Yong-Il Kim

Pusan National University, Tsau-liang-hai, Busan, South Korea

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Publications (39)32.44 Total impact

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    ABSTRACT: The purpose of this study was to establish multivariable regression models for the estimation of skeletal maturation status in Japanese boys and girls using the cone-beam computed tomography (CBCT)-based cervical vertebral maturation (CVM) assessment method and hand-wrist radiography. The analyzed sample consisted of hand-wrist radiographs and CBCT images from 47 boys and 57 girls. To quantitatively evaluate the correlation between the skeletal maturation status and measurement ratios, a CBCT-based CVM assessment method was applied to the second, third, and fourth cervical vertebrae. Pearson's correlation coefficient analysis and multivariable regression analysis were used to determine the ratios for each of the cervical vertebrae (p < 0.05). Four characteristic parameters ((OH2 + PH2)/W2, (OH2 + AH2)/W2, D2, AH3/W3), as independent variables, were used to build the multivariable regression models: for the Japanese boys, the skeletal maturation status according to the CBCT-based quantitative cervical vertebral maturation (QCVM) assessment was 5.90 + 99.11 × AH3/W3 - 14.88 × (OH2 + AH2)/W2 + 13.24 × D2; for the Japanese girls, it was 41.39 + 59.52 × AH3/W3 - 15.88 × (OH2 + PH2)/W2 + 10.93 × D2. The CBCT-generated CVM images proved very useful to the definition of the cervical vertebral body and the odontoid process. The newly developed CBCT-based QCVM assessment method showed a high correlation between the derived ratios from the second cervical vertebral body and odontoid process. There are high correlations between the skeletal maturation status and the ratios of the second cervical vertebra based on the remnant of dentocentral synchondrosis.
    Clinical Oral Investigations 02/2015; · 2.20 Impact Factor
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    ABSTRACT: We compared the skeletal and dental changes that resulted from the use of two methods of intermaxillary fixation (IMF)-miniscrews and surgical archwire-in 74 adult patients who had Class III malocclusion and were treated with the same orthognathic surgical procedure at a hospital in Korea. All the patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy with rigid fixation. They were divided into two groups according to the type of IMF used-group 1 underwent surgical archwire fixation and group 2 underwent orthodontic miniscrew fixation. In a series of cephalograms for each patient, we compared vertical and horizontal tooth-position measurements: (a) immediately after surgery (T0), (b) 3 months after surgery (T1), and (c) 6 months after surgery (T2). Cephalometric changes within each group were examined using one-way analysis of variance (ANOVA) while the independent samples t-test procedure was used to compare the two groups. After surgery, the maxillary incisors tended to be proclined in both groups although there were no significant differences. Incisor overbite increased significantly in both groups from T0 to T1, and the miniscrew group (group 2) showed slightly greater overbite than the archwire group (group 1). This study suggest that the use of orthodontic miniscrews and orthodontic surgical archwire for IMF in adult patients results in similar skeletal and dental changes.
    Korean journal of orthodontics. 01/2015; 45(1):3-12.
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    ABSTRACT: Objective: To evaluate axial cervical vertebral (ACV) shape quantitatively and built a prediction model for skeletal maturation level using statistical shape analysis for Japanese individuals. Materials and Methods: The sample included 24 female and 19 male patients with hand-wrist radiographs and cone-beam computed tomography images. Through generalized Procrustes analysis and principal components analysis, the meaningful principal components (PCs) were extracted from each ACV shape and analyzed for the estimation regression model. Results: Each ACV shape had meaningful PCs, except for the 2(nd) ACV. Based on these models, the smallest prediction intervals (PI) were from the combination of the shape space PCs, age, and gender. Overall, the PIs of the male group were smaller than those of the female group. There was no significant correlation between centroid size as a size factor and skeletal maturation level. Conclusions: Our findings suggest that the axial cervical vertebral maturation (ACVM) method, which was applied by statistical shape analysis, could confirm information about skeletal maturation in Japanese individuals as an available quantifier of skeletal maturation and could be as useful a quantitative method as the skeletal maturation index.
