Hyperosmotic Stimulus Down-regulates 1alpha, 25-dihydroxyvitamin D3-induced Osteoclastogenesis by Suppressing the RANKL Expression in a Co-culture System

The hyperosmotic stimulus is regarded as a mechanical factor for bone remodeling. However, whether the hyperosmotic stimulus affects 1alpha, 25-dihydroxyvitamin D3 (1alpha,25(OH)2D3)-induced osteoclastogenesis is not clear. In the present study, the effect of the hyperosmotic stimulus on 1alpha,25(OH)2D3-induced osteoclastogenesis was investigated in an osteoblast-preosteoclast co-culture system. Serial doses of sucrose were applied as a mechanical force. These hyperosmotic stimuli significantly evoked a reduced number of 1alpha,25(OH)2D3-induced tartrate-resistant acid phosphatase-positive multinucleated cells and 1alpha,25(OH)2D3-induced bone-resorbing pit area in a co-culture system. In osteoblastic cells, receptor activator of nuclear factor kappaB ligand (RANKL) and Runx2 expressions were down-regulated in response to 1alpha,25(OH)2D3. Knockdown of Runx2 inhibited 1alpha,25(OH)2D3-induced RANKL expression in osteoblastic cells. Finally, the hyperosmotic stimulus induced the overexpression of TonEBP in osteoblastic cells. These results suggest that hyperosmolarity leads to the down-regulation of 1alpha,25(OH)2D3-induced osteoclastogenesis, suppressing Runx2 and RANKL expression due to the TonEBP overexpression in osteoblastic cells.

A Comparison of pre and post-surgical characteristics in skeletal Class III malocclusion patients using counterpart analysis / 대한치과교정학회지

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of individuals has been developed. Counterpart analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. In this study we examined surgical changes in skeletal Class III malocclusion patients(male 40, female 40) and compared them with normal occlusion patients using counterpart analysis. The results indicated that : 1. Skeletal anterior-posterior discrepancy was relieved by shortening of the ramus width(B3). 2. The ramus alignment(R3, R4) was displaced posteriorly and the occlusal plane angle(R5) was rotated clockwise. 3. Skeletal Class III pattern was relieved in the post-operative group, but differences in the level of the cranium(R1, R2) was remaining compared to the normal occlusion patients. 4. In the comparison of surgery methods, the two-jaw surgery group presented changes in the maxillary length(A4), ramus alignment(R3,R4) and occlusal plane angle(R5) compared to the one-jaw surgery group, but the differences were not significant. In the past study about Korean skeletal Class III patients, the skeletal characteristics are upward backward rotation of the cranial base, posterior displacement of the maxilla, forward inclination of the ramus and lengthening of the mandibular body, but in this study, skeletal Class III pattern was relieved by shortening of the ramus width and maxillary advancement by orthognathic surgery, because orthognathic surgery is usually performed on limited areas in the maxilla and the mandible.

Treatment effects of the Teuscher appliance in skeletal Class II division 1 malocclusion / 대한치과교정학회지

Various methods have been used on patients with skeletal Class II division 1 malocclusion. The activator, Frankel appliance, headgear, Herbst appliance, and Twin-block appliance are some examples. The ideal treatment effect using these appliances would be to inhibit horizontal and vertical growth of the maxilla while promoting mandibular growth and obtaining optimum dentition. The Teuscher appliance has a simultaneous combined headgear effect with maxillary growth inhibition and an activator effect with mandibular growth promotion. The purpose of this study was to examine how well these effects were clinically obtained and the results are as follows. 1. The forward growth of the maxilla was effectively inhibited. 2. The downward-forward growth of the maxillary dentoalveolar complex was inhibited. 3. Growth promotion of the mandible was not observed. 4. The overjet, overbite, molar key were effectively improved. 5. The protruded upper lip and facial profile were improved.

