An Analysis of Xpert Test for Diagnosing Maxillofacial Tuberculosis.

Background: Maxillofacial tuberculosis is a diagnostic challenge for surgeons. The aim of this study was to present a detailed analysis of Xpert test in diagnosing maxillofacial tuberculosis and to analyse the accuracy of Xpert test results for various tissues of maxillofacial region.

Materials and methods: In this cross-sectional study, patients were selected randomly from outpatient department. The patients who had clinical picture and differential diagnosis highly suggestive of maxillofacial tuberculosis were included. Patients were divided into three different groups depending upon the site of involvement. The samples collected from the patients were further subdivided depending upon the type of specimen. Patients were screened first by routine tests, and the negative cases were followed by Xpert test for tuberculosis.

Results: A total of 54 patients were enrolled in the study, 13 patients were found to be positive for maxillofacial tuberculosis on routine screening tests for tuberculosis, and 41 tested negative on routine test and were evaluated further through Xpert test. Specimens from bone (n12), soft tissue and skin biopsy (n15) and aspirates from lymph nodes (n14) were obtained and tested. Twenty-one samples were found to be positive, and 20 were negative upon Xpert testing. There was a statistically significant difference seen between the test groups (p < 0.01) with higher frequency of negative results in routine test. The p value for various specimens containing pus, biopsies and aspirates was 0.045, 0.023 and 0.067, respectively.

Conclusion: Xpert test is more accurate when compared to routine test for diagnosing maxillofacial tuberculosis. Although accuracy of Xpert test is better for pus and biopsy samples in the specimens from bone and soft tissue, it gives poor accuracy for aspirated cells. The aspirates from lymph nodes were more susceptible for false negative test.