Orthodontics and Orthodontology Commons^™

Posterior Anatomic Limit For Mandibular Molar Distalization In Subjects With Different Growth Patterns, Genders, And Growth Status, Rehana Bashir

Theses & Dissertations

The objective of this study is to identify the anatomical limits for mandibular molar distalization, a technique frequently employed in orthodontics to address various malocclusions. Mandibular molar distalization plays a critical role in the management of crowding, and correction of the molar relationship.

It is imperative to assess the posterior anatomical space (PAS) in the mandibular retromolar area prior to distalization or uprighting the mandibular molars to avoid periodontal issues (dehiscence, orthodontically induced root resorption, and tooth mobility) and achieve successful treatment outcomes.

A clinical question that, however, isn't well understood is whether the amount of mandibular molar distalization is …

Outcomes Of Anterior Crossbite Correction On Alveolar Bone Morphology In Patients With Cleft Lip And Palate, Katherine J. Hayes

Theses and Dissertations

Objective: To determine if patients with cleft lip and/or cleft palate (CLP) with dental correction of the anterior crossbite during growth display differences in alveolar bone thickness around the maxillary central incisors compared to patients without crossbite correction.

Methods: This retrospective study evaluated post-treatment cone beam computed tomography (CBCT) images of growing patients with CLP with anterior crossbites who underwent Phase I orthodontic treatment (n=32). CBCTs were sorted by whether the crossbite was corrected (n=16) or not corrected (n=16) during Phase I. Alveolar bone thickness was measured on the buccal and palatal aspects of the central incisors at 3 mm, …

Evaluation Of Trabecular Bone Around The Impacted Maxillary Canine On Cbct Images By Fractal Analysis, Zeynep Betül Arslan, Berrin Çelik

Journal of Dentistry Indonesia

Objective: The aim of this study was to evaluate the position, angulation and surrounding trabecular bone structure of a unilateral impacted maxillary canine (IMC) tooth using fractal analysis. Methods: Cone beam computed tomography images of 50 patients (38 female, 12 male) with unilateral IMC were selected for this retrospective study. A 25x25 pixel region of interest (ROI) was selected in the trabecular bone between the premolars on the impacted and non-impacted side and fractal analysis was conducted. The angulation of unilateral impacted canines was measured and the position was categorized as vestibular, intra-alveolar and palatal. Results: Of …

Three-Dimensional Analysis Of Condylar Displacement After Orthognathic Surgery In Patients With Facial Asymmetry, Teresa Bae

Theses & Dissertations

Facial asymmetry is apparent when there is a clinically significant variation between the two halves of the face. There can be varying degrees of facial asymmetry and mild asymmetry can be treated by orthodontics alone. For severe facial asymmetry a combination of orthodontics and orthognathic surgery may be necessary. The condyle must be in a stable position following surgery to have functional and structural stability and prevent relapse. This research proposal is to perform a retrospective CBCT study on the displacement of the condyle following orthognathic surgery in patients with facial asymmetry. The CBCTs were obtained from Taipei Veterans General …

Assessment Of The Effects Of Edentulousness On Temporomandibular Components By Using Cone Beam Computed Tomography, Büşra Arıkan, Numan Dedeoğlu, Şuayip Burak Duman

Journal of Dentistry Indonesia

Objective: The aim of this study is to evaluate the effects of edentulousness on the temporomandibular joint using cone beam computed tomography (CBCT). Methods: In this study, CBCT images were evaluated in a total of 48 patients (24 dentulous, 24 edentulous). Ninety-six temporomandibular joint CBCT images were examined. Eminence inclination, condyle head widths and joint space were measured and statistically compared between the edentulous and dentulous groups. Results: The articular eminence inclination value the mediolateral width of the condyle and the anteroposterior width of the condyle were found significantly higher in the dentulous group than in the edentulous group. …

Superimposition Of Digital Dental Model, Wen-Ting Lin, Yu-Chuan Tseng, Pao-Hsin Liu, Hsuan-Chih Lin, Hong-Po Chang

