Based on Morphology, Pockets are classified into 2 types:
1. Gingival (pseudo pocket): This type of pocket is formed by gingival enlargements without destruction of underlying periodontal tissues. The sulcus is deepened because of the increased bulk of gingiva.
2. Periodontal pocket: It occurs with destruction of supporting periodontal tissues which leads to loosening and exfoliation of teeth.
Periodontal pocket can further be classified into 2 types:
a. Suprabony (supracrestal or supraalveolar): In this the bottom of the pocket is coronal to the underlying alveolar bone. Bone loss is horizontal.
b. Intrabony (infrabony, subcrestal or intra-alveolar): Here, the bottom of pocket is apical to the level of adjacent alveolar bone. Bone loss is vertical.
Suprabony v/s Infrabony:
1. Base of pocket is coronal to level of alveolar bone in case of suprabony pockets whereas it is apical in case of infrabony pockets.
2. Pattern of destruction of underlying bone is horizontal in suprabony pockets whereas it is vertical in case of infrabony pockets.
3. Trans-septal fibres are horizontal under suprabony whereas they are oblique under infrabony.
4. On facial and lingual surfaces, periodontal ligament fibres follow horizontal-oblique source between tooth and bone in case of suprabony ; whereas they follow angular pattern in case of infrabony pockets.
Based on number of surfaces involved, Pockets are classified into 3 types:
- simple pocket : Involving one tooth surface.
- Compound Pocket : Involving two or more tooth surface.
- Complex Pocket : Base of the pocket is not in direct communication with gingival margin.
Based on soft tissue wall, Pockets are classified into 2 types:
- Edematous Pocket
- Fibrotic Pocket
Based on disease activity, Pockets are classified into 2 types:
- Active Pocket
- Inactive Pocket