Objective: The purpose of this study was to compare the accuracy of cone beam CT (CBCT) imaging with digital orthopantomograms for determining bone quantity in the mandibular ramus. Methods: Twenty-nine cadaveric mandibles marked bilaterally with three fiducial markers were imaged using both CBCT and digital orthopantomography. After sectioning, four cross sectional measurements were made on the specimens and on the CBCT images. Two corresponding linear measurements were made on the orthopantomograms. Statistical analysis was used to compare the CBCT and orthopantomogram measurements with measurements from the anatomic specimens. Results: CBCT measurements were found to significantly differ from those made on the anatomic specimens (P<0.05). Linear measurements from the orthopantomograms varied by 15.9 percent compared to the anatomic specimens. Conclusion: CBCT and orthopantomogram measurements were significantly different from those of the anatomic specimens suggesting inaccuracies in the radiographic technology or a lack of precision in landmark identification.

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 2 judges. Intraclass correlation coefficient (ICC) was used to evaluate inter-judge reliability for evaluating airway volume and MCA measurements. Chi-square tests were used to compare proportions. Unpaired t-tests were used to compare mean differences and paired t-tests were used to compare pre- and post-treatment changes. Results: More vertical control and intrusion of molars was seen in non-growing (NG) subjects. There was more successful open bite correction in NG subjects. Even though there was a reduction in FMA, LFA, improved incisor position and open bite correction, there was not much influence on airway dimensions. There was no statistically significant change in airway in growing (G) and NG subjects when looking at the whole sample. Conclusion: With correction of an anterior open; intrusion of molars and a more forward mandibular position result. However, these changes did not result in an increase in oropharyngeal airway in our study.

Objective: Applications of Cone-beam computerized tomography (CBCT) have increased dramatically in dentistry. Incidental findings (IFs) beyond the area of interest may be encountered. The maxillary sinus incidental findings in CBCT were considered the highest in the literature. This systematic review aims to analyze present literature on IFs in the maxillary sinus using CBCT Methods: Electronic databases was searched for studies on the maxillary sinus incidental findings in CBCT to assess the prevalence and significance of the incidental findings. Results: The initial search retrieved 239 abstracts, of which only 9 studies met the inclusion criteria. The sample size ranged from 34-1029 participants with a mean age of 35.4. The prevalence of incidental findings in the maxillary sinus was between 27 to 62.4%. Such findings in the maxillary sinus vary in importance and the need for intervention. The most common incidental findings were the thickening of the mucosal membrane followed by the polypoid lesion. / Oral Biology

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ABSTRACT Objectives: Cone beam computerized tomography use is becoming more common in preparation for surgical planning and treatment diagnosis by clinicians. The scanning result gives clinicians a more accurate understanding of each patients’ anatomy, which aids in designing better treatment plan, avoidance of vital anatomy, etc. Modern treatments involving extraction of teeth has become more sophisticated due to advent of dental implant treatment. Along with the procedure, more sophisticated treatment techniques involving manipulation of sinus has flourished. Traditional periapical and panoramic radiograph are not as adapt at identifying sinus pathologies. As patients age, proximity of sinus floor and apex of teeth may become closely related where possibility of one affecting another is observed. This study aims to study the prevalence of odontogenic related pathologies in relation to maxillary sinus in the population who had CBCT images taken at Temple University Kornberg School of Dentistry. The study also looks in detail the relationship of such pathology in relation to teeth status, age, gender, and ethnicity. Methods: 821 CBCT scans completed at Temple University Kornberg School of Dentistry Department of Oral Maxillofacial Radiology from January 1st, 2009 to July 31, 2013 were evaluated with iCAT computer imaging software. Patients under 18, no posterior dentition, or complete edentulous were excluded from the study. A total of four hundred fourty four (444) CBCT scans were included in the study. Patients with odontogenic related maxillary sinus pathology were selected and teeth status, age, gender and ethnicity recorded. Individual scans had sinus pathology identified and examined for proximity and relationship to respective tooth/teeth. Each individual tooth’s status were also recorded. Chi-square test was conducted to verify validity Results: After reviewing 680 scans, only 444 were included in the study due to exclusions. Scans were subdivided by age (18-35: 77, 36-53: 113, 54-71: 188, 72&gt; : 46), gender (280 male and 164 female), ethnicity (African American 86, Asian 45, Caucasian 291, Hispanic 22), tooth status (caries, 26, crown 87, healthy 31, impacted 11, root canal 88, restoration 58), tooth position ( 3rd molar 9, 2nd molar 86, 1st molar 138, 2nd premolar 20, 1st premolar 6, canine 3). Overall 63.06% of scans were classified as healthy, and 36.04% were classified as presenting odontogenic related maxillary sinus pathology. None of the parameters showed significant predilection to odontogenic related pathology, however, 1st molar has the highest risk of exhibiting pathology in the maxillary sinus with 2nd molar second. The pathology incidence rates are slightly higher in male patients 41% vs 34%. Age is not a significant factor as all age groups demonstrates similar incidence rate except 72&gt; group. Dentition status showed root canal and crown being the most commonly associated with pathology at 29% each. In Caucasian population, crown and root canal was most commonly related. African American was restoration and healthy teeth. Asian population had the most link with large restorations. Conclusions: Maxillary 1st molar is the most commonly involved tooth with maxillary sinus pathologies with 2nd molar as second most common. Caucasian individuals had the most odontogenic related pathologies. In general, crown and root canal are associated with a significant number of pathologies found in the sinus and should be evaluated prior to any surgical evaluation prior to any sinus manipulative surgery or odontogenic treatment. / Oral Biology

