The key difference is that dehiscence is a defect in the bone, while recession is the resulting movement of the gingival (gum) margin. In other words, dehiscence is a potential cause of recession.
Here's a more detailed breakdown:
Dehiscence
- Definition: Dehiscence, in the context of dentistry, refers to a defect or a loss of alveolar bone, typically on the facial (buccal) surface of a tooth. It's characterized by a "window-like" defect where the root surface is exposed due to bone loss. Bone loss is usually limited to a single tooth surface.
- Characteristics: This defect is usually isolated and doesn't extend to the entire bony housing of the tooth.
- Appearance: It presents as a fenestration of the bone, exposing the root surface.
Recession
- Definition: Gingival recession is the apical migration (movement towards the root tip) of the gingival margin, resulting in the exposure of the tooth's root surface.
- Characteristics: Recession can occur due to various factors, including inflammation, aggressive brushing, thin gingival biotype, orthodontic treatment, and, importantly, underlying bony dehiscence.
- Relationship to Dehiscence: When a tooth has a dehiscence, the overlying soft tissue (gingiva) is often unsupported by bone. Over time, the gingiva may recede to the level of the underlying bone defect, leading to gingival recession. The inflamed or normal gingival soft tissue will keep up with the cervical bone level over time, resulting in gingival recession.
Summary Table
| Feature | Dehiscence | Recession |
|---|---|---|
| Definition | A defect or loss of alveolar bone, often on the facial surface, exposing the root. | The apical migration of the gingival margin, exposing the root surface. |
| Nature | A bony defect. | Soft tissue (gingival) displacement. |
| Relationship | Can cause recession by providing inadequate support for the gingiva. | Can be caused by dehiscence, among other factors. |
| Presentation | "Window-like" defect in the bone, exposing root surface. | Visible exposure of the tooth root. |
In short, dehiscence is a bony problem that can predispose a tooth to gingival recession. Understanding the difference is critical for diagnosis and treatment planning in periodontal care.
