Assessing Inter- and Intra-Examiner Reliability of Orthodontists in Devising Incisor Position Objectives on Cephalograms: a Comparative Study Between Senior and Junior Practitioners.

Background Effective orthodontic treatment planning hinges on accurately defining incisor position objectives (IPO) in cephalograms. The purpose of this study was to estimate the inter-examiner and intra-examiner reliability of different orthodontists in devising IPOs on cephalograms. Methods Ten orthodontists, who were divided into to the senior group (N = 5) and the junior group (N = 5) based on their clinical experience, formulated IPOs for 60 pre-treatment cephalograms twice with an interval of 2 weeks, utilizing SmartOrtho software. The type and magnitude of movement were read directly in the software. A paired t -test assessed the absolute differences between the first and second IPO devising within each group and between the senior and junior groups in each time’s IPO devising. The intra-examiner and inter-examiner reliabilities were calculated. Results There were significant differences in all types of upper incisor movement and lower incisor protrusion/retraction movement between the first and second IPO devising of the senior group. The junior group exhibited significant differences in the twice the upper incisor extrusion/intrusion movement and upper incisor torque movement devising. Additionally, significant differences in all types of incisor movement between the senior and junior groups in each time’s IPO devising. Intra-examiner reliabilities were excellent for both two groups and moderate for the junior group in most types of incisor movement, respectively. The inter-examiner reliability between the two groups ranged from moderate to good across different types of incisor movement. Conclusions Among orthodontists, both senior and junior practitioners displayed the best inter-examiner reliability in lower incisor extrusion/intrusion movement. In terms of intra-examiner reliability, senior orthodontists had better intra-examiner reliability in upper incisor position objectives devising than the junior orthodontists. Furthermore, senior orthodontists tended to adopt a more recessive, intrusive, and lingually torqued incisor position approach compared to junior orthodontists.