|Year : 2021 | Volume
| Issue : 1 | Page : 1-7
Comparative evaluation of alteration in salivary flow rate between betal Nut/Gutkha chewers with and without OSMF, and healthy subjects: A prospective case-control study
F Lalfamkima1, Suresh Babu Bommaji2, Kailasa Kumar Reddy3, K Venkata Chalapathi4, Manisha B Patil5, Tejal R Patil6, Abhishek Singh Nayyar7
1 Consultant Dental Surgeon, Dental Department, Civil Hospital, Aizawl, Mizoram, India
2 Department of Oral and Maxillofacial Surgery, Malla Reddy Institute of Dental Sciences, Hyderabad, Telangana, India
3 Department of Oral and Maxillofacial Surgery, St. Joseph Dental College, Eluru, India
4 Department of Oral Pathology and Microbiology, Care Dental College, Guntur, Andhra Pradesh, India
5 Department of Oral Pathology and Microbiology, Nanded Rural Dental College and Research Center, Nanded, India
6 Department of Oral and Maxillofacial Surgery, Bharati Vidyapeeth (Deemed to be University) Dental College and Hospital, Navi Mumbai, India
7 Department of Oral Medicine and Radiology, Saraswati-Dhanwantari Dental College and Hospital and Post-Graduate Research Institute, Parbhani, Maharashtra, India
|Date of Submission||03-May-2020|
|Date of Decision||10-Jul-2020|
|Date of Acceptance||21-Dec-2020|
|Date of Web Publication||14-Apr-2021|
Abhishek Singh Nayyar
Department of Oral Medicine and Radiology, Saraswati-Dhanwantari Dental College and Hospital and Post-Graduate Research Institute, Parbhani, Maharashtra
Source of Support: None, Conflict of Interest: None
Context: Oral submucous fibrosis (OSMF) has infested the oral cavities of “betel nut” and “gutkha” chewers in a pandemic manner. It has one of the highest rates of malignant transformation among the various oral potentially malignant epithelial lesions. Chewing of gutkha alters the salivary parameters including salivary flow rate (SFR) as well as salivary pH. Aim: The present study intended to assess and compare the SFR between betel nut/gutkha chewers with and without OSMF and healthy controls. Materials and Methods: We conducted a prospective case–control study comprising 90 individuals within an age range of 15–50 years who were divided into three groups with Group A consisting of 30 patients who were betel nut/gutkha chewers with OSMF, Group B consisting of 30 individuals who were betel nut/gutkha chewers but without OSMF and Group C consisting of 30 healthy controls who were included as normal controls. The assessment of the SFR was done and the results obtained were subjected to statistical analysis. Results: The mean SFR in Group B patients was significantly more than Group A and Group C individuals. Moreover, the mean SFR in patients with OSMF Stage I was significantly more as compared to patients in Stage II and Stage III OSMF. Conclusion: We concluded that reduced SFR could be an initial subjective sign of OSMF. An early diagnosis and management of these changes can help such patients to improve their quality of life significantly and decreases the chance of the ongoing malignant transformation with early intervention.
Keywords: Betel nut, gutkha chewers, oral submucous fibrosis, salivary flow rate
|How to cite this article:|
Lalfamkima F, Bommaji SB, Reddy KK, Chalapathi K V, Patil MB, Patil TR, Nayyar AS. Comparative evaluation of alteration in salivary flow rate between betal Nut/Gutkha chewers with and without OSMF, and healthy subjects: A prospective case-control study. Oncol J India 2021;5:1-7
|How to cite this URL:|
Lalfamkima F, Bommaji SB, Reddy KK, Chalapathi K V, Patil MB, Patil TR, Nayyar AS. Comparative evaluation of alteration in salivary flow rate between betal Nut/Gutkha chewers with and without OSMF, and healthy subjects: A prospective case-control study. Oncol J India [serial online] 2021 [cited 2021 Jul 25];5:1-7. Available from: https://www.ojionline.org/text.asp?2021/5/1/1/313664
| Introduction|| |
The world of medical science is replete with a plethora of conditions, both physiological and pathological, which exhibit a multitude of symptoms, some of which humankind has managed, while others, it is still waging a relentless war. Oral submucous fibrosis (OSMF) is an old enemy in this context which is gaining repeated mention in the oral health circles. OSMF has become a serious concern to the health-care providers as it largely affects the younger age groups. It is a debilitating condition in which the patients complains of intolerance to spicy food, rigidity in lip and tongue, difficulty in mouth opening and speech and swallowing and has high chances of developing into malignancy, thereby, reducing the quality of life (QoL), in other words, leading to increased morbidity as well as associated with a chance of mortality. The prevalence of OSMF in India is estimated to be about 0.2%–0.5% while the prevalence by gender varies from 0.2% to 2.3% in males and 1.2%–4.57% in the females owing to an increased prevalence of the habit of smokeless forms of tobacco usage in the females. The malignant transformation rate for OSMF varies from 2.3% to 7.6%.
