Reports of pain by children undergoing rapid palatal expansion

This study described and quantified the prevalence, timing, and intensity of pain during the expansion phase of rapid palatal expansion (RPE) in children and investigated whether pain was related to age, sex, or rate of expansion.

Ninety-seven children, 38 males and 59 females, between the ages of 5 to 13 years (median 7.7 years) undergoing RPE procedures with the Hyrax, Dentaurum, Newtown, PA, appliance were surveyed. The appliance was expanded with either one or two turns (1/4 mm/turn) per day based on the provider's preference. The child's pain response was measured no more than 5 minutes after each turn for the entire period of expansion using both the Facial Pain Scale and the Color Analog Scale.

Ninety-eight percent of the children reported at least some pain during RPE. The highest levels of pain were reported during the first 10 turns with the greatest intensity during the first 6 turns and a steadily decreasing amount of pain thereafter. Pain medication was taken after 7% of the expansion turns in the study with the majority of children taking the medication during the first 6 turns. Forty-eight percent of the children took pain medication at least once during the expansion phase of RPE. There was no difference in either reported pain or use of pain medication based on age, sex, or stage of dentition. During the first 10 turns, children whose rate of expansion was two turns/day were more likely to report pain and take pain medication than children whose rate of expansion was one turn/day, thereafter there were no differences.

The vast majority of children undergoing the active phase of rapid palatal expansion with a Hyrax appliance report pain. The pain generally occurs during the initial phase of expansion and diminishes thereafter, with two turns/day resulting in reports of pain greater than those expanding only once/day.