Journal of Interdisciplinary Dentistry

: 2019  |  Volume : 9  |  Issue : 3  |  Page : 119--124

Bacteriological correlation between dental plaque and chronic tonsillitis

Muath K Al-Otaibi1, Suhael Ahmed2, Fawaz A Al-Abdullah1, Omar M Sabbagh1, Jarallah M Al-Qahtani1, Faisal H Al-Mutairi1, Mohammed A Al-Ansari1, Abdulghani S Al-Zahrani1, Yazeed A Al-Furaydi1, Abdullah A Al-Duhaymi1, Salah Mohammed3, Yasser Al-Otaibi4, Nafeesa Tabassum5,  
1 Department of Oral and Diagnostic Sciences, Riyadh Elm University, Riyadh, Kingdom of Saudi Arabia
2 Department of Oral and Maxillofacial Surgery, Riyadh Elm University, Riyadh, Kingdom of Saudi Arabia
3 Department of Microbiology, Riyadh Elm University, Riyadh, Kingdom of Saudi Arabia
4 Department of Periodontics, Prince Sultan Military Medical City, Riyadh, Kingdom of Saudi Arabia
5 Department of Oral and Maxillofacial Surgery, Dar Al Uloom University, Riyadh, Kingdom of Saudi Arabia

Correspondence Address:
Suhael Ahmed
Po Box 84891, Department of Oral and Maxillofacial Surgery, Riyadh Elm University Opposite Passport Office, Namuthajiyah, Riyadh
Kingdom of Saudi Arabia


Aims and Objectives: The aim of this study is to investigate the role of supragingival dental plaque bacteria as potential etiology of chronic tonsillitis. Materials and Methods: A total of sixty patients were part of the study. Among them, thirty patients had chronic tonsillitis and thirty patients had no tonsillitis. The age range was 3–12 years. Swab samples were obtained from dental plaque and tonsils to identify the bacterial flora. Identification methods included metabolic capability, microscopic reading, and biochemical reaction. Statistical analysis was done using SPSS 18 software. Results: The bacteria isolated according to the prevalence in decreasing order of frequency were Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus haemolyticus, Streptococcus mutans, Streptococcus sanguis, Streptococcus viridans, Streptococcus mitis, Streptococcus salivarius, Streptococcus oralis, Candida albicans, and Peptostreptococcus. Statistical analysis conducted with SPSS 22 indicated that strains of bacteria present in the plaque are more likely to represent the bacteria in the tonsils, particularly S. pyogenes.Conclusion: Group A Streptococcus in dental plaque could possibly be a causative factor for chronic tonsillitis.

How to cite this article:
Al-Otaibi MK, Ahmed S, Al-Abdullah FA, Sabbagh OM, Al-Qahtani JM, Al-Mutairi FH, Al-Ansari MA, Al-Zahrani AS, Al-Furaydi YA, Al-Duhaymi AA, Mohammed S, Al-Otaibi Y, Tabassum N. Bacteriological correlation between dental plaque and chronic tonsillitis.J Interdiscip Dentistry 2019;9:119-124

How to cite this URL:
Al-Otaibi MK, Ahmed S, Al-Abdullah FA, Sabbagh OM, Al-Qahtani JM, Al-Mutairi FH, Al-Ansari MA, Al-Zahrani AS, Al-Furaydi YA, Al-Duhaymi AA, Mohammed S, Al-Otaibi Y, Tabassum N. Bacteriological correlation between dental plaque and chronic tonsillitis. J Interdiscip Dentistry [serial online] 2019 [cited 2022 May 24 ];9:119-124
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Full Text

 Clinical Relevance to Interdisciplinary Dentistry

There is a correlation between microflora of the tonsils and the micro organisms found in plaque which holds good for the clinical relevance to interdisciplinary dentistry involving Periodontics and oral surgery divisions.


