Identifying Great Auricular Nerve via Bony Landmarks: A Cadaver Study

Area of Science:

• Anatomy
• Surgical Anatomy
• Nerve Identification

Background:

• The great auricular nerve (GAN) provides sensation to the lower ear and jaw angle.
• It is frequently encountered and sometimes sacrificed during neck surgeries.
• Sacrificing the GAN typically does not significantly impact patient quality of life.

Purpose of the Study:

• To evaluate bony landmarks for reliably identifying the great auricular nerve (GAN).
• To establish a ratio using the angle of the mandible (AOM) and mastoid process for GAN localization.
• To provide a dependable range for GAN identification in surgical settings.

Main Methods:

• Dissection of 46 cadaver sides to expose the GAN, AOM, and mastoid process.
• Two independent observers calculated the ratio between AOM-mastoid process distance and AOM-GAN distance.
• Statistical analysis included mean, standard deviation, and coefficient of variation to assess reliability.

Main Results:

• The mean ratio for GAN identification was 0.457 (SD ±0.085).
• Data exhibited normal distribution, with coefficients of variation of 14.21 (AOM-GAN) and 22.00 (AOM-mastoid).
• Interobserver reliability was confirmed via coefficient of variation analysis.

Conclusions:

• The great auricular nerve (GAN) can be reliably located by bisecting the distance between the angle of the mandible (AOM) and the mastoid process.
• This anatomical landmark ratio offers a practical guide for surgeons.
• Accurate GAN identification can aid in preserving the nerve during relevant surgical procedures.