Increased SNA indicates which type of mandible?

Increased SNA indicates a prognathic mandible, which means that the maxilla (upper jaw) is positioned more forward relative to the cranial base than the mandible (lower jaw). In orthodontics and cephalometrics, SNA is the angle formed by the intersection of the nasion, sella, and A-point. An increase in the SNA angle typically suggests that the maxilla is protruded in relation to the cranial structure. Consequently, when the maxilla is more forward, the relationship with the mandible may appear more pronounced, leading to the classification of a prognathic mandible as the jaw appears to retreat when evaluated in relation to the maxilla.

This evaluation is crucial in orthodontics for diagnosing and planning treatment for patients with different skeletal relationships. Recognizing distinct classifications—like prognathic, retrognathic, or mesognathic—helps clinicians make informed decisions on how to move teeth or reposition jaws to achieve optimal dental alignment and occlusion.