Assessment of orthodontic treatment need, treatment complexity, treatment priority, and oral health-related quality of life of healthy children and adolescents: A scoping review

<b>Aim:</b> To identify report and discuss the tools assessing orthodontic treatment need (OTN), - complexity (OTC), -priority (OTP), and Oral Health-Related Quality of Life (OHRQoL in children and adolescents, defining their strengths and weaknesses and to pinpoint research gaps to inform orthodontic practitioners, policy makers, and future research endeavours. <b>Methods:</b> The databases of PubMed, Cochrane, Embase, and Web of Science were searched from inception to January 2025. Epidemiological studies, controlled trials, and comparative studies involving subjects ≤18 years old, using different tools to assess OTN, OTC, OTP, and OHRQoL were included. Three authors independently assessed study eligibility, extracted and analysed the data. <b>Results:</b> 15,898 articles were initially identified, from which 171 were finally included for analysis. For OTN, the Index of Orthodontic Treatment Need was the most frequently used, followed by the Dental Aesthetics Index. Both score occlusal traits and do not take into account other factors contributing to overall OTN. The Index of Complexity and Orthodontic Need was the third most used. Several OHRQoL questionnaires were retrieved, identifying Child Perception Questionnaire (CPQ) as most frequently used. <b>Conclusions:</b> A range of assessment tools were identified for OTN and OHRQoL. OTN indexes mainly rate dental malocclusion severity and don't consider patient-specific factors, such as patient perception. A tool assessing OTC that takes into account treatment-specific factors, required skills of the orthodontist, treatment time, and costs is required. Additionally, no tool was found to assess OTN, which is crucial for allocation of public healthcare resources and insurance coverage for orthodontic treatment.