Betel nut chewing, the main cause for the causation of OSMF in India, has been reported as the fourth dependent substance among the substances of abuse followed by nicotine, alcohol, and caffeine. It is directly linked to the oral cavity and saliva is the first biological fluid exposed to such products., During gutkha chewing, many harmful chemicals and metals are leached-out into the saliva. Betel nut, the main ingredient of gutkha, contains alkaloid arecoline which is a known genotoxic constituent while lime, another significant constituent of gutkha, causes intense local irritation of the mucosa. Another important ingredient of betel nut, catechu, contains an alkaloid, catechin, which when combined with lime, is known to produce heavy amounts of reactive oxygen species which are, also, proven to be mutagenic. Therefore, gutkha represents a convoluted mixture of adverse constituents which not only increase the chances of morbidity and mortality in the individuals but alter the salivary parameters including the salivary flow rate (SFR) as well as the salivary pH. Several studies have documented the normal range of salivary pH to be within 5.5–7.9 while the normal SFR in a range of 0.33–1.42 ml/min. Due to a scarcity of the literature on this aspect of the disease process and the impact of gutkha chewing on the salivary parameters including the SFR, the present study intended to assess and compare the same among betel nut/gutkha chewers with and without OSMF and healthy controls.
| Materials and Methods|| |
The present study was designed as a prospective case–control study comprising 90 individuals within an age range of 15–50 years who had reported to the outpatient department of oral medicine and radiology from June 2018 to May 2019. The study population was divided into three groups such as Group A consisting of 30 patients who were betel nut/gutkha chewers with OSMF, Group B consisting of 30 individuals who were betel nut/gutkha chewers but without OSMF and Group C consisting of 30 healthy controls who were included as controls. Ethical clearance was obtained from the Institutional Ethics Committee before the start of study through letter approval number SDDC/IEC/01-37-2018. The subjects were informed in detail about the study and a written, informed consent was obtained from each participant before the start of study after which the patients were examined thoroughly and a detailed case history was recorded in a specially designed pro forma. Significant inclusion criteria included a positive history for betel nut/gutkha chewing habit of more than 6 months' duration and with clinically diagnosed OSMF in case of Group A while a positive history for betel nut/gutkha chewing habit of more than 6 months' duration but with no clinical evidence of OSMF in case of Group B. Group C consisted of 30 healthy controls who were not positive for a history of habit and who were included as controls. Individuals with habits such as smoking and/or alcohol consumption, patients with any known systemic disorders, pregnant and lactating females, patients who had received any type of treatment for OSMF or, frank malignancies were excluded from the study. The demographic details, habit history, if, found positive and clinical parameters, were recorded in the predetermined pro forma after a thorough clinical examination in day light. Armamentarium for clinical examination is shown in [Figure 1].
Detailed procedure of collection of saliva sample was explained to the patients while the patients were advised to refrain from intake of any food and/or, beverage (water exempted) 1 h before the test session. Saliva was collected between 9:00 a.m. and 12:00 p.m. to avoid diurnal variations, if any. The subjects were advised to rinse their oral cavity with water and then, asked to relax for 5 min. Then, patients were asked to swallow whole saliva from the mouth and after that no movement was allowed to be made before and during the collection of salivary samples. The patients were, then, asked to lean their head forward over the test tube and funnel while keeping their mouth slightly open and allow saliva to drain into the test tube [Figure 2] and [Figure 3]. Saliva was collected for 10 min. At the end of the collection period, patients were asked to collect any remaining saliva in the mouth and spit it into the test tube.
