Bad breath
Bad breath, also known as halitosis, is a symptom in which a noticeably unpleasant breath odour is present. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder.
The concerns of bad breath may be divided into genuine and non-genuine cases. Of those who have genuine bad breath, about 85% of cases come from inside the mouth. The remaining cases are believed to be due to disorders in the nose, sinuses, throat, lungs, esophagus, or stomach. Rarely, bad breath can be due to an underlying medical condition such as liver failure or ketoacidosis. Non-genuine cases occur when someone complains of having bad breath, but other people cannot detect it. This is estimated to make up between 5% and 72% of cases.
The treatment depends on the underlying cause. Initial efforts may include tongue cleaning, mouthwash, and flossing. Tentative evidence supports the use of mouthwash containing chlorhexidine or cetylpyridinium chloride. While there is tentative evidence of benefit from the use of a tongue cleaner, it is insufficient to draw clear conclusions. Treating underlying disease such as gum disease, tooth decay, tonsil stones, or gastroesophageal reflux disease may help. Counselling may be useful for those who falsely believe that they have bad breath.
The estimated rates of bad breath vary from 6% to 50% of the population. Concern about bad breath is the third most common reason people seek dental care, after tooth decay and gum disease. It is believed to become more common as people age. Bad breath is viewed as a social taboo and those affected may be stigmatized. People in the United States spend more than $1 billion per year on mouthwash to treat it.
Signs and symptoms
Bad breath is when a noticeably unpleasant odour is believed to be present on the breath. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder.Causes
Mouth
In about 90% of genuine halitosis cases, the origin of the odour is in the mouth itself. This is known as intra-oral halitosis, oral malodour or oral halitosis.The most common causes are odour-producing biofilm on the back of the tongue or other areas of the mouth due to poor oral hygiene. This biofilm results in the production of high levels of foul odours. The odours are produced mainly due to the breakdown of proteins into individual amino acids, followed by the further breakdown of certain amino acids to produce detectable foul gases. Volatile sulfur compounds are associated with oral malodour levels, and usually decrease following successful treatment. Other parts of the mouth may also contribute to the overall odour, but are not as common as the back of the tongue. These locations are, in order of descending prevalence, inter-dental and sub-gingival niches, faulty dental work, food-impaction areas in between the teeth, abscesses, and unclean dentures. Oral based lesions caused by viral infections like herpes simplex and HPV may also contribute to bad breath.
The intensity of bad breath may differ during the day, due to eating certain foods, smoking, and alcohol consumption. Since the mouth is exposed to less oxygen and is inactive during the night, the odour is usually worse upon awakening. Bad breath may be transient, often disappearing following eating, drinking, tooth brushing, flossing, or rinsing with specialized mouthwash. Bad breath may also be persistent, which affects some 25% of the population in varying degrees.
