Adult monkey coronoid process after resection of trigeminal nerve motor root

Area of Science:

• Oral and Maxillofacial Surgery
• Neuroscience
• Primate Research

Background:

• Previous studies reported conflicting results on coronoid process development after temporalis muscle resection in growing animals.
• Factors like surgical trauma and altered muscle function were hypothesized to influence outcomes.

Purpose of the Study:

• To investigate the effect of unilateral temporalis muscle neurofunctional inactivation on the fully grown coronoid process in adult Macaca mulatta.
• To differentiate the effects of muscle inactivation from surgical trauma.

Main Methods:

• Intracranial resection of the motor root of the trigeminal nerve in adult rhesus monkeys to inactivate the temporalis muscle unilaterally.
• Sham surgery without nerve resection was performed on control animals.
• Morphological analysis of the mandible, including the coronoid process, was conducted one year post-surgery.

Main Results:

• Temporalis muscle atrophy was observed on the nerve-resected side.
• No significant morphological differences were found in the mandible or coronoid process between operated and control sides, or between sexes.
• Consistent and conspicuous calculus deposits were noted on the buccal surfaces of teeth on the operated nerve side.

Conclusions:

• Neurofunctional inactivation of the temporalis muscle in adult primates does not alter the morphology of the fully grown coronoid process.
• The study highlights calculus deposition as a notable consequence of trigeminal nerve motor root resection.