Inclination of the infraorbital canal studied on dry skulls expresses the maxillary growth pattern: a new contribution to the understanding of change in inclination of ectopic canines during puberty

Abstract

Objective. The purpose of this study was to analyze the correlation between direction of the infraorbital canal and maxillary width on frontal radiographs of dry human skulls. Material and methods. Forty-two symmetrical, dry human skulls (late adolescence and adult) with no dental or skeletal anomalies. Frontal radiographs were taken of each skull placed in the Frankfort horizontal plane, with a radiopaque marker in the infraorbital canal. The maxillary transversal growth pattern was expressed as the infraorbital transversal angle (IOt) formed between a line through the contour of the bilateral orbita (lo) and a line parallel to the infraorbital marker. Three cephalometric widths were measured on the skulls, two anteriorly (the width of the piriform aperture (AP) and the interorbital width (IO)) and one posteriorly (the palatal width (PW)). A general linear model was used for statistical analysis. Results. The direction of the infraorbital canal (66.08°, 95% CI: 62.53–69.64) depended on the transversal growth: an increased PW of 1 mm resulted in a decreased IOt of 1.84° (p=0.041); an increase in IO of 1 mm resulted in an increased IOt of 2.24° (p=0.017); and an increased AP of 1 mm resulted in a decreased IOt of 3.30° (p=0.066). Conclusions. The study indicates that the direction of the infraorbital canal in frontal view reflects the transversal growth of the maxilla. A wide maxilla posteriorly resulted in a small infraorbital transversal angle. These findings might explain the different inclination of ectopic canines.

• Anthropology
• growth
• infraorbital
• maxilla
• nerve canal