Dental arch restoration using tooth macrowear patterns with application to Rudapithecus hungaricus, from the late...

Dental arch reconstructions present as much of a challenge in paleoanthropology as in orthodontics and maxillo-facial surgery. Dentists and dental technicians know that it is very difficult to find the precise physiological crown positions that will yield individually correct occlusal kinematics in living individuals, and this difficulty is compounded by damage and deformation in fossil specimens. Typically, dental arch reconstructions of fossils are not validated, although a functionally correct reconstruction is of undoubted importance for accurate morphological descriptions and comparative studies of fossil dentitions. Here we describe a new method for functional dental arch reconstruction derived from detailed wear facet mapping (Occlusal Fingerprint Analysis, OFA) and dental-technical approaches. OFA was used to restore the entire dental arches of the most complete late Miocene fossil great ape dentition, that of Rudapithecus hungaricus, from Rudabánya in Hungary. Dental stone casts of the maxillary and mandibular dentition were repositioned in a dental articulator. The correct alignment of the tooth crowns was monitored by physically and virtually testing the tooth contacts during occlusal movements. The characteristic distribution pattern of the individual macrowear facets strongly constrains the antagonistic crown relationships in the Rudabánya specimen. We propose that the method used to reconstruct the functional dental arches of R. hungaricus, derived from kinematic evidence encoded in macrowear patterns, can be used as a reliable foundation for dental and facial restorations in fossils, and for individual occlusal crown morphology and dental arch reconstructions in modern dentistry and prosthetics.