Study on Korean skeletal Class III craniofacial pattern by counterpart analysis / 대한치과교정학회지

Enlow's counterpart analysis reflects the characteristics of each individual sample to find out the cause of the malocclusion and further applying them to the clinic. Enlow's counterpart analysis was performed on 100 Korean samples (50 male, 50 female) with normal occlusion and 100 skeletal class III patients (50 male, 50 female) scheduled for orthognathic surgery. The following conclusions were obtained. 1. The cause of malocclusion in skeletal class III patients were complex and interrelated ; backward upward rotation of the cranial base, forward inclination of the ramus, increase in the mandibular body length, and posteriorly located maxilla. 2. Seen on R2 (male-1.68mm, female-2.33mm), in skeletal class III, the maxilla is more posteriorly located than the normal group. 3. The cause of malocclusion in skeletal class III patients, consists of retrognathic maxilla(A1) male 22%, female 26%, prognathic mandible(B1) male 44%, female 34%, and combination of an retrognathic maxilla and prognathic mandible were male 28%, female 38%. 4. There was no significant difference in the anterior-posterior length of the maxilla(A4) between skeletal class III males with the normal group, while in the female subjects, the skeletal class III group showed a smaller maxilla(A4) compared to the normal group. 5. In skeletal class III patients the proganthic mandible was primarily caused by the inclination of the ramus(R3, R4) and mandibular body length(B4, B6) rather than ramus width(B3).

A study on the postoperative stability of occlusal plane in Class III orthognathic surgery patients / 대한치과교정학회지

In Patients with severe skeletal discrepancy, surgical orthodontic treatment must be accompanied, and recently two jaw surgery has become a common procedure, resulting in improved esthetics and function. Choosing the position of the occlusal plane in this two jaw surgery is an important factor in postoperative stability. Therefore this must be taken into consideration during the diagnosis and treatment plan. In this study, among patients with skeletal Class III occlusion, 25 patients(8 male, 17 female, average age 23.2+/-3.17) who have undergone two jaw surgery, setting the ideal occlusal plane according to Delaire's architectural and structural cranial analysis. In comparing preoperative(T1). postoperative(T2, average of 15.4 days), and long-term postoperative(T3, average of 32.6 months) lateral cephalometric radiography, the following conclusions have been made. 1. There were no significant changes of the occlusal plane angle after the two jaw surgery, and there were no significant differences between the surgical technique(SSRO and IVRO). 2. The postoperative changes of the occlusal plane had no relationship with the amount of jaw movement, amount of posterior impaction, nor the time relapse after surgery. 3. After two jaw surgery, in the SSRO group there was significant forward movement of the mandible, and in the IVRO group the lower incisors extruded as the mandible moved backward and downward which makes the gonial angle and the mandibular plane angle significantly increased.

Study on the Korean craniofacial skeletal pattern by counterpart analysis / 대한치과교정학회지

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of individuals has been developed. The analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. This study was to clarify the Korean craniofacial skeletal pattern using Enlow's counterpart analysis considering the fact that the craniofacial skeletal pattern has racial and regional variations. This research will be helpful in the future for growth research and research of the orthognathic For this study, the samples were consisted of 100 Korean adult subjects(50 males and 50 females) who had normal occlusion and pleasing face. Measurement points and lines were established using Enlow's counterpart analysis and they were statistically evaluated. The results indicated that: 1. The average angle between PCF and PMV was 38.54 degrees in males and 38.43 degrees in females, and the average Wits' appraisal was -2.51 in males and -2.3 in females. The ramus alignment(R4) was 1.89 in males and 2.36 in females. 2. It shows that females have a longer ramus than the PCF compared to the males, because there was a significant difference in Ramus/PCF horizontal dimensions (Skeletal A3-B3) between female and male subjects 3. It shows that males have a longer mandibular corpus than the maxilla compared to the females, because there was a significant difference in Maxillary/Mandibular arches(Skeletal A4-B4) between male and female subjects 4. In cranial floor+maxilla/ramus+corpus at A and B points(A1-B1), which represents difference in total horizontal length between the maxilla and mandible, there was no significant difference between males and females. In conclusions, compared to Caucasian, Korean have more depressed midface, prognathic mandible, and ramus that rotates inferioposterior. Also, we observe that Korean women have larger ramus posterior cranial base, as compared with Korean men. Consequently, the total length of maxilla and mandible does not show any difference, because man's mandible is longer than maxilla in comparison with woman's one.