The data were analyzed using SPSS version 16.0 (SPSS Inc., Chicago, IL, USA). The comparison of the mean SFR with various parameters was done using analysis of variance (ANOVA) and Tukey's post hoc test. P < 0.05 was considered statistically significant.
| Results|| |
[Table 1] provides the distribution of subjects according to age, sex, and habits with respect to Group A, Group B, and Group C. The mean age in Group A was found to be 30.96 (±7.51) years, in Group B, it was 32.2 (±7.12) years while in Group C, was 27.5 (±6.05) years. There was no statistically significant difference between three groups with respect to age distribution (P = 0.06). The number of females in all the groups were found to be less than the number of males, although the difference was found to be statistically insignificant (P = 0.06). Majority of patients were having habit of chewing gutkha in both the Group A and Group B than other forms of habits such as chewing betel nuts only or chewing both betel nuts and gutkha; the difference was found to be statistically significant (P = 0.01). Since Group C was the control group, none of the individuals included had any type of habit.
|Table 1: Age, gender, and habit distribution among Group A (oral submucous fibrosis patients), Group B (habit without oral submucous fibrosis) and Group C (control)|
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[Table 2] shows the distribution of the habit among the Group A and Group B participants according to the frequency, exposure, and duration of the habit. The majority of OSMF patients had higher frequency of the habit (>3 times a day) than that of patients without OSMF (80% vs. 26.7%; P = 0.01). In both the groups, the majority of patients with habit consumption had the exposure time of more than 11 min. However, such longer exposure time was seen more among OSMF patients (Group A) when compared to patients without OSMF (89.7% vs. 46.7%; P = 0.002). Therefore, we suggested that use of betel nut/gutkha with increased frequency and/or increased exposure time raises the possibility of OSMF development. The majority of patients in both the groups had duration of habit for more than 5 years (Group A-86.7%, Group B-63.3%) with the difference between the groups being insignificant (P = 0.15).
|Table 2: Distribution of participants according to frequency, exposure, and duration of habit|
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[Table 3] and [Figure 4] illustrate the comparison of mean SFR among the three groups. One-way ANOVA revealed the mean SFR to be 3.2586 (±1.02313) ml/10 min among Group A patients, 5.3333 (±1.16854) ml/10 min among Group B patients while 3.6667 (±0.46113) ml/10 min in Group C individuals and this difference was found to be statistically significant (P = 0.001). Further, pair-wise comparison by Tukey's post hoc test showed that the mean SFR in Group B patients was significantly more than Group A and Group C individuals while the mean SFR amongst Group A patients and Group C normal healthy controls was found to be the same.
|Figure 4: Comparison of mean salivary flow rate (ml/10 min) among different groups, different stages of oral submucous fibrosis, and various habits|
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|Table 3: Comparison of salivary flow rate among different groups, stages of oral submucosal fibrosis, and habits|
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According to the staging of OSMF (n = 30), Stage I, Stage II, and Stage III accounted for 8 (26.7%), 12 (40%), and 10 (33.3%) patients, respectively. Furthermore, on comparison of the mean SFR between the various stages of OSMF [Table 3] and [Figure 4]], OSMF stage I patients had higher mean SFR (4.5000 ± 0.65465 ml/10 min) in comparison to Stage II (2.9091 ± 0.66401 ml/10 min) and Stage III (2.6500 ± 0.70907 ml/10 min), and the difference was found to be statistically significant (P = 0.001).
Likewise, on comparison of the mean SFR by one-way ANOVA between the participants with various types of habits [Table 3] and [Figure 4], the mean SFR among individuals without any habit was found to be 3.6667 ± 0.46113 ml/10 min. Whereas, it was significantly higher among the individuals with the habit of betel nut chewing only (5.1923 ± 1.18213 ml/10 min) in comparison to individuals with gutkha chewing habit (4.1341 ± 1.55734 ml/10 min), and both betel nut and gutkha chewing habits (3.5000 ± 1.00000 ml/10 min) and this difference was found to be statistically significant (P = 0.002).
| Discussion|| |
OSMF is one of the classic “Diseases of Civilization.” It is globally accepted as the disease that belongs to the Indian subcontinent which has one of the highest rate of malignant transformation among the various oral potentially malignant epithelial lesions. The incidence of epithelial dysplasia appearance in OSMF tissues varies from 7% to 26% and the malignant transformation rate among OSMF patients varies from 7% to 13%. The condition is characterized by burning sensation and depigmentation of oral mucosa along with reduced movement and depapillation of tongue and progressive reduction of mouth opening. Some patients may, also, have excessive salivation, probably, due to their inability to swallow the normal amount of saliva as a result of reduced tongue movement. Apart from this, some studies have, also, documented dryness of the mouth due to xerostomia and altered taste perception due to xerostomia and atrophy of the papilla. There is a relative dearth, though, of the studies on the assessment of the SFR among OSMF patients and individuals having the habit of betel nut or, gutkha chewing but those who have not developed the same. With this background, the present prospective case–control study was designed on a sample size of n = 90 within an age range of 15–50 years and were divided into three groups such as betel nut/gutkha chewers with OSMF (Group A), betel nut/gutkha chewers without OSMF (Group B), and healthy controls (Group C).
