Quantification of white spot lesions using image analysis during orthodontic treatment with fixed appliances – An invitro study

Aim: To use image analysis to compare the pre and post treatment photographs and measure the incidence and severity of white spot lesions in patients who underwent fixed orthodontic treatment. Materials and Methods: The orthodontic pre treatment and post treatment intra oral (frontal view) digital photographs taken immediately after debonding are analysed by using Image J software version 1.50i. The facial surfaces of the anterior 6 maxillary teeth (canine to canine) are evaluated for WSLs. Teeth identified as having WSLs had their total facial surfaces and the lesion areas outlined with the free hand tool in the Image J 1.50i software and the respective areas are calculated using the same software. The area of the WSL was divided by the area of the total facial surface of the tooth to calculate the percentage of the facial surface affected. Teeth without WSLs are recorded as a zero percentage. The percentage of WSL per total facial tooth surface provided a relative value that controlled for differences in magnification of the digital photos. Results: Comparison of WSLs in pre and post treatment photographs showed incidence of WSLs were more in right canine. The decreasing order of incidence of WSLs (comparison between WSLs in pre and post group) was right canine, left canine, right lateral, left central, left lateral, right central. The decreasing order of severity of WSLs in pre treatment group was right lateral right canine, left canine, left lateral, left central and right central. In post treatment group was left lateral, right lateral, left central, right canine, left canine and right central. The WSLs were developed more in lateral incisor (24%) when compared with other teeth. Among all the patients 73% developed WSLs on the labiogingival areas of the teeth included in this study. On average 54.5% develop WSLs and 45.5% did not develop WSLs. Among 20 patients 51% of patients develop WSLs on right canine, 46% on right lateral, 55.6% on right central, 42.4% on left central, 49.2% on left lateral, 40.1% on left canine. Conclusion: Comparison between pre and post treatment photographs showed more incidence of WSLs on right canine. In post treatment group the increase in WSLs was highest in lateral incisors. 73% of patients develop WSLs on the labio gingival areas of the teeth.