The Dorsal Nasal Complex in Asians: Anatomical Variations and Injection Guide for Botulinum Toxin Type A.

Area of Science:

• Aesthetic medicine
• Facial anatomy
• Dermatology

Background:

• Dorsal nasal lines (DNLs) formation involves multiple muscles, impacting nasal aesthetics.
• Limited research exists on DNL distribution patterns for precise injection planning.

Purpose of the Study:

• To classify DNL distribution types.
• To propose an improved injection technique for DNLs.
• To validate the technique through clinical and cadaver studies.

Main Methods:

• Patients classified into 4 DNL types.
• Botulinum toxin type A injections administered at 8 points.
• Wrinkle reduction and patient satisfaction assessed.
• Cadaver dissection to analyze DNL-related musculature.

Main Results:

• 320 patients (349 treatments) classified into complex, horizontal, oblique, and vertical DNL types.
• Significant DNL severity reduction and high patient satisfaction reported.
• Cadaver study revealed connecting muscular fibers, termed the dorsal nasal complex (DNC).
• Four DNC anatomical variations identified, supporting the DNL classification.

Conclusions:

• A novel anatomical concept, the dorsal nasal complex (DNC), and a DNL classification system were established.
• Each DNL type correlates with a specific DNC anatomical variation.
• A refined, effective, and safe injection technique for DNLs was developed and validated.