If the normal SNA angle is 82 degrees, what does a value of 78 degrees indicate about the maxilla?

If the normal SNA angle is 82 degrees, what does a value of 78 degrees indicate about the maxilla?

• A. The maxilla is more anterior or excessive
• B. The maxilla is more posterior or deficient
• C. The maxilla is in a normal position
• D. The maxilla is vertically displaced

Answer: (B)

A value of 78 degrees for the SNA angle, which measures the anteroposterior position of the maxilla in relation to the cranial base, indicates that the maxilla is positioned more posteriorly than normal. In cephalometric analysis, a normal SNA angle is defined as 82 degrees. Therefore, a measurement that is lower—such as 78 degrees—suggests that the maxilla is retruded or situated further back relative to the cranial base. This finding usually points towards a maxillary deficiency, which can have implications for dental and orthodontic treatment as it may affect occlusion and facial aesthetics.

A value of 78 degrees for the SNA angle, which measures the anteroposterior position of the maxilla in relation to the cranial base, indicates that the maxilla is positioned more posteriorly than normal. In cephalometric analysis, a normal SNA angle is defined as 82 degrees. Therefore, a measurement that is lower—such as 78 degrees—suggests that the maxilla is retruded or situated further back relative to the cranial base. This finding usually points towards a maxillary deficiency, which can have implications for dental and orthodontic treatment as it may affect occlusion and facial aesthetics.