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Rizk M, Niederau C, Florea A, Kiessling F, Morgenroth A, Mottaghy FM, Schneider RK, Wolf M, Craveiro RB. Periodontal ligament and alveolar bone remodeling during long orthodontic tooth movement analyzed by a novel user-independent 3D-methodology. Sci Rep 2023; 13:19919. [PMID: 37964111 PMCID: PMC10646115 DOI: 10.1038/s41598-023-47386-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023] Open
Abstract
The structural process of bone and periodontal ligament (PDL) remodeling during long-term orthodontic tooth movement (OTM) has not been satisfactorily described yet. Although the mechanism of bone changes in the directly affected alveolar bone has been deeply investigated, detailed knowledge about specific mechanism of PDL remodeling and its interaction with alveolar bone during OTM is missing. This work aims to provide an accurate and user-independent analysis of the alveolar bone and PDL remodeling following a prolonged OTM treatment in mice. Orthodontic forces were applied using a Ni-Ti coil-spring in a split-mouth mice model. After 5 weeks both sides of maxillae were scanned by high-resolution micro-CT. Following a precise tooth movement estimation, an extensive 3D analysis of the alveolar bone adjacent to the first molar were performed to estimate the morphological and compositional parameters. Additionally, changes of PDL were characterized by using a novel 3D model approach. Bone loss and thinning, higher connectivity as well as lower bone mineral density were found in both studied regions. Also, a non-uniformly widened PDL with increased thickness was observed. The extended and novel methodology in this study provides a comprehensive insight about the alveolar bone and PDL remodeling process after a long-duration OTM.
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Affiliation(s)
- Marta Rizk
- Department of Orthodontics, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Christian Niederau
- Department of Orthodontics, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Alexandru Florea
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
- Department of Radiology and Nuclear Medicine, Academic Hospital Maastricht, Maastricht, The Netherlands
- School for Cardiovascular Diseases (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, University Clinic Aachen, RWTH Aachen University, Aachen, Germany
| | - Agnieszka Morgenroth
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
| | - Felix M Mottaghy
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
- Department of Radiology and Nuclear Medicine, Academic Hospital Maastricht, Maastricht, The Netherlands
- School for Cardiovascular Diseases (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Rebekka K Schneider
- Institute of Cell and Tumor Biology, RWTH Aachen University, Aachen, Germany
| | - Michael Wolf
- Department of Orthodontics, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Rogerio B Craveiro
- Department of Orthodontics, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany.
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Dynamic changes in tooth displacement and bone morphometry induced by orthodontic force. Sci Rep 2022; 12:13672. [PMID: 35953700 PMCID: PMC9372182 DOI: 10.1038/s41598-022-17412-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 07/25/2022] [Indexed: 11/08/2022] Open
Abstract
This study used a novel 3D analysis to longitudinally evaluate orthodontic tooth movement (OTM) and bone morphometry. Twelve-week-old male Wistar rats were subjected to OTM by applying a constant orthodontic force (OF) of 25cN between one of the upper first molars and a mini-screw. In vivo micro-CTs were taken before and after 10, 17, 24 and 31 days of force application, and superimposed by a novel and rigid voxel-based registration method. Then the tooth and alveolar bone segment at different time points became comparable in the same coordinate system, which facilitated the analysis of their dynamic changes in 3D. By comparison between time points and between OF and no OF sides, this study showed that the OTM rate was not constant through time, but conformed to a ‘V’ shape changing pattern. Besides, OF induced displacement of both loaded and unloaded teeth, and the latter mirrored the former in a delayed manner. In addition, bone morphometric changes synchronized with OTM rate changes, implying that a higher OTM rate was concomitant with more alveolar bone loss. The pressure and tension areas might not be in two opposite sides, but actually adjacent and connected. These findings might provide instructive evidence for both clinical, translational and basic research in orthodontics.
