Cephalic Malposition of the Lateral Crura and Parenthesis Deformity: A Cadaver Study in Caucasians

Background: Improving the shape and contour of the nasal tip is a major goal in rhinoplasty. Extreme bulbosity and parenthesis deformity of the nasal tip are both frequently encountered. However, the underlying anatomical features that cause this kind of tip deformity are still not fully understood. Objectives: To evaluate the relation between the shape of the nasal tip and the anatomical position, orientation and shape of the lateral crura of the lower lateral cartilages and to estimate the incidence of cephalic malposition of lateral crura in Caucasian noses. Materials and Methods: Nineteen Caucasian cadaver noses were studied, and the alar cartilages were measured and evaluated using a standardized method. Results: Fourteen of the total 38 lateral crura evaluated had cephalic malposition (long axis angle with the midline equal to or less than 30°). Of the nasal tips classified as having parenthesis deformity, 84.6% had cephalic malposition of lateral crura and 46.2% had convex lateral crura. Vertical orientation of the short axis of the lateral crura was no more common in noses with parenthesis deformity of the nasal tip than in other kinds of nasal tip. Conclusions: The incidence of cephalic malposition of the lateral crura in this series of Caucasian noses was 36.8%. There was a statistically significant association between parenthesis deformity of the nasal tip and cephalic malposition of the lateral crura, as well as with convex shape of the lateral crura. No statistically significant association was found between the sagittal angle of the lateral crura and the type of nasal tip. Level of Evidence V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.