Some medical plans roll in dental insurance so that it's part of one plan and premium. It is possible to purchase dental insurance coverage without having medical insurance.
Depending on the health insurance that a person has, it is possible for medical insurance to cover some dental procedures. Namely, it can cover oral surgeries. This may include facial bone or muscle diseases that can impact the teeth. Oral surgeries that are specifically related to the teeth, such as extraction, tend to be solely covered by dental insurance. It is best to check with an insurance company to determine what type of coverage is available for dental health from a person's medical and dental insurances.