Evaluation of Incisors Inclination in Five Cephalometric Analysis Methods

Various cephalometric analyses may provide conflicting results for the skeletal sagittal relationship and incisors inclination. The aim of this study was to evaluate the various cephalometric analyses by relating the upper and lower incisors to different reference points and lines. One hundred and two pre-treatment lateral cephalometric radiographs were selected and stratified into three groups according to their skeletal sagittal relationship. Five methods for measuring the upper and lower incisors inclination were applied and then compared using Analysis of Variance (ANOVA) statistical test. The findings of the present study demonstrated that there is a statistically significant (p<0.05) difference between the angular and the linear evaluation methods in lower incisors. More than half (55%) of the cases showed a difference of > 3 standard deviations (SD) between the five methods in the mandibular incisors. L1-NA (mm) and L1-APog (mm) had a weak correlation with the other measurements, while the angular measurements were strongly correlated. Variations in the measurements of incisors inclination exist due to many factors. The clinicians should understand the weaknesses of each method and interpret the results cautiously.