Bad Breath (halitosis)

The diagnosis, treatment and prevention of bad breath has been gaining increasing interest among professionals in the area of medicine and dentistry.

Dental medicine mainly focuses on the diagnosis, treatment and prevention of diseases such as:

  • Caries;
  • Diseases of the pulp tissue of the teeth, better known as “dental nerve” (eg: pulpitis, dental abscesses, etc.);
  • Diseases of the soft tissues of the mouth (eg: gingivitis, periodontitis, gingival abscesses, candidiasis, herpes, burning mouth syndrome and tumors);
  • Diseases of maxillary bones (eg: cysts, tumors);
  • Problems in the masticatory muscles and in the temporomandibular joints, often causing pain associated with the face, neck, ears and head, as well as joint blockages;
  • Problems of missing teeth solved using removable dentures (e.g. acrylic, skeletal, flexible prostheses, some of which may be secured using implants) or fixed prostheses (e.g. supported bridges or supported implants).

So, do I have bad breath?

Due to recent circumstances, the diagnosis, treatment and prevention of bad breath has become a subject of increasing interest among professionals in the field of dental medicine. In fact, halitosis can cause serious disorders in the social, affective and professional life of an individual, and can even affect his or her emotional stability. To further complicate this problem :

  • Usually halitosis sufferers find it difficult to self-identify halitosis because of the ability of our nose to become accustomed to different odors;
  • When they detect halitosis, few health care professionals warn patients, either out of modesty or out of fear that this will trigger a negative reaction in the patient;

But how do I know if I have halitosis? The best way to start is to ask someone you trust about your breath (eg: your dentist, hygienist, doctor, or just a friend). Basically, there are 2 clinical methods to evaluate halitosis. The first is “organoleptic” and involves the examiner using his or her olfactory skills to classify the odor emanated by the patient. This method, while embarrassing to the patient, also depends a lot on the refined sense of smell of the examiner. The second method is “analytical” and involves the use of electronic equipment that objectively quantifies the volatile sulfur compounds (CSV) responsible for the unpleasant odors expelled by the mouth.

It is important to note that, on average, for every 10 patients seeking treatment for halitosis, 4 do not show positive results. Objectively, they do not have halitosis, but believe they suffer from halitosis. This is known as Pseudo-halitosis. Usually, this is due to a disorder that modifies the gustatory (dysgeusia) and/or olfactory (cacosmia) precept, which results in the patient concerned experiencing difficulty in differentiating taste from olfaction, and so in certain situations, he or she interprets a bad taste as bad breath, believing that he or she is suffering from halitosis. In these cases, it is necessary to explain to the patients that the intensity of the oral odor detected is perfectly normal, within the socially acceptable range and that, possibly, a more specific consultation should be arranged to detect this type of disorder. Usually, after such an explanation and especially if the result was based on concrete, analytical readings (e.g. gas chromatography or even a Halimeter), patients accept the result and respond favorably.

However, a small number of patients remain convinced that they continue to suffer from bad breath, either after diagnosis and clarification of pseudo-halitosis or after successful treatment of actual halitosis from which they once suffered, but no longer do (the high values obtained with equipment suitable for oral odor before treatment, compared with the normal values obtained after treatment). These cases are classified as Halitophobia, a condition analogous to olfactory reference syndrome characterized by a persistent concern among patients with body odor. Such cases should be referred to psychologists or psychiatrists, as they are usually associated with depression or social rejection.

In the morning, the breath generally has a stronger and more unpleasant odor due not only to the hypoglycemia of fasting, which forces the body to degrade reserves of fat, resulting in the release of an unpleasant odor via pulmonary ketone bodies, but also due to a drastic reduction during sleep of either salivary flow or of the tongue and lips movements that contribute to the self-cleaning of the mouth. These facts favor the accumulation and putrefaction of desquamated epithelial cells from the oral cavity or from food residues, which cause the formation of a whitish layer that mainly sticks to the posterior 1/3 of the tongue (a region not greatly influenced by salivary flow), called “Lingual sores”.

However, this bad morning breath or physiological halitosis is transient if it is controlled with appropriate oral hygiene. If halitosis persists throughout the day, then it must be pathological halitosis, which should be the subject of careful diagnosis, guidance and treatment. Most halitosis is related to the degradation of the aforesaid lingual smear by bacteria residing on the surface of the tongue, resulting in the release of compounds with an unpleasant odor, mainly the said volatile sulfur compounds (CSV). Other important causes of halitosis are:

