Evaluation of Submandibular Infections using 3-Dimensional Reconstruction of Computed Tomography Images DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Hashim G. Elmshiti Graduate Program in Anatomy The Ohio State University 2016 Dissertation Committee: Professor Kirk McHugh, Advisor Assistant Professor Jennifer Burgoon Assistant Professor Eileen Kalmar Professor Gregory Ness Assistant Professor Luciano Prevedello Copyright by Hashim G. Elmshiti 2016 Abstract Purpose This study presents the use of three-dimensional computed tomography (3D-CT) in the evaluation of odontogenic maxillofacial infections. A secondary surgical procedure is common amongst maxillofacial infected patients to establish drainage of an abscess. These secondary procedures lead to an increase in hospital length of stay (LOS), which creates a problem for the surgeons, patients, and insurance companies. In this study, we examined the following variables: second surgery (SS), and increasing hospital LOS as the outcome variables, and the other clinical and three-dimensional (3D) factors as predictive variables. This retrospective study will determine if there is a relationship between the predictive and outcome variables. Study Design This imaging project was approved by the Institutional Review Board (IRB) using 103 deidentified patient scans. Patient records were collected from the Wexner Medical Center at The Ohio State University by the Division of Maxillofacial Surgery between November, 2011 and September, 2014. Patient ages included in the study ranged from 18 to 73 years. The proposed analytic method is divided into two basic approaches: clinical data collection and 3D data collection. In addition to the computed tomography images, the clinical variables recorded from the patient‘s chart were age, sex, race, ethnicity, ii etiology, number of surgical interventions, past medical history (ie. hypertension, diabetes, cancer, and renal insufficiency) and time of admission, operation and discharge. The 3D image variables examined included the volume of submandibular infection, volume of associated muscles, and spatial relationship of 3D polygonal shape of the infection to adjacent structures. Moreover, we selected the following three clinical variables as outcome variables: Second Surgical Procedures (SS), and Hospital length of stay (LOS). The other remaing clinical variables (demographic, autoimmune suppression diseases, infected facial spaces, time frame variables and etc) and 3D variables are predictive variables. Results: All of the participants included in this study were clinically diagnosed with a submandibular space infection with or without extension to other facial spaces. The predictive variables that were found to be significantly associated with second surgery (SS): retromolar trigon region (p = 0.021), and submental space (p = 0.040). By comparison, the predictive variables that were found to be significantly associated with LOS included age (p = 0.031), submental space (p = 0.022), and air-way narrowing (p = 0.035). 3D-CT reformatted images showed a measurable difference in volume between the masseter (3DIM) (t = 7.300, p = 0.001) and medial pterygoid (3DIMP) (t = 6.390, p = 0.001) muscles on the infected versus uninfected side, while the volume of the lateral pterygoid (3DILP) remained statistically unchanged. iii Conclusions: The difference in volume between the muscles on the affected side and the unaffected side appear to represent a good predictive measure for the severity of infection. However, when we used to predict the severity of infections, can not show any significant statistical relationship with the outcome variables. Although most of the health professional who treat patients with the odontogenic infections correlated the size of swelling with the severity of infection, 3D volume of the submandibular space infection can not show any significant relationship with the second operation and Hospital LOS, which inturn could not predict the sverity of the submandibular space infections. Using 3D-CT in evaluating submandibular space infection can provide a better orientation and understanding of the anatomical relationship between the infection and adjacent structures, which can‘t be easily shown in 2D-CT. This study illustrates that the computed tomography images and 3D-CT can assist in diagnosing and presurgical planning for the treatment of submandibular space infections and may prove useful in the treatment of other deep neck facial space infections. iv Dedication This document is dedicated to my family. v Acknowledgments I have no words that can express my thanks for everyone who helped and assisted me during the preparation for the PhD in Anatomy. I am fully