    Dento-maxillo-facial radiology. Supplement 11/2014;
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    ABSTRACT: The purposes of this study were to investigate the relationship between occlusal vertical dimension (VD) changes and postsurgical skeletal changes in the surgery-first approach and to derive regression models for the final mandibular setback at B-point. This retrospective study included 40 patients (16 men, 24 women; ages, 22.6 ± 4.0 years) who had undergone a bimaxillary surgery-first approach. Using cephalograms generated from cone-beam computed tomography representing the presurgical, postsurgical, and posttreatment stages, skeletal landmarks in the maxilla and mandible were investigated to derive multivariate linear regression-based prediction models. Additionally, a patient classification based on the VD was established and verified to generate regression models for the classified groups. For the nonincreased VD group, the surgical setback of B-point was its predictor for the final mandibular setback (R(2) at 92%). Meanwhile, the final mandibular setback of the increased VD group was predicted according to the surgical upward movement of pogonion, the postsurgical horizontal position of A-point, and the postsurgical vertical position of the coronoid process (R(2) at 94%). The results of this study support the clinical observation that the more increased the vertical occlusal dimension after surgery, the less predictable the position of B-point at the posttreatment stage. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
    American Journal of Orthodontics and Dentofacial Orthopedics 11/2014; 146(5):612-9. · 1.44 Impact Factor
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    ABSTRACT: Objective To comparatively evaluate condylar surface bone formation and cortical thickening in patients with temporomandibular joint osteoarthritis (OA), with or without stabilization splint (SS) therapy. Study Design This retrospective study of 57 OA patients included 18 patients that had undergone SS therapy (SS group), compared with 39 patients that had not received SS therapy (non-SS group). To evaluate osseous changes on the condylar bone formation and cortical thickening, pre- and post-treatment cone beam computed tomography images of each patient were superimposed using voxel registration. Results The SS group exhibited a higher ratio of bone formation in the anterior division of the condyle; the non-SS group exhibited mostly no change. The SS group demonstrated higher frequencies of cortical thickening in the anteromedial, anterior-intermediate, anterolateral, posteromedial, and posterior-intermediate sections than the non-SS group. Conclusion SS therapy in TMJ OA induced favorable bone remodeling in the anterior division of the condylar head.
    Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 09/2014; · 1.50 Impact Factor
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    ABSTRACT: Purpose To evaluate the maxillary stability after Le Fort I osteotomy with posterior-superior movement using pterygoid process fracture or removal, and mandibular setback surgery for skeletal Class III deformities. Materials and Methods We performed a retrospective cohort study of the changes in 28 skeletal Class III patients’ three-dimensional (3D) measurement-point coordinates, obtained by cone-beam computed tomography (CBCT) superimposition. The predictor variables were the management of pterygoid process (fracture and removal method). The outcome variables were the changes of measurement points based on 3D coordinates, obtained preoperatively (T0), immediately postoperatively (T1) and 6 months after surgery (T2). The linear mixed-effects models were applied to the evaluation of postoperative stability. Results The 3D cephalometric outcome variables for 14 subjects who had undergone pterygoid process fracture were compared with those for 14 subjects who had undergone pterygoid process removal. The postoperative NPC points moved superiorly 0.11 mm and inferiorly 0.06 mm for the fracture and removal groups, respectively. However, most of the extent of the postoperative relapse was within 1 mm. There were no differences in the postoperative skeletal changes shown by the fracture and removal groups (P<0.05). Conclusions The results suggest that surgeons could achieve very stable skeletal stability from Le Fort I osteotomy with posterior-superior movement, regardless of the pterygoid process method (fracture or removal).
    Journal of Oral and Maxillofacial Surgery 09/2014; · 1.28 Impact Factor
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    ABSTRACT: A recent study suggested that rs6504340, a polymorphism within the homeobox B (HOXB) gene cluster, is associated with the susceptibility for malocclusions in Europeans. The resulting malocclusions require orthodontic treatment. The aim of this study was to investigate the association of rs6504340 and other dentition-implicated polymorphisms with dental and occlusal traits in Korean and Japanese populations. The study participants included 223 unrelated Koreans from the Busan area and 256 unrelated Japanese individuals from the Tokyo metropolitan area. DNA samples were extracted from saliva specimens. Genotyping for rs6504340 and four single nucleotide polymorphisms (SNPs) that have been shown to be associated with the timing of first tooth eruption and the number of teeth at 1 year of age (rs10506525, rs1956529, rs9674544, and rs8079702) was performed using TaqMan assays. The Index of Orthodontic Treatment Need (IOTN), overjet, overbite, arch length discrepancy, crown sizes, and length and width of the dental arches were measured. Spearman's correlation coefficients were calculated to evaluate relationships between rs6504340 and these dental/occlusal traits. We evaluated the aesthetic components and dental health components of the IOTN in the Korean and Japanese populations and found that neither rs6504340 nor the other four SNPs showed any association with dental and occlusal traits in these East Asian populations. These negative results suggest that further research is needed to identify the genetic determinants of malocclusions in order to reach a consensus.
