1. A processor implemented method comprising: (a) capturing, by a hardware processor, a user name, a user keyword and one or more images of a set of teeth of each of one or more users using an image capturing device, to obtain one or more captured images; (b) obtaining, by said hardware processor, a selected image from said one or more captured images of said one or more users, based on one or more selection parameters being applied to said one or more captured images; (c) extracting, by said hardware processor, a portion of said selected image of said one or more users to obtain an extracted image of each of said one or more users; (d) converting, by said hardware processor, said extracted image into a grayscale image and storing said grayscale image in a database along with said username and said user keyword of each of said one or more users; (e) generating, by said hardware processor, a unique signature matrix from said grayscale image and storing said unique signature matrix in said database along with said username of each of said one or more users; (f) generating, by said hardware processor, a pattern vector for each of said one or more users by combining a set of alphanumeric characters, said user keyword of each of said one or more users, and a pattern indicator to refer to one of a set of patterns which has been selected for said grayscale image and storing said pattern vector in said database along with said username of each of said one or more users; (g) obtaining, by said hardware processor, one or more images comprising a set of teeth of at least one user using an image capturing device, to obtain one or more captured images of said at least one user and repeating the steps (b) to (e) to obtain a unique signature matrix for said at least one user; (h) performing a comparison between said unique signature matrix with a set of unique signature matrices previously stored in said database; and (i) triggering at least one action based on said comparison.