Taiwanese Journal of Orthodontics

The cephalometric radiography, dental model, intra-oral and extra-oral photos are essential traditional baseline data as orthodontic diagnostic tool to develop a comprehensive treatment plan. With the advent of the digital era, 3D digital dental model will gradually replace the traditional bulky plaster casts, and become an inevitable trend in the future. The purpose of this review article was to discuss about: (1) Digital dental models. (2) Pre-treatment and post-treatment stability of palatal rugae. (3) Via serial 3D digital dental model superimposition registered on palatal rugae and palatal vault, it is feasible to analysis the direction and magnitude of 3D individual …

Accuracy And Reproducibility Of A Manual 3-Dimensional Superimposition Method To Register Dental Model Images To Cone-Beam Computer Tomography (Cbct) Image – A Preliminary Study, Yu-Shu Liao, Sam Sheng-Pin Hsu, Pei-Ju Lin, Chien-Hsuan Wang, Hsiu-Hsia Lin, Dhruv Singhal, Cheng-Hui Lin, Chiung-Shing Huang, Lun-Jou Lo, Ellen Wen-Ching Ko, Yu-Ray Chen

Taiwanese Journal of Orthodontics

Purpose: The purposes of this study was to evaluate the registration error and its reproducibility for implementation of the laser-scanned dental model images onto the CBCT scan data by using the manual 3D superimposition. Materials and methods: Twelve arches out of 8 consecutive patients were enrolled in this study. Both CBCT and dental impression were taken as orthodontic records and the dental casts were then laser-scanned into dental model images with STL file format. In SimPlant OMS software, we register the dental model images onto CBCT teeth images with manual 3D superimposition technique. Afterwards, validation was performed in 3dMDvultus and …

Evaluation Of Gender Difference At Orthodontic Miniscrew Placement Sites In The Mandible: A Cbct Study, Ming-Wei Wei, Yu-Chuan Tseng, Hong-Po Chang, Yi-Hsin Yang

Taiwanese Journal of Orthodontics

Purpose: the purpose of this study is to evaluate mandible bone density and gender difference through three-dimensional images. The Images was captured by cone-beam computer tomography (CBCT) and transfer into DICOM format for further examination. Material and method: CBCT images were obtained from 36 males and 34 females aged from 18 to 40 years. Mandible bone density was measured in 4 sites bilaterally. Inter-gender and intra-class comparison were made to distinguish the difference of acquired data. Result: Bone density measurement of females showed greater bone density at almost all sites but only showing significant difference in left retromolar area (p=0.0067). …

Cbct Use In Orthodontic Residency Programs In Usa, Su Min Han

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background and Objectives: Cone beam computed tomography (CBCT) scans in dentistry have been up and coming forms of x-ray technology that allows cross-sectional images to form a comprehensive 3-dimensional representation of the mouth. While the typical use for CBCT imaging is reported to be for implant dentistry, there are many contexts in which it is indicated in orthodontics. There are various schools of thought regarding when CBCT is indicated for specific diagnosis of problems or general use in the collection of initial, progress and post-treatment orthodontic records. There are programs that follow the Radiology guidelines for taking CBCT scans10 and …

The Influence Of Cbct-Derived 3d-Printed Models On Endodontic Microsurgical Treatment Planning And Confidence Of The Operator, Shreyas Oza, Johnah C. Galicia

Orthodontics and Endodontics Theses

Aims Use of 3D printed models in Endodontics has been gaining popularity since the technology to create them became more affordable. Currently, there are no studies that evaluate the influence of 3D models on endodontic surgical treatment planning and on operator confidence. Therefore, aims of this study were to: (i) Determine whether the availability of a 3D printed analogue can influence treatment-planning and operator confidence; and, (ii) Assess which factors of operator confidence are influenced, if any.