    Korean Journal of Orthodontics 03/2014; 44(2):96-102. · 0.37 Impact Factor
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    ABSTRACT: To evaluate condylar head remodeling after mandibular set-back sagittal split ramus osteotomy (SSRO) with rigid fixation in skeletal class III deformities. The correlation between condylar head remodeling and condylar axis changes was determined using cone-beam computed tomography (CBCT) superimposition. The CBCT data of 22 subjects (9 men and 13 women) who had undergone mandibular set-back SSRO with rigid fixation were analyzed. Changes in the condylar head measurements and the distribution of the signs of condylar head remodeling were evaluated by CBCT superimposition. The subjects showed inward rotation of the axial condylar angle; reduced condylar heights on the sagittal and coronal planes; and resorptive remodeling in the anterior and superior areas on the sagittal plane, superior and lateral areas on the coronal plane, and anterior-middle and anterior-lateral areas on the axial plane (p < 0.05). The CBCT superimposition method showed condylar head remodeling after mandibular set-back SSRO with rigid fixation. In skeletal class III patients, SSRO with rigid fixation resulted in rotation, diminution, and remodeling of the condylar head. However, these changes did not produce clinical signs or symptoms of temporomandibular disorders.
    Korean Journal of Orthodontics 12/2013; 43(6):263-70. · 0.37 Impact Factor
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    ABSTRACT: Tooth agenesis is the most common developmental anomaly of human dentition, occurring most often in the third molar (wisdom tooth). It is affected by genetic variation, so this study aimed to identify susceptibility genes associated with third molar agenesis. Examination of panoramic radiographs and medical history about third molar extraction were used to diagnose third molar agenesis. We then conducted a genome-wide association study of 149 cases with at least one-third molar agenesis and 338 controls from Japan and Korea using the Illumina HumanOmniExpress BeadChip. After rigorous quality-control filtering, approximately 550 000 single-nucleotide polymorphisms (SNPs) were analyzed in association tests with the status. We identified three SNPs showing evidence of association at P<1 × 10(-5) and 69 SNPs showing evidence of association at P<1 × 10(-4). SNP rs1469622, which maps to an intron of THSD7B (thrombospondin, type I, domain containing 7B) on chromosome 2, showed the strongest association (combined odds ratio=1.88, 95% confidence interval=1.43-2.47, P=7.5 × 10(-6)). The identified SNPs may be considered candidates for future replication studies in independent samples.Journal of Human Genetics advance online publication, 31 October 2013; doi:10.1038/jhg.2013.106.
    Journal of Human Genetics 10/2013; · 2.53 Impact Factor
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    ABSTRACT: Objective: To evaluate the effect of postoperative condylar axis changes on mandibular condylar remodeling by comparing the condylar head in three-dimensional (3D) surface reconstructions before and after surgery in skeletal Class III deformities (one-jaw [mandibular setback] or two-jaw surgery), and also to determine the relationship between condylar inward rotation and condylar surface remodeling after orthognathic surgery. Materials and Methods: A retrospective analysis was conducted of 30 patients with skeletal Class III deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 ± 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 ± 2.2 years). Sixty condyles were reconstructed and superimposed pre- and postoperatively to compare the changes of condylar surfaces. The relation between the condylar axis change and the surface change using the Pearson correlation were investigated from the 3D image software. Results: Condylar surface changes before and after the surgery were significant. The postoperative inward rotation of the condyles was correlated with the average absolute deviation of the condyles, regardless of the surgery type (one- or 2-jaw surgery; r = .70, P < .05). Conclusion: After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface.