A longitudinal study on the interrelationship between the growth change of the gonial angle and IMPA / 대한치과교정학회지

This study was undertaken to investigate the growth change of gonial angle and interrelationship between the growth change of gonial angle and IMPA in the longitudinal data from 7 years to 15 years. By analyzing the serial lateral cephalograms of 15 males and 18 females of 7 years old to 15 years old who had no abnomality in growth and development and no history of orthodontic treatment, the following conclusion were obtained. 1. Gonial angle gradually decreased with aging in 25 children and in 9 children increased or maintained. 2. There was a tendency that children who decreased gonial angle with aging showed gradual increase of IMPA and children who increased of maintained gonial angle with aging showed decrease of IMPA 3. There was a tendency that regardless of the change of gonial angle, interincisal angle decreased with aging.

A semilogitudinal study on cranial base, maxilliary and mandibular growth of Korean children aging 7 to 17 years old / 대한치과교정학회지

lateral cephalograms of 251 males and 286 females were taken and pubertal growth pattern of cranial base, maxillary and mandible of 7 to 17 years old Korean Children was evaluated. 10 landmarks and 16 analytical measurements were evaluated. Analytical measurement and annual difference for each age group was calculated and tested for statistical significance. Analytical measurements were classified into three groups which wee cranial base. maxillary and mandibular measurements and also classified into make and female measurements. Following results were achieved. 1. The circumpuberal growth spurt was earlier in Korean females than in males. 2. Cranial base, maxilla and mandible showed cirumpuberal growth. The cranial base showed a relatively smaller amount of growth the facial complex. 3. Middle and posterior cranial base length showed a greater increased than anterior cranial base length and circumpuberal growth spurt was also more definite. 4. The forward and downward growth of maxilla results from maxillary growth itself and transposition of the maxilla due to circumsutural growth around the maxilla. Ar-ANS and Ar-Pr which represent maxillary position relative to the cranial base showed more growth than ANS-PNS which represents maxillary bone growth. 5. mandible showed more vertical growth than horizontal growth but without significance. 6. Alveolar growth of maxilla and mandible show maximum growth rate of the time of permanent teeth eruption following loss of deciduous teeth. After this period alveolar growth shows a decreasing tendency.

Growth and develoment of arch form / 대한치과교정학회지

Study on growth change of dental arch is considered to both an important data in orthodontic diagonsis and treatment planning as well as analysis of treatment results ; also, arch form is important in anthropology and dentistry, even more so in prosthodontics and orthodontics. In the field of orthodontics, studies on the functional aspect of upper and lower teeth and maintenance of stability of dentition and occlusion were carried out from the early days. Some of the early studies include explanation of growth change in dental arch from measuring directly four human skull, and afterwards, cephalometcics x-rays were introduced; accordingly, studies using cephalometr c measurement and linear measurements of study models were often performed. By this method, arch width, arch depth and perimeters were measured, and growth change of dental arch was studied. The subject for this study were 600 children( boys and girls) of ages from 3 years to 12 years from Kang-won district and Seoul, who has no history of orthodontic treatment and who show healthy status and normal growth and development. Cephalometric x-ray, panoramic x-ray, and study model were taken for each subject consecutively for 2 years, and the subjects are still followed up. 400 pairs of study models from the past two years were used in this study,: mesio-distal diameater of each tooth, intercanine width, intermolar width, canine depth, molar depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and representation graph were drawn. The following conclusion were obtained. 1. Intercanine width showed gradual increase until the age of 10-years and after that, showed no increase. 2. Intermolar width in upper arch showed gradual increase = intermolar width in lower arch showed no significant chang, and after the age of 9-years, showed increase. 3. Gainine arch depth showed relatively rapid increase after the age of 6-years, and this pattern was more obvious in lower arch. 4. Molar arch depth increased gradually in both archs and it decrease after the age of 10-years : this phenomenon was more prominent in the lower arch. 5. Arch perimeter showed gradual inerease and convert to plateau at the age of 10-years, after that it decreased. this pattern was more prominent in lower arch.

