AimTo compare panoramic imaging (PAN) and CBCT and assess observer variation in recording radiographic factors withrelevance prior to removal of a maxillary third molar, with special focus on root resorption in the distal surface of thesecond molar.Material and MethodsThe study included 120 maxillary third molars that had both a PAN and a CBCT examination. Four observers assessedthe panoramic images and CBCT volumes and registered the following parameters:1) Tooth angulation (vertical/mesio-angulated/disto-angulated/horizontal/transversal/inverted);2) Number of roots (1/2/3/4/>4);3) Bony impaction (yes/no);4) Size of follicular space (normal/>2-4mm/>4mm);5) Bone separation to maxillary sinus (yes/no);6) Marginal bone loss on the distal surface of the second molar (1-3mm/>3-5mm/>5mm);7) Resorption in the second molar (none/suspicion/< half into dentine/> half into dentine/pulp involvement).Comparison of recordings in PAN and CBCT and observer variation were described as percentage agreement and withkappa statistics.ResultsAgreement (%;kappa) between PAN and CBCT scores was: tooth angulation (75-88%;0.56-0.79), root numbers(24-48%;0.00-0.21), bony impaction (67-85%;0.11-0.41), follicular space size (63-72%;0.05-0.10), bone separation(43-65%;0.09-0.19), marginal bone loss (50-62%;0.12-0.26), resorption (25-43%;0.07-0.24). The observer agreement forresorption was poor to fair in PAN (34-60%;0.08-0.40) and fair to good in CBCT (48-71%;0.34-0.62).ConclusionAgreement between PAN and CBCT in recording root resorption and other radiographic factors related to the maxillarythird molar was on average poor to fair among the observers, except for tooth angulation (good), and observer variationseemed smaller in CBCT than in PAN for resorption, root numbers, and bone separation while the opposite was the casefor other factors.