    The Angle Orthodontist 08/2013; · 1.28 Impact Factor
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    ABSTRACT: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance.
    Korean Journal of Orthodontics 08/2013; 43(4):168-77. · 0.37 Impact Factor
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    ABSTRACT: To compare three-dimensionally the midfacial hard- and soft-tissue asymmetries between the affected and the unaffected sides and determine the relationship between the hard tissue and the overlying soft tissue in patients with nonsyndromic complete unilateral cleft lip and palate (UCLP) by cone-beam computed tomography (CBCT) analysis. The maxillofacial regions of 26 adults (18 men, 8 women) with nonsyndromic UCLP were scanned by CBCT and reconstructed by three-dimensional dental imaging. The frontal-view midfacial analysis was based on a 3 × 3 grid of vertical and horizontal lines and their intersecting points. Two additional points were used for assessing the dentoalveolar area. Linear and surface measurements from three reference planes (Basion-perpendicular, midsagittal reference, and Frankfurt horizontal planes) to the intersecting points were used to evaluate the anteroposterior, transverse, and vertical asymmetries as well as convexity or concavity. Anteroposteriorly, the soft tissue in the nasolabial and dentoalveolar regions was significantly thicker and positioned more anteriorly on the affected side than on the unaffected side (p < 0.05). The hard tissue in the dentoalveolar region was significantly retruded on the affected side compared with the unaffected side (p < 0.05). The other midfacial regions showed no significant differences. With the exception of the nasolabial and dentoalveolar regions, no distinctive midfacial hard- and soft-tissue asymmetries exist between the affected and the unaffected sides in patients with nonsyndromic UCLP.
    Korean Journal of Orthodontics 06/2013; 43(3):113-9. · 0.37 Impact Factor
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    ABSTRACT: The purpose of this study was to investigate, through cone beam computed tomography, volumetric changes to the upper airway space in patients with skeletal class III skeletal deformities who had undergone mandibular setback surgery (group A [n = 24]) or bimaxillary surgery (mandibular setback surgery and maxillary setback Le Fort I osteotomy; group B [n = 23]). All of the patients underwent a cone beam computed tomographic examination for assessment of the upper airway volume and skeletal changes before surgery (T0) and 6 months after surgery (T1). In an evaluation of the anatomic characteristics of the upper airway, the anteroposterior length (APL), the largest transverse width (LTW), and the cross-sectional area (CSA) on the axial planes (the posterior nasal spine-posterior point of vomer (PNS-Vp), 1st cervical vertebra (CV1), 2nd cervical vertebra (CV2), 3rd cervical vertebra (CV3), and 4th cervical vertebra (CV4) planes) were calculated at T0 and T1. No significant differences between the groups A and B (P > 0.05) were found. In group A, the mandibular setback movement affected the oropharyngeal and hypopharyngeal volumes and reduced the APL, the LTW, and the CSA on the CV1, CV2, and CV3 planes (P < 0.05). The APL and the CSA on the CV4 plane also were reduced (P < 0.05). In group B, the maxillary and mandibular setback movement narrowed the upper airway volumes. Specifically, the APL on the CV1, CV2, CV3, and CV4 planes, the LTW on the PNS-Vp, CV1, and CV3 planes, and the CSA on the PNS-Vp, CV1, CV2, CV3, and CV4 planes decreased after the surgery (P < 0.05). Between the 2 groups, there were statistical differences (P < 0.05) in the APL, the LTW, and the CSA on the PNS-Vp plane.