Study on masticatory pattern of adult having anterior cross bite / 대한치과교정학회지

mastication is basically regulated by central pattern regulator(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 diffemce 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 state of mandible, anterior cross-bite showed the high r muscle activities in all the muscle.(exeeption: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 operiing,the maximum anterior-posterior movement from centric-occlusion, the lateral deviation from centric-occclusion, normal group showed the higher value than anterior cross-bite group.

Semi-longitudinal study of growth and development of children aged 6 to 17 Part I : Growth and development of arch form / 대한치과교정학회지

This study was carried out as a part of the semi-longitudinal study on growth and development of Korean children, with purpose of observing the growth change in arch form, 736 pairs of study models were taken for 3 years. Mesio-distal diameter of each tooth, intercanine width, intermolar width, canine arch depth, molar arch depth and arch perimeters were measured. Afterwards, mean value and each standard deviation of each age group and each gender were obtained, and corresponding graphs were drawn. The following conclusions were obtained: 1. Mesio-distal diameters of maxillary central incisor, maxillary 2nd molar, mandibular canine, and mandibular 2nd molar showed statistical differences between boys and girls. 2. Intercanine width shows a gradual increase until age of 11. 3. Intennolar width in maxilla shows continuous increase, and the tendency of increase is more apparent between age of 9 and 14. In mandible, various pattern was shown until age of 9, and after, a slight increase. 4. Canine arch depth shows the increasing tendency until age of 13 in maxilla and 11 in mandible. 5. Molar arch depth shows the pattern of increase until age of 10 in male and 9 in female, which is more apparent in maxilla. After age of 9 or 10, dereasing pattern was significantly shown until age of 15 in maxilla and age of 12 in mandible. 6. Arch perimeters in maxilla and mandible showed gradual increase until age of 10, and the tendency of increase was more apparent in maxilla; however, between the age of 10 and 14, arch perimeters of maxilla and mandible showed gradual decrease which was more apparent in mandible.

Comparative study on muscle activities of pre-and post-orthognathic surgery in skeletal Class III malocclusion patients and normal group / 대한치과교정학회지

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 performed. The selected sample groups were 15 normal male patients, 15 skeletal CI Ill pre-orthognatic surgery patients and 15 skeletal CI Ill 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 ant. 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.

An analysis of stress distribution in the case of unilateral molar expansion with precision lingual arch by finite element method / 대한치과교정학회지

Orthodontic tooth movement is closely related to the stress on the periodontal tissue. In this research the finite element method was used to observe the stress distribution and to find the best condition for effective tooth movement in the case of unilateral molar expansion. The author constructed the model of lower dental arch of average Korean adult and used .032" x .032" x 60mm TMA wire. The wire was deflected in the horizontal and vertical direction to give the 16 conditions. The following results were obtained; 1. When the moment and force were controlled properly the movement of anchor tooth was minimized and the movement of moving tooth was maximized. 2. As the initial horizontal deflection increased the buccal displacement of both teeth was also increased. As the initial vertical deflection increased the lingual movement of anchor tooth and the buccal movement of moving tooth increased. 3. When the initial horizontal and vertical deflection rate was 1.5 the effective movement of moving tooth was observed with minimal displacement of anchor tooth.

