There are three reasons for having to carry out this x-ray. Firstly and most commonly to check the position of your wisdom teeth and to see if there is room in your mouth to house them. Secondly, we look at bone levels. This allows us to assess the mouth if, for example you require an implant or if we suspect bone loss secondary to gum disease. Lastly, an OPG will be performed if you are commencing orthodontic treatment and the Orthodontist feels this is necessary for a perfect smile. Again, please tell us if you may be pregnant.