To be honest, not a lot of thought went into it. In those days you just choose one of the big three: law, medicine or dentistry. It wasn't until I began studying and practising that I really started to think about what I wanted to achieve as a dentist.

How did you become involved in treating bad breath?
Once I started practising, it became obvious how many people have a problem with bad breath - the medical term is halitosis. This isn't something that dentists are taught at university and it's a huge problem that largely goes untreated. I started thinking about how I could solve this problem. I made contact with a guru in the United States who had his own bad-breath clinic. After seeing the treatments available, I tried to adapt and apply what I had learned to the Australian market. I started working with researchers to develop a range of oral-care probiotics and started the Australian Bad Breath Clinic.

What does your work involve?
I split my time. In the morning, I am a dentist and, in the afternoon, I see my breath patients. Bad breath is still a very touchy subject. Many people aren't willing to discuss it. We developed a website where people can get the information and answers they need in private.

What is the most satisfying part of your job?
Bad breath is not a problem that's taken seriously by society. I've treated people who are suicidal because of their breath and couples who are forced to sleep in different rooms. When you can help someone to become normal again there's a lot of gratitude and a lot of gratification. It's very different from my work as a dentist - you see the patient, do the filling and that's it. Dentistry is a fear industry, people dread going to the dentist. Seeing a bad-breath patient is completely different - they want you to help them.

Dealing with bad breath all day must be difficult?
You do become immune to certain levels of bad breath, however, when it's really bad you just keep a straight face and cop it sweet. Wearing a mask would only increase the patient's paranoia. I had a patient once with plastic dentures that hadn't been removed in 20 years. The patient thought they would stop breathing without the dentures. When we finally took the dentures out, we had to keep the windows wide open all afternoon. What can be more difficult than bad smells are cynical and reluctant patients, mostly men who have been forced by their wives to come and see me. Treating these patients means changing their perceptions.