Dental plaque is a phenotype of many different bacteria that grow on tooth surfaces,[1] which may account for more than 580 different bacterial species.[2] Bacteria could cause diseases, such as tonsillitis, which is known as an inflammation of the palatine tonsils, usually due to Group A Streptococcus pyogenes (GAS), or less commonly, to a viral infection.[3] Tonsillitis is the most common disease encountered by otorhinolaryngology (ear, nose, and throat [ENT]) surgeons, pediatricians, and general practitioners, in their daily practice, which occurs more prominently in patients below the age of 15 years old and has a higher tendency of affecting males over females.[3] The tonsils are situated in areas where microorganisms are teeming, enabling the passage of organisms through areas of deficient epithelium, bearing the effect of individual attacks of tonsillitis.[4] It is important to identify the individual pathogen causing tonsillitis, GAS characterized by β-hemolysis. S. pyogenes is the most common bacterial cause of tonsillopharyngitis. In addition to tonsillitis, S. pyogenes may cause acute otitis media, pneumonia, and cardiovascular diseases.[5] With several studies conducted in relation to oral hygiene and chronic tonsillitis, such as in Iraq, it was proven that chronic tonsillitis in children between the age of 4 and 5 years was due to the patients' poor oral hygiene.[6] Another study has proved that dental plaque accumulation can act as a reservoir for many diseases.[7] However, using the decayed, missing, filled, teeth index, researchers found that there is no relation between oral hygiene and tonsillitis.[8] Tonsillar infection may arise from bacteria within the tonsillar parenchyma or crypts or from the bacteria on the surface, which may be colonizing the tonsil, without essentially infecting it. Therefore, a look into the colonization of bacteria in the vicinity of tonsils may be worthwhile.

We aimed to investigate the role of supragingival dental plaque bacteria as a potential etiology of chronic tonsillitis.

 Materials and Methods

In this cross-sectional study consisting of sixty patients, thirty patients with chronic tonsillitis (study group) and thirty with no chronic tonsillitis (control group) were included. The age group of the patients was between 3 and 12 years for both males and females. Samples were obtained from four hospitals in Riyadh city, namely, Yamamah Hospital, King Abdulaziz University Hospital, Prince Sultan Military Medical City, and dental hospital affiliated to Riyadh Elm University. A larger sample size would have given a wider perspective to the investigation. The sample size was restricted to sixty in our study owing to the demographics of the region of Saudi Arabia as the hospitals selected for the study were not from a densely populated region, and consideration was also given to acceptance of the patients in participating in the study. The swab samples were collected under supervision of an ENT doctor. Samples from dental plaque of the cervical area of upper molar teeth and medial surface of the tonsils were obtained. Amie's transport medium [Figure 1] was used to transport the samples. Bacteria were cultured by streaking them into four quadrants on blood agar [Figure 2]. Isolation was done by a standardized procedure for each patient to identify the microorganisms in aerobic and anaerobic bacteria for dental plaque and tonsil samples. All the plates were incubated at 37°C for 48 h. For bacterial growth, we used the anaerobic jar [Figure 2] with gas. After bacterial growth, we made two colonies on each microscopic slide [Figure 3]. Cedar oil on oil immersion lens was applied for microscopic reading. In addition, we used the optochin disc to differentiate between Streptococcus pneumonia and Streptococcus viridans [Table 1], [Table 2].{Figure 1}{Figure 2}{Figure 3}{Table 1}{Table 2}

We used the metabolic capability, microscopic reading, and biochemical reaction for recording all the samples. The fact that the study group was not under antibiotic coverage within 2 weeks of sample collection, which may interfere with the results, was taken into consideration.

Ethical clearance was obtained from the Ethical Committee of College of Dentistry, Riyadh Elm University, with the registration number FUCRP 2015/191, and the study was conducted in full accordance with ethical principles, including the World Medical Association Declaration of Helsinki.


