Anatomical Variations in Keystone Area in Nepalese Noses: A Descriptive Cross-sectional Study

Area of Science:

• Anatomy
• Anthropology
• Rhinology

Background:

• The keystone area is vital for nasal dorsum structural integrity.
• Anatomical variations in this region are well-documented.
• Understanding these variations is crucial for reconstructive and aesthetic nasal surgery.

Purpose of the Study:

• To evaluate the anatomical variations of the keystone area in Nepalese noses.
• To provide data on nasal bone caudal margin shape and nasal bone-upper lateral cartilage overlap.
• To measure key dimensions of the keystone area and associated cartilages.

Main Methods:

• Observational, analytical study involving dissection of 31 Nepalese cadaveric noses (26 male, 5 female).
• Assessment of nasal bone caudal margin shape and nasal bone-upper lateral cartilage overlap pattern.
• Measurement of dorsal keystone, lateral keystone, and dorsal quadrangular cartilage lengths, and calculation of overlap proportion.

Main Results:

• The most common nasal bone caudal margin shape was curvilinear (48.39%).
• Mean dorsal keystone length was 6.97±2.57 mm, lateral keystone was 2.22±1.20 mm, and dorsal quadrangular cartilage was 29.77±4.6 mm.
• The mean overlap proportion of nasal bone over upper lateral cartilage was 23.82±7.33%.

Conclusions:

• This study confirmed significant anatomical variations in the keystone area of Nepalese noses.
• Findings highlight specific variations in nasal bone morphology and cartilage dimensions within the Nepalese population.
• These anatomical details are important for surgical planning in this demographic.