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Abstract
PURPOSE To determine the true need for orthognathic surgery in patients with repaired cleft lip and/or palate (CL/P) at a high-volume craniofacial center. METHODS An institutional retrospective review of patients with CL/P born between 1975 and 2008 was performed. Patients with adequate documentation reflecting cleft care who were ≥ 18 years at the time of last craniofacial/dentistry follow-up were included. Patients with non-paramedian clefts or a comorbid craniofacial syndrome were excluded. Primary outcome variable was the total proportion of patients with CL/P who either underwent or were referred for orthognathic surgery Le Fort I (LF1) to correct midface hypoplasia. Secondary outcome variables were associations between cleft phenotype, midface hypoplasia severity, and number of cleft related surgeries with the eventual LF1 referral/recipiency. RESULTS One hundred seventy-seven patients with CL/P met inclusion criteria. A total of 90/177 (51%) patients underwent corrective LF1; however, 110/177 (62%) of patients were referred for surgery. Patients with secondary cleft palate involvement were referred for and underwent LF1 at significantly greater rates than those without secondary palate involvement (referred: 65% versus 13%, P = 0.001; underwent: 55% versus 0%, P < 0.001). Patients with bilateral cleft lip/palate were referred for and underwent LF1 at significantly higher rates than those with unilateral cleft lip/palate (referred: 71.0% versus 50.4%, P= 0.04; underwent: 84% versus 71%, P = 0.02). Number of secondary palate surgeries was positively correlated with increased LF1 referral (P = 0.02) but not LF1 recipiency (P = 0.15). CONCLUSIONS The incidence of orthognathic surgery redundant in patients with repaired CL/P was 51% at our institution, marginally above the higher end of previously reported rates. However, this number is an underrepresentation of the true requirement for LF1 as 62% of patients were referred for surgical intervention of midface hypoplasia. This distinction should be considered when counseling families.
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Teh NHK, Sivarajan S, Asif MK, Ibrahim N, Wey MC. Distribution of mandibular trabeculae bone volume fraction in relation to different MOP intervals for accelerating orthodontic tooth movement. Angle Orthod 2020; 90:774-782. [PMID: 33378515 DOI: 10.2319/032820-227.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 06/01/2020] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVES To investigate the effect of micro-osteoperforation (MOP) on the horizontal and vertical distribution of mandibular trabeculae bone volume fraction in relation to different MOP intervals during canine retraction. MATERIALS AND METHODS This single-center, single-blinded, prospective randomized split-mouth clinical trial included 30 healthy participants aged 18 years and older, randomized into three groups of different MOP intervals (4, 8, and 12-weekly). Cone beam computed tomography images were taken to assess the bone volume fraction (bone volume over total volume or BV/TV). RESULTS BV/TV was significantly reduced (mean difference: 9.79%, standard deviation [SD]: 11.89%; 95% confidence interval [CI]: 4.77, 14.81%; P < .01) and canine retraction increased (mean difference: -1.25 mm/4 mo, SD: 0.79 mm; 95% CI: -1.59, -0.92 mm; P < .01) with MOP, compared to control sites. MOP significantly changed the vertical and horizontal patterns of trabeculae bone with lower values nearer to intervention sites. Only the 4-weekly MOP interval group showed significant decrease in BV/TV (mean difference: 14.73%, SD: 12.88%; 95% CI: 3.96, 25.50%; P = .01) despite significant increase in canine retraction rate for all interval groups. With the use of MOP, BV/TV was found to be inversely correlated to the rate of canine retraction (r = -0.425; P = .04). CONCLUSIONS Mandibular trabecular alveolar bone volume fraction was reduced and rate of orthodontic tooth movement increased with MOP, especially in the 4-weekly interval. However, this effect was limited to the immediate interdental region of MOP.
