Chronicles of Young Scientists

: 2010  |  Volume : 1  |  Issue : 4  |  Page : 36--39

Halitosis: An oral microbial faction

Rajiv Saini1, Santosh Saini2, Sugandha R Saini3,  
1 Department of Periodontology and Oral Implantology, Rural Dental College-Loni, Maharashtra, India
2 Department of Microbiology, Rural Dental College-Loni, Maharashtra, India
3 Department of Prosthodontics, Rural Dental College-Loni, Maharashtra, India

Correspondence Address:
Rajiv Saini
Department of Periodontology and Oral Implantology, Rural Dental College - Loni, Tehsil- Rahata, District - Ahmednagar, Maharashtra - 413 736


Halitosis is a widespread condition and believed to affect one-quarter of the population around the world; also, most people have this condition from time to time. Breath malodour may be an important factor in social communication, and therefore may be the origin of concern not only for a possible health condition but also for frequent psychological alterations, leading to social and personal isolation. The most conspicuous malodorous compounds are termed volatile sulphur compounds (VSCs), with hydrogen sulphide, methyl mercaptan, and dimethyl sulphide accounting for roughly 90% of the VSCs. A number of oral bacteria, especially Gram-negative anaerobic species found in the subgingival plaque, produce a diverse array of malodorous compounds as byproducts of their metabolism, including VSCs and short-chain organic acids. Assessment and management of halitosis is of paramount importance in enhancing the overall health; moreover, dentists play a significant role in combating halitosis by reducing the oral microbial stack. Thus, the aim of the present review was to describe the aetiological factors, assessment tools, and therapeutic approaches related to halitosis.

How to cite this article:
Saini R, Saini S, Saini SR. Halitosis: An oral microbial faction.Chron Young Sci 2010;1:36-39

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Saini R, Saini S, Saini SR. Halitosis: An oral microbial faction. Chron Young Sci [serial online] 2010 [cited 2020 Jan 27 ];1:36-39
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Oral halitosis-bad breath originating from the oral cavity-regularly affects about one in four adults. [1] Halitosis is widespread and is believed to affect one-quarter of the population around the world, and most people suffer with this condition from time to time. [2] Because of its personal nature, this condition can cause social embarrassment, emotional, and psychological distress leading to a lack of self-esteem, self-image, and self-confidence. [3] In this context, breath malodour may be an important factor in social communication, and therefore may be a matter of concern not only for a possible health condition but also for frequent psychological alterations, leading to social and personal isolation. [4] Halitosis should not be confused with momentary disturbing odour caused by morning bad breath, food intake, or smoking because these odours do not reveal a health problem as a persistent breath malodour, by definition, reflects some pathology. In a special patient category, subjects imagine that they have breath malodour. This condition is called imaginary breath odour or halitophobia and is associated with obsessive compulsory disorders and hypochondria. [5] Halitosis-causing bacteria are the primary sources of volatile sulphur compounds (VSC). Its chief components are hydrogen sulphide and methyl mercaptans, which are produced through the bacterial metabolic degradation of food debris, desquamated cells, saliva proteins, dental plaque, and microbial putrefaction. The intensity of clinical bad breath has been shown to be appreciably associated with amount of intraoral VSC level and directly correlated with periodontal health status. The success of any halitosis intervention appears to pivot on reduction of VSC levels and other foul volatiles and, consequently, a majority of it focus on mechanical and chemical options.