Tongue
The most common location for mouth-related halitosis is the tongue. Tongue bacteria produce malodourous compounds and fatty acids, and account for 80 to 90% of all cases of mouth-related bad breath. Large quantities of naturally occurring bacteria are often found on the posterior dorsum of the tongue, where they are relatively undisturbed by normal activity. This part of the tongue is relatively dry and poorly cleansed, and the convoluted microbial structure of the tongue dorsum provides an ideal habitat for anaerobic bacteria, which flourish under a continually-forming tongue coating of food debris, dead epithelial cells, postnasal drip and overlying bacteria, living and dead. When left on the tongue, the anaerobic respiration of such bacteria can yield either the putrescent smell of indole, skatole, polyamines, or the "rotten egg" smell of volatile sulfur compounds such as hydrogen sulfide, methyl mercaptan, allyl methyl sulfide, and dimethyl sulfide. The presence of halitosis-producing bacteria on the back of the tongue is not to be confused with tongue coating. Bacteria are invisible to the naked eye, and degrees of white tongue coating are present in most people with and without halitosis. A visible white tongue coating does not always equal the back of the tongue as an origin of halitosis; however, a "white tongue" is thought to be a sign of halitosis. In oral medicine, generally, a white tongue is considered a sign of several medical conditions. Patients with periodontal disease were shown to have a sixfold prevalence of tongue coating compared with normal subjects. Halitosis patients were also shown to have significantly higher bacterial loads in this region compared to individuals without halitosis.Gums
Gingival crevices are the small grooves between teeth and gums, and they are present in health, although they may become inflamed when gingivitis is present. The difference between a gingival crevice and periodontal pocket is that the former is <3mm in depth and the latter is >3mm. Periodontal pockets usually accompany periodontal disease. There is some controversy over the role of periodontal diseases in causing bad breath. However, advanced periodontal disease is a common cause of severe halitosis. People with uncontrolled diabetes are more prone to have multiple gingival and periodontal abscesses. Their gums are evident with large pockets, where pus accumulation occurs. This nidus of infection can be a potential source for bad breath. Removal of the subgingival calculus and friable tissue has been shown to improve mouth odour considerably. This is accomplished by subgingival scaling and root planing and irrigation with an antibiotic mouth rinse. The bacteria that cause gingivitis and periodontal disease are invariably gram negative and capable of producing VSC. Methyl mercaptan is known to be the greatest contributing VSC in halitosis that is caused by periodontal disease and gingivitis. The level of VSC on breath has been shown to positively correlate with the depth of periodontal pocketing, the number of pockets, and whether the pockets bleed when examined with a dental probe. Indeed, VSCs may themselves have been shown to contribute to the inflammation and tissue damage that is characteristic of periodontal disease. However, not all patients with periodontal disease have halitosis, and not all patients with halitosis have periodontal disease. Although patients with periodontal disease are more likely to develop halitosis than the general population, the halitosis symptom was shown to be more strongly associated with the degree of tongue coating than with the severity of periodontal disease. Another possible symptom of periodontal disease is a bad taste, which does not necessarily accompany a malodour that is detectable by others.Other causes
Other less common reported causes from within the mouth include:- Deep carious lesions – which cause localized food impaction and stagnation
- Recent dental extraction sockets – fill with blood clot, and provide an ideal habitat for bacterial proliferation
- Interdental food packing – – this can be caused by missing teeth, tilted, spaced, or crowded teeth, or poorly contoured approximal dental fillings. Food debris becomes trapped, undergoes slow bacterial putrefaction and release of malodourous volatiles. Food packing can also cause a localized periodontal reaction, characterized by dental pain that is relieved by cleaning the area of food packing with an interdental brush or floss.
- Acrylic dentures – inadequate denture hygiene practises such as failing to clean and remove the prosthesis each night, may cause a malodour from the plastic itself or from the mouth as microbiota responds to the altered environment. The plastic is actually porous, and the fitting surface is usually irregular, sculpted to fit the edentulous oral anatomy. These factors predispose to bacterial and yeast retention, which is accompanied by a typical smell.
- Oral infections
- Oral ulceration
- Fasting
- Stress or anxiety
- Menstrual cycle – At mid cycle and during menstruation, increased breath VSC were reported in women.
- Smoking – Smoking is linked with periodontal disease, which is the second most common cause of oral malodour. Smoking also has many other negative effects on the mouth, from increased rates of dental decay to premalignant lesions and even oral cancer.
- Alcohol
- Volatile foods – e.g. onion, garlic, durian, cabbage, cauliflower and radish. Volatile foodstuffs may leave malodourous residues in the mouth, which are subject to bacterial putrefaction and VSC release. However, volatile foodstuffs may also cause halitosis via the blood-borne halitosis mechanism.
- Medication – often medications can cause xerostomia, which results in increased microbial growth in the mouth.
Nose and sinuses
Halitosis is often stated to be a symptom of chronic rhinosinusitis; however, gold standard breath analysis techniques have not been applied. Theoretically, there are several possible mechanisms of both objective and subjective halitosis that may be involved.