Masticatory function in growing individuals with hypohidrotic ectodermal dysplasia: A longitudinal study

Background: Hypohidrotic ectodermal dysplasia (HED) is a hereditary disorder with agenesis of ectodermal derivatives, causing oligodontia or anodontia. Dentures are needed to improve the patients' mastication. Aim: This study aimed at preliminarily evaluating the masticatory function changes in Chinese individuals with HED after prosthetic rehabilitation from childhood to adolescence. Design: This longitudinal study enrolled 10 HED patients. Data were collected during childhood and adolescence, respectively. The healthy children and adolescents were recruited as the control group. The surface electromyography (EMG) of masseter (MM) and anterior temporalis (TA) muscles during clenching and chewing were recorded. The EMG activity, asymmetry index (As), activity index (Ac), and chewing cycle were analyzed. The masticatory efficiency was measured by spectrophotometry with subjective masticatory ability assessed by a questionnaire. Results: The EMG activities and masticatory efficiency of HED patients during childhood and adolescence were mostly lower with a higher As (p < .05). The chewing process enhanced the TA activity and balanced the As of HED adolescents (p > .05). The HED adolescents showed a more prevalent TA activity (p < .05). Conclusion: The masticatory function of the growing HED patients was functionally inferior to the dentate individuals with a narrowed gap from childhood to adolescence.