The proximal surfaces of roots that are narrower on the lingual than the facial surface are more readily approached from the lingual because there is more proximal space there for the adaptation of instruments.

Question

Quizplus · Accepted Answer

When proximal surfaces of roots converge markedly toward the lingual and the roots have a very narrow lingual surface, then there is much more proximal space for access with instruments. This is especially so for maxillary central incisors.

The Proximal Surfaces of Roots That Are Narrower on the Lingual