The anterior insula and anterior cingulate cortex are associated with avoidance of dental treatment based on prior experience of treatment in healthy adults.

Chia-Shu Lin,Long-Ting Wu,Shih-Yun Wu

doi:10.1186/s12868-015-0224-9

Abstract

BackgroundFear concerning stressful medical or dental procedures is one of the major factors that distance patients from health care. Fear and avoidance of dental treatments can be shaped by a patient’s prior experience with receiving dental procedures or by imagining the procedures.MethodsWe performed two functional magnetic resonance imaging (fMRI) experiments to investigate the role of the anterior insula (aINS) and dorsal anterior cingulate cortex (dACC), which are both critical to threat perception, in dental avoidance. Dental avoidance based on both prior treatment experience and imagination was assessed using a customized questionnaire. In an fMRI task-based study, we investigated brain activation in 17 healthy participants when they viewed images depicting dental procedures that evoked a moderate degree of fear. Region-of-interest analysis was performed to assess the association between dental avoidance and aINS as well as dACC activation. In a resting state fMRI study, we investigated 18 healthy participants for the association between the intrinsic functional connectivity of the aINS and dACC and dental avoidance.ResultsWe found that (1) the participants showed a higher activation of the right aINS and bilateral dACC when they viewed images of dental procedures compared with the brain activation observed when they viewed scrambled images (p < 0.05 corrected for small volume and family-wise error). (2) The avoidance ratings based on prior experience of dental treatment were significantly positively correlated with the activation in the right aINS (r = 0.67, p = 0.003), right dACC (r = 0.65, p = 0.005) and left dACC (r = 0.63, p = 0.007). (3) The intrinsic functional connectivity between the aINS and the orbitofrontal cortex was positively correlated with the avoidance ratings based on experience (uncorrected p < 0.001).ConclusionsThe findings highlight prior experience of dental treatment as a predominant factor in shaping patients’ avoidance behavior. Individual differences in threat perception may play a key role in the development of dental avoidance.

Highlights

Fear concerning stressful medical or dental procedures is one of the major factors that distance patients from health care
Individual differences in threat perception may play a key role in the development of dental avoidance
The ratings of elicited fear were significantly positively correlated with the modified dental anxiety scale (MDAS) score (r = 0.71, p = 0.001) (Table 2C; Fig. 2a), which indicated that the visual stimuli successfully elicited fear with respect to receiving dental procedures

Summary

Introduction

Fear concerning stressful medical or dental procedures is one of the major factors that distance patients from health care. Lin et al BMC Neurosci (2015) 16:88 treatment experience being associated with increased fear toward treatment [7, 8], or it can be due to an imagined fear that is typically shaped by verbal instruction (e.g., messages from the media) or observation [9]. It remains unclear how the experience of prior dental treatment influences avoidance because the underlying neural mechanisms have not been fully investigated. AINS and dACC connectivity may be associated with the degree of dental avoidance, which could be associated with a prior stressful experience [7, 28, 29]

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