On isolating the aerobic bacterial strains from dental plaque [Figure 4], it was found that S. pneumonia percentage was 38.5% in control group, and 32.6% in study group; S. pyogenes [Figure 4] and [Figure 5] was 20.5% and in 22.5% in study group S. hemolyticus was 18 23.1% for control group and 27% in study group; Streptococcus salivarius was16.7% for control and 4.5% for study group; Candida albicans [Figure 4], [Figure 5], [Figure 6] was1.3% for control group and 4.4% for study group. Streptococcus oralis and Streptococcus mutans were found only in the study group, with three species for each one (3.4%) and Peptostreptococcus with Streptococcus mitis one species for each one which is 1.1%. In aerobic tonsils [Figure 5], we found S. pneumonia percentage was 30was 32.6% in controlled group and 40.3% in study group, S. pyogenes was 26.1% in controlled group and 20.8% in study group, S. hemolyticus was 21.7% for controlled group and 25% for study group, S. salivarius was 19.6% for controlled 8.3% for study group, Peptostreptococcus found only in study group two species 2.8%. S. mitis and S. mutans only found in study group about one species for each one 1.4%. In anaerobic dental plaque [Figure 6], we found Streptococcus sanguis percentage was 23.9% in controlled group and 22.8% in study group, S. mutans was 20.5% in controlled and 13.4% in study, S. mitis was 22.2% for controlled group and 11.8% for study, S. viridans was 12% for controlled and 14.2% for study group, S. pyogenes was 2.6% in controlled and 18.1% in study group, C. albicans was 3.4% for controlled and two 1.6% for study group. In anaerobic tonsils [Figure 7] situation we found, S. mutans 26.2% in controlled and 22.3% in study, S. mitis was 23.3% for controlled group and 19.6% for study, S. viridans 19.4% for controlled and 19.6% for study group, S. pyogenes was 12.6% in controlled and 16.1% in study group, S. hemolyticus 18.4% for controlled and 21.4% for study group. S. salivarius was found only in study group (0.9%).{Figure 4}{Figure 5}{Figure 6}{Figure 7}

Using Chi-square program, it was found that there was no statistical difference between the results for the control group and the study group as P = 0.076. Aerobic S. pyogenes in the plaque of the control and test groups (16 species [20.5%] and 20 species [22.5%], respectively) reflect approximately the same amount in the tonsillitis control and test groups (24 species [26.1%] and 15 species [20.8%], respectively). For the anaerobic S. pyogenes, it was found that the plaque in the test group (23 species [18.1%]) reflects approximately the amount in the tonsils (18 species [16.1%]). In the control group, anaerobic S. pyogenes in plaque showed a significant difference in the amount in tonsils with a percentage of 2.6% and 12.6%, respectively, and the low percentage may be because of the fact that in an anaerobic environment, surviving bacteria grow and depend on oxygen for the adenosine triphosphate production. SPSS software version 18 IBM SPSS was used for statistical analysis.


S. pneumoniae [Figure 8] and [Figure 9] is a Gram-positive alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), facultative anaerobic member of Streptococcus family.[1]S. pneumoniae is the main cause of meningitis and pneumonia in children and elderly population.[7] In 1920, S. pneumoniae was known as Diplococcus pneumonia owing to its shape in the sputum stain.[9]{Figure 8}{Figure 9}

C. albicans [Figure 10] and [Figure 11] is a fungal pathogen, which usually causes candidiasis in humans.[10] However, it becomes opportunistic pathogen for immunocompromised patients, for some immunologically weak individuals, or even for healthy persons. The infection caused by C. albicans is commonly known as candidiasis. Candidiasis can be classified into two categories depending on the severity of the disease. In the first category are the mucosal infections, and the best known among these mucosal infections is thrush which is characterized by white spots in the infected membranes. These infections generally affect gastrointestinal epithelial cells and vaginal or oropharyngeal mucosa. Furthermore, vulvovaginal candidiasis (VVC) is quite common among women, and some of them experience repeated occurrences of this infection, which is known as recurrent VVC. However, it causes life-threatening, systemic infections to severely ill patients in whom the mortality rate is about 30%. Systemic Candida infections are common to immunocompromised individuals, including HIV-infected patients, transplant recipients, chemotherapy patients, and low-birth weight infants. Although some nonalbicans species such as Candida glabrata, Candida krusei, Candida dubliniensis, Candida parapsilosis, and Candida tropicalis are recovered from infected individuals, C. albicans remains a major infectious fungal agent.[11] In a study of 100 patients with chronic tonsillitis, Mallya and Abraham found that isolates identified by surface swabbing were consistent with those identified by core sampling in most patients.[12] The pathogenesis of chronic and recurrent tonsillitis remains largely unknown and therefore attributing the cause to a particular pathogen in a plethora of organisms does not hold good. Therefore, the source of pathogens can possibly be from neighboring inflammatory regions also.{Figure 10}{Figure 11}

