Halitosis
Synonyms and keywords: oral malodor; breath odor; foul breath; fetor oris; fetor ex ore; bad breath

# Overview
The word halitosis is derived from the Latin word halitus, meaning more than a socially acceptable degree of bad breath from the mouth. The majority of the time, it is due to poor dental, tongue hygiene, and gum infections. It can be physiological due to decreased saliva flow or an underlying disease. The patient can perceive the bad breath, or others might complain about it. It adversely affects the patients social and professional life.

# Classification
- Halitosis can be classified into physiologic, pathologic, or subjective:
Physiologic halitosis occurs due to decreased saliva production. It occurs in the morning when the mouth is dry, and there is an overgrowth of oral bacteria. Tobacco smoking and certain food items like garlic and onion also cause bad breath due to aromatic compounds. Physiological halitosis improves significantly by flossing, tooth brushing, rinsing with mouthwash, and drinking water.
Pathological halitosis occurs due to an underlying disease. The common causes include postnasal drip, sinusitis, gingivitis, and caries. The tonsillar inflammation and peri-tonsillar abscesses can also result in bad breath.
Subjective halitosis is also called psychogenic halitosis. The patient thinks that they have bad breath, while the diagnostic tests are negative for halitosis.
- Physiologic halitosis occurs due to decreased saliva production. It occurs in the morning when the mouth is dry, and there is an overgrowth of oral bacteria. Tobacco smoking and certain food items like garlic and onion also cause bad breath due to aromatic compounds. Physiological halitosis improves significantly by flossing, tooth brushing, rinsing with mouthwash, and drinking water.
- Pathological halitosis occurs due to an underlying disease. The common causes include postnasal drip, sinusitis, gingivitis, and caries. The tonsillar inflammation and peri-tonsillar abscesses can also result in bad breath.
- Subjective halitosis is also called psychogenic halitosis. The patient thinks that they have bad breath, while the diagnostic tests are negative for halitosis.

# Pathophysiology
- It is thought that halitosis is produced by bacterial overgrowth in the oral cavity.
- Poor oral hygiene, dental caries, or gum infection results in the growth of gram-negative anaerobes in the mouth.
- These bacteria thrive on debris material entrapped between teeth and gums. Lysosomal enzymes secreted by the bacteria break down the glycoproteins in the food particles. It results in volatile compounds like hydrogen sulfide, dimethyl sulfide, and methyl mercaptan, resulting in halitosis.
- The Bacteroides, Prevotella, and Fusobacterium species are mainly responsible for halitosis.

# Causes
Common causes of halitosis include:
- Gingivitis
- Plaques on the tongue
- Inflammation of the gum around the impacted wisdom tooth
- Ucerative gingival infection
- Herepes stomatitis
- Chronic sinusitis
- Allergies
- Post-nasal drip
- Foreign objects in the nasal cavity
- Tonsillitis and peri-tonsillar abcsess
- Chronic bronchitis
- Bronchial carcinoma
- Gastroesophageal reflux disease
- Food containing onion, garlic and spices
- Caffeine intake
- Smoking
- Psycogenic halitosis

# Differntiating Halitosis from other Diseases
Halitosis must be differentiated whether it has a physiological cause, some underlying disease, or psychogenic cause.

# Epidemiology and Demographics
- The prevalence of halitosis is approximately 32,000 per 100,000 individuals worldwide.
- Halitosis affects men and women equally.
- It is more common in middle and lower socioeconomic classes.
- The prevalence of halitosis is increasing with time.

# Risk Factors
Common risk factors in the development of halitosis include:
- Hepatic cirrhosis and hepatic failure
- Chronic kidney disease
- Diabetic ketoacidosis
- Xerostomia
- Gastritis due to Helicobacter pylori infection

# Screening
There is insufficient evidence to recommend routine screening for halitosis.

# Natual History, Complications, and Prognosis
Common complications of untreated halitosis include mood disorders like depression, anxiety, paranoia, phobia, and obsessive-compulsive disorder.

