UCLA

Orthodontic appliances including temporary anchorage devices (TADs) have a long history of creating plaque traps. TADs are versatile anchorage devices that are also used to attachMini-screw Assisted Rapid Palatal Expanders (MARPE) to the hard palate during palatal expansions. Studies have shown that poor oral hygiene and inflammation can compromise TAD retention and cause mobility, where the treatment may fail and requires MARPE removal. When placing TADs in the hard palate, an artificial environment is created that has similar characteristics to the natural ecological niche present at the tooth or implant (hard tissue/ surface)- gingiva (soft tissue) interface of the gingival crevice. Currently, there is no information available on the microbiome and host inflammatory markers associated with TADs used to anchor MARPE devices. This study aims to start filling this knowledge gap and examine if the presence of TADs in the hard palate induces a shift in the palatal microbiome and host inflammatory markers and how these compare to the bacteria and host inflammatory markers in the gingival crevicular fluid (GCF) of the same patient. The subjects consisted of ten patients who received MARPE devices as part of their treatment. At each study visit during four different time points, samples (plaque and GCF around teeth/TADs) were collected from each participant. The plaque index (PI), gingival index (GI), and hard palate scores were measured as periodontal parameters. The samples were sent for sequencing and cytokine analyses to determine microbiome composition and cytokine profiles. Our study concluded that the microbiome around transpalatal TADs used in MARPE treatment differs significantly from gingival microbiomes, potentially due to the unique structure of the hard palate. Clinical observations suggested that MARPE may influence the progression of periodontal inflammation. Additionally, certain bacteria and cytokines show a distinct distribution between the hard palate and gingival regions, indicating niche specialization and varied immune responses associated with orthodontic appliance use.