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Hong SY, Shin JW, Hong C, Chan V, Baik UB, Kim YH, Chae HS. Alveolar bone remodeling during maxillary incisor intrusion and retraction. Prog Orthod 2019; 20:47. [PMID: 31867679 PMCID: PMC6926139 DOI: 10.1186/s40510-019-0300-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/12/2019] [Indexed: 11/27/2022] Open
Abstract
Background Maxillary incisor protrusion is a prevalent dental deformity and is often treated by upper incisor intrusion and retraction. The mechanical loading triggers the resorption and apposition of the bone. Alveolar bone remodeling is expected to follow orthodontic tooth movement in a one-to-one relationship. However, in many cases, the outcomes are different. Alveolar bone might still remain thick causing lip protrusion and other aesthetic problems after treatment. Additional corrective procedures such as alveoloplasty. On the other hand, if the labial bone becomes too thin, periodontal problems like gingival recession might occur. The unpredictability of the treatment result and the risk of requiring corrective procedures pose significant challenges to both the providers and patients. The aim of this study is to determine factors that can help to predict the alveolar bone reaction before maxillary incisor intrusion and retraction. Methods The cohort included 34 female patients (mean age 25.8 years) who were diagnosed with skeletal class II malocclusion with upper incisor protrusion. These patients underwent extraction and orthodontic treatment with upper incisor intrusion and retraction. Lateral cephalograms at pre-treatment and post-treatment were taken. Linear and angular measurements were analyzed to evaluate the alveolar bone changes based on initial conditions. Results The study found that the relative change, calculated as change in alveolar bone thickness after treatment divided by the initial alveolar thickness, was inversely correlated with the initial thickness. There was a significant increase of labial alveolar bone thickness at 9-mm apical from cementoenamel junction (B3) (P < 0.05) but no statistically significant change in the thickness at other levels. In addition, the change in angulation between the incisor and alveolar bone was inversely correlated with several initial angulations: between the initial palatal plane and upper incisor angle, between the initial palatal plane and upper incisor labial surface angle, and between the initial palatal plane and bone labial surface angle. On the other hand, the change in labial bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction. Conclusion The unpredictability of alveolar bone remodeling after upper incisor intrusion and retraction poses significant challenges to treatment planning and patient experience. The study showed that the initial angulation between the incisor and alveolar bone is correlated with the change in angulation after treatment, the initial thickness of the alveolar bone was correlated with the relative change of the alveolar bone thickness (defined as change in thickness after treatment divided by its initial thickness), and the amount of intrusion was correlated with the alveolar bone thickness change at 9-mm apical from the cementoenamel junction after treatment. The results of the present study also revealed that the change in labial alveolar bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction.
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Affiliation(s)
- Seok Yoon Hong
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea
| | - Jeong Won Shin
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea
| | - Christine Hong
- Division of Orthodontics. School of Dentistry, University of California, San Francisco, CA, USA
| | - Vania Chan
- School of Dentistry, University of California, Los Angeles, CA, USA
| | - Un-Bong Baik
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea
| | - Young Ho Kim
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea
| | - Hwa Sung Chae
- Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea.
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Shipley T, Farouk K, El-Bialy T. Effect of high-frequency vibration on orthodontic tooth movement and bone density. J Orthod Sci 2019; 8:15. [PMID: 31497574 PMCID: PMC6702681 DOI: 10.4103/jos.jos_17_19] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVES: Previous reports have shown that high-frequency vibration can increase bone remodeling and accelerate tooth movement. The aim of this study was to evaluate the effects of high-frequency vibration on treatment phase tooth movement, and post-treatment bone density at initiation of retention, with cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Thirty patients with initial Class I skeletal relationships, initial minimum-moderate crowding (3–5 mm), treated to completion with clear aligners and adjunctive high-frequency vibration, (HFV group) or no vibration, (Control group) were evaluated. The patients were instructed to change aligners as soon as they become loose. Changes in bone density associated with orthodontic treatment were evaluated using i-CAT cone-beam computed tomography (CBCT) and InVivo Anatomage® software to quantify density using Hounsfield units (HU) between treated teeth in 10 different regions. HU values were averaged and compared against baseline (T1) and between the groups at initiation of retention (T2). RESULTS: The average time for aligner change was 5.2 days in the HFV group, and 8.7 days in the control group (P = 0.0001). There was significant T1 to T2 increase of HU values in the upper arch (P = 0.0001) and the lower arch (P = 0.008) in the HFV group. There was no significant change in average HU values in the upper (P = 0.83) or lower arches (P = 0.33) in the control group. The intergroup comparison revealed a significant difference in the upper, (P = 0.0001) and lower arches (P = 0.007). CONCLUSION: High-frequency vibration adjunctive to clear aligners, allowed early aligner changes that led to shorter treatment time in minimum-moderate crowded cases. At initiation of retention, the HFV group demonstrated statistically significant increase as compared with pre-treatment bone density, whereas control subjects showed no significant change from pre-treatment bone density.
