An impacted tooth is a tooth that fails to fully erupt into its proper position in the dental arch, remaining partially or completely enclosed within the alveolar bone or overlying soft tissue. Third molars — commonly called wisdom teeth — are the most frequently affected, though maxillary canines and premolars can also become impacted due to crowding or developmental anomalies.
Why It Matters
When a tooth cannot erupt normally, it creates a cascade of clinical concerns. The partially erupted crown may trap bacteria beneath the overlying gingival flap — a condition called pericoronitis — leading to localized infection, pain, and swelling. Over time, pressure from an impacted tooth can cause root resorption in adjacent teeth, compromise the periodontal ligament, and contribute to the formation of dentigerous cysts arising from the dental follicle.
Types of Impaction
Impactions are classified based on the angulation and depth of the unerupted tooth:
- Mesioangular: crown tilted toward the front of the mouth — the most common presentation
- Distoangular: crown angled toward the back of the mouth
- Vertical: tooth is upright but physically blocked by insufficient space or bone
- Horizontal: tooth lies roughly parallel to the jawbone
- Soft tissue impaction: the crown has penetrated bone but remains beneath the gingiva
Diagnosis and Treatment
Impacted teeth are identified through periapical or panoramic radiographs, which reveal the tooth’s angulation, depth, and proximity to critical structures such as the inferior alveolar nerve. Treatment is guided by clinical risk: an asymptomatic, fully bony impaction may be monitored over time, while surgical extraction is indicated when there is pain, recurrent infection, cyst formation, or threat to adjacent teeth. For impacted canines, orthodontic traction — using brackets and wires to guide the tooth into proper alignment — offers an alternative to extraction when the tooth is otherwise viable.
Early detection through routine radiographic screening allows clinicians to intervene before complications develop, protecting both the patient’s comfort and the long-term integrity of the surrounding dentition.