Reconstructing facial features (nose, mouth, eye, and ear)
Gerasimov’s objective was to elaborate a method of reconstructing the most important features – nose, mouth, ear, eye, and eyelids. These parts, entirely composed of soft tissues (cartilages, muscles, etc.) are variously associated with the bone base (the skull). Neither anatomy nor anthropology provided reliable data on such associations. Long-term and thorough studies were needed.
Reconstruction of nose profile
Reconstruction of nose shape was one of the major challenges. Gerasimov succeeded in solving the “nose problem” by locating the crossing of lines which determine the nasal point. He defined the relationship between nose shape (wings, nostrils) and the dimensions and shape of the pyriform aperture with adjoining bones.
Principal types of occlusion
Gerasimov concluded that mouth and lip shape depended on the shape and size of teeth, jaw structure, occlusion type, and projection of jaws. Hundreds of measurements and comparisons showed that the level of the vermilion border coincides with the upper point of the enamel of the medial incisor, the mouth outline matches the occlusal contour, and mouth width equals the distance between the outer sides of the second upper molars. The major task was to reconstruct the muscles of the lower face, which are very labile and largely account for the expressive patterns of the human face, and the masticatory muscles. Principal types of dental occlusion and corresponding types of lip closure in profile: (a) stepwise occlusion
(b) edge-to-edge occlusion
(c) scissor occlusion
(d) roof occlusion
(e) cornice occlusion
Main orbital shapes
Gerasimov has found that eyeball size depends on the shape of the orbit and of the orbital edge. Eye shape is determined by the relative position of the orbital tubercle and the lacrimal fossa. The eye slit normally follows the line connecting these two elements of the facial skeleton. The remaining details, related to eye lid morphology, are defined by the reconstructed eye. Main orbital shapes:
(a) angular, common among the Caucasoids;
(b) round, most frequent among the Mongoloids;
(c) low, distinctive of early Homo sapiens;
(d) high, frequent in Slavs and less common in Caucasoids of western Central Asia
Position of the ear
It has long been known that ear length matches that of the nose. Ear width roughly equals half the ear length. Ear position is associated with the position and shape of the mastoid process of the temporal bone and with the slope of the ascending ramus of the mandible. Ear shape is quite variable, the range of its variation being comparable to that of the digital patterns.
Variability of mouth and chin shape
Reconstruction of the chin and of the forehead appeared less difficult since their shape is largely determined by the bone base (mandible and frontal bone).
However, here as well, Gerasimov made several important observations. It turned out that chin prominence depended not so much on the anterior part of the mandible, as on ramus angle, whereas chin shape was associated with robustness, width, and relief of the mandibular edge.
When reconstructing forehead shape, age characteristics must be taken into account since wrinkles are unrelated to bone base.