Introduction
Pyogenic spondylitis, an infection of the vertebrae, is commonly caused by hematogenous spread from other infectious diseases such as pneumonia or urinary tract infections. However, recent evidence suggests that oral bacteria may also be a significant source of infection. Given the increasing recognition of this link, this study investigates the relationship between oral hygiene and the development of lumbar pyogenic spondylitis, with a focus on oral health factors such as dental caries and periodontitis.
Subjects and Methods
This retrospective study examined 28 patients with lumbar pyogenic spondylitis treated at our institution between 2021 and 2024 (Group S: 17 males, 11 females, mean age 73.0 years). Data collected included demographic information (age and gender), causative bacteria, affected vertebral levels, oral hygiene status (presence of dental caries and periodontitis), and history of prior infections. To serve as a comparison, we used a control group (Group T) consisting of 81 patients (16 males, 65 females, mean age 67.6 years) who underwent oral examinations at the Department of Oral and Maxillofacial Surgery prior to hip replacement surgery during the same period. The proportion of patients with poor oral hygiene and preceding infections was compared between the two groups, and statistical significance was determined using a p-value threshold of <0.01.
Results
Causative bacteria were successfully identified in all cases in Group S, with a notable proportion of cases linked to oral commensal bacteria such as Streptococcus salivarius, Streptococcus mitis, and Streptococcus oralis, which together accounted for 21.4% of the isolates. Poor oral hygiene, defined by the presence of untreated dental caries and periodontitis requiring dental intervention, was observed in 64.3% of Group S, compared to only 27.1% of Group T. This difference was statistically significant (p<0.01), indicating a strong association between poor oral hygiene and pyogenic spondylitis. Furthermore, 60.7% (17 out of 28) of patients in Group S had a history of preceding infection. Among these, the most common infection sources were dental caries and periodontitis (35.7%), followed by urinary tract infections (7.1%), and respiratory infections such as pneumonia (3.5%).
Discussion
While Staphylococcus aureus has traditionally been considered the primary causative pathogen in pyogenic spondylitis, our findings indicate an increasing role for oral bacteria, particularly among patients with poor oral hygiene. The significant presence of oral commensal bacteria suggests that bacteria from untreated dental infections may translocate to the bloodstream and colonize the vertebrae, leading to spondylitis. These findings underscore the importance of maintaining good oral hygiene, particularly in elderly individuals who are already at an elevated risk for systemic infections.
Conclusion
This study highlights a potentially preventable risk factor for lumbar pyogenic spondylitis: poor oral hygiene. Oral bacteria associated with untreated dental caries and periodontitis were found to contribute to lumbar pyogenic spondylitis in a substantial portion of cases. Promoting good oral hygiene and regular dental care may play an important role in reducing the incidence of this condition. Further research, including larger cohort studies, is needed to explore the specific mechanisms linking oral bacteria and vertebral infections and to develop targeted preventive strategies.