No abstract available.

No abstract available.
Malocclusion* ; Malocclusion, Angle Class I* ; Molar*

No abstract available.
Animals ; Bone Resorption* ; Dinoprostone* ; Rats* ; Tooth Movement* ; Tooth*

This experiment was performed to study the effect of prostaglandin E2 on tooth movement and root resorption in orthodontically treated cats. Twenty five cats were divided into five groups and closed coil springs delivered 80gm were stretched between upper canine and 3rd premolar. 10microgram of PGE2 was injected locally in the submucosal area of the upper right canine, while the left side served as a control and was injected saline 0.1ml. The distance between canine tip and central cusp tip of the 3rd premolar was measured. Scanning electron photomicrographs were made of the coronal half of the distal root surface of canines and cemental craterings were observed and quantified using point-counting volumetry. Data were analyzed by 2-way ANOVA and paired t-test. The results were as follows: 1. The rate of tooth movement of the PGE2 side was increased, particularly at 1 day, compared with the control side. 2. The rate of tooth movement was minimum from 7 days to 10 days. 3. The resorption of root surface of the PGE2 side was decreased from 4 days to 10 days, compared with the control side.
Animals ; Bicuspid ; Cats* ; Dinoprostone* ; Root Resorption* ; Tooth Movement* ; Tooth*

This study was undertaken to investigate soft tissue profile changes by orthodontic treatment in female patients. Traditional cephalometric appraisal yields data of dubious scientific value, the soft tissue profile forms were evaluated by finite element method. The subject was divided into three groups according to Angle' s classification and each group was composed of 25 female patients averaged aged 12-14 years at the start of treatment. The changes in soft tissue form were evaluated by computing the degree of distortion in each triangle after treatment compared with the triangle before treatment. The conclusions were as follows; 1. The soft tissue profile forms were evaluated by finite element method and independent evaluation of each element by local changes was possible. 2. Maximum and minimum principal strains showed marked variability depending on the particular finite element and each group and Class II, III sample was greater than Class I sample. 3. Soft tissue size changes as a result of orthodontic treatment was not related to those of shape. 4. Soft tissue changes by orthodontic treatment were variable in individual patient, and were not related to Angle' s classification.
Classification ; Female* ; Humans

The purpose of this study was to evaluate the effects of the chincap therapy on the craniofacial structure in persons with skeletal Class III malocclusion. The patients selected for this study were treated with extra-oral chincap therapy only. Both control and treatment samples were obtained from Seoul National University Hospital where these longitudinal data were gathered. 35 treated patients and 14 control patients were studied. The mean ages at the 1st evaluation was 8 years 3 months in the treatment sample and 9 years 4 months in the control sample. The duration of chin cap therapy was variable but averaged 2 years of treatment. Post-treatment observation procedeeded for 1 year 2 months. Active treatment and post treatment effects were evaluated. The results were as follows: 1. Neither significant restraint nor acceleration of growth was found in the cranial base and maxilla during treatment. 2. A distal rotation of the mandibular complex was seen. 3. Some amount of restraint of growth was found in mandibular body length, ramus height, mandibular length during treatment. 4. The gonial angle was reduced. 5. After removal of the chin-cap, forward displacement of the mandible took place.
Acceleration ; Chin ; Humans ; Malocclusion* ; Mandible ; Maxilla ; Seoul ; Skull Base