indebted to Dr. McHugh, my advisor, for his patience and continuous support to help achieve my goal. My deep gratitude to Professor Gregory Ness who assisted me greatly in brainstorming the ideas of this dissertation; moreover, I greatly appreciate Dr. Luciano Prevedello who provided assistance in the 3-D segmentation portion of the dissertation. Also, I extend my appreciation to Dr. Jennifer Burgoon and Dr. Eileen Kalamar for their assistance and suggestions throughout my dissertation. Thanks also extend to the past members who taught me the different courses of the Anatomy including Dr. Kenneth Jones, Dr. Doug Gould, and Dr. Lisa Lee. I also thank the staff including Melody Barton, Mark Whitmer, and Michelle Whitmer in the Division of Anatomy. Thanks also extend to Dr. Robert DePhilip, Dr. Jahanzeb Chaudhry, and Darlene who supported me in the early stages of this dissertation. I also thank Ryan Ziegler, Data Analyst at the department of biomedical informatics, for providing the information and CT images of different participants. Moreover, I greatly appreciate Dr. Mark Hubbe for his statistical consultation. I especially thank my mom for her prayer to finish my study. Last but not least, I would like to acknowledge my wife and sons who encourage and kept me going up to the end point. vi Vita August 1980 …………. .................................Elfateh high school, Elbeida, Libya 1986................................................................B.D.S. in Dentistry, Garyounis University, Benghazi, Libya 1986 to 2002 ..................................................General Dental Practitioner, Central Dental Clinic, Benghazi, Libya 2002…............................................................MSc. in Anatomy and Embryology, Garyounis University, Benghazi, Libya 2002 to 2007 ..................................................Lecturer, Division of Anatomy, Medical School, Garyounis University, Benghazi, Libya July 2012…………………………………. M.S. Anatomy, The Ohio State University, Columbus, Ohio 2012 to present ..............................................PhD Student, Division of Anatomy, The Ohio State University, Columbus, Ohio Fields of Study Major Field: Anatomy vii Table of Contents Abstract ............................................................................................................................... ii Dedication ........................................................................................................................... v Acknowledgments………………………………………………………………………..vi Vita .................................................................................................................................... vii Table of Contents ............................................................................................................. viii List of Tables ................................................................................................................. ..xiv List of Figures...................................................................................................................xvi Chapter 1: Introduction & Literature Review……………………………………………..1 1.1 Overview of Study……………………………………………………………….....1 1.2 Background of the problem and Significance of the study………………………....3 1.2.1 Problem statement……………………………………………………………….3 1.2.2 Head and Neck infection………………………………………………………...4 1.2.3 Odontogenic infection…………………………………………………………...5 1.2.4 Overview of natural progression (primary to secondary spaces to remote spread) ………………………………………………………………………………………....6 1.2.5 Characteristics of infection (abscess vs. cellulitis, ability to spread)…………...8 viii 1.3 Significance…………………………………………………………………..……..8 1.3.1 Increase fundamental understanding of natural history of this condition……8 1.3.2 Evaluate utility of technique for clinical diagnosis and treatment planning…9 1.4 Normal Anatomy…………………………………………………………….…….12 1.4.1 Head and Neck Fascia……………………………………………………..…12 1.4.2 Head and neck fascial spaces……………………………………………..….14 A. Superficial Spaces……………………………………………………………14 B. Deep Spaces……………………………………………………………….….15 I. Spaces around the mandible………………………………………………...…15 II. Spaces running through the entire length of the neck…………………..……17 1.5 Maxillofacial Infections and Diagnosis…………………………………………...21 1.6 Standard Clinical Imaging ……………………………………………………….22 1.7 Techniques for 3D Reconstruction……………………………………………….24 1.8 Osirix (3D open-source software)………………………………………………..25 1.9 Potential Novel Applications of 3D images………………………………….…..26 1.10 Research questions……………………………………………………………...27 1.11 Purpose of the study………………………………………………………….....27 1.12 Hypotheses……………………………………………………………………..27 1.12.1 Hypothesis I…………………………………………………………….27 1.12.2