 Halitosis: Origin and Aetiology

Halitosis can arise from a variety of sources, including sinuses, gastrointestinal tract, ingested food, lungs, and, most frequently, the oral cavity. Oral production of malodorous substances is most commonly associated with byproducts of bacterial metabolic degradation and occurs on oral surfaces, in periodontal pockets, and especially on the dorsal tongue surface. These products result from microbial fermentation of proteins, peptides, and mucins found in saliva, blood, gingival crevicular fluid, lysed neutrophils, desquamated epithelial cells, and any residual food retained on the oral surfaces. [6] The most conspicuous malodorous compounds are termed volatile sulphur compounds (VSCs), with hydrogen sulphide, methyl mercaptan, and dimethyl sulphide accounting for roughly 90% of VSCs. [7] Many oral bacteria, especially Gram-negative anaerobic species found in the subgingival plaque, produce a diverse array of malodorous compounds as byproducts of their metabolism, including VSCs and short-chain organic acids such as valeric acid, butyric acid, putrescine, and skatole. [6],[8] An estimated 90% of halitosis cases originate within the oral cavity, and the VSCs are believed to be produced by Gram-negative proteolytic anaerobes. These microbes are located in the stagnant areas of the mouth, such as the periodontal pockets, tongue surface, and interproximal areas between the teeth. The putrefaction of amino acids within the oral cavity per se is a physiological process; however, it is enhanced by other modifying factors, such as periodontal diseases, circumstances leading to dry mouth, and other systemic conditions. [3] It is thus understandable that the VSC levels in mouth positively correlates with depth of periodontal pocket; moreover, the amount of VSCs in breath increases with the number, depth and bleeding tendency of periodontal pockets. The low oxygen tension in deep periodontal pockets also results in low pH and an activation of the decarboxylation of amino acids to cadaverine and putrescine, two malodorous diamines. [5] Periodontal diseases, in particular, Acute Necrotising Ulcerative Gingivitis (ANUG), severe periodontitis, pericoronitis, dry socket, and other oral infections and ulcers have been classically associated with oral malodour. [4] Predisposing factors include poor oral hygiene, gingival and periodontal disease, disorders of the oral mucosa, reduced salivary flow and wearing of dental appliances. [9] The oral microorganisms most likely to cause oral malodour are Gram-negative bacteria species such as Treponema denticola, Porphyromonas gingivalis, P. endodontalis, Prevotella intermedia, Bacteroides loescheii, Enterobacteriaceae, Tannerella forsythensis, Centipeda periodontii, Eikenella corrodens, and Fusobacterium nucleatum. However, no obvious association exists between halitosis and any specific bacterial infection, which suggests that bad breath reflects complex interactions between several oral bacterial species. [10]

 Assessment and Monitoring

The right approach for halitosis includes evaluating and assessing all local and systemic parameters of the patient and correlating with best available scientific diagnostic tool for its confirmation. The various methods for assessment are listed in [Table 1]. Organoleptic measurement and gas chromatography are reliable methods, but clinically not easily implemented. The use of organoleptic measurement is suggested as the gold standard. Gas chromatography is the preferable method if precise measurements of specific gases are required. Sulphide monitoring is an easily used method, but has the limitation that important odours are not detected. The scientific and practical value of additional or alternative measurement methods, such as the benzoyl-arginine-naphthyl-amide (BANA) test, chemical sensors, salivary incubation test, quantifying b-galactosidase activity, ammonia monitoring, ninhydrin method, and polymerase chain reaction, have yet to be fully established. [9] Detection of VSC in the breath does not mean it is halitosis. When VSC level detected in mouth exceeds 150-200 ppb, only then the condition is classified as halitosis. [11] {Table 1}

 Management of Halitosis

After a constructive diagnosis for oral halitosis has been made, the treatment plan is implemented, which comprises riddance of the contributory agent and improvement of oral health. The treatment modalities include mechanical and chemical reduction of oral microbiota, conversion of VSCs, masking the malodour, and regular view. Key characteristics of each are listed in [Table 2]. The primary prevention of oral malodour is done by reduction in bacterial populations, especially those present on the tongue, by using a variety of antimicrobial agents (chlorhexidine, triclosan, essential oils) or mechanical devices, like regular toothbrushing and interdental cleaning by dental floss, toothpick, and tongue cleaners.{Table 2}

 Conclusion and Remarks

In conclusion, it is suggested that a majority of cases of oral malodour are the result of bacterial proteolytic activity in the mouth; therefore, dentists can assist patients to control the condition by providing full-mouth disinfection and treatment modality for oral problems, eg, providing suggestions on oral hygiene, or referring them for medical opinion when a non-oral cause is assumed. Like other oral diseases with microbial etiology, halitosis may be acquiescent to specific and non-specific antimicrobial rehabilitation targeted towards the associated bacteria.[28]


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