AB S TRACT purpose : To further investigate the effects of respiratory motions on CBCT imaging, as well as 4D-CT examinations, with a future goal of using obtained results to implement new methods for individual margins and daily matching procedures into routine clinical practice. background : Since the implementation of CBCT combined with modern accelerators, a higher degree of accuracy has been made possible in RT. However, due to the slow gantry speed of linear accelerators, the imaging procedure of CBCT is a slow process which is thereby degraded by internal motion such as respiration. material and methods : Attain patient specific respiratory motion patterns from CBCT projection data of previous examinations. Utilize this data to perform simulations for both CBCT and 4D-CT using a steering system which allows for arbitrary motion patterns in the longitudinal direction. results : Various imaging with CBCT showed that the resulting images during respiratory motion, can be described by the Probability Density Function of the motion for as long as it does not cause related distortions. This also meant that convolution could be implemented as a model to estimate the CBCT images during oscillation, knowing the object and motion pattern. The 4D-CT examinations using the steering system showed that irregular motion patterns were less accurately described than regular patterns, making the actual motion an important feature to combine together with the measured amplitude. conclusions : It was made clear that CBCT images can be described by the PDF, and thus can be seen as a Color Intensity Projection of the object position. Also it has been shown that the projection data of CBCT images contains valuable information about the respiratory motion of the patient. Another conclusion is that with the help of fiducials, the position of the target within the respiratory cycle can be determined relative to the 4D-CT examination, enabling further input data as to the daily matching procedure, proper applied margins as well as dose to the OAR.

L'imagerie est maintenant partie intégrante des traitements de radiothérapie. Avec la technologie CBCT embarquée sur les appareils de traitement, l'imagerie tomographique permet non seulement de repositionner fidèlement le patient tout au long de son traitement mais aussi d'adapter la planification initiale aux modifications quotidiennes de volume. C'est la radiothérapie adaptative, objet des travaux de cette thèse. Nous avons établi les limites techniques de précision de repositionnement des équipements utilisé. Ensuite, à partir des acquisitions CBCT quotidiennes de patients traités pour la prostate, nous avons élaboré une stratégie de traitement basée sur une banque de plans personnalisés. Nous avons mis au point une méthode semi-automatique de sélection du plan de traitement du jour qui a montré une efficacité supérieure à la sélection par des opérateurs expérimentés. Enfin, nous avons quantifié les doses additionnelles à la dose thérapeutique associées à l'utilisation quotidienne de l'imagerie CBCT. En conclusion, on peut dire qu'avec l'imagerie CBCT embarquée, on peut voir ce que l'on veut traiter, irradier ce que l'on a vu et contrôler ce qu'on a traité. / Imaging is now fully integrated in the radiation therapy process. With on-board CBCT systems, tomography imaging allows not only patient positioning but also treatment planning adaptation with patient anatomy modifications, throughout the entire treatment. This is called adaptive radiation therapy, and is the main subject of this PhD thesis. During this work, we measured the repositioning accuracy of the system used. We also developed a treatment strategy using daily CBCT images and a personalized plan database to adapt treatment plan to patient anatomy. We found a way to select the daily treatment plan that shows superiority over operator selection. Then we also quantified the additional dose delivered while using this technique and the impact with regards to the risks added to patients. As a conclusion, with CBCT imaging, radiation therapy has entered an era where one can see what need to be treated, can treat what has been seen and can control what has been treated.

BACKGROUND: The use of three-dimensional imaging has shown to provide advantages to the clinician in assessing bone morphology. The aim of this study will be to compare the diagnostic efficacy of cone beam computed tomography (CBCT) versus diagnostic clinical measurements in patients presenting with furcation involved maxillary first molars. METHODS: The study population included 20 patients with 34 maxillary first molar teeth with furcation involvement. Clinical horizontal and vertical probing measurements were compared to CBCT measurements taken by two calibrated examiners. RESULTS: Horizontal measurements showed a significant difference between Glickman class II and class III. There were no statistical significant differences with the horizontal measurements between clinical probing, bone sounding and CBCT measurements. CBCT vertical measurements were statistically greater than clinical probing measurements. CONCLUSION: The CBCT can provide similar horizontal measurements to standard clinical horizontal probing measurements and will provide a greater vertical dimension of a furcation defect to standard vertical probing measurements.

Respiration introduces large tumor motion in the thoracic region which influences treatment outcome for lung cancer patients. Tumor motion management techniques require characterization of temporal tumor motions because tumor motion varies patient to patient, day to day and cycle to cycle. This work develops a markerless algorithm to estimate 3 dimensional (3D) lung-tumor trajectories on free breathing cone beam computed tomography (CBCT) projections, which are 2 dimensional (2D) sequential images rotating about an axis and are used to reconstruct 3D CBCT images. A gold standard tumor trajectory is required to guide the algorithm development and estimate the tumor detection accuracy for markerless tracking algorithms. However, a sufficient strategy to validate markerless tracking algorithms is lacking. A validation framework is developed based on fiducial markers. Markers are segmented and marker trajectories are xiv obtained. The displacement of the tumor to the marker is calculated and added to the segmented marker trajectory to generate reference tumor trajectory. Markerless tumor trajectory estimation (MLTM) algorithm is developed and improved to acquire tumor trajectory with clinical acceptable accuracy for locally advanced lung tumors. The development is separate into two parts. The first part considers none tumor deformation. It investigates shape and appearance of the template, moreover, a constraint method is introduced to narrow down the template matching searching region for more precise matching results. The second part is to accommodate tumor deformation near the end of the treatment. The accuracy of MLTM is calculated and compared against 4D CBCT, which is the current standard of care. In summary, a validation framework based on fiducial markers is successfully built. MLTM is successfully developed with or without the consideration of tumor deformation with promising accuracy. MLTM outperforms 4D CBCT in temporal tumor trajectory estimation.