  Citation: Maithri, M.; Ballal, D.G.; Kumar, S.; Raghavendra, U.; Gudigar, A.; Chan, W.Y.; Macherla, S.; Vineetha, R.; Gopalkrishna, P.; Ciaccio, E.J.; et al. Development of a Computational Tool for the Estimation of Alveolar Bone Loss in Oral Radiographic Images. Computation 2022, 10, 8. https://doi.org/10.3390/ computation10010008 Academic Editor: Vitaly Volpert Received: 24 November 2021 Accepted: 7 January 2022 Published: 12 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). computation Article Development of a Computational Tool for the Estimation of Alveolar Bone Loss in Oral Radiographic Images M. Maithri 1 , Dhanush G. Ballal 1 , Santhosh Kumar 2, * , U. Raghavendra 3 , Anjan Gudigar 3 , Wai Yee Chan 4 , Shravya Macherla 2 , Ravindranath Vineetha 5 , Pratibha Gopalkrishna 2 , Edward J. Ciaccio 6 and U. Rajendra Acharya 7,8,9 1 Department of Mechatronics, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India; maithri.m@manipal.edu (M.M.); dhanushgballal@gmail.com (D.G.B.) 2 Department of Periodontology, Manipal College of Dental Science, Manipal, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India; shravya.m@learner.manipal.edu (S.M.); pratibha.pk@manipal.edu (P.G.) 3 Department of Instrumentation & Control Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India; raghavendra.u@manipal.edu (U.R.); anjan.gudigar@manipal.edu (A.G.) 4 Department of Biomedical Imaging, Universiti Malaya Research Imaging Centre, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia; waiyeec@ummc.edu.my 5 Department of Oral Medicine and Radiology, Manipal College of Dental Science, Manipal, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India; vineetha.manu@manipal.edu 6 Department of Medicine, Columbia University, New York, NY 10032, USA; ciaccio@columbia.edu 7 School of Engineering, Ngee Ann Polytechnic, Singapore 599489, Singapore; aru@np.edu.sg 8 Department of Biomedical Informatics and Medical Engineering, Asia University, Taichung 41354, Taiwan 9 Department of Biomedical Engineering, School of Science and Technology, SUSS University, Singapore 599494, Singapore * Correspondence: santhosh.kumar@manipal.edu Abstract: The present study evaluated a newly developed computational tool (CT) to assess the alveolar bone space and the alveolar crest angle and compares it to dentist assessment (GT). The novel tool consisted of a set of processes initiated with image enhancement, points localization, and angle and area calculations. In total, we analyzed 148 sites in 39 radiographic images, and among these, 42 sites were selected and divided into two groups of non-periodontitis and periodontitis. The alveolar space area (ASA) and alveolar crest angle (ACA) were estimated. The agreement between the computer software and the ground truth was analyzed using the Bland–Altman plot. The sensitivity and specificity of the computer tool were measured using the ROC curve. The Bland–Altman plot showed an agreement between the ground truth and the computational tool in all of the parameters assessed. The ROC curve showed 100% sensitivity and 100% specificity for 12.67 mm of the alveolar space area. The maximum percentage of sensitivity and specificity were 80.95% for 13.63 degrees of the alveolar crest angle. Computer tool assessment provides accurate disease severity and treatment monitoring for evaluating the alveolar space area (ASA) and the alveolar crest angle (ACA). Keywords: alveolar crest angle; alveolar space area; computer aided tool; periodontitis; sensitivity; specificity 1. Introduction Periodontal disease is associated with the loss of alveolar bone. The loss rate can be slow and continuous, or episodic, and is manifested as a horizontal or angular type [1]. Loss of alveolar bone occurs as a consequence of pathogenic microorganisms, or the red- complex bacteria due to the host and the bacteria-induced inflammatory response [2]. It is manifested clinically by losing the surrounding soft tissue that anchors and attaches the teeth with the underlying alveolar bone. A diagnosis can be established via a clinical Computation 2022, 10, 8. https://doi.org/10.3390/computation10010008 https://www.mdpi.com/journal/computation