Correlation between periodontal soft tissue and hard tissue surrounding incisors in skeletal Class III patients

To investigate the association between the periodontal soft tissue, alveolar bone and dental parameters surrounding the incisors at baseline in patients with skeletal Class III malocclusion.

The study sample comprised 154 teeth from 28 patients with skeletal Class III malocclusion (19 men and 9 women, 21.15 ± 4.02 years). Periodontal soft tissue examination and hard tissue measurements with cone-beam computed tomography (CBCT) were performed. Factor analysis was used to reduce the CBCT variables, and correlation analysis between the hard tissue factors and soft tissue parameters was performed. Differences in hard tissue parameters between thick and thin gingival types were evaluated.

CBCT measurements were reduced to three hard tissue factors: lingual plate, coronal-buccal plate, and apical-buccal plate. Keratinized gingiva width and thickness were positively correlated with the coronal-buccal plate factor and negatively correlated with the apical-buccal plate factor. In the thin gingival biotype, mandibular incisors were more proclined, and the apical part of the buccal alveolar plate and the coronal part of lingual alveolar plate were thicker than in the thick gingival biotype.

In the anterior teeth in cases of skeletal Class III malocclusion, hard tissue structures on the buccal side can be grouped based on coronal and apical factors that are significantly correlated with keratinized gingival width and thickness. Thick and thin gingival biotypes exhibited differences in tooth inclination and alveolar plate thickness with regard to the mandibular incisors.