<p>Maxillectomy produces extensive oral and maxillofacial defects that disrupt normal physiology and often require obturator prostheses for functional and aesthetic rehabilitation. Although these devices are routinely used, their influence on salivary characteristics and oral microbiota remains insufficiently understood. To compare pre- and postoperative salivary parameters, periodontal indices, and selected microbial species in patients undergoing partial maxillectomy and rehabilitated with obturator prostheses. In this pilot prospective cohort study, 14 adults scheduled for maxillectomy were evaluated. Unstimulated whole saliva was collected at baseline and at 6–8 months post maxillectomy. Clinical examinations assessed salivary flow, viscosity, periodontal indices, and semi-quantitative microbial profiles using commercial hybridization assays. Statistical tests were selected according to data type. Probing depth increased modestly (3.7 ± 0.7 mm to 3.9 ± 0.8 mm; <i>P</i> = 0.02), while plaque and gingival indices showed no significant changes. No significant changes were detected in either salivary flow and viscosity (6.97 ± 1.86 ml to 8.58 ± 2.29 ml, P = 0.58 and 1.50 ± 0.97&#xa0;cps to 1.54 ± 0.96 cps, <i>P</i> = 0.64, respectively). Similarly, no statistically significant changes were detected in the prevalence of the selected microbial species, although a non-significant decrease in Aggregatibacter actinomycetemcomitans and an increase in Porphyromonas gingivalis were observed. Most other fungal and bacterial species showed similar prevalence across time points. Within the early postoperative period, salivary characteristics and oral microbial patterns remained generally unchanged following maxillectomy and obturator placement. Given the small and heterogeneous cohort, these preliminary outcomes warrant cautious interpretation and underscore the need for larger studies with extended follow-up time.</p>