We found a mean age of 30.96 years among OSMF patients, similar to the findings in the existing literature wherein a peak incidence of OSMF has been reported to be in the third decade of life., Wahab et al. found the maximum number of patients (73%) of OSMF in the second decade of life followed by the third decade as the second peak. Similarly, there have been varying reports on sex ratio in different published studies. In the present study, a definite male predominance observed in the OSMF group with a male to female ratio of 14:1. It was found to be similar to the findings reported by the other studies.,, Moreover, Reddy et al., in their study on 390 patients of OSMF, found the peak incidence of the disease in the third decade of life and 70.26% of the patients as male while 29.74% of the patients as females, showing a definite male predominance for the disease. This might be due to more social exposure at this age and relative ease in the availability of such products at this age without any hindrance. Contrary to our findings, Rao and Rajendran et al. found a female predominance over male for OSMF while the disease process in such cases might be related to factors like the more common usage of the smokeless forms of tobacco including betel nut and a relative deficiency of iron, vitamins, and many other nutritional factors in the females as prevalent in the Indian subcontinent.
We found 12 out of 30 OSMF cases (40%) with Stage II which was slightly higher than Stage I and Stage III in contrast to the studies conducted by Nigam et al. and Reddy et al. where they observed maximum number of patients in Stage I OSMF followed by Stage II and Stage III. OSMF is a multi-factorial disease process with areca nut chewing being the major etiological factor behind the causation of OSMF as suggested in the various epidemiological and in vitro experimental studies. There might be seen regional variations in the different parts of the subcontinent depending on the various forms and concentrations and additives used with this form of smokeless, areca nut chewing habit. Areca or, betel nut is the inner kernel or, seed which is obtained after removing husk of areca nut and gutkha is a mixture of areca nut, tobacco, slaked lime, catechu, and numerous other spices.
In the present study, majority of OSMF patients have habit of gutkha chewing (76.7%) followed by habit of betel nut chewing (10.0%), and both betel nut and gutkha chewing (13.3%) habit. This was in accordance with the findings of the study conducted by Sharma et al. which reported that out of the 231 OSMF, 135 (58.44%) patients had habit of gutkha chewing while 22.51% had a habit of areca nut and tobacco, and 19.04% had areca nut chewing habit. Reddy et al. showed that gutkha and other areca nut product users to be the main etiologic factor in the causation of OSMF.
The present study revealed that increase in the frequency and exposure time of the habit significantly increased the incidence of OSMF, thereby, highlighting a dose dependence relationship between habit chewer and OSMF as has been confirmed in the published literature. Whereas, habit duration, had no significant relation with increased the incidence of OSMF. Reddy et al., in their study, stated that increase in habit frequency, duration, and exposure were all the primary etiological factors deciding the causation of OSMF. Sinor et al. found increase in relative risk of OSMF with the duration as well as the frequency of areca nut chewing highlighting the dose dependence relationship between areca nut and the causation of OSMF. Maher et al., in their study, reported that the frequency of areca nut chewing was more important than duration of the habit in the causation of OSMF while Abdul Khader and Dyasanoor found the duration of the habit to be more important than frequency and exposure. In contradiction to these studies, Pindborg et al. reported 31.8% of the patients of OSMF without positive history of any chewing or smoking habit and stated against the theory of tobacco playing important role in the development of OSMF.
Saliva is the most easily accessible body fluid maintaining oral health/homeostasis. It plays an important role in lubrication of the oral mucosal tissues, re-mineralization of the initial de-mineralization defects of the dental hard tissues, pH balance as well as facilitation of the processes leading to mastication and deglutition and digestion of the ingested food. The normal daily saliva production is between 0.5 and 1.5 l. Numerous studies have documented a change in the SFR under physiological conditions. During betel nut chewing, the physicochemical composition as well as the properties of saliva get altered as many chemicals and metals leach-out into the saliva during ingestion of such products. It results in alteration in SFR and salivary pH as reported in various literatures.
