Afraid of the dentist?

Researchers in Japan believe that the fear of the dentist may be triggered by the grating sound of dental drills and the scraping of pointy instruments as oppose to the pain of surgery.

A recent UK population survey of oral health indicated that around 10% of the population have extreme anxiety associated with going to the dentist. A large percentage of the population put off dental visits entirely unless absolutely necessary such as in the case of an abscess or painful toothache. This fear presents serious health problems for patients who could have been treated sooner.

According to data reported at the recent Society for Neuroscience meeting , measuring the way the brain reacts to certain sounds may help doctors treat patients with anxiety. Pediatric dentist, Hirokuyi Karibe, worked with psychiatrists to test the way sound triggers parts of the brain–especially those linked to stress and dental visits. Karibe found that subjects who were frightened by going to the dentist showed marked differences in the brain’s neural activity in response to sound. ‘As a pediatric dentist, I’ve seen many patients since 1987, and from my clinical experience, I found that the sound of drilling can evoke anxiety in dental patients,’Karibe told The Guardian.

Based on survey scores, Karibe separated participants into high fear and low fear groups and then scanned his participants in a functional magnetic resonance imaging machine (fMRI) while playing a series of wrenching dental sounds. He also played neutral sounds.

‘All of the participants were isolated in the fMRI room when they listened to the dental sounds, so we couldn’t see if they responded visibly or audibly to the dental sounds, but we could recognize their responses from their brain activity,’ said Karibe.

The low fear group showed little to no signs of anxiety about going to the dentist. Their brain activity showed that when listening to dental sounds, the part of the brain called the left and right superior gyri (one of the primary auditory areas of the brain) was triggered more than when hearing neutral sounds.

The high fear group showed some interestingly different results. When more anxious people listened to sounds it triggered a response in the left caudate nucleus (the part of the brain that may play a role in learning).

‘We believe the findings can be applied to assess the effectiveness of interventions such as cognitive behavior therapy for patients who have a strong fear of dental treatment,’ Karibe said.

Fear of the dentist is an inherited trait, according to Martin Tickle, a professor of health at Manchester University. Kids whose parents are afraid of the dentist are more likely to be afraid themselves. But a survey by Tickle indicates that pain during dental surgery is very rare.

He compiled data from 451 adult patients visiting the dentist and found that 75 per cent of patients reported no pain whatsoever.
Anxiety may actually be more a cause of pain than the procedure.’The strongest predictor of pain during dental procedures was dental anxiety. Anxious patients were four times more likely to experience pain than non-anxious patients after controlling for other factors,’ Tickle said.

Tickle believes that more must be done to prevent tooth decay among children than quell dental anxiety.

‘We need to improve the amount and quality of research looking at how to effectively manage children and adults who are dentally anxious and provide guidelines for dentists on how to use research-proven interventions,’ he said’

As for anxiety, Tickle thinks talk therapy and counseling may help patients lessen their stress and therefore lessen pain.