1. A method for determining a reference standard comprising: selecting a set of subjects meeting a first set of aesthetic criteria; determining a 3 dimensional (3D) representation of a head and mouth of each subject from photographic images of the head and mouth of each subject, the 3D representation including an indication a central point of a left pupil and a right pupil of each subject; identifying at least one dental feature and at least one facial feature in the 3D representation of the head and mouth of each subject; identifying at least one landmark on the at least one dental feature and at least one landmark on the at least one facial feature in the 3D representation of the head and mouth of each subject; defining a mid-axial plane extending horizontally through the central point of both pupils of each subject; defining a mid-coronal plane extending vertically through the central point of both pupils of each subject; defining a left sagittal plane extending vertically through the left pupil of each subject; defining a right sagittal plane extending vertically through the right pupil of each subject; determining a first dental landmark distance from at least one of the mid-axial plane, the mid-coronal plane, the left sagittal plane, and the right sagittal plane to the at least one landmark on the at least one dental feature; and determining a first facial landmark distance from at least one of the mid-axial plane, the mid-coronal plane, the left sagittal plane, and the right sagittal plane to the at least one landmark on the at least one facial feature.