Endodontics · single question
Which tooth is LEAST likely to have two canals?
Show answer and explanation
Correct answer: C. Maxillary lateral incisor
The maxillary lateral incisor almost always has a single canal, making it the least likely of these to have two canals.Other options: Maxillary first premolars frequently have two canals; mandibular first premolars can have a second canal; maxillary molars typically have multiple canals including the MB2.Key exam takeaway: Anterior single-rooted incisors usually have one canal; premolars and molars commonly have more.
- A. Incorrect. Maxillary first premolars have TWO canals as the NORM (~60–80% of cases — very commonly two-rooted).
- B. Incorrect. Mandibular first molars nearly always have at least 3 canals (2 mesial, 1 distal).
- C. Correct. The MAXILLARY LATERAL INCISOR is LEAST likely to have two canals — nearly 100% single-rooted, single-canal. One of the simplest endodontic anatomies.
- D. Incorrect. Mandibular first premolars have two canals in ~25% of cases — more than maxillary lateral incisors.
Note: Take an angled radiograph on mandibular incisors and premolars — the second canal hides directly behind the first.