No abstract available.
Malocclusion*

No abstract available.
Malocclusion*

Variation in the facial pattern and effect of the rotational jaw growth on the facial proportion were studied in serial cephalometric radiographs of 40 Korean children (35 boys, 15 girls) ranging in age from 6 to 13 years. According to Y-axis (N-S-Gn) growth change during the 7 years of period, the subject who had exhibited "wave-like" manner of Y-axis growth change within +/- 2degrees was classified to the Parallelwise group and the subject who had exhibited Y-axis increase more than +/- 2degrees was classified to the Clockwise rotation group and the subject who had exhibited Y-axis decrease more than -2degrees was classified to the Counterlockwise rotation group. For the comparison of each group, a total of 22 morphologic variables were employed and the data were analyzed by means of computer morphometrics and statistical methods. On the basis of the finding of this study, the following trends were eatablished: 1. The Parallelwise group was 75%, the Clockwise rotation group was 12.5% and the Counterclockwise rotation group was 12.5%. 2. The growth pattern of cranial base was related to the rotation of mandible. 3. Maxillary prognathism was occured in the Counterclockwise rotation group and the rotation of palatal plane was occured in the Clockwise rotation group. 4. Mandibular prognathism was occured in the Parallelwise and the Counterclockwise rotation groups, especially in the Counterclockwise rotation group. 5. The degree of maxillo-mandibular divergency was constant in the Clockwise rotation group but decreased in the Counterclockwise rotation and the Parallelwise groups, especially in the Counterclockwise group. 6. There were no differences in the size of the anterior upper facial height (N-ANS) and the posterior lower facial height ((Go-Me)-PNS) but there were differences in the size of the anterior lower facial height (ANS-Me) and the posterior upper facial height ((S-N)-PNS) between each group. 7. The growth increment and the size of the facial gepth was not relater to the growth pattern of the face but the growth increment and the size of the facial height was related to the growth pattern of the face. 8. Proportional change due to the facial growth rotation was concentrated in the anterior lower face. 9. The most apparent difference between each group was happened in the size of the posterior cranial base (S-Ba) and the facial length (S-Gn).
Child ; Humans ; Jaw ; Mandible ; Prognathism ; Skull Base

The purpose of this study is to observe the effect of high pull headgear on the craniofacial structures of mixed dentition with Class II malocclusion. The cephalometric headplates of 16 children treated by high pull headgear during 6 months and 18 children during 12 months were traced, digitized and statistically analyzed. The results were as follows. 1. Inhibition of forward growth of maxilla was observed in both group. 2. Clockwise rotation of maxilla was observed in both group. 3. There were distal movement of maxillary 1st molar and inhibition of alveolar bone growth of maxilla. 4. There was compensatory extrusion on mandibular 1st molar. 5. The ratio of anterior facial height to posterior facial height was almostly not changed. In the treatment plan of C II malocclusion by high pull headgear, we must prevent the mandibulasr 1st molar from extruding, and for orthopedic effect, at least 6 months is needed.
Bone Development ; Child ; Dentition, Mixed ; Humans ; Malocclusion* ; Maxilla ; Molar ; Orthopedics

The objective of this experiment is to observe structural differences in the orthodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/Kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results were examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root surface. From the results of the study, the following conclusions may be drawn: 1. The root resorption and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resorption of endodontically and vital teeth when both were subjected to orthodontic forces.
Anesthesia, General ; Animals ; Bicuspid ; Blood Vessels ; Dental Cementum ; Dental Pulp Cavity ; Dentin ; Dogs* ; Gutta-Percha ; Jaw ; Osteoblasts ; Pentobarbital ; Radiography ; Root Resorption* ; Tooth Movement* ; Tooth* ; Tooth, Nonvital

The primary objective of this study is to estimate of the mesiodistal crown diameters of the unerupted permanent successors derived from the mesiodistal crown diameters of the deciduous teeth in Korean population. The subjects were 54 indiciduals (twenty nine boys and twenty five girls) with normal occlusion aged 6 to 13 years. The mesiodistal crown diameters of the deciduous and the successional permanent teeth were measured from the longitudinal dental cast models using the shding calipers (Mitutoyo Co.) From the study, the results are as follows, 1. Sex differences of mesiodistal crown diameters were less in the deciduous teeth, but male were more than that of female in the successional permanent teeth. 2. The mesiodistal crown diameters of the deciduous central incisors, lateral incisors, canines were smaller than that of the successional permanent teeth and the deciduous 1st molars, and 2nd molars were more larger than that of the successional permanent teeth. 3. Size differences between sum of the mesiodistal crown diameters of central meisors and lateral meisors in the decidous teeth and the successional permanrnt teeth were 7.20 +/- 1.79 mm in upper, 5.38 +/- 1.64 mm in lower and that of canine, 1st molar and 2nd molar in the deciduous teeth and the successional permanent teeth were 0.56 +/- 1.19 mm in upper, 2.22 +/- 1.19 mm in lower. 4. In male, the correlation coefficients between the upper deciduous central incisor and the successional permanent tooth (r=0.57) and in female, the correlation coefficients between the upper deciduous 1st molar and the successional permanent tooth (r=0.67) appeared the highest. 5. The regression constants were determined to estimate the mesiodistal crown diameters of the unerupted successional permanent teeth.
Crowns* ; Female ; Humans ; Incisor ; Male ; Molar ; Sex Characteristics ; Tooth* ; Tooth, Deciduous

