A dental pantomograph shows the lower left third molar as unerupted and tilted backwards. What type of impaction is present?

A lower left third molar that is unerupted and tilted backwards indicates a disto-angular impaction. In this type of impaction, the tooth is positioned at an angle towards the back of the mouth, often leading to difficulties in eruption and potential complications such as crowding, infection, or damage to adjacent teeth.

In the context of dental anatomy and impaction types, the orientation of the tooth plays a critical role. The disto-angular position specifically means the tooth is angled toward the distal aspect of the arch, which corresponds with the description of being tilted backwards. This categorization helps dental professionals in diagnosing and planning appropriate treatment options for impacted teeth.

The other types of impaction are characterized by different angles and orientations. For instance, horizontal impaction would mean the tooth is lying flat and parallel to the plane of the jaw, mesio-angular impaction would indicate the tooth is tilted towards the front of the mouth, and transverse impaction refers to a condition where the tooth is positioned sideways. Understanding these distinctions is essential for effective dental practice and managing impacted teeth.