Materials and Methods Endodontists were asked to analyze a pre-selected CBCT scan of an endodontic surgical case and to answer a questionnaire that …

Accuracy And Reliability Of A Fully Automated Landmark Identification System On Cone Beam Computed Tomography, Ali Ghowsi, David Hatcher, Heeyeon Suh, Joorok Park, Heesoo Oh

Orthodontics and Endodontics Theses

ABSTRACT Introduction: Medical imaging continues to play an increasing role in health care and is an integral part of medicine and dentistry. Recent technological advancements have led to the development of fully automated landmark identification (ALI) systems capable of tracing Cone-Beam Computed Tomography (CBCT). The purpose of this study was to evaluate the accuracy and reliability of an ALI system as a tool for automatic landmark location compared to human judges. Methods: One hundred subjects’ CBCT volumes from multiple imaging centers were traced by two human judges who were calibrated and had an ICC close to 1. Fifty-three landmarks were …

Outcomes Of Unilateral Alveolar Clefts Grafted Using Recombinant Human Bone Morphogenetic Protein-2: A Retrospective Volumetric Analysis Using Cbct, Landon Robert Peterson

Theses & Dissertations

Purpose of this study is to evaluate the success rates of secondary alveolar grafts using recombinant human bone morphogenetic protein with CBCT and to evaluate the effects of several variables on these outcomes. After our inclusion/exclusion criteria, records of 24 patients receiving secondary alveolar grafts at the University of Nebraska Medical Center were evaluated. Pre-graft and 6-month post-graft cleft volumes were measured using ITK-SNAP 3.8.0 software to determine a percent residual defect following surgery. Of the 24 patients, one was excluded as the graft surgery was deemed a failure. The patients’ gender, age, side of cleft, cleft side canine root …

Prevalence Of Short Root Anomaly In Patients Seeking Orthodontic Treatment, Tim Howarth, James Chen, Heesoo Oh

Orthodontics and Endodontics Theses

Introduction: The purpose of this study was to investigate variance in prevalence and severity of short root anomaly (SRA) in patients seeking orthodontic treatment, stratified by ethnicity and sex. Materials and Methods: In this retrospective cross-sectional study, we evaluated 896 patients who had initial cone-beam computed tomographies (CBCTs) taken from July 1, 2014 to May 30, 2019. Panoramic radiographs and images from the CBCTs of each patient were extracted and placed in a database. The crown-to-root ratio of maxillary central incisors, lateral incisors, canines, and all pre-molars were evaluated to determine the presence, severity and associations of SRA. A Chi-square …

Oropharyngeal Airway Changes Following Orthodontic Treatment Of Anterior Open Bite In Growing Vs Non-Growing Patients, Mona Awadi, Heeyeon Suh, Joorok Park, Heesoo Oh

Orthodontics and Endodontics Theses

Introduction: Orthodontic treatment of anterior open bite can result in a counter-clockwise rotation of the mandible and a more ideal forward position of the tongue. Usually this movement is thought to increase the oropharyngeal airway. The primary aim of the present study was to evaluate changes in vertical dimension and airway in AOB patients following orthodontic treatment. Methods: 52 subjects were included in this retrospective study of anterior open bite malocclusion treated in the graduate orthodontics clinic at the University of the Pacific, Arthur A. Dugoni School of Dentistry between 2006 – 2019. Cephalometric and airway measurements were done by …

Soft Tissue Effects From Maxillomandibular Advancement With Counterclockwise Rotation, Timothy Yu, Audrey Yoon, Stanley Yung Chuan Liu, Heeyeon Suh, Joorok Park, Heesoo Oh

Orthodontics and Endodontics Theses

Introduction: The purpose of the study was to evaluate the effects of maxillomandibular advancement (MMA) surgery with counterclockwise rotation on soft tissue oral and nasal structures. Materials and Methods: This retrospective study included 34 subjects diagnosed with OSA who underwent MMA at the Stanford Sleep Clinic. Initial (T1) and Final (T2) CBCTs were evaluated and compared for 10 hard tissue and 15 soft tissue measurements. Additionally, the external nasal valve surface area was measured and compared between the two time points. A 3D superimposition was performed and used to evaluate the relative hard and soft tissue movements. Results: There was …

Comparison Of Skeletal And Dental Differences Between Class I And Class Ii Sides And Their Relationship With Asymmetric Molar Relationships In Class Ii Subdivision Malocclusions – A Cbct Study, Ivan Lo, Heeyeon Suh, Joorok Park, Heesoo Oh

Orthodontics and Endodontics Theses

Introduction: The purpose of this study is to compare dental and skeletal differences between Class I and Class II sides and their contributions to the degree of asymmetric molar relationship in Class II subdivision malocclusions using CBCT.

