The document discusses various anatomical variations that can occur in human maxillary molars. It describes variations in the number of roots and root canals, including the presence of 5-6 roots in some cases. The shape of the crown can also vary, with some individuals having 6-7 cusps rather than the typical 4. Specific variations are described for each maxillary molar, including the potential for taurodontism, accessory roots, root fusions, and additional cusps. A variety of environmental and developmental factors are believed to influence these anatomical variations.