Prediction of maxillary canine width by maxillary and mandibular central incisors by the aid of an equation as a preventive measure

Background: Mixed dentition analysis is critical for early diagnosis of malocclusion because many malocclusions appear in this period. The aim of the present study is finding out specific prediction equation for estimation of mesio-distal width of maxillary unerupted canine at mixed dentition period depending on the width of upper and lowers central incisors. Materials and methods: Hundred orthodontic patients’ (50 males and 50 females) study casts visited a private clinic in Sulaimani City/Iraq were randomly selected and the largest mesio-distal dimensions of maxillary and mandibular central incisors and maxillary canines were measured by a digital calliper. The age range of patients was 14-24 years according to the inclusion criteria. Correlation and linear regression tests were applied on the collected data to find a prediction equation to estimate the mesio-distal width of maxillary permanent canine at early mixed dentition period relying on mesio-distal width of either mandibular or maxillary permanent central incisor. Results: Correlation coefficients of maxillary and mandibular central incisor were 0.664 and 0.639, respectively. It indicates a moderately strong correlation between the width of maxillary and mandibular central incisors and maxillary canine width. Establishment of valid practical prediction equations, one for maxillary central incisors (1.205+ 0.796 x Maxillary central incisor width) and the other for mandibular central incisors (1.205+ 1.205 x Mandibular central incisor width) with the former one being more reliable than the second one have a significant influence on construction of treatment plan at mixed dentition period. Conclusion: Moderately strong prediction equation is established to the mesio-distal width of maxillary permanent canine prior to their emergence in the oral cavity as an attempt to prevent their impaction or malposition.