Objective characterization of dental occlusal and fissure morphologies: Method development and exploratory analysis

Abstract

Objective: To develop clinically applicable methods to characterize occlusal topography and assess possible associations between morphology and caries incidence and development.

Design: In this retrospective clinical study, we evaluated caries presence and severity pre- and post-orthodontic treatment for first molars of 147 patients (384 teeth). These teeth were previously scanned using a clinical intraoral scanner, and the obtained digital elevation models were used to 1) analyze the 3D occlusal surface parameters (n = 384) and 2) quantitatively characterize the mandibular molars' (n = 166) fissure patterns using three novel methods. Pearson correlation coefficients were calculated to evaluate the associations among the measurements, and presence/severity of caries pre- and post-treatment were assessed using generalized linear mixed-effects models.

Results: Robust quantitative fissure characterizations were developed, and reliable occlusal surface parameters were obtained. In the studied population, none of the parametric measurements (Slope: p = 0.62 for presence, p = 0.96 for severity; Relief Index (RFI): p = 0.36, p = 0.84; Orientation Patch Count rotated (OPCr): p = 0.48, p = 0.13; Dirichlet Normal Energy (DNE): p = 0.91, p = 0.15) or the fissure morphological measurements (Mesial Angle: p = 0.43; Distal Angle: p = 0.86; Average Angle: p = 0.52; Area Difference: p = 0.83; Percent Fissure: p = 0.68) were found to be significantly associated with caries status or severity.

Conclusion: Despite the lack of correlation in the limited studied sample, the tools developed to characterize occlusal surface topography and fissure morphology have the potential to be used in more comprehensive clinical evaluations.

Keywords: 3D Image Processing; Caries Risk Assessment; Occlusal Caries; Occlusal Topography.