Evaluation of mandibular incisor inclination and lip projection relative to the size of the mandibular symphysis in skeletal class i and ii in a Mexican population [Evaluación de la inclinación del incisivo mandibular y la proyección labial con respecto al tamaño de la sínfisis mentoniana en sujetos Mexicanos clase i y ii esqueletal] Article uri icon

abstract

  • The aim of this study was to compare the mandibular incisor inclination between class I and II skeletal of males and females in a Mexican population, as well as the size of the mandibular symphysis and how they affect the projection of the upper and lower lips. The lower incisor and its position in the arch are considered important factors in orthodontic treatment. One hundred and eighty-two lateral radiographies were traced and divided into two groups: skeletal class I (n=91) and class II (n=91). Measurements were taken from the lower incisor inclination relative to the mandibular plane; as well as the projection of the lips regarding the aesthetic line of Ricketts and the size of the mandibular symphysis, in order to compare these data with the standard parameters. Statistical significance was determined utilizing a t student test. The inclination of the lower incisor was greater in class II than class I and slightly greater than the standard parameters. It was found that the projection of the lower lip was slightly ahead than the one that is indicated by the line of Ricketts. These results show a difference in the pattern of growth between Caucasians and Mexicans; therefore, Mexican patients tend to have a typical growth of skeletal class II, with offset lower incisors, increasing their inclination and likewise, projecting the lower lip forward and with poor chin size. © 2019, Instituto de Investigaciones Clinicas. All rights reserved.

publication date

  • 2019-01-01