Dental research center > Hygienic information > Mouth odor

Mouth odor

There is no doubt that, mouth odor is embarrassing for many of the individuals.
Unfortunately, mouth odor can't be diagnosed personally.
Halitosis is considered as a disease and it should not be mistaken for the bad smell which may arise from eating some nourishment such as onion or garlic. Halitosis can be treated and decreased to a large extent.

Etiology of Halitosis

Dental caries

If you don't brush your teeth and also don't clean your interproximal surfaces, dental caries will occur. The food remnants between your teeth will be fermented-particularly on root surfaces- and cause mouth odor.

Gingival diseases

While you neglect your gingival hygiene, gums will be weakened as time passes. Bacterial accumulation on the surfaces that teeth are attached to gingival tissues will result into some difficulties such as mouth odor.

Increased anaerobic bacteria

Bacteria exist in the mouth as natural flora. Lack of proper oral hygiene, causes the germs to spread. The most common locations for bacterial growth are on the tongue's surface, nasal canals and throat. In some people anaerobic germs increase and grow more than normal for different reasons. Anaerobic bacteria cause mouth odor by decomposing food remnants.

Life style, diet

Commonly, halitosis is caused by lack of proper oral hygiene in gingiva and tongue. Different bacteria and decomposing of food remnants are effective to create this complication.

Food decomposition leads to sulfur generation and results in making mouth odor. Post extraction sockets that are filled with clot, uncleaned acrylic dentures, pericoronitis(inflammation of the gingival surrounding the crown of a tooth),tongue and tongue coat are operative to cause mouth odor.


Saliva has an important role in appropriate respiration. While bacteria increase in the mouth, salivary flow will decrease their accumulations.

As salivary flow is reduced during the night, generation and proliferation of oral microbes increase when we are asleep. Further more, low salivation causes hypoxia in oral tissues and provides good condition for reproduction of anaerobic bacteria. So this is the reason that some people suffer from halitosis.

Medical Causes

Infections: Recurrent infections of tonsils, bronchitis, pneumonia, and infections of digestive system, kidney, liver and diabetes can cause halitosis.

Post nasal drip: Accumulation of excessive mucus in sinuses, throat and at posterior part of the tongue can result in reproduction of anaerobic microbes. It has to be noted some dairy products, allergens and some specific drugs can be effective in creation of mucus.

Drugs: some drugs can cause xerostomia and increased mucus production. Antidepressants, antihistamines, and drugs taken to reduce blood pressure are among related dugs.

Diseases: Pulmonary diseases, blood, liver and kidney disorders and diabetes have a role in creating halitosis. Such diseases can cause mouth odor as well.

Other Factors: Stress, psychological pressures and smoking can be a reason for mouth odor.

Methods of Treatment

  • Good oral hygiene and brushing the teeth can be effective to lessen mouth odor. Brush your teeth accurately at least twice a day. Don't forget washing and brushing your tongue and oral mucosa.

  • Using mouth rinse will help to disinfect oral microbes and bacteria and is effective in treatment of halitosis.

  • Changing Life style and diet, relieving the stress, avoiding smoking, and drinking plenty of water can have an important role in mouth odor's treatment. Chewing parsley and eating vegetables such as rosemary and cinnamon are effective in exterminating mouth odor.

  • Eating fruits with sour taste and chewing gums will be helpful, because they stimulate salivation. Besides drinking 6 to 8 glasses of water during a day is also effective. (probably because it reduces salivary PH and prevents the dissolution of compositions creating halitosis.)


Editor: Hamid Reza Arab ( Assistant Professor, Department of Periodontics)

Translated by Dr. Bahareh Hafez.(Dentist)



Last Update : 2017-12-12 00:24:56

Mashhad University of Medical Sciences Contact Details:
Main address: University St., Ghoraishy Building 91375-345 Mashhad, Iran ,
Tel:( 98 511) 841 2081-5 , Fax:( 98 511) 8430249 , E-mail: Info(at) Members: - Schools and Hospitals School: Dentistry , School: Health , School: Medicine , School: Nursing & Midwifery , School: Paramedical , School: Pharmacy , School: Traditional Medicine , Hospital: Dr.Sheikh , Hospital: Dr.Shariati , Hospital: Emam Reza , Hospital: Ghaem , Hospital: Hashemi Nezhad , Hospital: Ibn-e-Sina , Hospital: Khatam-al-Anbia , Hospital: Montaserie , Hospital: Ommul-Banin , Hospital: Omid , Hospital: Shahid Kamyab , Hospital: Taleghani , History: Mashhad Faculty of Medicine was officially opened on Nov. 23, 1949 by Dr Zanganeh, the minister of culture. The school started out with 61 students, one associate professor and seven tutors. In 1956, when the school of Arts opened, the two schools merged to form the University of Mashhad. In 1989, the faculties offering Medical Sciences' degrees across the country separated from the Ministry of Culture and Higher Education. New emerging Medical Universities have gone under management of Ministry of Health, Treatment and Medical Education. Thus the original University of Mashhad was divided into two independent universities: "Ferdowsi University of Mashhad" and "Mashhad University of Medical Sciences'. Mashhad University of Medical Sciences operates at present with 8 faculties, 32 hospitals, 179 rural and 147 urban health centers. It covers an enormous area stretching from the north east to the central parts of the country, which makes it the largest university of Medical Sciences providing health care and treatment services. With 597 teaching staff, 1645 MDs with different specialties, 138 dentists, 123 pharmacists and 25, 402 employees, the university provides health care and medical services to the area's large population as well as to over 25 million tourists a year.

Dental Research Center, Opposite Mellat Park, Vakilabad Blvd., Mashhad-Iran, Tel.: (+98 51) 38829501-15, Fax: (+98 51) 38829500, E-mail:
All rights reserved. No part of the contents of this Website may be reproduced or transmitted in any form or by any means, without the written permission