Aim Cluster analysis was conducted on data from 5,169 United States (U.S.) Arizona children, age's 5-59-months with the goal of delineating patterns of caries in the primary dentition of pre-school children without a priori pattern definitions.Methodology Cluster analyses were conducted using all data for children ages 0-4 years in aggregate: 1) for all subjects, and 2) for subjects without crowned restored teeth. Each of these two sets of analyses consisted of 8differently specified cluster analyses as a validation procedure.Results The caries patterns identified from the clustering analysis are: 1) smooth surfaces (other than the maxillary incisor), 2) maxillary incisor, 3) occlusal surfaces of first molars, and 4) pit and fissure surfaces of second molars. Conclusion The cluster analysis findings were consistent with results produced by multidimensional scaling. These cross-validated patterns may represent resulting disease conditions from different risks or the timing of various risk factor exposures. As such, the patterns may be useful case definitions for caries risk factor investigations in children under 60 months of age.