Numb to the Taste: Dental Anesthesia and Taste Loss

By Kiera Hallinan

Local anesthesia was a breakthrough for the field of dentistry when it was first introduced in the late 1800s, making visits a more comfortable and exponentially less painful experience. Advancements have been made in both application techniques and development of the solutions themselves to improve patient experience. 

There can be side effects from the use of these compounds, which are largely temporary, such as a loss of control in the muscles of the lower face, causing drooling or speech impediments that are resolved within the course of hours as the body metabolizes the substance at its own rate. 

Taste loss is also prevalent, as the receptors responsible for pain are found in close proximity to those associated with taste, and can therefore be shut off via the same mechanisms designed for pain management. This issue will often be reversed over a short period of time following a dental visit, but can potentially be relieved faster. Taste can be restored by gradually introducing a variety of tastants to your palate, such as acidic and spicy foods that are still within your normal threshold to prevent further damage to the tissue. Drinking water will counteract the dry mouth that could be brought on during a dental procedure, and as always keeping the oral cavity clean and free of tobacco and alcohol will lead to more healing and often coincidentally restoration of optimal conditions for normal taste perception.

These sensory losses are often brief, but one case study from 2008 highlights a particularly rare instance of dysgeusia, or taste change, brought on by a dental procedure. Dr. Klasser discusses the plight of a 66 year old man following a relatively common procedure - removal of his third molars or wisdom teeth. One year later, the patient reported a consistent loss of taste, specifically noting that food “tasted like cardboard”. 

Due to the rarity of such cases, doctors took a particularly in depth analysis of the patients’ health history in order to rule out other causes for such a response. Extraoral and intraoral examination ruled out the possibility of infection or oral conditions being responsible, and cataloging of behaviors and salivation rates. Although the patient did have a systemic condition of hypothyroidism that can often be connected to taste change, this was ruled out due to the timing of the diagnosis. While the patient’s symptoms continued to be monitored and improved with medication, doctors concluded that physical or chemical trauma to the chorda tympani nerve could have transpired, possibly at the inclusion of the dental anesthetic injection. The patient ended up having some improvement to his taste alteration following changes to his diet relating to texture and spices, which have allowed him to mostly retain his quality of life. 

Dental anesthetic is an essential tool in any dental practice. It allows for less pain and discomfort in patients, in turn allowing for doctors to perform the fine motor movements needed to complete longer and more complicated restorative and endodontic treatments. With it comes the necessity of dental practitioners to be clear to patients about the risks and have discussions about whether these anesthetics are the right choice based on other health concerns, such as those that may be pregnant or facing cardiovascular issues. Patients have a right to stay informed in order to properly advocate for themselves.

If you are interested in learning more about the use and risks of dental anesthetics outside of the scope of taste, take a look at this paper: https://www.ncbi.nlm.nih.gov/books/NBK580480/