Anatomical study of the medial crura and the effect on nasal tip projection in open rhinoplasty

Overview

The medial crura are the inner legs of the tip cartilages running down the columella. Their shape varies. The authors tested in cadavers how each shape responds to the steps of open rhinoplasty: lifting the skin, placing tip sutures and adding a strut, measuring tip projection after each step.

Sections of note

• 17 cadaver heads dissected via open rhinoplasty; tip projection, columellar length and width measured.
• Three medial crura types: type 1 asymmetric parallel (n = 7), type 2 flared symmetric (n = 5), type 3 straight symmetric (n = 5).
• After skin elevation and closure, projection change differed significantly between types 1 and 3 (p = 0.004); type 2 lost a mean 1.0 mm.
• Interdomal and medial crural sutures returned types 1 and 2 to baseline projection.
• Columellar strut placement increased projection in all types.
• Cadaver study; no living patients or long-term data.

What it means for a patient

• Opening the nose can itself drop the tip a little, depending on the shape of the cartilage in the columella.
• For most cartilage shapes the surgeon must add sutures to get back to the starting projection, and a strut to add more.
• Cadaver tissue lacks muscle tone and healing, so the sizes of these effects may differ in living patients.

Why this paper matters

It gives an anatomic reason why some open rhinoplasties lose projection and supports classifying the medial crura before deciding on sutures and struts. Whether the classification predicts results in patients is untested.

Terms

• Medial crura: the inner legs of the tip cartilages that run down the columella.
• Tip projection: how far the tip stands out from the face.
• Skin envelope: the skin and soft tissue covering the nasal framework.
• Interdomal suture: a stitch that pulls the two tip domes together.
• Medial crural suture: a stitch joining the two medial crura to stabilize the columella.
• Floating columellar strut: a cartilage rod between the medial crura that does not touch the bone beneath.