The oral biology of bad breath

1
The oral biology of bad breath

• DENT 5301
• Introduction to Oral Biology
• Dr. Joel Rudney

2
Why is it important?

• Mouth odor can be a sign of undiagnosed disease
• Mouth odor has negative connotations in many
  cultures
• Affects patient's self-image
• Affects others attitudes towards patient
• Bad breath is big business
• Mouthwashes, mints, drops, gums, toothpastes
• Commercials reinforce existing attitudes
• Dentists are consulted for advice, treatment
• Active marketing of "breath treatment clinic"
  franchises

3
What smells?

• Products of bacterial activity
• Volatile sulfur compounds (VSC)
• Hydrogen sulfide (H2S) - rotten eggs
• Methyl mercaptan (CH3SH) - natural gas
• Major components of mouth odor in most persons
• Cadaverine - diamino acid - spoiled meat
• Also important
• Produced independently of VSC
• Organic acids - goaty smells
• Acetic, propionic, butyric, isovaleric

4
What smells too?

• Products of metabolic activity
• Volatile food components
• Garlic, onions, etc.
• Broccoli, cauliflower (sulfur-rich)
• Ketones (acetone)
• Low carb diets
• Trimethylamine (fishy odor)
• Tobacco smoke
• Beer, wine, and liquor

5
How much does it smell?

• Instruments for odor detection
• Gas chromatography of breath samples
• Most informative
• Extremely sensitive and precise
• Expensive and cumbersome
• Limited to research centers
• Portable sulfide meter (the Halimeter)
• Can be used in a dental office
• Detects only VSC
• Must be calibrated regularly to maintain accuracy

6
Who smells it?

• Organoleptic ratings - the odor judge
• Trained noses partly agree with sulfide meters
• May be more relevant clinically
• Requires extensive training, periodic calibration
• Mainly for research, specialized clinics
• The jury of one's peers
• Your spouse or your best friends
• Your dentist (or your patient)
• Relevant to the social consequences of mouth odor
• Self-incrimination - least reliable
• Many cannot detect odors apparent to others
• Some perceive odors no one else can detect

7
Where does it smell?

• Posterior tongue
• Odor scores associated with degree of tongue
  coating
• Tongue anatomy may increase risk (deep fissures)
• May be primary source of odor in younger patients
• Worse with dry mouth, after sleeping
• Periodontal pockets in periodontal disease
• Odor scores associated with disease/severity
• VSC can be measured in fluid from deep pockets
• Mouth odor/VSC proposed as early sign of
  periodontitis
• Not all periodontal patients have mouth odor
• Other oral lesions (e.g. abcesses, impactions)
• Oral candidiasis - "Sweet, fruity odor"

8
Tongue coating
http//www.dent.ohio-state.edu/oralpath2/Tongue/25
_2.jpg
9
Which bacteria are smelly?

• Tongue bacteria
• Streptococcus salivarius - a sign of health?
• May be dominant in persons w/o halitosis (n 5)
• Gram-negative, proteolytic anaerobes
• May predispose towards halitosis
• Many novel species (n 6)
• Digest nasal discharges, food debris,
• saliva components, sloughed cells
• Produce VSC, cadaverine
• BANA hydrolysis test (Perioscan) used for
  detection
• Periodontal pathogens

10
Systemic smells

• About 90 of halitosis originates in the mouth
• The other 10
• Systemic disease
• Diabetes - ketoacidosis - acetone smell
• Cirrhosis, liver failure - "mousy", "musty"
  smells
• Renal failure - fishy smell
• Leukemia - "decaying blood" smell
• Respiratory system
• Exhalation of volatile food compounds
• Volatile medications - DMSO, amyl nitrate
• Nasal/sinus/lung infections
• Tonsils and tonsiloliths (may not contribute to
  mouth odor)
• Treated by laser cryptolysis
• Carcinoma

11
Other systemic smells

• Gastrointestinal system (considered rare)
• Reflux
• Carcinoma
• Helicobacter pylori infection (gastric ulcers)
• Genetic disorders (enzyme deficiencies)
• Trimethylaminuria (fishy odor) - autosomal
  recessive
• Cystinuria, cystathionuria heterozygotes
• Recessive defects in cysteine metabolism
• Very high VSC levels (gut bacteria)

12
Iatrogenic/idiopathic smells

• Frustrating to diagnose and treat - expensive
• Iatrogenic odors
• Gauze pad left behind after cleft palate surgery
• Foreign objects
• Inserted up the nose
• Young children and developmentally disabled
• If undetected, may lead to odor in adults
• Idiopathic odors
• Detectable by others, no apparent oral or
  non-oral cause
• Cause presumed rare, not yet defined