In the present study, salivary flow was evaluated by simple drooling method by asking patients to lean their head forward over the test tube and allow to drain the accumulating saliva into it. Kanwar et al. and Rooban et al. evaluated SFR by spitting method while a modified Schirmer's test was used by Dyasanoor and Saddu in their study. The SFR varies widely in individuals. The unstimulated normal SFR in the adults ranges from 0.33 to 1.42 ml/min. The mean SFR among the normal healthy individuals in our study was found to be 3.6667 ml/10 min which was in accordance with the study conducted by Rooban et al. where SFR amongst the healthy individuals to be around 3.5 ml/10 min. Moreover, Dawes in a nonsystematic review reported the unstimulated normal SFR to be from 0.3 to 0.4 ml/min.
In the present study, the mean SFR is significantly increased among the individuals with betel nut/gutkha chewing habit without OSMF than that among OSMF patients (5.3333 ml/10 min vs. 3.2586 ml/10 min). Our finding is in accordance with the findings of the study conducted by Abdul Khader and Dyasanoor. This increase in the SFR among the individuals with habit chewer without OSMF could probably be explained on the basis of parasympathomimetic activity of arecoline. Contrary to the findings of these studies, the study conducted by Rooban et al. did not find any statistically significant difference in the SFR among the chewers and nonchewers, though, a relative high SFR was observed amongst the individuals who had a habit of chewing raw areca nut. Kanwar et al. evaluated the long-term effect of tobacco on saliva and found decreased SFR among the tobacco users with the effect being more pronounced in the individuals with a habit of using the smokeless form of tobacco as compared to smoked form. Rad et al. found that the long-term smoking habit significantly reduces the SFR affecting the oral soft and hard tissues which become more vulnerable to pathology under the xerostomic states.
The SFR can be used as a noninvasive diagnostic tool in assessing the oral mucosal pathology. In the present study, the mean SFR was found to be more among the patients with Stage I OSMF than as compared to the patients with Stage II and Stage III OSMF. The probable cause for this reduction in the mean SFR could be attributed to the acinar cell atrophy which occurs on the progression of OSMF as was documented in the study conducted by Nyachhyon et al. To conclude, the results obtained in the present study were found to be encouraging as it was demonstrated that SFR varied significantly between the patients with OSMF, those having a habit of betel nut/gutkha chewing but did not develop OSMF, and the control groups without any habit.
There are some limitations exists in the present study. The clinical parameters used in the present study in the form of SFR were indicators of morbidity and a decreased QoL in the individuals having habit of betel nut/gutkha chewing but these cannot be used as the relevant markers for the impending OSMF in such patients. Further research in this regard is highly desirable wherein the clinical data can be used to provide a scientific evidence to control or, halt the process of malignant transformation in such patients who are with or, without this deadly, potentially malignant condition, OSMF.
| Conclusion|| |
There was a definitive association between the frequency and duration of exposure of the habit, and the subsequent incidence of OSMF in such individuals. SFR was significantly reduced in OSMF patients and it was significantly less in Stage III OSMF patients than Stage I and Stage II OSMF. Although the SFR is significantly higher in the individuals with a habit positive history, those who did not reveal any clinical evidence of OSMF than in patients with OSMF. Hence, it could be concluded that “reduced salivary flow rate could be an initial subjective sign of OSMF.” An early diagnosis and management of these changes with the help of pharmacotherapy, physiotherapy and a proper, balanced diet by the concerned oral physicians, will help such patients to improve their QoL significantly and will decrease the chances of the ongoing malignant transformation with early intervention and stoppage of habit.
To all the patients who contributed in the study without whom this study would not have been feasible.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Khan S, Chatra L, Prashanth SK, Veena KM, Rao PK. Pathogenesis of oral submucous fibrosis. J Cancer Res Ther 2012;8:199-203.
Yoithapprabhunath TR, Maheswaran T, Dineshshankar J, Anusushanth A, Sindhuja P, Sitra G. Pathogenesis and therapeutic intervention of oral submucous fibrosis. J Pharm Bioallied Sci 2013;5:S85-8.
Selvam PN, Dayanand AA. Lycopene in the management of oral submucous fibrosis. Asian J Pharm Clin Res 2013;6:58-61.
Bhat SJ, Blank MD, Balster RL, Nichter M, Nichter M. Areca nut dependence among chewers in a South Indian community who do not also use tobacco. Addiction 2010;105:1303-10.
Kanwar A, Sah K, Grover N, Chandra S, Singh RR. Long-term effect of tobacco on resting whole mouth salivary flow rate and pH: An institutional based comparative study. European J Gen Dent 2013;2:296-9.
Rad M, Kakoie S, Niliye Brojeni F, Pourdamghan N. Effect of long-term smoking on whole-mouth salivary flow rate and oral health. J Dent Res Dent Clin Dent Prospects 2010;4:110-4.