  • Gingival disease (e.g. gingivitis, and especially periodontitis). Periodontal disease is caused by bacteria that release gases with an unpleasant odor. Studies have demonstrated that, in patients undergoing periodontal treatment, there was a consistent reduction in halitosis;
  • Presence of bacterial plaque and tartar on the surface of the teeth;
  • Carious cavities and poorly implemented dental restorations, which promote retention of food and bacteria;
  • Fissured tongue, which facilitates the accumulation of microorganisms and food debris and at the same time makes cleaning difficult;
  • Old, and especially, badly adapted removable dentures. As age progresses, atrophy of the jaw bone (especially in the edentulous areas), makes the prosthesis maladapted or even inappropriate insofar as it promotes the retention of food and bacteria and other problems such as a lack of stability and retention. In some cases, it is possible to retrofit the prostheses through a filling or overrun, but in other cases, only replacement effectively solves the basic problem. Fixed prostheses also suffer from this problem, but it is not possible to readapt them, they can only be substituted if the pillar teeth still offer guarantees;
  • Changes in saliva composition. Saliva plays a key role because, in addition to contributing to the self-cleaning of the oral cavity, it is essential for the balance of oral bacterial flora and the maintenance of pH, among other functions. Factors such as increased salivary viscosity, slightly alkaline pH or decreased salivary flow are known to make an individual more prone to halitosis;
  • Oral candidiasis, usually associated with chronic use of oral corticosteroid-based inhalers or prolonged antibiotic therapies;
  • Oral healing processes (e.g. alveolitis, i.e. poor healing post-tooth extraction).

Studies carried out by multidisciplinary teams composed of gastroenterologists, otorhinolaryngologists, dentists, nutritionists and even psychiatrists and psychologists, found that around 80% of the causes of halitosis are effectively of oral origin (oral etiology). Given this scenario, the dentist is the specialist best positioned to diagnose or treat, or even offer specialized advice if the cause of halitosis is suspected to be extraoral or even mixed (extraoral). Other causes that may trigger or aggravate halitosis are:

  • Otorhinolaryngological conditions, such as:
    • Amygdala cavities – small white “balls” composed mainly of food debris, desquamated epithelial cells and some microorganisms that are housed in small cavities or crypts of the tonsils;
    • Mouth breathing – this pathology is due to multiple factors that lead to nasal obstruction (e.g. nasal polyps) and secondarily dry mouth and presence of thick mucus adhered to the throat;
    • Sinusitis and allergic rhinitis cause unpleasant odor secretions that drip into the pharynx;
    • Presence of foreign bodies in the nasal cavity, typical in children and in patients with mental debilitation;
  • Some respiratory conditions;
  • Gastric disease, especially if accompanied by gastroesophageal reflux. Contrary to what most people believe, gastric conditions only intervene in a small percentage of cases of halitosis;
  • Diabetes and other metabolic changes causing xerostomia or “dry mouth”;
  • Autoimmune condition (e.g. Sjorgren’s syndrome);
  • Some medications can cause a dry mouth in some patients, and consequently halitosis (e.g. some antihistamines, some anti-depressants, some antihypertensives and some anti-Parkinson’s medicines, among others);
  • Heavy metal poisoning;
  • Hepatic and / or renal impairment;
  • Age. Younger patients have sweeter breath and older patients have stronger and heavier breath. In the elderly, a very peculiar characteristic that contributes to halitosis is the presence of furrows and lingual fissures that favor the deposit of lingual fur. In these cases, lingual hygiene is essential to prevent or reduce halitosis.
  • Periods of intense female hormonal activity (e.g. menstruation, pregnancy and breastfeeding) may often be associated with transient halitosis;
  • Stress and anxiety. Studies carried out with rats have shown that stress induced in these animals cause the production of the above volatile sulfurous compounds, mainly because in stressful situations, the autonomic nervous system reduces salivary flow. This phenomenon is clearly manifested when one has to speak in public (lecturer’s halitosis), which can be mitigated by the ingestion of water while speaking;
  • Misuse of mouthwash with alcohol. Alcohol has the particularity of drying the oral mucosa;
  • Alcohol abuse;
  • Tobacco and other drugs, mainly because, in the long term, they dry the mucosa and favor oral desquamation, while worsening gingival conditions at the same time. Studies indicate that tobacco residues that pervert oral odor have no influence on the breath after 2 hours;
  • Inadequate feeding.

In fact, halitosis should not be considered as a disease but rather should be seen as an indicator that something is not well in the body, either from a pathological, physiological standpoint or simply due to poor oral hygiene. However, it is still a public health problem, as demonstrated by the following data

  • It affects a large percentage of the population (some authors report rates of around 25% of the population, of which 2% is severe halitosis);
  • In North America, an average of $ 1 billion is spent on mouthwashes, oral deodorants, lozenges, etc. to combat halitosis.

That is why large economic groups continue to invest heavily in products aimed at improving bad breath:

  • It generates social incapacity and hampers human relations, and can even lead to neuroses, social isolation and divorce;
  • When halitosis is associated with the presence of lingual fur (a whitish coating on the back of the tongue, formed as already referred to by the remains of food, dead epithelial cells, bacteria, etc.), there is an obvious reduction of the palate due to obstruction of the lingual taste buds. To compensate for this lack of taste, many patients inadvertently increase the amount of sugar and salt in their diet, which aggravates and increases cases of hypertension and diabetes.

