Many preceding research results show that the correlation between the measurement values by use of halitosis measuring devices such as Halimeter™ or Oral Chroma™ and the organoleptic test (OLT) results is high [4, 23], although F. Brunner et al. argued that the organoleptic test would be a gold standard that could be used to diagnose halitosis so far [23]. Based on these arguments, we performed an organoleptic test in the KUMC Halitosis Clinic, measuring the perceivable distance of oral malodor with the patient's own mouth open, measuring the perceivable distance of exhaled oral malodor, based on the standards suggested by Seemann et al. [17, 24]. Among those who were complaining of physiological halitosis symptoms, we judged the patient with perceivable oral malodor at a distance of 10 cm or more from the patient’s lips (which is more than grade 1 by Seemann et al. [24]) as having physiological halitosis. At the same time as the organoleptic test, we measured the oral malodor of the 246 physiological halitosis patients with oral malodor measurement devices such as mBA-21 (TAIYO, Japan), Twin-Breasor II (iSenLab, Korea), and mBA-400(TAIYO, Japan), all approved by the Ministry of Food and Drug Safety in Korea. But the measurement results of these three types of devices did not show consistent correlations with the organoleptic test results, as Halimeter™ and Oral Chroma™ used in previous studies [3, 4, 23]. Therefore, in this study process we excluded those measurement results from our analysis. Because the gas output patterns of patients with physiological halitosis symptoms might differ from patient to patient, and because the three types of oral malodor measuring devices would each have their own characteristic measuring spectrum, we thought a separate research report on this topic should be made in near future.
And as shown in Table 3 and Fig 1, patients who replaced with fast food or skipped breakfast were analyzed to be more than those who used to have breakfast of ordinary Korean menu, then it was inferred that the breakfast pattern could cause symptoms and it was also interpreted to uphold the assertion of A Wälti et al., who claimed to consume foods high in fiber for breakfast in order to reduce the occurrence of oral malodor [17]. Whereas patients who had preferred coffee, tea, or carbonated beverages were found to be more numerous than those who seldom drank those beverages, we concluded that patient preference for these beverages could affect the occurrence of physiological halitosis symptoms. There were more patients who drank insufficient amounts of water during a day as compared to those who regularly drank sufficient amounts of water. Thus we concluded that the amount of water drunk daily could affect the occurrence of physiological halitosis. Among patients with physiological halitosis symptoms, 89.0% of them were aware of their own halitosis, and 97.6% of those had anxiety or stress because of oral malodor. It was found that by recognizing their own halitosis, they were worrying about this condition and progressed through to physiological halitosis symptoms. This was in accord with the results of reports from Wang and He, Troger B et al., and M. Fukui et al., who insisted that in many halitosis patients, anxiety, stress and worry could be found [8, 15, 20]. In the evaluation of the patient's own personality, a statistically significant number of responding patients said that their own personality was introspective. Therefore, it was thought that people with tendencies towards introversion were likely to be exposed to the risk of physiological halitosis symptoms as compared to people with a tendency to extraversion.
As shown in Table 3 and Fig 1, the frequencies of several factors that were expected to cause physiological halitosis symptom were statistically analyzed to be significantly high in the proportion of patients with a healthy lifestyle (p < 0.05). Thus, we inferred that the patients’ failure to adhere to a three-meal-a-day habit, their preference for a stimulating diet, a toothbrushing frequency of at least four times a day, their smoking or mouth breathing habits, or a drinking frequency at least twice a week might only be a problem in a small number of the patients suffering physiological halitosis symptoms. In addition, there was no statistical difference in patient snack preference that could remain in the oral cavity for a long time, which had been suspected as a predisposition to physiological halitosis symptom. Thus we concluded that a questionnaire related to this factor could be omitted if such would be developed later for investigating Korean physiological halitosis patients.
