Detailed examination of caries progression in 4-year-old children in a non-fluoridated area in Ireland.

314 4-year-old children were examined in Mallow, Ireland (a non-fluoridated area). 30.6% were found to be caries free. Investigation of the pattern of decay in the dentitions of these children showed the primary secondary molar as the tooth most commonly affected by caries irrespective of def score. The distribution of the disease is examined on a surface by surface basis. Decay occurring on the occlusal surface is predominant and no homogeneous pattern is found among the other surfaces. A statistical method for examining possible patterns of surface involvement is introduced.