Paradoxically, in contrast to the great public concern it raises, there continues to be little scientific research associated with halitosis. More scientific research is needed, mainly to evaluate the effectiveness of the auxiliary chemical agents used to combat halitosis, as well as its causes. The treatment of halitosis should basically consist of reducing the production of the above volatile sulfur compounds (CSV), which are responsible for the bad odor, and not only masking bad breath. The universally accepted measures to combat halitosis are:

  • Improving dental brushing technique;
  • Brushing the teeth 3 times a day. Studies have shown that removing plaque every 8 hours is sufficient, and it has been found that the results obtained from brushing the teeth 4 times a day do not justify the adoption of such a measure;
  • Use of dental floss;
  • Lingual scraping after brushing the teeth, a very rare habit, but undoubtedly the most important when considering halitosis.

A study in which different methods for cleaning the back of the tongue (e.g. a tongue scraper, toothbrush, gauze, or a simple coffee spoon) were tested, it was concluded that the lingual scraper not only provides better performance, but also decreases the propensity to vomit. The gauze method proved to be the least efficient method.

• Proper feeding every 3-4 hours;

• Avoiding the consumption of alcohol and tobacco;

• Controlling stress;

• Keeping the mouth healthy, free of cavities, gingivitis or periodontitis;

• Where the patient has removable prostheses or other removable dental appliances, the patient should be instructed to brush their dentures after meals and before bedtime by immersing them in a solution designed for this purpose, or alternatively, in a solution of one tablespoon of 0.5% sodium hypochlorite diluted in ½ cup of water.

Due to the limitation of mechanical methods to effectively reach and eliminate the bacteria responsible for the degradation of sulfur-rich proteins and the consequent production of CSV, it is imperative, at least in an initial phase, to associate one or more mouthwashes with a specific composition base of essential oils (chlorhexidine, cetyl-pyridinium chloride, triclosan, chlorine dioxide or sodium lauryl sulfate), wherever possible without alcohol, of proven effectiveness and for limited periods of time. Its use for gargling is recommended, rather than as a mouthwash, at least twice a day to disinfect the posterior area of the palate or the “roof of the mouth”, the base of the tongue and the tonsillar region. After using a mouthwash, nothing should be eaten, or even chewed, such as tablets.

Carvalho y cols. 2004 conducted a clinical study that included the suppression of mechanical plaque cleansing for 4 days to evaluate the effectiveness of 4 mouthwashes on morning halitosis. The mouthwashes tested were 0.03% triclosan, 0.12% chlorhexidine, essential oils and 0.05% cetyl-pyridinium chloride, with a placebo as a negative control and 0.2% chlorhexidine as a positive control. The reduction of halitosis (reduction of volatile sulfur compounds): 1-chlorhexidine 0.2% 2 – chlorhexidine 0.12% 3-triclosan 4 – essential oils with cetyl-pyridinium chloride.

However, according to Alves, Daniel; Costa, Ana L .; Almeida, Ricardo F .; Carvalho, João F.C .; Acknowledgments Posted in Rev Port Estomatol Med Dent Cir Maxilofac.. 2012;53:181-9, although the scientific evidence is still scarce, the use of CPC-containing mouthwashes as a complement to the mechanical forms of oral hygiene seems to provide a small but significant benefit in reducing bacterial plaque and gingival inflammation when compared to brushing or brushing followed by mouthwash with placebo. In addition to these measures, food must be adapted, namely:

  • Avoidance of foods rich in sulfur, especially if they are part of the usual diet: mainly garlic, onions and yellow cheeses (usually higher-fat). Others, like watercress, avocado, hazelnuts, broccoli, sweet potatoes, cauliflower, peas, beans, lentils, melon, watermelon, turnip, cucumber, radish, peppers, honey cabbage and grapes, are also foods rich in sulfur;
  • Avoidance of fatty meat;
  • Avoidance of fried foods;
  • Avoidance of alcoholic beverages and even carbonated beverages;
  • Avoidance of prolonged fasting;
  • Adequate water consumption. Every day, we lose about 2.5 L of water through sweat, urine and respiration. A good part is replenished through proper diet, and the rest must be compensated – by direct intake at frequent intervals. This is why a daily intake of between 1.5 L and 2 L is recommended, depending on the atmospheric conditions and amount of physical exercise. Usually when we feel thirst, it means that the body is already dehydrated. Another sign of dehydration is dark-colored urine.

Foods can cause bad breath for oral and systemic reasons. Although, at the beginning, most halitosis is of oral origin (e.g. remains of food in the mouth), after 3 hours, most bad breath has a systemic origin, mainly because, after intestinal absorption of food has occurred, the compounds causing bad breath pass into the bloodstream and are released little by little through the lung alveoli or through breathing.

Recently, there has been some research into probiotic medicines i.e. medicines whose goal is to nourish the good bacteria we have in the mouth, in order to make the oral ecosystem more balanced or contain less of the bacteria responsible for the production of unpleasant odors. Where halitosis, whether oral or systemic, has been detected, the progression of halitosis treatment will obviously depend on the success of the treatment of the underlying disease (e.g. periodontitis, sinusitis, etc.).