Skip to main content
Toggle Menu of ADA WebSites
ADA Websites
Partnerships and Commissions
Toggle Search Area
Toggle Menu
e-mail Print Share

Associated Topics

Adenoidectomies decrease the pathogenic nasopharyngeal bacterial

Lisa Jacob DDS, MS .


Systematic Review Conclusion

There is limited evidence that adenoidectomies have a beneficial effect on the pathogenic nasophyaryngeal bacterial flora

Critical Summary Assessment

This review of eight studies has a low quality of evidence to support its conclusions that adenoidectomies decrease the number of pathogenic nasopharyngeal bacterial flora. There is no correlation in these studies with the relationship of bacterial flora and its relationship with recurrence of upper respiratory infections in children.

Evidence Quality Rating

Limited Evidence

Structured Abstract

Clinical Questions:

Do children with recurrent respiratory tract infections show a decrease in the nasopharyngeal bacterial flora after an adenoidectomy?

Review Methods:

Two electronic databases were searched to identify studies on the effect of adenoidectomies on the nasopharyngeal bacterial flora published up to May 3, 2008. Two of the authors reviewed the 1,237 citations and used the following inclusion criteria: 1) children less than 18 years of age 2) children who had undergone adenoidectomy or adenotonsillectomy 3) nasopharyngeal bacterial flora were studied before and after or only after surgery 4) study contained original data. From these inclusion criteria, 42 studies were selected in which 34 were excluded. Thus, 8 citations were reviewed and compared. The methodological quality of the included studies was assessed with a checklist designed by Downs and Black for randomized and nonrandomized studies. The outcome measure was the percentage of children with a positive culture for potentially pathogenic bacteria before and after surgery.

Main Results:

Overall, the methodological quality of the studies was poor. There were three subgroups of children: 1) children with sinonasal symptoms 2) children with middle ear disease 3) diverse symptoms related to the adenoid and/or tonsils. Streptococcus pneumonia and Staphylococcal aureas were the most common in children with the sinonasal symptoms. Heaemophilus influenzae was the most common in children with diverse symptoms. In most studies, the carriage of potential pathogens decreased following adenoidectomy. In fact within one month, the carriage rate of Streptococcus pneumonia and Haemophilus influenzae decreased in six of seven studies. True quantitative microbiology results were not reported. In the majority of studies the postoperative swab was taken after a short period (10 days to one month).


Carriage potential pathogens in the nasopharynx appear to decrease after adenoidectomy but the carriage of nonpathogens increases. The methodological quality of the design was poor. Other factors may have biased the effect of adenoidectomy on the colonization of bacteria in the nasopharynx. For instance, the use of antibiotics was only reported in three publications. Also, the postoperative swabs were taken after a short period of time varying from 10 days to three months. There should be more long term data.

Source of Funding:



Importance and Context:

It is important to know if a patient has a respiratory infection and/or is taking any antibiotics before starting dental treatment on a patient in order to determine the methods used for dental treatment.

Strengths and Weaknesses of the Systematic Review:

This low quality systematic review included a comprehensive literature search strategy, well defined inclusion/exclusion criteria . It also included a list of studies with its characteristics provided in a clear table format. The weakness of this systematic review is that there was not enough evidence to prove the authors conclusions.

Strengths and Weaknesses of the Evidence:

There appears to be no publication bias. This review had great heterogeneity which prohibited the authors from performing a meta-analysis. Thus, there limited evidence. Furthermore, of the 8 studies reviewed, not one addressed if the number of upper respiratory infections actually decreased after adenoidectomy.

Implications for Dental Practice:

A good review of a patient’s medical history is important at each dental visit. The treatment plan options will be created based on the patient’s medical history. For example, nitrous oxide/oxygen inhalation is contraindicated in patients with upper respiratory infection, nasal obstruction or otitis media. If a patient has ever has middle ear disease or damaged ear drums, they may suffer either transient or permanent hearing loss if nitrous oxide/oxygen inhalation is administered. It is just as important to know what types of antibiotics a patient is taking or has taken recently due to the increase in bacterial resistance to antibiotics among patients these days. In addition, it is important to note that the conjugate pneumococcal vaccine was implemented after publication of the studies included in this review.

Critical Summary Publication Date:


These summaries are not intended to, and do not, express, imply, or summarize standards of care, but rather provide a concise reference for dentists to aid in understanding and applying evidence from the referenced systematic review in making clinically sound decisions as guided by their clinical judgment and by patient needs. American Dental Association © 2019