New three-dimensional cephalometric analyses among adults with a skeletal Class I pattern and normal occlusion

Mohamed Bayome,Jae Hyun Park,Yoon-Ah Kook 대한치과교정학회 2013 대한치과교정학회지 Vol.43 No.2

Objective: The purpose of this study was to assess new three-dimensional (3D) cephalometric variables, and to evaluate the relationships among skeletal and dentoalveolar variables through 3D cephalometric analysis. Methods: Conebeam computed tomography (CBCT) scans were acquired from 38 young adults (18 men and 20 women; 22.6 ± 3.2 years) with normal occlusion. Thirty-five landmarks were digitized on the 3D-rendered views. Several measurements were obtained for selected landmarks. Correlations among different variables were calculated by means of Pearson’s correlation coefficient values. Results: The body of the mandible had a longer curve length in men (102.3 ± 4.4 mm) than in women (94.5 ± 4.7 mm) (p < 0.001), but there was no significant difference in the maxillary basal curve length. Men had significantly larger facial dimensions, whereas women had a larger gonial angle (117.0 ± 4.0 vs. 113.8 ± 3.3; p < 0.001). Strong-to-moderate correlation values were found among the vertical and transverse variables (r = 0.71 to 0.51). Conclusions: The normative values of new 3D cephalometric parameters, including the maxillary and mandibular curve length, were obtained. Strong-to-moderate correlation values were found among several vertical and transverse variables through 3D cephalometric analysis. This method of cephalometric analyses can be useful in diagnosis and treatment planning for patients with dentofacial deformities.

New three-dimensional cephalometric analyses among adults with a skeletal Class I pattern and normal occlusion

Bayome, Mohamed,Park, Jae Hyun,Kook, Yoon-Ah The Korean Association Of Orthodontists 2013 대한치과교정학회지 Vol.43 No.2

Objective: The purpose of this study was to assess new three-dimensional (3D) cephalometric variables, and to evaluate the relationships among skeletal and dentoalveolar variables through 3D cephalometric analysis. Methods: Cone-beam computed tomography (CBCT) scans were acquired from 38 young adults (18 men and 20 women; $22.6{\pm}3.2$ years) with normal occlusion. Thirty-five landmarks were digitized on the 3D-rendered views. Several measurements were obtained for selected landmarks. Correlations among different variables were calculated by means of Pearson's correlation coefficient values. Results: The body of the mandible had a longer curve length in men ($102.3{\pm}4.4$ mm) than in women ($94.5{\pm}4.7$ mm) (p < 0.001), but there was no significant difference in the maxillary basal curve length. Men had significantly larger facial dimensions, whereas women had a larger gonial angle ($117.0{\pm}4.0$ vs. $113.8{\pm}3.3$; p < 0.001). Strong-to-moderate correlation values were found among the vertical and transverse variables (r = 0.71 to 0.51). Conclusions: The normative values of new 3D cephalometric parameters, including the maxillary and mandibular curve length, were obtained. Strong-to-moderate correlation values were found among several vertical and transverse variables through 3D cephalometric analysis. This method of cephalometric analyses can be useful in diagnosis and treatment planning for patients with dentofacial deformities.

Comparison of treatment effects between four premolar extraction and total arch distalization using the modified C-palatal plate

조성윤,Mohamed Bayome,Justyn Park,임희진,국윤아,한성호 대한치과교정학회 2018 대한치과교정학회지 Vol.48 No.4

Objective: The purpose of this study was to compare the skeletal, dental, and soft-tissue treatment effects of nonextraction therapy using the modified C-palatal plate (MCPP) to those of premolar extraction (PE) treatment in adult patients with Class II malocclusion. Methods: Pretreatment and posttreatment lateral cephalographs of 40 adult patients with Class II malocclusion were retrospectively analyzed. The MCPP group comprised 20 patients treated with total arch distalization of the maxillary arch while the PE group comprised 20 patients treated with four PE. Fifty-eight linear and angular measurements were analyzed to assess the changes before and after treatment. Descriptive statistics, paired t-test, and multivariate analysis of variance were performed to evaluate the treatment effects within and between the two groups. Results: The MCPP group presented 3.4 mm of retraction, 1.0 mm of extrusion, and 7.3o lingual inclination of the maxillary central incisor. In comparison, the PE group displayed greater amount of maxillary central incisor retraction and retroclination, mandibular incisor retraction, and upper lip retraction (5.3 mm, 14.8o, 5.1 mm, and 2.0 mm, respectively; p < 0.001 for all). In addition, the MCPP group showed 4.0 mm of distalization and 1.3 mm of intrusion with 2.9o distal tipping of the maxillary first molars. Conclusions: These findings suggest the MCPP is an effective distalization appliance in the maxillary arch. The amount of incisor retraction, however, was significantly higher in the PE group. Therefore, four PE may be recommended when greater improvement of incisor position and soft-tissue profile is required.[Korean J Orthod 2018;48(4):224-235]

