In health, there are two types of gum tissues that surround the tooth. The part that is around the neck of the tooth is firmly attached to the tooth and underlying bone, and is called attached gingiva. The attached gingiva is immovable and tough and deflects food as it hits the gum. Below the attached gingiva is looser gum, or alveolar mucosa. This tissue contains muscle and is flexible to allow movement of the cheeks and lips. The muscles in the alveolar mucosa are constantly contracting, which pulls on the bottom edge of the attached gingival. However, normally the attached gingival is wide and strong enough to act as a barrier which prevents the gum from being pulled down (receding).
Insufficient Attached Gum
Some people are born without sufficient attached gingival to prevent the muscle in the alveolar muscoa from pulling the gum down. In these cases the gum slowly continues to recede over time, even though the patient may be very conscientious with their oral care. This is not an infection, as is seen with periodontal disease, but rather simply an anatomic condition.
Unfortunately, bone recession is occurring at the same time the gum is receding. This is because the bone which is just under the gum, will not allow itself to become exposed to the oral cavity and moves down with the gum.
Causes of Dentin Hypersensitivity
Connective Tissue Graft
When there is gum recession, the root of the tooth often shows and is unsightly. Gum grafting is needed to restore health (See Gum Recession). But root coverage may also be desired to improve appearance. This is generally accomplished with a connective tissue graft, which provides new attached gingival while covering the root surface.