Anatomical Study of the Medial Crura and the Effect on Nasal Tip Projection in Open Rhinoplasty

Abstract

Background: 

Common variations in morphology of the medial crura have been described. The authors’ observation is that changes in nasal tip projection depend on the shape and strength of the medial crura. The authors investigated how differences in medial crura shape affect tip projection after surgical intervention.

Methods: 

Seventeen cadaver heads were dissected with an open rhinoplasty approach. Nasal tip projection and columellar length and width were measured. Medial crura shape was noted and classified. Anthropometric measurements were made preoperatively and after each of the following procedures: (1) elevation of skin envelope and closure of the columellar incision, (2) interdomal and medial crural sutures, and (3) placement and fixation of a floating columellar strut.

Results: 

Three anatomical variations of the medial crura were noted: type 1, asymmetric parallel (n = 7); type 2, flared symmetric (n = 5); and type 3, straight symmetric (n = 5). A significant difference in tip projection after elevation of the skin envelope and closure was discovered between types 1 and 3 (p = 0.004). Type 2 medial crura were found to have a mean reduction of 1.0 mm. Suture techniques resulted in return to baseline tip projection for types 1 and 2. Columellar strut placement increased tip projection in all types.

Conclusions: 

Changes in tip projection after an open rhinoplasty depend on the shape of the medial crura. Straight symmetric (type 3) cartilages can maintain tip projection without any additional intervention during an open rhinoplasty. Asymmetric parallel (type 1) or flared symmetric (type 2) variants will require interdomal and medial crural sutures to maintain baseline tip projection.