What is the effect of an incorrect placement of local anesthetic solution within the parotid gland?

The correct effect of incorrect placement of local anesthetic solution within the parotid gland is the causation of facial nerve paralysis. This occurs because the facial nerve (cranial nerve VII) runs through the parotid gland, and if the local anesthetic is inadvertently injected into this area, it can block the nerve's function. This paralysis may present as weakness or inability to control movements on the affected side of the face, such as drooping of the eyelid or corner of the mouth, which can be distressing and alarming for the patient.

Understanding this potential complication underscores the importance of proper technique during local anesthetic administration, particularly in areas where critical nerves are closely situated to the intended target. The anatomy of the region must be well understood to avoid such adverse effects.