# Diagnosis

## Diagnostic Study of Choice
Organoleptic measurement is the gold standard test for the diagnosis of halitosis.

### Organoleptic Measurement
- It is one of the oldest techniques to detect a bad smell.
- The air expelled from both nose and mouth is smelled to detect a foul odor.
- The patient inspires from the nose with mouth close and then expires from the mouth, while the examiner detects it from a distance of 20 cm through a pipette.
- This diagnostic test is highly subjective, and the examiner grades the smell from a grade of 0 to 5, with zero being no smell and five being severe pungent smell.

## History and Symptoms
- The hallmark of halitosis is a bad odor from the mouth.
- A detailed history should be taken from the patient to rule out physiological and pseudo-halitosis. The frequency, onset, time, duration, exacerbating and relieving factors should be asked. A detailed medication history, Alchohol consumption and smoking should also be inquired .

## Physical Examination
- Physical examination of patients with halitosis is usually remarkable for dental caries, gingivitis, post-nasal drip and sinusitis.
- A detailed oral examination should be carried out to rule out any dental or gum disease.
- Upper Respiratory tract examination should be done to rule out nasal polyps, adenoids, post-nasal drip, and tonsillar hypertrophy. A detailed chest examination should be done to rule out chest infection.

## Laboratory Findings
- An elevated level of the volatile sulfur compound in exhaled air from the mouth is diagnostic of halitosis.
- Volatile Sulfur compound monitors can measure the levels of volatile sulfur compounds content in exhaled air from the mouth.
- Patients are asked to close their mouths and hold their breath for two to three minutes.
- Air is then collected from the mouth through a particular instrument, and the level of volatile sulfur compound is measured in parts per billion (ppb).
- Patients with halitosis have greater than 100 ppb levels of volatile sulfur compounds.
- BANA is a test by which chemicals that cause halitosis are detected by strip.
- The main substrate on the test strip is benzoyl-DL-arginine-a-naphthylamide. Obligate anaerobes in the mouth hydrolyze BANA and release volatile compounds that cause halitosis.
- In addition, it also detects bacteria responsible for dental and gingival diseases.

## Electrocardiogram
There are no ECG findings associated with halitosis.

## X ray
There are no x-ray findings associated with halitosis.

## Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with halitosis.

## CT scan
There are no CT scan findings associated with halitosis.

## MRI
There are no MRI findings associated with halitosis.

## Other Diagnostic Studies
Other diagnostic studies for halitosis include gas chromatography, which demonstrates elevated levels of volatile sulfur compounds, including hydrogen sulfide, and methyl mercaptan. The pros of gas chromatography are that it has higher sensitivity than organoleptic measurements and can even detect low levels of volatile sulfur compounds. The drawbacks are this test is expensive and requires a skilled person to perform it.

# Treatment

## Medical Therapy
Supportive therapy for halitosis includes:
- Adequate hydration to keep the oral cavity moist.
- Regular brushing and flossing with proper technique to avoid the buildup of food residue, dental plaques, and carries.
- Proper cleaning of the tongue to remove plaque and coating.
- Dietary modification with decreased intake of food products releases aromatic compounds, i.e., onion, garlic, alcohol, and caffeine.
- Quit smoking
- During the daytime, patients should chew sugar-free gums, as gums stimulate saliva production and keep the oral cavity moist.
- Rinse and gargle with mouthwash at least once a day, preferably at bedtime.
- Underlying dental and gum diseases should be appropriately treated as this will significantly reduce the oral bacterial flora.
- If an underlying medical disease is the cause of the halitosis, the patient needs to be referred to a particular specialty consultant.
- In patients with psychogenic halitosis, the physician should give the patients an appropriate assurance.  The patients might need to be referred for psychiatric consultation for proper treatment.

## Surgery
Surgical intervention is not recommended for the management of halitosis.

## Primary Prevention
There are no established measures for the primary prevention of halitosis.

## Secondary Prevention
There are no established measures for the secondary prevention of halitosis.