Retrospective study of maxilla growth in a Spanish population sample.

This study has been designed to evaluate the vertical and sagittal changes in the maxilla due to growth. A sample group was chosen of 38 individuals with normal occlusion, composed of 16 females and 22 males between the ages of 8 and 18. The total sample was divided into three groups: prepubescent (8-11 years), pubescent (12-14 years) and post-pubescent (15-18 years). A series of cephalometric angle parameters (SNA, maxillary height, slope of the palatal plane and maxillary depth) and lineal parameters (effective maxillary length, palatal plane length, middle third of the face height and convexity) were traced. Superimpositions of the initial and final cephalometries in the Ba-N plane and in the Nasion fixed point were carried out to measure growth. An analytic statistical analysis was applied using a Student t test for independent samples in order to evaluate the differences found according to sex. An analysis of variance followed by Duncan's multiple range test was done to study the evolution of each variable throughout the duration of the experiment. In light of the results obtained, we have come to the following conclusions: sagittal growth of the maxilla is constant from the age of 8 to 18 years with an average increase of 0.2 mm/year. Vertical growth, as well as general maxillary growth, is greater in the prepubescent group.