What is the threshold measurement used to define macrodontia in the mesio-distal sum?

• A. 28 mm
• B. 32 mm
• C. 35 mm
• D. 40 mm

Answer: (B)

Macrodontia in this context is judged by the mesio-distal sum of the four permanent incisors—that is, adding up the widths of the four front teeth measured from the mesial to distal edges. In a normal dentition, this four-incisor sum is around 28–32 mm. If the combined width exceeds 32 mm, the incisors are considered macrodontic. So 32 mm serves as the cut-off point. The other values either lie within the normal range (28 mm) or represent more extreme enlargement, but the standard threshold used to define macrodontia in the mesio-distal sum is 32 mm.