Methods: One hundred and eight patients presenting with Angle Class II subdivision malocclusions (mean age =21.05 years) were assessed with 3-dimensional cone-beam computed tomography scans. Paired t-tests were used to compare linear skeletal, angular and dental measurement differences between Class I and Class II sides. Correlations of linear skeletal, angular and dental measurement differences between Class I and Class II sides were made …

Retrospective Evaluation Of The Changes In The Nasal And Pharyngeal Airway Volume After Miniscrew Assisted Rapid Palatal Expansion (Marpe) Appliance, Joanna Song

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background and Objectives: A transverse deficiency of the maxilla is a pervasive skeletal problem that can affect almost a quarter of the primary dentition population. The interesting relationship between rapid maxillary expansion (RME) and its effects on the surrounding airway is not well described in the literature. For today’s contemporary orthodontist, there are a variety of rapid palatal expanders (RPE) and expansion protocols to prescribe for patient treatment. Of late, the miniscrew-assisted RPE (MARPE) has been receiving attention by clinicians because of its increased orthopedic effects when compared to conventional RPE while avoiding the surgical procedure needed with SARPE. …

Comparison Of Skeletal And Dentoalveolar Changes Between Two Bone-Borne Maxillary Expanders, Mohamad Sarraj

Graduate Theses, Dissertations, and Problem Reports (ETD)

Introduction: Bone-borne maxillary expander (BBME) are designed to provide additional anchorage to widen the maxillary arch for patients who exhibit maxillary transverse deficiency. One form of BBME is the hybrid BBME which uses mini-implants (bone-borne) and posterior teeth (tooth-borne) as anchorage for maxillary expansion. The other form of BBME is absolute BBME which only uses mini-implants as anchorage. It is not clear in the literature if there is a difference in skeletal and dental changes with these two types of expanders. The objective of this study was to compare the skeletal, dentoalveolar, and periodontal changes between the hybrid and the …

Orthodontically Induced External Root Resorption In Extraction Versus Non-Extraction Treatment Modalities – A Retrospective Cone-Beam Computed Tomography (Cbct) Study, Jaykishan Patel

Theses & Dissertations

Purpose of this study was to evaluate orthodontically induced external apical root resorption using cone beam computed tomography in patients receiving orthodontic treatment with or without extractions. Records of 188 consecutively treated patients who received orthodontic treatment with or without extractions were evaluated. Pre-and post-treatment root lengths of maxillary incisors, volumes of maxillary central incisors, and apex displacement of either right or left maxillary central incisors were measured using Invivo 5.4 or ITK-SNAP 3.8.0 software. After adjusting for initial length, treatment duration, tooth, sex, race, bracket type, and malocclusion, maxillary incisor reduction of root length in extraction group was 0.37 …

Impact On The Pharyngeal Airway Space After Maxillomandibular Advancement Procedure For Obstructive Sleep Apnea Patients, Ghaddy Alsaty

Graduate Theses, Dissertations, and Problem Reports (ETD)

Background and Objectives: Obstructive sleep apnea (OSA) is a sleep-related breathing disorder, characterized by disrupted snoring and repetitive upper airway obstructions. Continuous positive airway pressure (CPAP) is considered the therapeutic mainstay for OSA patients. However, CPAP therapy has compliance limitations. An alternative treatment options is maxillomandibular advancement (MMA) surgical procedure. Genial tubercle advancement (GTA) is often performed concomitant with MMA for esthetic purposes. Cone-beam computed tomography (CBCT) provides the ability to visualize the upper airway and perform three-dimensional (3D) reconstructions. The purpose of this study is to evaluate the impact of MMA procedure with or without GTA on oropharyngeal …

