Relationship between alignment conditions of teeth in anterior segments and incisal wear.

This report describes the alignment condition and incisal wear of the anterior teeth in individuals 16-19 years of age. Tooth alignment and incisal wear were assessed on casts in accordance with two index systems NONAT (non-aligned tooth) and IwI (incisal wear index). Tests of the methods showed that the reproducibility of the assessments of tooth alignment and incisal wear were satisfactory. The results of the study of tooth irregularity demonstrated that the prevalence of non-alignment of one or more of the anterior teeth were much the same (approximately 50%) for the maxillary and mandibular jaws. The highest frequency was found for the maxillary lateral incisors and the mandibular central incisors (approximately 45%). A relationship between the alignment conditions and incisal wear of the anterior teeth was established. It appeared that non-alignment of one or more teeth in one or both jaws was associated with less severe incisal wear of the anterior teeth. This was most pronounced for non-aligned maxillary central incisors and non-aligned mandibular central incisors.