© 2015 Australian Dental Association. Acoustic neuroma, also known as vestibular schwannoma, is a rare benign brainstem tumour involving the abnormal growth and proliferation of Schwann cells surrounding the vestibular division of the eighth cranial nerve. Although the most common symptoms are non-dentally related, there are instances where diagnosis of this potentially life-threatening condition is triggered by an emergency presentation to the dentist for the most trivial of reasons. A 56-year-old male presented to a dental clinic complaining of a toothache. Following history taking, examination and radiographs a carious lower right molar was extracted. The patient reported relief but later described post-extraction numbness on the opposite side (left) of his lower jaw that could not be explained by anatomical principles or previous dental history. Further investigations revealed an acoustic neuroma as the underlying cause. This case highlights that not all signs and symptoms that occur in the mouth are abnormalities within the mouth. In particular, this case underscores the importance of recognizing that the spontaneous onset of certain symptoms may be due to significant non-dental pathology. Any numbness over the distribution of the trigeminal nerve must be investigated. The importance of the basic sciences and referring will also be emphasized.