Tooth Eruption and Microbial Correlation in Pediatric Appendicitis: An Exploratory Case–Control Study

Background/Objectives: The oral cavity has been discussed as a possible reservoir for pathogens involved in pediatric appendicitis. In a previous study, microbial similarities between oral and appendix samples were observed, but clinical dental findings showed no significant associations. The present study aimed to (1) perform a more detailed analysis of dental variables—such as eruption status, caries indices, oral hygiene behavior, and the Periodontal Screening Index (PSI)—to identify potential overlooked associations with appendicitis, and (2) compare two oral sampling sites (buccal mucosa and dental sulcus) in terms of their correlation with appendix microbiota. Methods: This secondary analysis used previously collected clinical and microbiological data from 36 children who had undergone appendectomy or elective surgery. Quantitative PCR (qPCR) was used to assess bacterial mRNA levels in appendix, buccal mucosa, and sulcus samples. Dental variables were derived from standardized clinical examinations performed at the time of surgery. Results: No significant group differences were observed in caries indices, PSI, or oral hygiene behavior. However, patients with appendicitis had a significantly higher number of erupting teeth compared to controls (3.82 vs. 1.68; p = 0.021). Bacterial mRNA levels did not differ notably between oral sites, and neither showed stronger correspondence with appendix samples; notably, sulcus swabs were not obtained from erupting teeth, limiting the ability to test a site-specific eruption mechanism. Conclusions: Tooth eruption may be associated with appendicitis, although this remains speculative and requires confirmation in larger studies.