Modality of malocclusion according to regional difference using HLD(handicapping labiolingual deviation), TPI(treatment priority index) and HMAR(handicapped malocclusion assessing record) / 대한치과교정학회지

We tried to evaluate frequencies and severities of malocclusion of various socioeconomic areas according to growth and development. To obtain objective validity, we used Handicapping Labiolingual Deviation (HLD) suggested by Draker, Treatment Priority Index (TPI) by Grainger, Handicapped Malocclusion Assessing Record (HMAR) by American Dental Association and American Association of Orthodontist. Seoul and Kwangju were selected as an urban group, Ahnyang as an middle socioeconomic group and Hwasun near the Kwangju area as an rural group. 140 (male 63, female 73) of 5th grade in 'E' elementary school students in Seoul, 202 (male 101, female 101) of 'S' elementary school students in Kwangju, 207(male 105, female 102) of 'H' elementary school students in Hwasun, and 100(male 49, female 51) of 'M' elementary school students of in Ahnyang of all the same grade were analyzed and we obtained the results as follows; 1. TPI, HLD, and HMAR showed high coincidence and reproducibility between different observer. (p<0.01) 2. In comparison of TPI, HLD, and HMAR according to clinical decision, there was statistically difference between each other. (p<0.01) 3. As the severity of malocclusion increases there was high correlation between TPI and HLD, and between HLD and HMAR (p<0.05) 4. With respect to differences between areas in TPI and HLD, there was statistically difference between Ahnyang and other areas. 5. In Seoul as an urban group there was a high incidence of periodic checkup and history of orthodontic treatment than other area. 6. Mode of feeding and posture during sleeping did not affect the severity of malocclusion. As a conclusion, TPI, HLD and HMAR are so reproducible and coincident that they can be used as a guide on evaluating the frequency and severity of malocclusion and determining the priority of orthodontic treatment to determine the need and supply of orthodontic treatment. Furthermore these indices can provide objectively valid data for establishing public health problem solution.

The center of resistance of the maxillary anterior segment in the horizontal plane during intrusion by using laser reflection technique / 대한치과교정학회지

Tooth movement by segment is one of the means which are frequency used in daily orthodontic practice. When we retract or intrude a tooth or teeth, we should recognize the center of resistance of the certain tooth or teeth. There have been many studies about the center of resistance of a single tooth, not so much was about the tooth-segment. At the present study the center of resistance of the maxillary anterior segment is experimentally investigated by using laser reflection technique and metal splints on the human dry skull. The variables of intrusive force magnitude are divided into two groups, 50g and 100g groups. The results were as follows; 1. The center of resistance of the maxillary anterior segment composed of the central and lateral incisors was at the mesial portion of canine crown at the coronal level. 2. The center of resistance of the maxillary anterior segment composed of the central and lateral incisors and canines is between the canine and the 1st premolar crowns at the coronal level.

A study on the craniofacial morphology of operated congenital cleft lip & palate / 대한치과교정학회지

A cephalometric study was undertaken to reveal significant differences of craniofacial morphology of operated congenital cleft lip and palate subjects and control subjects. The material for this study consisted of 73 subjects with operated congenital cleft lip and palate subjects(53 males, 20 females) and 110 control subjects (7 males, 34 females) ranging from 3 to 14 years old. Each group was divided into four age groups (3-5, 6-8, 9-11, 12-14 year) and analyzed by Coben's method and Burstone's method. The following conclusions were obtained; 1. In Wit's appraisal, there was no difference the cleft lip and palate subjects and the control subjects. 2. In the eleft lip and palate subjects, they had smaller and more retrusive maxilla than the control subjects in both sexes. 3. In the cleft lip and palate subjects, they had more retrusive mandible than the control subjects in both sexes. 4. In the cleft lip and palate subjects, they had more concave profile than the control subjects.

