Deep masseteric triangular area to define masseter neurovascular bundle: A cadaveric study

Area of Science:

• Anatomy
• Surgical Anatomy
• Head and Neck Surgery

Background:

• Facial reanimation is crucial for restoring mimetic function, impacting physical and psychological well-being.
• The masseteric neurovascular bundle (NVB) is vital for these procedures, requiring precise identification at the mandibular notch.
• The deep masseteric triangle (DMT) was identified as a potential landmark for masseteric NVB localization.

Purpose of the Study:

• To evaluate the reliability of the deep masseteric triangle (DMT) as a landmark for locating the masseteric neurovascular bundle (NVB).
• To determine the anatomical measurements of the DMT and the depth of the masseteric NVB.
• To establish an improved technique for masseteric NVB localization in surgical procedures.

Main Methods:

• Performed 40 dissections of the parotideomasseteric region in donated cadavers (10 male, 10 female).
• Measured the dimensions of the deep masseteric triangle (DMT) and the masseteric NVB's depth from the skin.
• Identified and measured the masseteric NVB after dissection.

Main Results:

• The mean lengths of the DMT margins were 17.3 mm (superior), 25.9 mm (posterior), and 26.3 mm (anterior).
• The total length of the masseter muscle's upper edge averaged 52.7 mm.
• The masseteric NVB was located at an average depth of approximately 17 mm from the skin surface.

Conclusions:

• The DMT is a valuable landmark for accessing the branch-free portion of the masseteric nerve.
• A line from the mandibular angle to the DMT's midpoint aids in masseteric NVB localization.
• This anatomical approach improves accuracy in masseteric nerve harvesting and nerve block procedures.