    The Journal of craniofacial surgery 03/2013; 24(2):387-91. · 0.68 Impact Factor
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    ABSTRACT: INTRODUCTION: To investigate the effect of intended manual condylar positioning on skeletal changes from preoperative stage to posttreatment stage. MATERIALS AND METHODS: The sample comprised 23 patients divided into two groups according to surgery type: mandible-only setback surgery (group I) versus 2-jaw surgery (group II). CBCT-generated Half-Cephalograms were fabricated to evaluate the skeletal, dental, and condylar positioning changes for each subject at three time points (preoperatively (T0), immediate-postoperatively (T1), and posttreatment (T2)). RESULTS: The angle of the proximal segment in group II was reduced immediate-postoperatively. In both groups, the result showed a negative mean value for the horizontal mandibular position (B point to N-perpendicular plane at T2-T1 stage). In group II, the vertical mandibular position (B point to FH plane at T2-T1 stage) also had a negative mean value. In group I, the change of the B point to N-perpendicular plane (T2-T1) had statistically significant correlations with the change of the Cd to Po-perpendicular plane (T2-T1). In group II, the change of the B point to the N-perpendicular plane (T2-T1) had statistically significant correlations with the change of the ∠Cd-Cp-FH plane angle (T2-T1) and the Cp to FH plane (T1-T0). CONCLUSIONS: In this study, the change from the T1 to T2 stage, though not statistically significant, showed a negative short-term relapse. Intended manual condylar positioning may suppress the short-term skeletal relapse.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 02/2013; · 1.25 Impact Factor
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    ABSTRACT: To evaluate the presurgical orthodontic tooth movement of mandibular teeth after dental decompensation for skeletal Class III deformities on the basis of vertical skeletal patterns. This cohort was comprised of 62 patients who received presurgical orthodontic treatment. These patients were divided into 3 groups according to their vertical skeletal patterns. Changes in the positions of the mandibular central incisor, canine, premolar, and 1st molar after presurgical orthodontic treatment were measured using a cone-beam computed tomography (CBCT) superimposition method. The incisors moved forward after dental decompensation in all 3 groups. The canines in group I and the 1st premolars in groups I and III also moved forward. The incisors and canines were extruded in groups I and II. The 1st and 2nd premolars were also extruded in all groups. Vertical changes in the 1st premolars differed significantly between the groups. We also observed lateral movement of the canines in group III and of the 1st premolar, 2nd premolar, and 1st molar in all 3 groups (p < 0.05). Movement of the mandibular incisors and premolars resolved the dental compensation. The skeletal facial pattern did not affect the dental decompensation, except in the case of vertical changes of the 1st premolars.
    Korean Journal of Orthodontics 10/2012; 42(5):227-34. · 0.54 Impact Factor
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    ABSTRACT: Studies on the heredity of dental characteristics in humans have indicated that the variance in many dental traits results from genetic variation. However, the genetic factors that influence commonly occurring dental variants are poorly understood. Paired domain box 9 (PAX9) codes a transcription factor that is important in tooth development. We investigated whether PAX9 polymorphisms are associated with normal variations in tooth agenesis and morphology. The study subjects were 273 Japanese and 223 Korean adults. Single-nucleotide polymorphisms (SNPs) in PAX9 (rs2295222, rs4904155, rs2073244, rs12881240 and rs4904210) were genotyped, and third molar agenesis and mesiodistal and buccolingual diameters were measured. We found that four of the five SNPs were significantly associated with the crown size. However, no SNP was associated with third molar agenesis. In additional analyses on non-metric dental traits, we found significant associations of PAX9 SNPs with shoveling of upper first incisors. In summary, common variants in PAX9 contributed to morphological variation in permanent teeth in humans.
