Q I have heard that there is such a thing as a cone beam CT x-ray machine designed for dentistry. What is this and should my dentist have one?

A Cone beam CTs (CBCTs) are a family of units, each slightly different based on the manufacturer, like cars, but each basically similar. These units produce images that are 2D and 3D, and can be used for dental implant planning, to localize impacted teeth and look at some other disease processes involving the jaws and TMJs. The radiation dose for CBCTs is considerably lower than for standard CTs (1/10 to 1/100), but they do not show most soft tissue (non bone) very well. Also, these are expensive units, and to diagnose from them requires specialized training and knowledge. Your dentist can refer you to such a person, if there is a need.

Q I have been bothered with mouth ulcers for a number of years. What are mouth ulcers and can anything be done to treat them?

A These ulcers are also called aphthous ulcers. They appear within a day or two, usually heal in 7-14 days, and can be painful and annoying. We do not completely understand what causes aphthous ulcers , but they are not an infection and are completely different from fever blisters which occur on the outside of the lips and are caused by a virus. The discomfort caused by aphthous ulcers can be controlled by using topical steroid mouth rinses and ointments.