Saddle Angle And Maxillary Prognathism
Write short note on SNA angle.
Answer. The angle formed by the intersection of SN plane and a line joining nasion and point A.
- This angle indicates position of maxilla in relation to cranium.
- The mean value is 82°
- SNA angle assesses the degree of prognathism of maxilla.
- Planes of SNA angle are SN plane which is horizontal plane and NA plane which is vertical plane.
- Value of SNA angle is increased in prognathic maxilla (Class 2).
- Value of SNA angle is decreased in retrognathic maxilla (Class 3).
Leave a Reply