The work was undertaken to evaluate the calcification of the second and the third molars in skeletal Class II and III malocclusions. The differences in the calcification stages between skeletal Class II and III malocclusion were evaluated and statistically analysed from panoramic radiographs of 202 males and females ranging in age from 11 to 15 years old. The results were as follows, 1. The calcification stages of the second and the third molars were not different between the skeletal Class II and III malocclusions in each age groups of both sexes. 2. The calcification stages of lower second and third molars of the skeletal Class III malocclusion are more advanced than those of the skeletal Class II malocclusion in male. 3. The clacification stages of upper second and third molars are more advanced than those of lower second and third molars in skeletal Class II malocclusion. 4. The calcification stages of lower second and third molars are more advanced than those of upper second and third molars in skeletal Class III malocclusion.
Adolescent ; Female ; Humans ; Male ; Malocclusion* ; Molar, Third*

To investigate the relationship of skeletal maturity among the normal occlusion group and each malocclusion groups, the author used hand and wrist X-ray of 133 Korean 13 year old boys (normal occlusion 30, Class I malocclusion 35, Class II malocclusion 35 and Class III malocclusion 33) and assessed their skeletal maturity. In this study, fourteen skeletal maturity stages were selected from; Radius, Hamate, Pisiform, Ulnar sesamoid of the metacarpophalangeal joint of the first thumb, proximal phalanges of the first, second and third finger, middle and distal phalanx of the third finger. The difference of skeletal maturity of each malocclusion groups in relative to normal occlusion group and that of each malocclusion groups were analyzed. The findings of this study can be summerized as follows: 1. Average skeletal maturity stage of each groups were MP3cap stage in normal occlusion group, H-2 stage in Class I malocclusion group, midstage between S and H-2 stage in Class II malocclusion group, MP3cap stage in Class III malocclusion group. 2. There was no significant difference in skeletal maturity of Class J malocclusion and Class III malocclusion groups in relative to normal occlusion group. 3. There was significant retardation of skeletal maturity in Class II malocclusion group in relative to normal occlusion group. 4. There was no significant difference in skeletal maturity between Class I and Class II malocclusion groups. 5. There was no significant difference in skeletal maturity between Class I and Class III malocclusion groups. 6. There was significant retardation of skeletal maturity in Class II malocclusion group in relative to Class III malocclusion group.
Adolescent ; Fingers ; Hand ; Humans ; Malocclusion* ; Metacarpophalangeal Joint ; Radius ; Thumb ; Wrist

The purpose of this study was to investigate the root resorption and repair pattern of human teeth according to the force magnitude, direction and duration during the initial leveling and alignment phase. 40gms to 500gms of force applied to the 37 experimental teeth with duration of 3 weeks to 7 months. Then, the experimental teeth were extracted. 13 control teeth were extracted without treatment. The results are as follows: 1. 59.5% of 37 teeth exhibited root resorption. The initial resorption site was visible at the apex within 3 weeks with 100 gins samples, and the initial repair site was visible at the apex within 3 months with 400 gms samples. 2. Number of resorbed teeth increased with the duration of the force. 3. The depth of the resorption increased with the magnitude of the,force. 4. The areas of resorbed root corresponded with the loading pattern. 5. The areas of resorbed root were highly correlated with the magnitude of the force. The result of this study suggest that root resorption could occur during the initial leveling and alignment phase. These initial injuries are all small and insignificant. It is the extensive type of apical root resorption that must be regarded as deleterious to the function and stability of the tooth moved. During the initial leveling and alignment phase lighter force of the interrupted type and short treatment period would be favorable with regard to avoidance of root resorption and repair of resorbed root surface.
Humans ; Microscopy, Electron, Scanning ; Orthodontics* ; Root Resorption ; Tooth

The present paper describes 3 clinical cases in which the orthodontic, treatment was effected by the Bioprogressive therapy following the extraction of the upper and lower first premolars. What is most noteworthy in the present treatment is the use of a systems approach to diagnosis and treatment by the application of the visual treatment objective in planning treatment, evaluating anchorage and monitoring results, and the rest being performed routinely by Bioprogressive mechanism. The result achieved by this method is very favorable and the efficiency of the Bioprogressive therapy is quite satisfactory.
Bicuspid ; Diagnosis ; Malocclusion*