Long-term results after cranioplasty for trigonocephaly often show bitemporal depressions and a residual hypotelorism. Both findings fuel the perception that the growth of the periorbital region and the forehead as a whole continues to be restricted, even after correction. The aim of this study is to evaluate the growth process of the periorbital region after correction for trigonocephaly in the long term. From 1986 to 2004, 123 patients underwent a cranioplasty for the correction of trigonocephaly. Cephalometric analysis was performed on the radiographs taken at presentation and on the last available radiograph before the age of 6 years (92 posteroanterior and 93 lateral cephalograms). Cephalic landmarks were used to analyze the growth of the forehead: Mo (medial orbital wall), Lo (lateral orbital wall), Losp (crosspoint between lateral orbital wall and sphenoid), and Eu (most lateral point of the skull). As a result of the lack of standardized cephalograms, growth ratios were used instead of absolute numbers. The Eu-Eu growth rate was higher than the Lo-Lo rate, which in its turn surpassed the Losp-Losp rate. An initial undercorrection of the hypotelorism was noted followed by an increased limited autocorrection. A higher Mo-Mo growth rate was noted in the group operated after 1 year of age. Increased interorbital growth accounts for an autocorrection of the residual hypotelorism. The growth rate of the anterotemporal area (Losp) was shown to be the lowest, which could explain the bitemporal depressions so often seen after a frontosupraorbital cranioplasty.