It is important to try to get any major dental work completed prior to starting oral appliance therapy, because these are long term medical devices that treat a chronic and possibly life threatening condition. It is important that they fit well and for as long as possible. Oral appliances can easily accommodate crowns, bridges and veneers. Oral appliances will not damage existing dental work unless it is already loose or failing, and oral appliances can be adjusted to ensure they do not damage teeth that may have existing bone loss or other issues.