Bone dehiscence is a serious dental condition that affects more than just the way your teeth look. Sometimes confused with dental fenestration, bone dehiscence affects the length of the bony aspect of the tooth. In both fenestration and dehiscence, only the periosteum (connective tissue that overlays the tooth) and a thin layer of gum tissue covers the tooth’s root. With dental fenestration there is still bone at the coronal end of the tooth. At least one of these two conditions will affect up to 20% of teeth.

What is bone dehiscence?

Dental dehiscence in bone is a condition when the bone of your tooth wears away below the gumline. This exposes the tooth’s root (there is no marginal bone loss with dental fenestration). The outline of the root appears like a cylinder and you may see it protrude beneath the gumline. This occurs most frequently on the surface that faces forward (the facial surface).

Three basic stages of bone dehiscence include:

Gingival recession

Receding gums are also referred to as gingival recession.

This first stage of bone dehiscence occurs as the gums begin to pull away from the crown of the teeth. As it progresses, the bone below the gumline is exposed.

Alveolar bone loss

Teeth are held in tooth sockets located in the alveolar bone, a thicker ridge of bone in the jaw. As gingival recession continues, alveolar bone loss occurs. Dentists also refer to this alveolar bone loss due to dehiscence as “resorption.”

Root exposure

As the bone continues to thin and be resorbed, exposed tooth roots in the gums can become very sensitive. In addition to visible symptoms of bone dehiscence, pain is a symptom of this condition.

Dental dehiscence occurs most often on both sides in the front of the mouth. There are four classes of gum recession that can lead to bone dehiscence.

Class I

The mucogingival junction is where the moveable gum and cheek tissue meets the immoveable soft tissues of the mouth. Class I bone dehiscence is marked by only moderate levels of gum recession that has not yet resulted in soft tissue or bone loss or moved into the mucogingival junction.

Class II

This class of gum recession has still not damaged soft tissues of bone but has begun to extend into or beyond the mucogingival junction.

Class III

Bone loss begins to occur and soft tissue damage is also present. Damage is limited to the area where the tooth root meets the dental pulp.

Class IV

Bone loss and soft tissue damage occurs, reaching well into the tooth’s roots. This is the most serious form of this condition.

What causes dental dehiscence in the bone?

Poor oral hygiene is at the root of bone dehiscence. Improper, overly vigorous, or inadequate brushing and flossing causes gums to recede over time. This recession, combined with other risk factors, can cause dental dehiscence.

Common risk factors also include:

  • Tooth position: The location and position of the tooth in the socket of the alveolar bone can influence the development of bone dehiscence.
  • Attachment of the gingiva: Gum tissue (gingiva) attachment contributes to dental dehiscence. If the gingiva is poorly or loosely attached to the teeth, this makes it more susceptible to gum recession. Once gum recession begins, the teeth and their roots become vulnerable.
  • Thin bony housing: The alveolus is the bony lining in the alveolar bone in which the tooth inserts. If this is thin, it is less able to do its job of keeping the tooth in place in the alveolar bone.

What dental dehiscence treatment works?

Treatment for dental dehiscence treatment aims to cover the exposed tooth root to stimulate gingival repair and bone regrowth. Your dentist can achieve some degree of coverage for the exposed root, regardless of the class of your gum recession.

The first step is to improve your existing oral hygiene practices by thoroughly cleaning the teeth and talking to your dentist about proper at-home care. The exposed tooth root must be completely free from bacteria before your dentist does any procedure. If bacteria is sealed into the repaired gum, this can cause dangerous infection.

Your dentist has several options when it comes to covering the tooth root. Grafting and restoration are standard treatment protocols.

Types of treatments

Grafting is generally used for Class I and Class II bone dehiscence where aesthetic considerations are important (i.e. for the upper front teeth) but there is no gingival attachment. Tooth enamel should be healthy and stable in order to attempt th