Methods and parameters for digital evaluation of gingival recession: A critical review

Objectives The aim of the present review was to find, compare, and critically discuss digital methods for quantitative evaluation of gingival recessions dimensions. Data Collection of articles and classification related to digital evaluation of gingival recessions. Sources A search of PubMed, Web of Science, Scopus, and reference lists of articles was conducted up to April 2021 Study selection Twenty-two articles used digital evaluation of gingival recessions dimensions. The methods in the included articles were extracted, compared, and categorized. Results Digital measurements were performed on 2D intraoral photographs, 3D models, or cross-sections obtained from 3D models. Baseline measurement were performed for diagnostic and treatment planning and categorised into distance and area measurements. Follow-up evaluation of treatment was based either on repeating the “baseline” measurements and calculating differences or measuring differences directly on composite images, composed from two superimposed images obtained at two time-points. Direct measurements were categorised into distance, area, and volume measurements. Conclusions Digital evaluation predominantly means just digitalization of the established evaluation methods; therefore, increasing measurements accuracy and maintaining comparability with past studies. At present, a large variability of digital evaluation workflow among the included studies renders the comparison among different studies difficult if not impossible. The potential of digital evaluation seems not to have been fully exploited as only a few novel measurements and parameters introduced, i.e., volumetric evaluation of soft tissue dynamics. For reproducible and comparable studies in the future, the research should be aimed at evaluation, optimization and standardization of all phases of the digital evaluation. Clinical Significance Digital evaluation, based on 3D image superimposition is a promising approach as it increases measurements accuracy, maintains compatibility with past studies and simultaneously introduces novel evaluation possibilities.