Depressor Septi Nasi Modifications in Rhinoplasty: A Review of Anatomy and Surgical Techniques

Abstract

The anatomy of the nasal muscles contributes a social harmony in aesthetic rhinoplasty because these muscles coordinate the nose and the upper lip while smiling. Sometimes this coordination can be interrupted by the hyperactivity or variations of these muscles and may result as a deformity because of their dynamic functions and relations with the nose. In our daily practice, we usually perform the rhinoplasty without considering the dynamic functions. When the patients recover the muscle functions after operation and start to use their mimics, such as smiling, the undamaged dynamic forces may start to rotate the tip of the nose inferiorly in a long-term period, correlated with their preoperative function. To avoid this unexpected rotation it is essential to remember preoperative examination of the smile patterns. To manage this functional part of rhinoplasty, we aimed to clarify the smiling patterns or deformities mainly focused on depressor septi nasi muscle in this article. This muscle creates downward movement of the nasal tip and shortens the upper lip during smiling. The overactivity of this muscle can aggravate the smiling deformity in some patients by a sharper nasolabial angle correlated with levator labii superioris alaeque nasi and orbicularis oris muscle activities. The article not only stresses the correction of this deformity, but also aims to guide their treatment alternatives for correlation of postoperative results and applicability in rhinoplasty.

Effects of open rhinoplasty on upper lip position in profile and frontal views

“…To prevent this from happening, it is essential to carefully examine the facial muscles and preoperative smile patterns. 11 Consistent with our study, in a review study on the effects of interventions on DSN muscle in rhinoplasty, Sinno et al showed that treatment of DSN muscle, which involves transection or displacement of the muscle, results in improved aesthetic outcomes in rhinoplasty. 12 Transection or displacement of this muscle improves the position of the nose tip and increases the smile line and enhances the beauty of the face.…”

The Role of the Depressor Nasi Septi Muscle in Nasal Air Flow

“…Some reports in the literature emphasize that the depressor septi nasi muscle should be cut during rhinoplasty to prevent the nasal tip from being pulled down, especially when laughing, and to prevent a decrease in nasolabial angle during the postoperative period [47,52]. However, these reports only took aesthetic results into consideration; moreover, RMM and EMG were not performed and the dynamic functions of the nose were not evaluated.…”

“…In such patients, it is appropriate to add surgical maneuvers that support the ENV. However, patients with thin skin, strong cartilage, a gummy smile, and nasal resistance within the normal limits should not undergo DCL repair [ 21 , 44 – 47 ]. We do not recommend DCL repair for patients with prominent nasal humps, especially those with a hypertrophic M. depressor septi nasi; nasal tip droop increases after hump resection [ 48 ].…”

Anatomical Study and Comprehensive Review of the Incisivus Labii Superioris Muscle: Application to Lip and Cosmetic Surgery

“…During the procedure, the incisivus labii superioris is also cut at the labial vestibular incision; this enhances the result of the operation. Also in rhinoplasty [ 27 ], many surgeons transect the ILS to approach the depressor septi nasi muscle.…”