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Affiliation(s)
- Thomas Shipley
- Department of Dentistry, Division of Orthodontics, Arizona School of Dentistry and Oral Health, A.T. Still University, Mesa, Arizona, USA.,Department of Orthodontics, Mesa, Arizona, USA
| | - Khaled Farouk
- Department of Orthodontics, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt.,Department of Dentistry, Division of Orthodontics, University of Alberta, Edmonton, Canada
| | - Tarek El-Bialy
- Department of Dentistry, Division of Orthodontics, 7-020D Katz Group Centre for Pharmacy and Health Research, University of Alberta, Edmonton, Alberta, Canada
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Campos MJDS, Silva KS, Lupatini PM, Fraga MR, Vitral RWF. Tooth root and alveolar bone grey values derived from cone-beam CT imaging in maxillary incisor teeth with and without apical root resorption. J Orthod 2017; 45:23-28. [PMID: 29280412 DOI: 10.1080/14653125.2017.1417780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION In orthodontic treatment, an increased bone mineral density of the alveolar bone is considered as a risk factor for apical root resorption (ARR), whereas the mineral density of cementum has been associated with root protection against resorption. METHODS This study aimed at evaluating the grey values (GVs) of the apical third of the root and of the alveolar bone adjacent to maxillary incisors with and without ARR in orthodontic patients. Twenty-one patients under treatment who presented one incisor with ARR and its corresponding contralateral without ARR were selected and submitted to cone-beam computed tomography. GVs were evaluated on the images obtained of four areas of the apical third of the root and of four areas of the adjacent alveolar bone. RESULTS AND CONCLUSIONS The radicular tissue of the apical third of the incisors with ARR showed greater root GV (p < .05) than that of the incisors without ARR. Supra-apical alveolar bone exhibited greater GV in the incisors without ARR than incisors with ARR (p < .05). Root GV was not associated with root protection, but rather seemed to have facilitated the process of resorption. The GV of the lingual bone was associated with a higher progression of ARR in the incisors.
