Introduction: Palatally displaced canines is a clinical entity which is recently related to other dental anomalies, on the assumption that they share the same origin, as is the deviation of the mandibular second premolar eruptive path. Objectives: (i) to develop a measurement method for the correct characterization of mandibular second premolars inclination in a panoramic radiograph; (ii) to determine the relationship between this inclination and palatally displaced canines; (iii) to establish an angle that will allow the prediction; and (iv) to determine the reliability and accuracy of this prognostic factor. Material and methods: The sample comprised of 100 patients: an experimental (palatally displaced canine patients) and a control sample. A new system for determining the angle of the second premolars was introduced, measuring four angles: 2 pm-MP and 2 pm-OP (left and right). Results: The measuring method showed an intraobserver and interobserver error of 2.7 and 3.5%, respectively. Statistically significant differences were observed between both groups. The relationship between unerupted lower second premolar inclination and palatally displaced canines is statistically significant. A value greater than 35º in the sum of 2 pm-MP + 2 pm-OP should lead to the suspicion that we are dealing with a patient susceptible to palatally displaced canines. Conclusions: The proposed method is appropriate to characterize inclination as well as being reproducible, and this finding could be used for the early detection of palatally displaced canines with a positive prediction factor.
(Rev Esp Ortod. 2015;45(2):086-092)