Abdul Khader NF, Dyasanoor S. Assessment of salivary flow rate and pH among areca nut chewers and oral submucous fibrosis subjects: A comparative study. J Cancer Prev 2015;20:208-15.
Chadha P, Yadav JS. Studies on the genotoxicity of gutkha. Int J Hum Genet 2011;11:277-82.
Wu KP, Ke JY, Chung CY, Chen CL, Hwang TL, Chou MY, et al
. Relationship between unstimulated salivary flow rate and saliva composition of healthy children in Taiwan. Chang Gung Med J 2008;31:281-6.
Navazesh M, Kumar SK, University of Southern California School of Dentistry. Measuring salivary flow: Challenges and opportunities. J Am Dent Assoc 2008;139 Suppl: 35S-40S.
Gupta MK, Mhaske S, Ragavendra R, Imtiyaz K. Oral submucous fibrosis: Current concepts in etio-pathogenesis. People's J Sci Res 2008;1:39-44.
More CB, Das S, Patel H, Adalja C, Kamatchi V, Venkatesh R. Proposed clinical classification for oral submucous fibrosis. Oral Oncol 2012;48:200-2.
Wahi PN, Kapur VL, Luthra UK, Srivastava MC. Submucous fibrosis of the oral cavity. 1. Clinical features. Bull World Health Organ 1966;35:789-92.
Sinor PN, Gupta PC, Murti PR, Bhonsle RB, Daftary DK, Mehta FS, et al
. A case-control study of oral submucous fibrosis with special reference to the etiologic role of areca nut. J Oral Pathol Med 1990;19:94-8.
Wahab N, Asifali S, Khan M, Khan S, Mehdi H, Sawani A. Frequency of clinical presentation of oral submucous fibrosis. Pak J Med Dent 2014;4:48-53.
Shah N, Sharma PP. Role of chewing and smoking habits in the etiology of oral submucous fibrosis (OSF): A case-control study. J Oral Pathol Med 1998;27:475-9.
Ranganathan K, Devi MU, Joshua E, Kirankumar K, Saraswathi TR. Oral submucous fibrosis: A case-control study in Chennai, South India. J Oral Pathol Med 2004;33:274-7.
Jha VK, Kandula S, Ningappa Chinnannavar S, Rout P, Mishra S, Bajoria AA. Oral submucous fibrosis: Correlation of clinical grading to various habit factors. J Int Soc Prev Community Dent 2019;9:363-71.
Rao AB. Idiopathic palatal fibrosis. Br J Surg 1962;50:23-5.
Rajendran RK, Babu N, Nair KM. Serum levels of some trace and bulk elements in oral submucous fibrosis. J Indian Dent Assoc 1992;63:251-5.
Nigam NK, Aravinda K, Dhillon M, Gupta S, Reddy S, Srinivas Raju M. Prevalence of oral submucous fibrosis among habitual gutkha and areca nut chewers in Moradabad district. J Oral Biol Craniofac Res 2014;4:8-13.
Sharma R, Raj SS, Miahra G, Reddy YG, Shenava S, Narang P. Prevalence of oral submucous fibrosis in patients visiting dental college in rural area of Jaipur, Rajasthan. J Indian Acad Oral Med Radiol 2012;24:1-4. [Full text]
Maher R, Lee AJ, Warnakulasuriya KA, Lewis JA, Johnson NW. Role of areca nut in the causation of oral submucous fibrosis: A case-control study in Pakistan. J Oral Pathol Med 1994;23:65-9.
Pindborg JJ, Mehta FS, Gupta PC, Daftary DK. Prevalence of oral submucous fibrosis among 50,915 Indian villagers. Br J Cancer 1968;22:646-54.
Rooban T, Mishra G, Elizabeth J, Ranganathan K, Saraswathi TR. Effect of habitual arecanut chewing on resting whole mouth salivary flow rate and pH. Indian J Med Sci 2006;60:95-105.
] [Full text]
Dyasanoor S, Saddu SC. Association of xerostomia and assessment of salivary flow using modified schirmer test among smokers and healthy individuals: A preliminary study. J Clin Diagn Res 2014;8:211-3.
Dawes C. Salivary flow patterns and the health of hard and soft oral tissues. J Am Dent Assoc 2008;139 Suppl: 18S-24.
Nyachhyon R, Boaz K, Sumanth KN. Minor salivary gland changes in oral submucous fibrosis (OSMF): Retrospective pilot study. J Nepal Dent Assoc 2011;12:26-8.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3]