Anatomy and Management of the Depressor Septi Nasi Muscle: A Systematic Review

INTRODUCTION:

Rhinoplasty is considered one of the most challenging surgical procedures plastic surgeons are asked to perform. In addition to the standard maneuvers of rhinoplasty, many master rhinoplasty surgeons have added additional techniques to refine the art of nasal surgery. The role of the depressor septi nasi (DSN) muscle manipulation in achieving tip projection and upper lip lengthening has been well described in several series. To our knowledge, a comprehensive review of the literature of DSN muscle manipulation has not been performed.

METHODS:

A comprehensive search of the PubMed, MEDLINE, and the Cochrane databases was conducted for articles published through March 2014 on the approach to the DSN muscle in rhinoplasty.  Prospective and retrospective studies were included, and cadaver studies were excluded.  Technique used, number of patients operated on, operative outcomes, complications, and patient satisfaction were noted.

RESULTS:

Nine articles met the predetermined criteria for inclusion, yielding a total of 717 patients who received DSN treatment.  All nine articles concluded that patients presenting with hypertrophy of the DSN, causing nasal tip depression and upper lip shortening during animation, are ideal candidates for manipulation of the muscle.  Techniques were varied, utilizing the intranasal or intraoral approach, and the muscle was manipulated either through excision or transposition.  Different pre- and post-operative measures were taken and could not be directly compared across all papers.  The most common measure was nasolabial angle; 3 studies (33.3%) analyzed nasolabial angles pre- and post-operatively with a mean change of 14.5 degrees.  Other measurements included nasal length and upper lip height.  No permanent complications were reported, although one study noted transient upper lip asymmetry or paresthesias.  No relapse was evident up to 2 years postoperatively in two articles.  Overall outcomes reported included correction of nasal tip ptosis, increase in upper lip length, decrease in nasal length, and decrease in gingival show during animation.  Improvement in nasal contour was seen in 99% (n=710) of patients.

 

CONCLUSIONS:

Manipulation of the DSN when indicated is a powerful tool in rhinoplasty as supported by the literature. Future studies should aim to standardize outcomes by providing pre- and post-operative measurements. Nevertheless, manipulation of a hypertrophic DSN muscle is certainly a time-tested tool in the rhinoplasty surgeon’s armamentarium.