When we measured the amount of salivation, we adopted one of the standards (the adopted standard: 3.0mL / 3.0min) suggested by the JAMS [3] and the Korean Academy of Halitosis Control under the KAPDOH [1]. As for the domestic research related to the amount of salivation in Korean people, Kim et al. suggested that the unstimulated salivation amount was 0.66 ± 0.41g/min and the stimulated salivation amount was 1.61 ± 0.69g/min [25]. Most other domestic researchers had only suggested a range of salivation amount according to age groups. So, we inferred that research aimed at suggesting a standardized amount of salivation for men and women in Korea was needed. In this study, in the case of the unstimulated saliva, 78.5% of patients showed lower measurement values than the baseline measurement value (3.0mL / 3.0min), and this result was also consistent with the report of N. Suzuki et al., who insisted that there was a decrease of unstimulated salivation amounts in the halitosis patients [12]. In the case of stimulated salivation amounts, some sufficient amount of saliva was measured, so 87.0% of the patients exceeded the reference value that the JAMS had suggested [3] and that the KAPDOH had approved [1] (p < 0.05). Only in a few cases was it confirmed that the level of the stimulated salivation amount was less than the suggested value. Therefore, it could be inferred that if there were no properly applied stimulations for salivary secretion, most patients with physiological halitosis symptoms could not utilize their properly produced saliva. This would then cause dryness in the oral cavity, resulting in oral malodor. On the other hand, the patients with a salivary sedimentation ratio of less than 10%, also determined by the standard suggested and approved by the JAMS and the KAPDOH [1, 3], were statistically significantly greater than the number of patients with a salivary sedimentation ratio of 10% or more. But in about 43.5% of the physiological halitosis symptom patients, we could measure salivary sedimentation ratios of 10% or greater. So we could not help reasoning the relationship between the salivary sedimentation ratio and the physiological halitosis symptom. M. Ueno et al. argued that salivary turbidity was associated with halitosis [18]. Thus we inferred that in our study, the degree of salivary turbidity and of salivary contamination of patients with a salivary sedimentation ratio of 10% or more was highly correlated with the occurrences of physiological halitosis.
As a result of the analysis of patient tongue records, cases of patient red tongue or coated tongue caused by excessively wiping off or the accumulation of tongue coating, occurred in 91.5% of the patients. We concluded that incorrect management of the patient’s own tongue could be closely related to physiological halitosis. This conclusion is in accord with the results of studies by previous scholars [9, 12, 21], so we suggest patient education on correct tongue management. As a result of our analysis of intraoral photographs, we found postnasal drip in the throat and posterior tongue coating in 92.3% of the patients with physiological halitosis, and it could be expected that postnasal drip and posterior tongue coating would increase the viscosity of the patient’s saliva. Based on the argument of M. Ueno et al., who stated that high saliva viscosity could increase the possibility of physiological halitosis [19], we thought that postnasal drip in the throat and posterior tongue coating could be also one cause of physiological halitosis. It would then be desirable to add an intraoral photograph of the postnasal drip in the patient’s throat and the posterior tongue coating to aid in diagnosing physiological halitosis.
By synthesizing the results of the frequency analysis as described above, we identified the 10 variables as being “the sex” variable, “the breakfast pattern” variable, “the soft drink” variable, “the water intake” variable, “the self-awareness” variable, “the anxiety or stress for one’s own halitosis” variable, “the character” variable, “the unstimulated saliva” variable, “the red tongue or coated tongue” variable, and “the postnasal drip or posterior tongue coating” variable. We set these variables as being the potential common risk factors related to physiological halitosis. Then, when examining or consulting patients with physiological halitosis, we concluded that it would be necessary to investigate these 10 factors in our investigation.
On the other hand, as shown in the results of the correlation analysis between the bivariate variables in Table 4, the correlation coefficient Phi of twelve combinations were all recognized as being statistically significant, but considering the research report of DK Lee that a moderate correlation could be recognized when the Phi value should be 0.20 - 0.40 [26], we could conclude that in the results of this study, the Phi values between the breakfast pattern variable and the regular diet variable(0.394), between the stimulating menu variable and the drinking variable(0.238), between the unstimulated saliva variable and the stimulated saliva variable(0.203), between the unstimulated saliva variable and the sedimentation ratio of saliva variable(0.360), and between the stimulated saliva variable and the sedimentation ratio of saliva variable(0.294) could be judged to have a moderate correlation. Therefore, in a future study on the causative factors or treatment methods of physiological halitosis symptoms, we would suggest that a comprehensive study on the possibility of physiological halitosis outbreaks caused by the interactions of these correlated factors would be necessary.