The use of BokaFlo™ instrument to measure salivary flow

Abstract

Background: Dry mouth currently affects roughly 20% of the population and is a condition characterized by chronic hyposalivation and/or subjective reports of xerostomia. Low saliva flow can be indicative of other undiagnosed diseases, such as primary Sjogren's syndrome, and may contribute to difficulty chewing, increased caries susceptibility and infection. The passive drool test (PDT) is the primary method used to evaluate patients for hyposalivation but it is time-consuming and inconvenient. New methodology is needed to facilitate increased testing for hyposalivation in the dental clinic. The aim of this study was to evaluate an alternative method to measure salivary flow in dental offices.

Methods: In this study, we tested a new biomedical device, the BokaFlo™, to measure salivary flow in subjects in comparison to the current PDT standard. Participants completed an oral health questionnaire and saliva flow was evaluated by the PDT and the BokaFlo™ system.

Results: Saliva flow as measured by the BokaFlo™ positively correlated with the saliva flow measured by the PDT methodology (r = 0.22, p < 0.05). The device predicted low saliva flow in subjects with a sensitivity of 0.76 and specificity of 0.84 for subjects with hyposalivation, defined as a saliva flow rate of ≤ 0.1 ml/min. A significant negative correlation between the total oral health questionnaire score and the likelihood of participant exhibiting low salivary flow was observed (r = - 0.31, p < 0.006).

Conclusion: The BokaFlo™ was effectively able to measure low saliva flow correlating with the PDT methodology and may provide more efficient testing of saliva flow in the dental office.

Keywords: BokaFlo; BokaFlo™; Dry mouth; Hyposalivation; Passive Drool Test; Saliva Flow; Sialometry; Sjogren’s syndrome; Testing saliva flow; Xerostomia.

Fig. 1

Outline of study illustrating the enrollment process, performed procedure, and data analysis

Fig. 2

Saliva collection protocol for the BokaFlo™ and passive drool test (PDT). Saliva collection protocol demonstrating methodology used to assess subject salivary flow as measured with BokaFlo™ and PDT. a Participants cleared their mouth of any existing saliva, opened their mouth and the BokaFlo™ disposable device was placed under the participant's tongue for 3 s. b The disposable device was placed on the BokaFlo™ instrument, removed, and another disposable device placed on the instrument to tare. Subjects were then asked to allow saliva to pool in mouth for 60 s. The second BokaFlo™ disposable device was placed under subjects’ tongue for 3 s and then placed on BokaFlo™ instrument. BokaFlo™ instrument displays salivary flow as milliliters/minute (ml/min). c The PDT was performed by first having subject clear mouth of saliva, then allowing saliva to passively flow into the saliva collection tube for 5 min while sitting upright and with their head tilted forward and down. Resulting PDT rendered saliva flow as ml/min

Fig. 3

Demographics of study participants. The cohort of 79 participants consisting of 41 males and 38 females took part in this study. The age of participants ranged from 18 to 80 years of age with an average participant age of 39.20 ± 16.87 years of age

Fig. 4

Unstimulated saliva flow measured by BokaFlo™ correlates with PDT. Passive drool test (PDT) identified 45 (56.9%) participants with saliva flows ≥ 0.3 ml/min, the lower limit of normal salivary function. 17 (21.5%) participants had measured PDT results of less than or equal to 0.1 ml/min, the clinical range for hyposalivation. BokaFlo™ identified 50 (63.3%) participants with saliva flows ≥ 0.3 ml/min, the lower limit of normal salivary function. 23 (29.1%) participants had measured PDT results of less than or equal to 0.1 ml/min, the clinical range for hyposalivation

Fig. 5

Oral Health Questionnaire identified a significant, negative correlation to BokaFlo™ measurement. Pearson correlation analysis comparing survey results to the BokaFlo™ indicated a significant negative correlation between the total questionnaire score, equating to increased oral health symptomology, and the likelihood of participant exhibiting low saliva flow (r = − 0.31, *p < 0.006)

Fig. 6

Increased score on oral health questionnaire in participants with low saliva flow as measured by PDT and BokaFlo™. Comparison of the summed questionnaire score for all 15 questions grouped by flow categorization based on both PDT and BokaFlo™. For PDT, a significant difference in mean questionnaire score for low flow and mean questionnaire score for normal flow was present (*p < 0.02). According to BokaFlo™ results, a significant difference in mean was present between both low flow versus borderline questionnaire scores (***p < 0.001) and for low flow versus normal questionnaire scores (**p < 0.002)