In a patient with poor oral hygiene, the best solution, with regard to the prognosis of the remaining teeth, is to abstain from any prosthetic treatment. [ncbi.nlm.nih.gov]

oral hygiene Illnesses including diabetes, high blood pressure, and rheumatoid arthritis Medical treatments and medications including chemotherapy Accidents and facial trauma Whatever the reason you might be missing teeth, the team at My Rivertown Dentist [rivertownfamily.com]

Other causes of edentulism include the following: Poor oral hygiene habits: Not brushing and flossing daily can cause the development and progression of tooth decay and gum disease. [yourdentistryguide.com]