The mandibular central incisor and right lateral incisor radiographs demonstrate an error caused by which factor?

• A. Excessive vertical angulation
• B. Insufficient exposure
• C. Incorrect horizontal angulation
• D. Motion artifact

Answer: (A)

Distortion from beam angle is the key idea here. Vertical angulation affects how long the tooth appears on the image. If the x-ray beam is directed too steeply (excessive vertical angulation), the anterior teeth—like the mandibular central incisor and the right lateral incisor—tend to look longer than they actually are, causing elongation on the radiographs. That elongation matches what you’d observe in these incisor images.

If the vertical angle were not enough (not enough tilt), you’d see foreshortening instead, where the tooth looks shorter. Horizontal angulation errors would cause overlap or misalignment of features rather than length distortion, and motion artifact would blur the image rather than change tooth length.