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Affiliation(s)
| | - Karine Simões Silva
- a Department of Orthodontics , Juiz de Fora Federal University , Juiz de Fora , Brazil
| | - Paula Moraes Lupatini
- a Department of Orthodontics , Juiz de Fora Federal University , Juiz de Fora , Brazil
| | - Marcelo Reis Fraga
- a Department of Orthodontics , Juiz de Fora Federal University , Juiz de Fora , Brazil
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Al-Zahrani MS, Elfirt EY, Al-Ahmari MM, Yamany IA, Alabdulkarim MA, Zawawi KH. Comparison of Cone Beam Computed Tomography-Derived Alveolar Bone Density Between Subjects with and without Aggressive Periodontitis. J Clin Diagn Res 2017; 11:ZC118-ZC121. [PMID: 28274060 PMCID: PMC5324485 DOI: 10.7860/jcdr/2017/22767.9305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/06/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Understanding the changes in bone density of patients affected by aggressive periodontitis could be useful in early disease detection and proper treatment planning. AIM The aim of this study was to compare alveolar bone density in patients affected with aggressive periodontitis and periodontally healthy individuals using Cone Beam Computed Tomography (CBCT). MATERIALS AND METHODS This cross-sectional study was conducted on 20 patients with a confirmed diagnosis of aggressive periodontitis. Twenty periodontally healthy patients attending the dental clinics for implant placement or extraction of impacted third molars served as controls. Alveolar bone density was measured using CBCT scanning. Comparisons between aggressive periodontitis group and controls for age and alveolar bone density of the anterior and posterior regions were performed using an independent sample t-test. Multivariable linear regression models were also performed. RESULTS The differences between groups in regard to age, anterior and posterior alveolar bone density was not statistically significant (p<0.05). In the posterior region, the multivariable regression model showed that bone density was not associated with age, gender or the study groups. Whereas, in the anterior region, patient's age was found to be significantly associated with bone density, p=0.014. CONCLUSION Alveolar bone density as measured by CBCT in aggressive periodontitis patients was not different from periodontally healthy individuals. Further studies are needed to confirm these findings.
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Affiliation(s)
- Mohammad S. Al-Zahrani
- Professor, Department of Periodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Eman Y. Elfirt
- Associate Professor, Department of Periodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia and Cairo University, Cairo, Egypt
| | - Manea M. Al-Ahmari
- Resident, Department of Periodontics, Assir Dental Center, Ministry of Health, Abha, Saudi Arabia
| | - Ibrahim A. Yamany
- Assistant Professor, Department of Oral Diagnostic Sciences, Division of Oral and Maxillofacial Radiology, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Maher A. Alabdulkarim
- Consultant, Department of Periodontics, King Saud Medical Complex, Ministry of Health, Riyadh, Saudi Arabia
| | - Khalid H. Zawawi
- Professor, Department of Orthodntics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
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Abstract
Few studies involving human participants have been conducted to investigate the effect of orthodontic treatment on alveolar bone density around the teeth. Our previous study revealed that patients who received 6 months of active orthodontic treatment exhibited an ∼24% decrease in alveolar bone density around the teeth. However, after an extensive retention period following orthodontic treatment, whether the bone density around the teeth can recover to its original state from before the treatment remains unclear, thus warranting further investigation.The purpose of this study was to assess the bone density changes around the teeth before, during, and after orthodontic treatment.Dental cone-beam computed tomography (CBCT) was used to measure the changes in bone density around 6 teeth in the anterior maxilla (maxilla central incisors, lateral incisors, and canines) of 8 patients before and after orthodontic treatment. Each patient underwent 3 dental CBCT scans: before treatment (T0); at the end of 7 months of active orthodontic treatment (T1); after several months (20-22 months) of retention (T2). The Friedman test was applied to evaluate the changes in the alveolar bone density around the teeth according to the 3 dental CBCT scans.From T0 to T1, a significant reduction in bone density was observed around the teeth (23.36 ± 10.33%); by contrast, a significant increase was observed from T1 to T2 (31.81 ± 23.80%). From the perspective of the overall orthodontic treatment, comparing the T0 and T2 scans revealed that the bone density around the teeth was relatively constant (a reduction of only 0.75 ± 19.85%). The results of the statistical test also confirmed that the difference in bone density between T0 and T2 was nonsignificant.During orthodontic tooth movement, the alveolar bone density around the teeth was reduced. However, after a period of bone recovery, the reduced bone density recovered to its previous state from before the orthodontic treatment. However, the bone density around ∼10% of the teeth in this region could not recover to 80% of its state from before the orthodontic treatment.