Recurrent tonsillitis is the most common throat disorder,[7] in which the tonsils' core comprises of numerous bacteria, some of which are potentially pathogenic, aerobic, and anaerobic bacteria,[13] with a quantity of the bacteria in the surface and core of the tonsils being almost equal.[14] There are many factors that influence the growth of the bacteria, namely, temperature, redox potential, power of hydrogen, and nutrients.[7] These bacteria can be causative of the following in pediatric patients: sleep disorders, breathing, recurrent tonsillitis, and peritonsillar abscess.[15]

Group A Streptococci (GAS) is known as an important cause of morbidity and mortality[16] because it can cause serious diseases such as rheumatic heart disease, acute poststreptococcal glomerulonephritis, and acute rheumatic fever (ARF).[17] The only nonsurgical treatment for tonsillitis is antibiotic drugs (Manandhar, Bhandary et al. 2014). However, as the bacteria can develop some resistance to these drugs, surgical removal of the tonsils is the treatment of choice (tonsillectomy). In a study in the Kingdom of Saudi Arabia, with a history of sore throat 1 to 4 weeks before ARF and after the incubation of the bacteria from the throat in the laboratory, GAS was found positive,[18] and it was even found in healthy children.[19] As GAS is highly infectious, there are now studies that show a newly developed vaccine that can work against S. pyogenes, but it has been only tested on animals and not licensed for human use.[20] With recent studies, we can infer that maintaining good oral hygiene can give a good quality of life.[21]

The diagnosis of tonsillitis generally requires the consideration of GAS. However, numerous other bacteria (alone or in combinations) and viruses may cause tonsillitis. In our study, isolation of S. pyogenes [Figure 12] and [Figure 13] was 20.5% in control and 22.5% in study group, which suggests that there could be a close association between the microflora of plaque in the maxillary buccal region and the flora found in tonsils and that the presence of S. pyogenes in the vicinity of tonsils could possibly be a causative factor for tonsillitis.{Figure 12}{Figure 13}

In most cases, the cause of the chronic tonsillitis is from the Streptococcus family. From that aspect, we may conclude that the bacterial flora of tonsils reflects the bacterial flora of plaque, more lodgment of bacteria in the plaque could mean more relocation to the tonsils, and accumulation in and around tonsils may cause recurrent chronic tonsillitis. However, as metabolic capability, microscopic reading, and biochemical reaction were done, there are a few limitations to our study, and therefore, additional tests such as serological identification and molecular biology techniques could add to the investigations.


Keeping into consideration the limitations of our study, it may be concluded that isolation of tonsillitis-causing organisms from supragingival dental plaque may have a role in the etiology of chronic tonsillitis, as plaque may act as a reservoir for lodging of these potentially harmful organisms.

Therefore, emphasizing the need for maintaining good oral hygiene in order to prevent harboring of these bacteriological colonies may affect the patient's quality of life.

However, further conclusive studies may be required to further validate this hypothesis.


We express our gratitude to the hospitals and doctors for their help and support during the research.

Dental hospital affiliated to Riyadh Elm University, RiyadhPrince Sultan Military Medical City, RiyadhKing Abdulaziz University Hospital, RiyadhYamamah Hospital (YH), RiyadhDr. Susan. A. George, ENT surgeon at YH.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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