Dental magnetic resonance imaging for bone loss assessment and disease activity classification in severe periodontitis.

OBJECTIVES

To evaluate the reliability and accuracy of dental MRI (dMRI) for volumetric infrabony and furcation bone loss compared to cone-beam computed tomography (CBCT) and to correlate to clinical signs of inflammation in patients with severe periodontitis.

METHODS

In this cross-sectional study nineteen patients with severe periodontitis underwent standardized clinical examination as well as pre-treatment CBCT and 3T-dMRI. Bone lesion volumetry was performed in CBCT, contrast-enhanced-T1-weighting (T1W + C) and T2-weighting (T2W) dMRI. Lesions whose T2W signal significantly exceeded T1W/CBCT margins (indicating excessive edema) were classified as T2W-mismatch. Volumetric data were compared to clinical findings.

RESULTS

Ten female and nine male patients with 253 bony lesions were examined. Reliability for bone lesions was highest in CBCT (ICC [95% CI] T1W + C/T2W/CBCT: 0.78 [0.74-0.83]/0.82 [0.77-0.85]/0.87 [0.94-0.89]). Overall, T1W + C and T2W dMRI strongly correlated with CBCT (rs = 0.86 [95% CI: 0.82-0.89], p < 0.001 and rs = 0.91 [95% CI: 0.88-0.93], p < 0.001 respectively) but volume was significantly overestimated by dMRI (median percentage error of T1W + C-T2W: 19-55%). A T2W-mismatch was found in 44.1% and correlated with bleeding (85.8% vs. 70.9%, p = 0.005), giving 47.5% sensitivity and 71.2% specificity.

CONCLUSIONS

While dMRI offers good reliability, T2W- and to a lesser extent T1W + C imaging overestimate infrabony and interradicular periodontal bone lesion volumetry compared to CBCT. While this could increase the risk of overtreatment, dMRI detects periodontal inflammation beyond areas of bone loss, and T2W-mismatch is closely related but not identical to signs of active inflammation in clinical examination. This may provide additional diagnostic information and could serve as a supplemental tool for higher-risk patients.

CRITICAL RELEVANCE STATEMENT: Dental MRI excels in detecting inflammation beyond bone loss, identifying high-risk tissue. This study assesses reliability in evaluating periodontitis-related bone loss, highlighting its tendency to overestimate lesion volume. A novel "mismatch lesion pattern" was observed, potentially linked to disease activity.

KEY POINTS: Dental MRI (dMRI) reliably assesses bone loss in periodontitis but overestimates volume vs. cone-beam computed tomography (CBCT). dMRI detects excess bone marrow edema, indicating inflammation beyond visible bone loss. dMRI could aid periodontal diagnosis and guide targeted therapeutic interventions.