Maxillary labial frenum and malocclusion: An overriding or an overlooked tissue?

Abstract

The influence of the maxillary labial frenum in relation to the midline diastema has been a proven fact to clinicians for many years. A pilot study was carried out to investigate the relationship between a low maxillary labial frenum attachment and skeletal malocclusions (class I, II, and III). Astonishingly, it was observed that the class III malocclusion had a statistically high number of cases with low frenum attachments. The objective of the study was to understand the underlying skeletal class III dysplasia in these cases. A comparative cross-sectional study was performed on 300 consecutive subjects between 13-30-years of age. Based on the cephalometric parameters the participants were categorized into 98 skeletal class I, 102 class II, and 100 class III subjects. Variations in the frenum attachment were clinically evaluated using Placek classification. The insertion level and width of the frenum were also measured by using a caliper and the data were statistically analyzed for determining the association between the frenum attachment and skeletal malocclusion. The prevalence of low frenum attachment in class III subjects was found to be 64%. Also, the mean attachment level of the frenum was significantly closer to the gingival margin in skeletal class III subjects compared with that of the other groups (p<0.01). The study identified that the subjects with a low frenum attachment had a tendency towards a retruded maxilla in terms of linear dimension. Therefore the present study supports the hypotheses that the skeletal Class III malocclusion may be associated with low frenum attachment.