    Journal of Human Genetics 07/2012; 57(10):654-9. · 2.53 Impact Factor
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    ABSTRACT: The aim of this article is to compare the soft-tissue changes in the midfacial areas of patients who had undergone mandibular setback sagittal split ramus osteotomy (SSRO) with that of mandibular setback SSRO with paranasal augmentation. The subjects included 15 patients (group I), SSRO with paranasal augmentation and 20 patients (group II), SSRO alone. To evaluate the difference of the midfacial soft-tissue changes between groups, cone-beam computed tomography superimposition was utilized and the soft-tissue changes were measured both preoperatively and postoperatively by a 10 × 27 grid. In group I, the soft tissues were changed at the areas bounded superiorly by the infraorbital foramen, zygomatic eminence, posteriorly by the masseteric muscle and medially by the lateral aspect of the nose and following the nasolabial fold. In group II, the midfacial soft-tissue measurements were unchanged. This study may help clinicians to predict improvement in the midfacial region from mandibular setback SSRO with or without a paranasal augmentation procedure in class III deformities.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 07/2012; · 1.25 Impact Factor
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    ABSTRACT: PURPOSE: To compare intersegmental displacements after mandibular setback sagittal split ramus osteotomy with reference to the fixation system applied: miniplate with monocortical screw, 3 bicortical screws, and 1 bicortical screw and 2 resorbable screws. MATERIALS AND METHODS: The 42 subjects were divided into 3 groups according to the osteosynthesis method applied. To evaluate the intersegmental displacements from immediately after surgery (T0) to 6 months after surgery (T1), 2 cone-beam computed tomographic data sets were superimposed on the symphyseal area and the lower part of the mandible below the root apex. On the superimposed 3-dimensional images, the mean and standard deviation of the differences of the coordinates (x, y, z) between T0 and T1 were calculated. RESULTS: From T0 to T1, group B (bicortical screws) manifested the greatest condylion (Cd) and coronoid process (Cp) displacements (P < .05). In group A, the right Cd moved anteriorly and the left Cd moved anteriorly and inferiorly, whereas the right and left Cps moved anteriorly. In group B, the right and left Cps moved laterally and inferiorly. In group C, the right Cd moved anteriorly and inferiorly, the left Cd changed laterally and anteriorly, the right Cp moved anteriorly, and the left Cp moved anteriorly and inferiorly. CONCLUSIONS: In the present study, group B (bicortical screws) showed the greatest displacement after the healing period. In view of these findings, surgeons should consider carefully their choice of osteosynthesis method to effectively decrease intersegmental displacement.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 06/2012; · 1.58 Impact Factor
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    ABSTRACT: Dental morphology is highly diverse among individuals and between human populations. Although it is thought that genetic factors mainly determine common dental variations, only a few such genetic factors have been identified. One study demonstrated that a nonsynonymous single-nucleotide polymorphism (370V/A, rs3827760) in the ectodysplasin A receptor gene (EDAR) is associated with shoveling and double-shoveling grades of upper first incisors and tooth crown size. Here, we examined the association of EDAR 370V/A with several dental characters in Korean and Japanese subjects. A meta-analysis that combined analyses of Korean and Japanese subjects revealed that the Asian-specific 370A allele is associated with an increase in the grades of shoveling and double shoveling, as previously found. We also showed a highly significant association between EDAR 370V/A genotype and crown size, especially mesiodistal diameters of anterior teeth. Moreover, we found that the 370A allele was associated with the presence of hypoconulids of lower second molars. These results indicated that the EDAR polymorphism is responsible, in part, for the Sinodonty and Sundadonty dichotomy in Asian populations, and clearly demonstrated that the EDAR polymorphism has pleiotropic effects on tooth morphology. As the 370A allele is known to be a most likely target of positive selection in Asian populations, some phenotypes associated with the variant may be 'hitchhiking phenotypes', while others may be actual targets of selection.
    Journal of Human Genetics 05/2012; 57(8):508-14. · 2.53 Impact Factor
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    ABSTRACT: BACKGROUND: The purpose of this study was to evaluate the reliability of measurements from cone-beam computed tomography (CBCT)-generated frontal cephalogram. MATERIALS AND METHODS: CBCT and conventional posteroanterior (PA) cephalograms were taken from 30 adult patients. CBCT image was set according to the Frankfurt-Horizontal (FH) plane as the horizontal plane and the midsagittal reference (MSR) plane. The CBCT frontal cephalograms were generated using the orthogonal Raycast method (group CT(raycast)), the orthogonal maximum intensity projection (MIP) method (group CT(MIP)) after the head reorientation according to the reference planes, and the generator tool provided by the employed 3-dimensional (3D) imaging software (group CT(generator)), respectively. The differences between the CBCT-generated frontal cephalograms and conventional PA cephalograms (group PA(ceph)) were compared by paired t-test (p<0.05). RESULTS: The significant differences were shown in two measurements for group CT(raycast), in 12 measurements for group CT(MIP), and in eight measurements for group CT(generator). It was confirmed that the CBCT frontal cephalograms, generated by means of the Raycast method (Group CT(raycast)), were more comparable to the conventional PA cephalograms in their measurements than were the others (Groups CT(MIP), CT(generator)). CONCLUSION: This study may well suggest that frontal cephalograms derived by 3D CBCT reorientation can be effectively employed in clinical applications.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 03/2012; · 1.25 Impact Factor