This study was performed to investigate the midline having the least difference between the right and left structure among the lines that had been used in the submentovertex analysis and secondarily to know the distribution of asymmetry and it's degree existed normal persons and asymmetric patients. The subjects consisted of 40 normal adult patients and 40 asymmetric adult patients. The computerized anaylses from submentovertex cepholometric radiograph were carried out. The results were as follows; 1. The right and left difference of the perpendicular bisecting line between right and left foramen spinosum was larger than the other midlines in the anterior area and it was decreased gradually as it progressed posteriorly. Specially the difference of this line was the smallest in the area where there was foramen spinosum. 2. The right and left difference of the perpendicular line through crista gali to the line between right and left foramen spinosum was smaller than the other midlines in the anterior area and it was increased gradually as it progressed posteriorly. 3. The right and left difference of the line between crista gali and anterior process of atlas was constant and smaller than the other midlines. 4. Asymmetry was a common finding in both normal and asymmetry group and left or right dominance of asymmetry was not statistically significant. 5. When the analyses were undertaken after submentovertex radiogram was divided into cranial base, upper face and lower face, the more inferior part showed relative asymmetry than the more superior part.
Adult ; Facial Asymmetry* ; Humans ; Skull Base

The purpose of this study was to evaluate treatment effects of bionator in Class II division 1 malocclusion by FEM(Finite Element Method). The 73 subjects were classified into good result group and poor result group in reference to posttreatment molar relation, posttreatment overbite and overjet, posttreatment profile, and relapse. Pretreatment and posttreatment lateral cephalograms were taken and FEM was performed. The results were as follow; 1. There was no statistical significance in treatment changes between the sexes, and between the treatment result groups. 2. Treatment changes were not significantly different among the age groups. 3. The effect of treatment period groups on skeletal and dentoalveolar changes were analyzed using ANOVA. Body of maxilla, upper incisor, anterior face, ramus, upper anterior face, lower anterior face and treatment effect were correlated with the treatment period, but correlation coefficients were low. 4. The results of present investigation confirm that Class II bionator can assist in the correction of Class II division 1 malocclusion, mainly due to dentoalveolar changes. 5. There is significant difference in skeletal and dentoalveolar pattern between good result group and poor result group. In poor result group, maxilla was relatively downward and backward rotated, mandible was relatively backward rotated, upper incisor was in relatively lingual position, lower incisor was in relatively labial position.
Activator Appliances* ; Humans ; Incisor ; Malocclusion* ; Mandible ; Maxilla ; Molar ; Overbite ; Recurrence

The purpose of this study was to estimate correlations of craniocervical posture and craniofacial morphology in Korean young adults. The sample consisted of 50 young adults (25 males and 25 females) who had good profile and Class I molar relationship. The analysis of craniocervical posture and craniofacial morphology was performed on lateral cephalograms taken in natural head position. The results were as follows; 1. The mean and the standard deviation of postural and morphologic variables were obtained. 2. Korean young adult had cervical lordosis of which degree between OPT and CVT shows 3.55+/-2.58degrees 3. Craniocervical posture and each of vertical ratio, facial prognathism, mandibular rotation showed high correlation. 4. Correlation coefficients between postural variables and each of intermaxillary relation, anteroposterior ratio were low. 5. The head positioning error of natural head position was smaller than the inter-individual variability of postural variables.
Animals ; Head ; Humans ; Lordosis ; Male ; Molar ; Posture* ; Prognathism ; Young Adult* ; Malocclusion, Angle Class III

This study was undertaken to investigate the difference of chin morphology and mandibular form in relation to different mandibular growth direction. The subject was divided into three group i.e., control group, vertical group, and horizontal group, according to the criteria of Bjork sum, and each group was composed of 15 females and 15 males. Medial axis analysis in addition to the routine cephalometric analysis using P.I.A.S. (personal image analysing system) was carried out to find out the differences of mandibular morphology on each group. The results were as follows: 1. The area of symphysis was larger in horizontal growth group than that of vertical growth group. 2. Protruding chin area was also larger in horizontal growth group than that of vertical growth group. 3. There was a close correlationship between protruding chin area and other form of mandible. 4. Antegonial notch depth and ramus posterior contour depth was deeper in vertical growth group than in horizontal growth group, and antegonial notch depth was more influenced by anterior part of notch than posterior part of notch. 5. Mental medial axis and incisal medial axis length, in relation to corpus medial axis length was larger in vertical growth group than in horizontal growth group.
Axis, Cervical Vertebra ; Chin* ; Female ; Humans ; Male ; Mandible