Periodontitis, affecting over 1 billion people globally, is linked to systemic diseases such as cancer, cardiovascular issues, and neurodegenerative conditions like Alzheimer’s disease. The disease results from microbial dysbiosis of the subgingival plaque (SubP), which are polymicrobial biofilms accreted to the tooth surface below the gum line. While microbiome studies provide insight into species composition and co-occurrence associations, they lack information about the spatial organization of the biofilm or the details of interspecies interactions. This spatial information is crucial for understanding how microorganisms interact and function. Recent confocal laser scanning microscopy (CLSM) studies reveal spatial organization in the healthy human supragingival microbiome at macro- and microscales. Polymicrobial interactions drive biofilm spatial organization, impacting disease progression. SubP has not been studied to the same level and is more heterogeneous since the periodontal pocket environment changes with depth and with the severity and activity of the disease. The CLSM studies that employ Fluorescence In Situ Hybridisation (FISH) staining help us identify species of interest in the SubP. In our preliminary analysis of the SubP using CLSM-FISH, we observed diverse structures resembling corncobs and test tube brushes (TTBs), alongside other microbial assemblages. The corncobs and TTBs were comprised of long central rods of filamentous bacteria, with spherical or short rod-shaped bacteria along the periphery of the central rod. These are interesting results deserving of much replication to unveil the composition and spatial organization of various microbial microcolonies or assemblages within the SubP. Like the supragingival plaque, SubP likely includes some very specific interactions, for example in TTBs, but also less specific interactions as well as microcolonies of particular species encased in their matrix.