title: Teeth segmentation of dental periapical radiographs based on local singularity analysis.
abstract: Teeth segmentation for periapical raidographs is one of the most critical tasks for effective periapical lesion or periodontitis detection, as both types of anomalies usually occur around tooth boundaries and dental radiographs are often subject to noise, low contrast, and uneven illumination. In this paper, we propose an effective scheme to segment each tooth in periapical radiographs. The method consists of four stages: image enhancement using adaptive power law transformation, local singularity analysis using Hölder exponent, tooth recognition using Otsu's thresholding and connected component analysis, and tooth delineation using snake boundary tracking and morphological operations. Experimental results of 28 periapical radiographs containing 106 teeth in total and 75 useful for dental examination demonstrate that 105 teeth are successfully isolated and segmented, and the overall mean segmentation accuracy of all 75 useful teeth in terms of (TP, FP) is (0.8959, 0.0093) with standard deviation (0.0737, 0.0096), respectively.
authors.affiliation: Department of Computer Science and Information Engineering, Providence University, Shalu, Taichung 43301, Taiwan. Electronic address: lan@pu.edu.tw.
authors.forename: P L
authors.initials: PL
authors.lastname: Lin
authors.affiliation: Department of Computer Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: phd9605@cs.nchu.edu.tw.
authors.forename: P Y
authors.initials: PY
authors.lastname: Huang
authors.affiliation: Department of Computer Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: powhei.huang@msa.hinet.net.
authors.forename: P W
authors.initials: PW
authors.lastname: Huang
authors.affiliation: College of Oral Medicine, Chung Shan Medical University and Chung Shan Medical University Hospital, Taichung 40201, Taiwan. Electronic address: kunzelhsu@gmail.com.
authors.forename: H C
authors.initials: HC
authors.lastname: Hsu
authors.affiliation: College of Oral Medicine, Chung Shan Medical University and Chung Shan Medical University Hospital, Taichung 40201, Taiwan. Electronic address: jff_chen1010@yahoo.com.tw.
authors.forename: C C
authors.initials: CC
authors.lastname: Chen
mesh_terms: D006801:Humans; D007091:Image Processing, Computer-Assisted; D011861:Radiography, Dental; D015203:Reproducibility of Results; D019227:Tooth Apex / Q000000981:diagnostic imaging*
keywords: Adaptive power law transformation; Periapical radiographs; Singularity analysis; Teeth segmentation