Cephalometric Analysis and Radiographic Interpretation Flashcards
7 cards from real ABO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Cephalometric Analysis and Radiographic Interpretation flashcards as text
In Steiner cephalometric analysis, what is the normal value for the SNB angle?
Answer: 80°
The normal SNB angle is 80° (±2°), representing the anteroposterior position of the mandible relative to the cranial base.
The Wits appraisal is performed by measuring the distance between which two projected points?
Answer: A and B points projected perpendicularly onto the functional occlusal plane
The Wits appraisal drops perpendiculars from A and B points to the functional occlusal plane, measuring the distance between those projected points (AO and BO).
In Tweed's diagnostic triangle, what is the ideal value for the IMPA (Incisor-Mandibular Plane Angle)?
Answer: 87°
Tweed's ideal IMPA is 87° (with FMA = 25° and FMIA = 68°), reflecting a slightly proclined lower incisor relative to the mandibular plane.
In Downs' cephalometric analysis, what does the Y-axis (Sella-Gnathion to Frankfort Horizontal) primarily indicate?
Answer: Direction and pattern of mandibular growth
The Y-axis angle (normal ~59–66°) indicates the direction of mandibular growth, with lower values suggesting forward growth and higher values suggesting downward-backward growth.
The cephalometric landmark A point (Subspinale) is defined as which point on the maxilla?
Answer: Deepest point on the curvature of the maxillary alveolar process between ANS and prosthion
A point is located at the deepest concavity on the anterior surface of the maxillary alveolar process, between the anterior nasal spine and the upper incisor.
In Ricketts' cephalometric analysis, the E-plane (esthetic plane) is a line connecting which two landmarks?
Answer: Tip of the nose to soft tissue pogonion
Ricketts' E-plane connects the tip of the nose to soft tissue pogonion; normally the upper lip is 4 mm behind and the lower lip is 2 mm behind this line.
What is the normal interincisal angle in standard cephalometric analysis?
Answer: 130–135°
The normal interincisal angle is approximately 130–135°; values below this indicate bimaxillary proclination and values above indicate retroclined incisors.