Quantification of tooth-tapping forces

Objective: Percussion of teeth with a handle of a mouth mirror is a common method of diagnosis in dentistry. Pain or discomfort in response to the percussive force can indicate a variety of problems including diseased periodontium or pulp via eliciting pain. The main objective was to instrument a mouth mirror to assess the forces that dentists routinely use in such percussion, as compared to maximum bite forces.Methods: The instrumented handle of a mouth mirror was used by one clinician to tap healthy teeth in 15 subjects. These percussive forces were compared to maximum voluntary forces produced by the subjects. A pilot study of 15 dentists was then run, who percussed the teeth of two healthy subjects.Results: In the preliminary study, biting forces were variably two orders of magnitude higher than for tapping, being higher on posterior teeth (p<0.001). In the multi-dentist dataset, tapping forces remained consistently in the low-Newton range, being significantly higher on posterior than anterior teeth and when male dentists were performing the percussion (p<0.001).Conclusions: Knowledge of the physiological sensitivity is important in formulating guidelines for training dentists in these techniques such that forces are kept appropriate for diagnosis.