The application of facial expressions to the assessment of orofacial pain in cognitively impaired older adults

Background. The anticipated rapid growth in the number of cognitively impaired older adults, declining edentulism and increasing oral health expectations suggest a greater need for comprehensive dental care and effective ways to evaluate orofacial pain in people with compromised mental function and impaired communication skills. The authors conducted a study to evaluate facial expressions as a means of identifying orofacial pain in cognitively impaired and cognitively intact older adults, compared with other available pain assessment tools. Methods. The authors conducted a prospective comparative study using three alternative pain measurement tools in a sample of 22 older adults. They divided subjects into cognitively impaired and cognitively intact groups on the basis of their mental status examination scores. The pain measurement methods evaluated were facial expressions quantified by the Facial Actions Coding System (FACS); self-reported pain via the Verbal Descriptor Scale; and physiological response to pain via changes in heart rate. The pain stimuli were local anesthetic injections in subjects who required them for routine dental procedures. Results. The average FACS scores during anesthetic injections were significantly higher than those during the preinjection period (prebuccal versus buccal, P =.016; prepalatal versus palatal, P =.0002). The differences between preinjection and injection segments were even higher in cognitively impaired patients than in cognitively intact patients. There were no correlations between the three pain measurements (P >.05). Conclusions. Changes in facial expression proved to be the most useful measure overall in identifying pain in both cognitively intact and cognitively impaired older patients. This measure appeared to be more sensitive in cognitively impaired patients because they demonstrated fewer facial movements in anticipation of pain stimuli.