motor component
Last reviewed 01/2018
The fifth cranial nerve supplies motor functions to the muscles of mastication. Assessment is the same as for motor function elsewhere:
- inspect for wasting of the temporal and masseter muscles
- check for function of masseter and pterygoid muscles:
- ask the patient to clench his teeth - palpate for contraction of the masseter above the mandible
- ask the patient to open his mouth - pterygoid muscles - and hold his mouth open as the examiner attempts to force it shut. Caution must be exercised.
If there is a unilateral fifth nerve lesion then there may be deviation of the jaw to the weaker, affected side.