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Affiliation(s)
- Jian-Hong Yu
- From the School of Dentistry (J-HY, H-LH, C-FL, J-TH), College of Medicine China Medical University, Taichung; Department of Bioinformatics and Medical Engineering (H-LH, J-TH), Asia University, Taichung; Department of Biomedical Imaging and Radiological Sciences (JW), National Yang-Ming University, Taipei; Institute of Environmental Health (Y-FL), China Medical University; and Department of Biomedical Engineering (M-TT), Hungkuang University, Taichung, Taiwan, ROC
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Jiang F, Kula K, Chen J. Estimating the location of the center of resistance of canines. Angle Orthod 2015; 86:365-71. [PMID: 26401827 DOI: 10.2319/051215-322.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To develop a method to quickly estimate the location of center of resistance (CR) in mesial-distal (MD) and buccal-lingual (BL) directions from the tooth's image. MATERIALS AND METHODS The maxillary cone-beam computed tomography (CBCT) scans of 18 patients were used. Finite element (FE) models of the canines and their surrounding tissues were built based on their CBCT scans to calculate the locations of CR. Root length, centroid of the contact surface (CCS), and centroid of projection of the contact surface (CPCS) were also obtained from the images. The CCS and CPCS locations were projected on the tooth's long axis, which were represented as percentages of the root length measured from the root's apex. RESULTS Using the FE results as the standards, the errors of using CCS or CPCS to estimate CR were calculated. The average location of CR calculated using the FE method was 60.2% measured from the root's apex in the MD direction and 58.4% in the BL direction. The location of the CCS was 60.9%. The difference in CR was 0.7% in the MD direction and 2.5% in the BL direction. The location of CPCS was 60.2% in the MD direction and 59.1% in the BL direction, which resulted in a 0.1% and 0.8% difference with the reference CR, respectively. The average difference of CR in the MD and BL directions was small but statistically significant (P < .05). CONCLUSION The locations of the CR of a human canine in the MD and BL directions can be estimated by finding the CPCSs in those directions.
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Affiliation(s)
- Feifei Jiang
- a PhD Candidate, Department of Mechanical Engineering, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Ind
| | - Katherine Kula
- b Professor and Chair, Department of Oral Facial Development, Indiana University, Indianapolis, Ind
| | - Jie Chen
- c Professor and Chair, Department of Mechanical Engineering, and Professor, Department of Oral Facial Development, Indiana University, Indianapolis, Ind
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Campos MJDS, de Souza TS, Mota Júnior SL, Fraga MR, Vitral RWF. Bone mineral density in cone beam computed tomography: Only a few shades of gray. World J Radiol 2014; 6:607-12. [PMID: 25170398 PMCID: PMC4147441 DOI: 10.4329/wjr.v6.i8.607] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 03/11/2014] [Accepted: 04/25/2014] [Indexed: 02/06/2023] Open
Abstract
Cone beam computed tomography (CBCT) has often been used to determine the quality of craniofacial bone structures through the determination of mineral density, which is based on gray scales of the images obtained. However, there is no consensus regarding the accuracy of the determination of the gray scales in these exams. This study aims to provide a literature review concerning the reliability of CBCT to determine bone mineral density. The gray values obtained with CBCT show a linear relationship with the attenuation coefficients of the materials, Hounsfield Units values obtained with medical computed tomography, and density values from dual energy X-ray absorciometry. However, errors are expected when CBCT images are used to define the quality of the scanned structures because these images show inconsistencies and arbitrariness in the gray values, particularly when related to abrupt change in the density of the object, X-ray beam hardening effect, scattered radiation, projection data discontinuity-related effect, differences between CBCT devices, changes in the volume of the field of view (FOV), and changes in the relationships of size and position between the FOV and the object evaluated. A few methods of mathematical correction of the gray scales in CBCT have been proposed; however, they do not generate consistent values that are independent of the devices and their configurations or of the scanned objects. Thus, CBCT should not be considered the examination of choice for the determination of bone and soft tissue mineral density at the current stage, particularly when values obtained are to be compared to predetermined standard values. Comparisons between symmetrically positioned structures inside the FOV and in relation to the exomass of the object, as it occurs with the right and left sides of the skull, seem to be viable because the effects on the gray scale in the regions of interest are the same.
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