Predicting orthodontic appointment adherence in adolescents and parents using an extended behavioral model

Poor adherence in orthodontic care is a complex issue involving both children and their parents. The study aimed to expand the theory of planned behavior (TPB) by integrating sense of coherence (SOC) to predict appointment attendance in adolescent orthodontic patients.

This prospective cohort study recruited adolescents from the University of Alberta Graduate Orthodontic Clinic. Baseline questionnaires captured sociodemographic data, TPB constructs, and SOC. Appointment attendance and oral hygiene were monitored over 1 year. Structural equation modeling (SEM) was used to examine relationships between TPB constructs and appointment adherence, with model fit assessed using χ2, chi-square/degrees of freedom ratio (CMIN/DF), root mean square error of approximation (RMSEA), and comparative fit index (CFI).

A total of 168 adolescent-parent pairs participated, and 57% of participants missed at least one appointment during the first year of treatment. SEM demonstrated moderate model fit (CMIN/DF = 1.74; RMSEA = 0.06; CFI = 0.84). Within the TPB constructs, only perceived behavioral control (PBC) significantly predicted intention (P < 0.05), whereas attitude and subjective norm were not significant predictors. SOC did not significantly predict intention, TPB constructs, or appointment adherence in either the adolescent or parent models. Intention also failed to significantly predict actual attendance.

Within the expanded TPB-SOC framework, PBC was the sole psychosocial predictor of orthodontic appointment-adherence intention. However, neither intention nor SOC translates into actual clinical attendance. The moderate model fit indicates that psychosocial constructs alone are insufficient to fully explain orthodontic appointment adherence. To build more effective adherence models, future research and clinical strategies must look beyond psychology and account for structural, logistical, and environmental barriers.