The most frequently impacted tooth in the oral cavity is the mandibular third molar. Impacted teeth are those that fail to erupt into the dental arch within the expected developmental window. Several factors contribute to impaction, including insufficient space in the jaw, angulation of the tooth, and delayed eruption.

- The mandibular third molar, commonly known as the wisdom tooth, is the last tooth to erupt, typically between the ages of 17 and 25.
- Due to its late eruption and the often limited space in the posterior mandible, the mandibular third molar is prone to impaction.
- Impaction can lead to complications such as pericoronitis, cyst formation, and damage to adjacent teeth.
- Although the maxillary canine is frequently impacted as well, it is less common compared to the mandibular third molar.
- Other teeth such as the maxillary lateral incisors and mandibular second premolars have a much lower incidence of impaction.

Summary:
- Mandibular third molars are the most commonly impacted teeth.
- This is primarily due to lack of space in the jaw and their late eruption time.
- Understanding the pattern of impaction is essential for planning dental treatments and surgical interventions.

Reference: Oral Pathology, Volume 1, Chapter 5 - Developmental Anomalies of Teeth