Dermot graduated with an honours degree in Dentistry from Trinity College Dublin in 1998. He worked in the Dublin Dental Hospital as a House Officer following graduation and went on to work as a dentist in Dublin, while studying for his Membership of the Faculty of Dentistry in the Royal College of Surgeons in Ireland, which he obtained in 2001.

In 2002, he began a 3 year specialist training program in Cardiff University as a Specialist Registrar, qualifying in 2005 with a Membership in Orthodontics from the Royal College of Surgeons in Edinburgh and qualifying with distinction from the Masters in Orthodontics degree program in Cardiff University.

Dr. Kavanagh is now the immediate Past President of the Metropolitan Branch of the Irish Dental Association. He is a member of the Irish Dental Association, Orthodontic Society of Ireland, British Orthodontic Society, and is on the Dental Council's Specialist Register for Orthodontics. He has presented at the annual conference of the American Association of Orthodontists and to the Metropolitan Branch of the Irish Dental Association.

He has worked as an Orthodontist in both the public service and private practice since 2005. In his spare time, Dr. Kavanagh used to play tennis and golf but is now fully occupied by his three year old daughter and one year old son!