Evaluation of the palatal soft tissue thickness by cone-beam computed tomography

Trang Vu,Mohamed Bayome,국윤아,한성호 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.6

Objective: The purposes of this study were to measure the palatal soft tissue thickness at popular placement sites of temporary anchorage devices (TADs) by cone-beam computed tomography (CBCT) and evaluate the age, gender, and positional differences in this parameter. Methods: The study sample consisted of 23 children (10 boys and 13 girls; mean age, 10.87 ± 1.24 years; range, 6.7 to 12.6 years) and 27 adults (14 men and 13 women; mean age, 21.35 ± 1.14 years; range, 20.0 to 23.8 years). Nine mediolateral and nine anteroposterior intersecting reference lines were drawn on CBCT scans of the 50 subjects, and the resultant measurement areas were designated according to their mediolateral (i.e., lateral, medial, and sutural) and anteroposterior (i.e., anterior, middle, and posterior) positions. Repeated-measures analysis of variance was performed to analyze intragroup and intergroup differences. Results: No significant age and gender differences were found (p = 0.309 and 0.124, respectively). Further, no significant anteroposterior change was observed (p = 0.350). However, the lateral area presented the thickest soft tissue whereas the sutural area had the thinnest soft tissue (p < 0.001). Conclusions: Clinical selection of the placement sites of TADs should be guided by knowledge of the positional variations in the palatal soft tissue thickness in addition to other contributing factors of TAD stability.

Treatment Effects of Maxillary Molar Distalization with Palatal Plate: CBCT Synthesized Cephalometric Analysis

국윤아,김혜진,Mohamed Bayome,Park,Vu Thi Thu Trang 대한통합치과학회 2014 대한통합치과학회지 Vol.3 No.1

The purpose of this study was to evaluate the clinical treatment effects of molar distalization with palatal plate using 2 dimensional (2D) cephalograms converted from CBCT. This retrospective clinical study included 20 consecutively treated patients (11 male, 9 female), with an average age of 15±3 years. Cephalometric analysis was made on 2D cephalogram images derived from 3D CBCT. Skeletal, dental, and soft tissue measurements were evaluated. Through the use of palatal plate, clinically successful distalization of maxillary molars was achieved. Statistically significant changes in molars positions were observed between T1 and T2 (before and after the distal movement). The first molar and second premolar distalization were 3.98±1.23 mm and 1.17±3.54 mm with distal tipping of 3.17±4.97°and 3.21±2.86°, respectively. Moreover, the incisors were retracted 3.12±3.24 mm, with 10.31±4.98°of tipping and 1.75±1.54 mm of extrusion. All skeletal changes during treatment were not significant. The upper and lower lips were retracted 1.57 and 1.49 mm respectively. The palatal plate could be a valid clinical option for efficient distalization of the maxillary first molars in Class II patients.

Displacement and stress distribution of the maxillofacial complex during maxillary protraction using palatal plates : A three-dimensional finite element analysis

Jusuk Eom,Mohamed Bayome,Jae Hyun Park,Hee Jin Lim,Yoon-Ah Kook,Seong Ho Han 대한치과교정학회 2018 대한치과교정학회지 Vol.48 No.5

Objective: The purpose of this study was to analyze initial displacement and stress distribution of the maxillofacial complex during dentoskeletal maxillary protraction with various appliance designs placed on the palatal region by using three-dimensional finite element analysis. Methods: Six models of maxillary protraction were developed: conventional facemask (Type A), facemask with dentoskeletal hybrid anchorage (Type B), facemask with a palatal plate (Type C), intraoral traction using a Class III palatal plate (Type D), facemask with a palatal plate combined with rapid maxillary expansion (RME; Type E), and Class III palatal plate intraoral traction with RME (Type F). In Types A, B, C, and D, maxillary protraction alone was performed, whereas in Types E and F, transverse expansion was performed simultaneously with maxillary protraction. Results: Type C displayed the greatest amount of anterior dentoskeletal displacement in the sagittal plane. Types A and B resulted in similar amounts of anterior displacement of all the maxillofacial landmarks. Type D showed little movement, but Type E with expansion and the palatal plate displayed a larger range of movement of the maxillofacial landmarks in all directions. Conclusions: The palatal plate served as an effective skeletal anchor for use with the facemask in maxillary protraction. In contrast, the intraoral use of Class III palatal plates showed minimal skeletal and dental effects in maxillary protraction. In addition, palatal expansion with the protraction force showed minimal effect on the forward movement of the maxillary complex.

