Despite its frequent omission from the dental record, the past dental history (PDH) is one of the most important components of the patient history. This is especially evident when the patient presents with complicating dental and medical factors such as restorative and periodontal needs coupled with a systemic disorder such as diabetes. Significant items that should be recorded routinely are the frequency of past dental visits; previous restorative, periodontic, endodontic, or
oral surgical treatment; reasons for loss of teeth; untoward complications of dental treatment; fluoride history, including supplements and the use of well water; attitudes towards previous dental treatment; experience with orthodontic appliances and dental prostheses; and radiation or other therapy for oral or facial lesions. Information on the general features of past treatment (rather than specific and detailed tooth-by-tooth descriptions) are needed at this time. In regard to radiation or other therapy for oral or facial lesions, exact information is needed about the date and nature of diagnosis; the type and anatomic location of treatment; and the names, addresses, and telephone numbers of the physicians and dentists involved and the facility (hospital or clinic) where the treatment was given. Likewise, clear details of any previous untoward complications of dental treatment must be recorded or must be obtained subsequently if not immediately available from the patient.