The effects of changes of mandibular position on temporomandibular joint in adult rabbits whose retrodiscal tissues were incised / 대한치과교정학회지

The purpose of this experiment was to study the effects of changes of mandibular position on temporomandibular joint in internal derangement patients. Twenty-four female New Zealand White Rabbits, weighing over 3.5kg, were utilized in this study. Bilateral temporomandibular joint surgery was performed in twenty one of the rabbits to displace disc anteriorly through incising the retrodiscal tissue 1-2mm posterior to the disc, thus inducing internal derangement. They were divided into three groups: nine were left untreated after surgery, six were fitted with functional protrusive appliances 4 weeks after surgery, and six wore collar appliances to apply 4 ounces of mandibular retractive force per side 4 weeks after surgery. The remaining three served as the control group. Histologic examinations were performed after sacrificing them by threes at 4-week intervals. The results were as follows: 1. Histologic findings similar to internal derangement were observed in the rabbits whose retrodiscal tissues had been incised. 2. In the rabbits untreated after surgery, articular surface on condylar process and articular eminence showed severe erosion and deformation, and displaced disc manifested changes in both shape and internal architecture. 3. Functional protrusion after surgery resulted in progressive remodeling on posterosuperior portion of condyle and glenoid fossa, while it also brought about erosion on articular eminence and anterior portion of condyle. 4. Mandibular retraction after surgery resulted in compression of retrodiscal tissue and regressive remodeling of posterior portion of condyle.

Experimental study on the effect of heat treatment on the orthodontic wires / 대한치과교정학회지

No abstract available.

A longitudinal study on the interrelationship between the growth change of the mandible and developmental age of growing girls / 대한치과교정학회지

This study was undertaken to investigate the interrelationship between the growth change of mandible and the developmental age of growing girls in the longitudinal data from 7 years to 15 years. The data were obtained from maturation stage of cervical vertebrae through the serial lateral cephalogram, height increment records which was taken at one year interval, menarche date through interview. On the basis of findings of this study, the following conclusions were obtained. 1. In general the growth of mandible (Ar-Pog, Ar-Go, Go-Pog) showed two peaks of growth velocity. 2. The maximum growth of mandible (Ar-Pog, Ar-Go, Go-Pog) almost appeared between stage 3 and stage 4 in maturation of cervical vertebrae. 3. It showed the tendency that the maximum increment of height appeared faster than that of mandible (Ar-Pog, Ar-Go, Pog-Go). 4. The maximum growth of height almost appeared between stage 2 and stage 3 in maturation of cervical vertebrae. 5. It showed the tendency that the menarche appeared later than the maximum growth of mandible (Ar-Pog, Ar-Go, Pog-Go). 6. The menarche almost appeared at stage 4, stage 5 in maturation of cervical vertebrae.

A statistical study of dental crowding with dental cast analysis / 대한치과교정학회지

Crowded group is composed of 60 subjects who visited Yonsei University for orthodontic treatment and has no history of orthodontic treatment. Noncrowded group is composed of 26 subjects who has no crowding, considered to have a normal occlusion and no history of orthodontic treatment. Currently available and approved analytic method was used. Interrelationship between tooth size and arch size, and it's correlation on tooth crowding was studied and the following results were obtained. 1. In comparison of sum of mesiodistal width, of crown size of teeth was greater in noncrowded group than that of crowded group on both arch. (p<0.01). 2. In comparison of arch lengths, the values measured from arch length 2 showed greater in non crowded group (p<0.01). Also in crowded group, arch length 1 showed greater value than arch length 2 on both arch (p<0.01). 3. In comparison of arch widths, upper interlateral (p<0.01) and upper intercanine width (p<0.05) showed greater value in noncrowded group on upper arch and intermolar width showed greater value in noncrowded group on both upper and lower arches (p<0.05). 4. In comparison of arch perimeters, arch perimeter 2 was greater value in noncrowded group on both upper and lower arches (p<0.01). 5. Dentoalveolar disproportion was greater in noncrowded group on both upper and lower arches (p<0.01). 6. In lower incisors MD/FL ratio, the central and lateral incisors were greater in crowded group, but statistial significance was only in lateral incisors (p<0.01) 7. The irregularity index of lower incisors showed greater value in crowded group (p<0.01).