Supernumerary Teeth

 Teeth fall into a series of continuous morphogenetic fields (incisor, canine and molar) within which gradients of size and shape exist. Supernumerary teeth may develop within a field where the odontogenic capacity for tooth formation is abnormally strong. Supernumerary teeth often occur at the periphery of a morphogenetic series. Supernumerary teeth may be either supplemental (identical to normal teeth) haplodont (have conical crowns with single roots) or be tuberculate (more complex occlusal surfaces but simple conical roots). Changes in tooth number have been reported in 5% of Gorilla, 4.3% of Pan and 8,5% of Pongo museum specimens. Supernumerary incisors and premolars in great apes are often either supplemental or haplodont teeth. Distomolars (M4), supernumerary premolars and incisors, which all occur in modern humans, have also all been reported in great ape collections. Among great apes, supplemental M4s, some even larger than M3, are relatively common in Gorilla and Pongo but more rare in Pan where they tend to be diminutive and conical.