Evaluation of the palatal soft tissue theickness by cone-beam computed tomography

Trang Vu,Mohamed Bayome,Yoon-Ah Kook,Seong Ho Han 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.6

Objectives: The purposes of this study were to measure the palatal soft tissue thickness at popular placement sites of temporary anchorage devices (TADs) by cone-beam computed tomography (CBCT) and evaluate the age, gender, and positional differences in this parameter. Methods: The study sample consisted of 23 children (10 boys and 13 girls; mean age, 10.87 ± 1.24 years; range, 6.7 to 12.6 years) and 27 adults (14 men and 13 women; mean age, 21.35 ± 1.14 years; range, 20.0 to 23.8 years). Nine mediolateral and nine anteroposterior intersecting reference lines were drawn on CBCT scans of the 50 subjects, and the resultant measurement areas were designated according to their mediolateral (i.e., lateral, medial, and sutural) and anteroposterior (i.e., anterior, middle, and posterior) positions. Repeated-measures analysis of variance was performed to analyze intragroup and intergroup differences. Results: No significant age and gender differences were found (p = 0.309 and 0.124, respectively). Further, no significant anteroposterior change was observed (p = 0.350). However, the lateral area presented the thickest soft tissue whereas the sutural area had the thinnest soft tissue (p < 0.001). Conclusions: Clinical selection of the placement sites of TADs should be guided by knowledge of the positional variations in the palatal soft tissue thickness in addition to other contributing factors of TAD stability.

Evaluation of the palatal soft tissue thickness by cone-beam computed tomography

Vu, Trang,Bayome, Mohamed,Kook, Yoon-Ah,Han, Seong Ho The Korean Association Of Orthodontists 2012 대한치과교정학회지 Vol.42 No.6

Objective: The purposes of this study were to measure the palatal soft tissue thickness at popular placement sites of temporary anchorage devices (TADs) by cone-beam computed tomography (CBCT) and evaluate the age, gender, and positional differences in this parameter. Methods: The study sample consisted of 23 children (10 boys and 13 girls; mean age, $10.87{\pm}1.24$ years; range, 6.7 to 12.6 years) and 27 adults (14 men and 13 women; mean age, $21.35{\pm}1.14$ years; range, 20.0 to 23.8 years). Nine mediolateral and nine anteroposterior intersecting reference lines were drawn on CBCT scans of the 50 subjects, and the resultant measurement areas were designated according to their mediolateral (i.e., lateral, medial, and sutural) and anteroposterior (i.e., anterior, middle, and posterior) positions. Repeated-measures analysis of variance was performed to analyze intragroup and intergroup differences. Results: No significant age and gender differences were found (p = 0.309 and 0.124, respectively). Further, no significant anteroposterior change was observed (p = 0.350). However, the lateral area presented the thickest soft tissue whereas the sutural area had the thinnest soft tissue (p < 0.001). Conclusions: Clinical selection of the placement sites of TADs should be guided by knowledge of the positional variations in the palatal soft tissue thickness in addition to other contributing factors of TAD stability.

New approach of maxillary protraction using modified C-palatal plates in Class III patients

Yoon-Ah Kook,Mohamed Bayome,Jae Hyun Park,Ki Beom Kim,Seong-Hun Kim,Kyu-Rhim Chung 대한치과교정학회 2015 대한치과교정학회지 Vol.45 No.4

Maxillary protraction is the conventional treatment for growing Class Ⅲ patients with maxillary deficiency, but it has undesirable dental effects. The purpose of this report is to introduce an alternative modality of maxillary protraction in patients with dentoskeletal Class Ⅲ malocclusion using a modified C-palatal plate connected with elastics to a face mask. This method improved skeletal measurements, corrected overjet, and slightly improved the profile. The patients may require definitive treatment in adolescence or adulthood. The modified C- palatal plate enables nonsurgical maxillary advancement with maximal skeletal effects and minimal dental side effects.

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Sung Youn Jo,Mohamed Bayome,Justyn Park,Hee Jin Lim,Yoon-Ah Kook,Seong Ho Han 대한치과교정학회 2018 대한치과교정학회지 Vol.48 No.5