Validity and reliability of intraoral ultrasonography for the assessment of human periodontal structures.

Abstract

Purpose: Recent advances in intraoral ultrasonography (US) have enabled quantitative evaluation of periodontal tissues; however, limitations regarding applicable measurement sites and structural visualization remain. This study aimed to investigate the anatomical accuracy and measurement reproducibility of intraoral US imaging for soft and hard periodontal tissues, comprising buccal and lingual palatal surfaces and dental calculus.

Methods: US images were captured from the gingival margin (GM), alveolar bone crest (ABC), and cementoenamel junction (CEJ) of 108 teeth from fixed human cadavers. These regions were sectioned and scanned to generate reference images. Three parameters were measured: (1) the distance between the ABC and GM, (2) the distance between the ABC and CEJ, and (3) the linear length of the dental calculus on the tooth surface. Three independent examiners performed all measurements twice for reliability analysis.

Results: US images clearly delineated the gingiva, CEJ, alveolar bone, and calculus based on their echogenic characteristics. No statistically significant differences were observed between the US and reference measurements (p > 0.05). Intraclass correlation coefficients ranged from 0.78 to 0.97 for intra-rater and 0.92 to 0.96 for inter-rater reliability. Bland-Altman analysis revealed 95% limits of agreement of - 0.27 to 0.94 mm for ABC-GM, - 0.28 to 1.12 mm for ABC-CEJ, and - 0.22 to 0.81 mm for calculus length. These findings confirm that intraoral US reliably represents anatomical structures with high fidelity.

Conclusion: US is a valid, reproducible modality for evaluating ABC, GM, CEJ, and calculus across buccal and lingual surfaces, providing a standardized anatomical foundation.