Photography and dentistry are two words that have not been associated together until the recent decade. It has only recently taken off due to the technological advances of digital photography and everyone being a "photographer". Taking photos in the dental setting has multiple purposes.
Photos are a great record of your mouth. If a restoration was required on a tooth, photos from the past would assist in restoring the tooth to its original shape and colour. Changes over time can also be monitored accurately. For example, if we are worried about your grinding, we can see how much of your tooth has worn away. The dentist will definitely not remember what the shape of your tooth was from 6 months ago!
Photos allow me to give you a tour of your mouth. Many problems in the mouth are painless. Because you cannot see or feel the problem, you are not aware of it and it is of little importance to you. A common complaint from dentists is that many people do not care about their teeth and do not agree to their suggested treatment. The reason why people do not care is because they are not aware of the severity or nature of the problem. Seeing the issue in a photo says a thousand words.
In a large photo of your teeth, many small details are easily visible. In dentistry, the quality of the work is dependent on the small details. A small gap in a filling will lead to tooth decay or sensitivity. A dentist who takes photos of their work and shows you, is confident in the quality of their dentistry.
Photography in itself, does not mean better dentistry, but it does mean both the dentist and patient are much better informed and striving to be the best they can. Isn't that what you would like when you are paying for a service?