The aim of this work is to present the golden ratio in dentistry and to verify the relationship between the golden ratio and facial aesthetics before and after orthodontic treatment using lateral cephalometric radiographs and frontal and lateral photographs. Lateral cephalometric radiographs and frontal and lateral photographs of 67 individuals before and after orthodontic treatment were used. A cephalometric programme was developed in Delphi 7.0, containing the cephalometric analysis of this research study. The A-Pog/V1S-C1MS, Ena-Enp/V1S-C1MS and V1S-C1MS/C1MS-DM16 ratios differed in a statistically significant way when comparing before and after orthodontic treatment. The V1S-C1MS/C1MS-DM16 ratio was not in golden ratio before treatment and became in golden ratio after treatment. Only the N-Ena/V1S-DM16 ratio differed in a statistically significant way when comparing before and after treatment. The A-Pog/V1S-DM16 ratio was golden before treatment and was no longer golden aftertreatment.