Canalis sinuosus

canalis sinuosus

What is the canalis sinuosus and do we need to worry about it?

Canalis sinuosus is a branch of the infraorbital canal with a very high degree of variation. It is a neurovascular canal through which the anterior superior alveolar nerve passes through. It typically reaches the the premaxilla in the canine and incisor region, most often between the central and lateral incisor. The lateral incisor is the site we most need to be careful of when placing a dental implant.

How common is the canalis sinuosus?

Very common but the the small size of it often makes it irrelevant clinically. Aoki 2020 and de Oliveira-Neto 2022 find it 67% and 80% of the time, respectively.  Shan JPD 2021 finds it in 37% of CT scans. However, they only look for canals 1mm or greater. The average diameter of the ones they find are 1.1 ±1mm, thus most could simply be just smaller than their 1mm cut off.

What does the canalis sinuosus look like on a cbct?

There are a few nice ct images and photos of a canalis sinuosus and the anterior superior alveolar nerve on Dr. Mataria instagram post.

When do we need to worry about the canalis sinuosus?

The time when dentists are most likely to cause a problem is when we are placing a dental implant in the lateral site according to Romanos JOI 2023. While the risk is low, we should be on the look out for an abnormally larger nerve in the area of the canine to canine in the maxilla.

What happens if we damage the nerve?

There can be pain in the area but most reports show resolution of pain either immediately, according to Machado 2016 and McCrea 2019 after implant removal or with pain resolving slowly after removal Volberg 2019. Most of the time the nerve is too small to cause any issue that the patient can sense.