Abstract

Abstract
Aim: Fluorine-18-labeled fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) has become essential in oncologic imaging, but its uptake patterns may also be seen in benign inflammatory or structural oral conditions, leading to diagnostic confusion. This study aims to compare metabolic activity (SUVmax values) among common dentomaxillofacial conditions—dental artifacts, periodontal infections, maxillary sinus pathologies, and temporomandibular joint (TMJ) disorders—against confirmed malignant lesions, to guide differential diagnosis and improve clinical interpretation.
Materials and Methods: A total of 100 FDG-PET/CT scans were retrospectively analyzed. Inclusion criteria comprised pre-treatment scans with available CT or MRI acquired within four weeks. Patients were categorized into five groups: Dental Artifacts (n=19), Periodontal Infections (n=23), Maxillary Sinus Pathologies (n=21), TMJ Pathologies (n=19), and Malignant Dentomaxillofacial Lesions (n=18; control group). All scans were reviewed by an oral and maxillofacial radiologist and a radiologist. SUVmax values were calculated using a 42% threshold. Statistical analyses were conducted using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction.
Results: Significant differences in SUVmax values were observed across all groups (χ² = 77.4, p < 0.000001). The malignant lesion group demonstrated the highest metabolic activity (mean SUVmax = 12.5 ± 3.0), significantly greater than all other groups (p < 0.000001). Among non-malignant conditions, maxillary sinus pathologies showed the highest SUVmax (4.2 ± 1.0), followed by periodontal infections (3.5 ± 0.8). TMJ pathologies and dental artifacts exhibited the lowest FDG uptake (2.0 ± 0.6 and 2.5 ± 0.7, respectively), suggesting minimal metabolic activity.
Conclusions: This study confirms that malignant dentomaxillofacial lesions exhibit significantly higher FDG uptake compared to inflammatory and mechanical conditions. Understanding these uptake patterns is crucial to avoiding false-positive interpretations, especially in oncologic patients. Multimodal imaging and interdisciplinary evaluation are recommended for accurate differentiation of dental and maxillofacial pathologies in FDG-PET/CT interpretation.

Key words: FDG-PET/CT, SUVmax, Dentomaxillofacial Lesions, Oral Cancer, Metabolic Imaging