Changes In Pharyngeal Airway Dimensions Due To Mara Treatment In Class Ii Malocclusions, James K. Dillehay

Theses and Dissertations (ETD)

Orthodontic treatment effects on the pharyngeal airway have recently become a hot topic in the field of orthodontics. Current literature has shown facial skeletal morphology to be correlated with pharyngeal airway shape and volume. This study used CBCT imaging to identify what, if any, effects two different treatment modalities for correcting Class II malocclusions have on the pharyngeal airway volume. This retrospective study consisted of two groups of Class II patients: 38 patients (15 females, 23 males) treated with the MARA and an Edgewise appliance and 32 patients treated with an Edgewise appliance and Class II elastics. Both pre and …

Treatment Effects Of The Mandibular Anterior Repositioning Appliance (Mara) And Conventional Orthodontic Mechanics On Temporomandibular Joint Morphology: A Comparison Using Cone Beam Computed Tomography, Brenton E. Glassell

Theses and Dissertations (ETD)

Introduction: An ongoing debate exists in orthodontics about the amount of condylefossa remodeling and growth seen in Class II patients using functional appliance therapy. Some clinicians and researchers have found that that the use of functional appliances increases the amount of condylar growth and subsequent Class II skeletal correction; others believe that the mandible has a preset amount of growth and that conventional orthodontics will result in a similar amount of condylar growth to functional appliance therapy. Purpose: The aim of this study was to compare condylar remodeling in functional appliance treatment using the mandibular anterior repositioning appliance (MARA) to …

Oropharyngeal Airway Volume Following Orthodontic Treatment: Premolar Extraction Versus Non-Extraction, Thomas Patrick Shannon

Theses and Dissertations (ETD)

Orthodontic correction of tooth size versus arch size discrepancy (TSASD) can be achieved with two distinct methods of treatment. The first involves the extraction of teeth to gain the space needed for tooth alignment. The second relies on arch expansion to gain the space needed for correction. In recent decades, arguments for and against the extraction of teeth for orthodontic purposes have become increasingly important, particularly in regards to oropharyngeal airway size. Purpose: The purpose of this study is to determine whether there is a decrease in oropharyngeal dimensions following the extraction of four premolars and subsequent orthodontic therapy. Methods: …

Oropharyngeal Airway Volume Following Orthodontic Treatment: Premolar Extraction Versus Non-Extraction, Thomas Patrick Shannon

Theses and Dissertations (ETD)

Orthodontic correction of tooth size versus arch size discrepancy (TSASD) can be achieved with two distinct methods of treatment. The first involves the extraction of teeth to gain the space needed for tooth alignment. The second relies on arch expansion to gain the space needed for correction. In recent decades, arguments for and against the extraction of teeth for orthodontic purposes have become increasingly important, particularly in regards to oropharyngeal airway size. Purpose: The purpose of this study is to determine whether there is a decrease in oropharyngeal dimensions following the extraction of four premolars and subsequent orthodontic therapy. Methods: …

Three-Dimensional Evaluation Of The Effect Of Maxillary Incisor Retraction On The Palatal Bone And Root Resorption, Jessica R. Lynch Dmd

Master's Theses

Introduction: The objective of this study was to compare pre-treatment and post-treatment cone-beam computed tomography images of patients to quantitatively evaluate the effect of orthodontically retracting maxillary incisors on the height and labiolingual thickness of labial and palatal alveolar bone and incisor apical root resorption. Methods: Maxillary central incisor apical root resorption, labial and palatal alveolar bone height, and labiolingual thickness were assessed on pre-treatment and post-treatment cone-beam computed tomography scans of 59 subjects (mean age, 13.00 years) with premolar extractions and 63 subjects (mean age, 13.40 years) who were treated with non-extraction therapy. Results: The mean incisor apical root …