to the undergrowth of the mandible, and deep bite was most frequent. 4. In the Angle's class II malocclusion, 94 persons $(34.2\%)$ were .in the pseudo type, 84 persons $(29.8\%)$ were due to the overgrowth of the mandible, and openbite and edge to edge bite were most frequent. 5. In the sexual distribution of the patients, female patients were 791 persons $(65\%)$, male patients were 426 persons $(35\%)$, and the number of females was 1.8 times than that of males. 6. In the age distribution of the patients, 572 persons $(47\%)$ were in the 9-13 years old. 7. In the regional distribution of the patients, most of them lived near the hospital.