Morphological changes in the attached and keratinized gingiva and gingival sulcus in the mixed dentition period. A 5-year longitudinal study.

A longitudinal study was undertaken to examine the changes in the sulcus probing depth, keratinized and attached gingiva during the mixed dentition period. 54 children aged 7 to 9 years at the first examination were examined twice, with an interval of 5 years. Sulcus probing depth and keratinized gingiva were examined at the buccal aspect of the incisors, and either right or left cuspids and posterior areas. The width of the attached gingiva was obtained by subtracting the probing depth from the width of the keratinized gingiva. When compared to primary predecessors, the permanent teeth had a deeper probing depth, narrower attached gingiva and at the maxillary teeth, a wider keratinized gingiva. When a permanent tooth was present at both examinations, there was a significant increase in width of the attached gingiva with a corresponding decrease in probing depth, and a slight beginning of an increase in the width of keratinized gingiva. Previous and the present findings indicate that during the early years after eruption of the permanent tooth, an increase in width of the attached gingiva takes place, without occlusal migration of the marginal gingiva whereas, at later stages, this coronal migration takes place, concomitant to tooth eruption.