Microbiome and Metaproteome of Craniofacial Implant Regions in Health and Disease

Background: Craniofacial defects from cancer surgery led to functional, aesthetic, and psychological challenges. Rehabilitation with craniofacial implants addresses these issues by improving prosthesis retention through osseointegration and providing predictable cosmetic results. However, maintaining a healthy transcutaneous region is essential for implant longevity. Objective: Evaluation of the microbial community and host response around extraoral implants. Methods: In an intrasubject control study design, 12 cancer patients who had undergone oculofacial rehabilitation with implant-supported prostheses were included. Biofilm and peri-implant fluid samples were collected from the transcutaneous region of healthy and diseased implants. Microbiome profiling was conducted through DNA sequencing of the V3–V4 region of the 16S rRNA gene, and proteome analysis was performed using liquid chromatography–tandem mass spectrometry. Results: Differentially abundant species were observed, with Streptococcus intermedius being the most abundant in diseased areas, followed by Corynebacterium diphtheriae and Prevotella bivia. Metaproteomic analysis revealed distinct protein expression patterns between the groups, with increased activation of proinflammatory responses and inactivation of anti-inflammatory responses in the diseased group. Conclusion: The study demonstrated an increased abundance of pathogenic bacterial community accompanied by an imbalanced immune response, thereby highlighting host–microbial factors that can influence the success of osseointegration and facial rehabilitation.