A dentist will ask questions about your oral health and hygiene, like how long you have been experiencing bad breath. He will examine your gums, teeth, salivary glands and oral tissues for relating the cause of your bad breath to dental problems. Bleeding, redness of gums, scarring of tissues and teeth cavity are checked by the dentist which are responsible for causing bad breath. You are required to see the dentist on an empty stomach and brushing your teeth three hours prior to your appointment.

This highly professional laboratory test measures molecular levels of sulfur compounds in mouth air. A sample of the patient’s breath is taken, which is further studied under gas chromatographs to identify the presence of three major VSCs (hydrogen sulfide, methyl mercaptan and dimethyl sulfide). The accurate results produced in graph forms can be viewed through a computer interface. Chromatography is christened as the ‘gold diagnostic standard’ for measuring oral malodor. The process as well as the machine is quite cumbersome and demanding to operate however, needs adequate training, and the test is expensive too. The test is therefore, mainly used in the research setting.

The dentist will smell the breath from your mouth as well as from your nose and he’ll rate the odor on a scale of 0 to 5. A 0 score indicates no odor, 1 is barely detectable and 5 being strongly foul. He may also scrape the back of your tongue with a plastic spoon and rate its odor because the back of the tongue is most often the source of smell. Such instrumentation and examinations, called organoleptic measurements, are widely used in breath clinics but are really expensive. So you can opt for various measures like the manual sniffing or professional instruments according to your own budget.

This portable sulfide monitor measures sulfur levels and volatile sulfur compounds (VSCs) in the mouth air through a blow pipe. The VSCs are the principal malodorants in chronic halitosis. These compounds are generated by anaerobic bacteria, located primarily on the back of the tongue. The amount of sulfur present in the breath can further indicate what type of treatment should be meted out to the patient. In the USA, the halimeter is manufactured by Interscan Corp, Califonia and is patented by the same company. The electrochemical sensor is sensitive to alcohol, so avoid consuming in any form for at least 10-12 hours prior to the test. Foods like garlic and onion produce strong amounts of sulfur in the breath, so avoid taking them too before the test. No special training is required for using a halimeter, it is quite portable and breath measurements can be made quite easy with this inexpensive device. That is why you can find this device in almost all dentists’ clinics.

The test is done to measure the salivary levels of enzymes which indicate the presence of halitosis related bacteria. This particular bacteria is responsible for causing periodontal disease (gum disease), which contributes to bad breath. The bacteria can produce a certain type of enzyme that degrades the compound named BANA (benzoyl-D L-arginine-naphthylamide). In this test, the patient’s saliva is tested with the BANA testing component that breaks it down, causing a color change in the testing medium. This test is performed in a laboratory by trained periodontists.

The salivary levels which this enzyme produces are supposed to cause oral malodor. Hence, this test is preformed to check the saliva levels for β galactosidase enzyme. The test is conducted by mixing lactose with ONPG (ortho-nitrophenyl-b-D-galactopyranoside) which will turn to a yellow color if this enzyme is present. The laboratory examination involves high levels of proficiency in carrying out an experiment which requires incubating ONPG with bacteria to induce the production of this specific enzyme. This is a very rare test and is only used for finding out the presence of a specific enzyme in a patient’s saliva sample.

The presence of compounds which produce bad breath can also be tested by the principle of chemiluminescence in a lab. A sample of mouth air containing sulfur compounds, such as VSCs, which cause bad breath is mixed with the mercury compound, the reaction results in fluorescence. Low levels of sulfur compounds are efficiently and selectively tested through chemiluminescence as compared to a halimeter. This, too, is an uncommon test and expensive one though mainly done to identify small and specific causative agent of halitosis.

Bad breath is an evident result of the inflammation of the respiratory tract. Infections such as sinusitis, hay fever and allergies can cause the respiratory tract as well as the nasal passages to function improperly and eventually causes bad breath. An X-ray of the chest or sinusitis can reveal blockage of the airways or presence of bacteria that is causing halitosis.

The diseases of the gastro-intestinal tract are also responsible for causing bad breath as the gases enter the mouth and the esophagus. A tube like instrument with light and camera, the endoscope is inserted through the mouth into the esophagus. The endoscope takes pictures of the internal organs and what’s going in the esophagus, and sends them to a computer where the gastroenterologist can view them. 10-12 hours of fasting prior to the test and rest of about 4-5 hours afterwards is required to let the anesthesia wear down.