Objective: The aim of this clinical study was to evaluate whether a correlation exists between three-dimensional tooth mobility (TM) and Periotest values for maxillary anterior periodontally involved teeth (pocket depth > 3 mm) before and after periodontal therapy. Method and Materials: Force-related TM was measured in 3 N intervals in 19 participants as they bit down on a load cell. Periotest values were evaluated at reproducible measurement points. Both measurement techniques were performed on maxillary central and lateral incisors and canine teeth before periodontal treatment and after a healing period of 3 months. The Pearson product-moment correlation coefficient was calculated to determine exploratory associations. Results: The comparison between TM and Periotest values indicated "high" and "optimum" correlations for maxillary central incisors before and after periodontal therapy. Lateral incisors exhibited "moderate" and "high" correlations, whereas canines exhibited "weak" and "moderate" correlations before and after periodontal therapy. Conclusion: Periotest values may provide valuable information about quantitative metric tooth mobility in periodontally involved teeth. In future investigations, the study design can expand on various dental fields, such as implantology and traumatology. Keywords: correlation study, diagnosis, Periotest, photogrammetry, tooth mobility