13
Psychosomatic smells

• Detectable only by patient - no apparent cause
• Patients often refuse to accept objective
  findings
• Associated with anxiety or depression
• Can be confused with genetic disorders
• Patients may show abnormalities by gas
  chromatography
• Trimethylaminuria heterozygotes
• May be more common than once thought
• Saliva TMA detectable by patient, but not others

14
Diagnosing smells

• History
• Onset, duration?
• Constant or intermittent, morning, how long after
  meals?
• Self-report, or reported by others?
• Dietary factors, smoking and alcohol use?
• Systemic disease and medication
• Neurological problems - taste and smell function?
• Currently under stress?
• Comprehensive oral examination

15
Diagnosis by smelling

• No commercial mouth rinses for 1 day previous
• No eating, drinking, brushing, gum, mints, rinses
  for 2 h
• Avoid perfumes or scented products (patient
  dentist)
• 2 min rest with lips closed - exhale through
  nostrils
• 2 min rest as before - close nostrils - exhale
  through lips
• 2 min rest as before - exhale with lips and
  nostrils open
• Sample posterior tongue with plastic spoon
• Compare odor strength for each condition
• Interpretation
• Strongest odor with lips closed - suggests nose,
  sinuses
• Strongest odor with nostrils closed - oral or
  gastric source
• Tongue sample to confirm oral origin
• Odor equally strong from nose or mouth - systemic
• No discernible odor - verify with others (spouse,
  friend)

16
Treating smells - the basics

• Non-oral etiologies - appropriate referral
• Oral etiologies
• Treat all existing conditions
• Attempt to improve hygiene, flossing
• Encourage posterior tongue hygiene
• Commercial tongue scrapers
• Many designs on the market
• The gag reflex is a barrier to compliance

17
Tongue scraping
http//www.yatan-ayur.com.au/images/tonguecleaning
2.jpg
One of many designs - no endorsement implied
18
Treating smells - short-term

• Masking fragrances
• Mouth rinses, drops, gums, mints, etc.
• Chemicals that interact with VSC
• Sold online - by dentists offering halitosis
  clinics
• Oxidizing agents - products based on chlorine
  dioxide
• Disinfectant - water treatment, pulp mills, cow
  udders
• FDA approved for 2ndary food use (disinfecting
  chickens)
• Appears to be safe at concentrations in breath
  products
• Only two published studies - short-term , small
  Ns
• Zinc reacts with VSC
• Safe when not used in excess
• More published evidence - small Ns
• Reduces VSC levels short-term

19
Treating smells - long-term

• Antibacterial products
• Should reduce bacterial odors, depending on
  efficacy
• Very few clinical studies document effects on
  odor long term
• Chlorhexidine is considered the gold standard
• High substantivity - remains on oral tissues for
  a long time
• Only by Rx in USA, problems with taste and
  staining
• Others with published evidence for odor reduction
• Two-phase oil-water mouthrinse (cetylpyridinium
  chloride)
• Sulfides lower after 6 weeks of use
• More effective than Listerine (essential oils) -
  both worked
• Currently available in Israel and Great Britain
• Toothpaste with substantive triclosan copolymers
  - short term
• Mixtures including low dose chlorhexidine -
  Halita

20
Treating smells - probiotics?

• The probiotic concept
• Replace bad bacteria with good bacteria
• Lots of ongoing research - NIH funded
• FDA approves human trial of probiotic S. mutans
• Genetically engineered to be non-cariogenic
• Lots of safeguards required
• Probiotic treatment of bad breath in New Zealand
  and Australia
• S. salivarius strain K12
• Indigenous strain that produces antibacterial
  peptides (BLIS)
• Patented, marketed as a dietary supplement (now
  in USA)
• Step 1 Use chlorhexidine to knock down tongue
  flora
• Step 2 Replace tongue flora with K12
• Limited data - 2 wks., N 13, only 3 controls,
  not yet published

21
ADA halitosis standards

• Must be met to get ADA seal for any bad breath
  claims
• Applies to products that already have ADA seal
  for other claims
• Two independent double-blind efficacy studies
• Minimum 3-week trial period
• Patients must have baseline organoleptic scores
  between 2-5
• Slight to Very Strong
• Gas chromatograph preferred to measure VSC
• Sulfide monitor OK if calibration data provided
• Multiple malodor measurements
• Parallel evaluation of hard/soft tissue effects,
  microbiology
• Long term safety data (six month follow up)
• Must include patient-reported adverse effects
  (taste/staining)
• Toxicity data (cytotoxic, mutagenic, carcinogenic
  effects)

22
Why so few studies?

• No product currently has the ADA seal for
  halitosis
• Some do have the ADA seal for other properties
• Plaque control or caries prevention
• Will the public make this distinction?
• Is there a marketing benefit to getting the
  halitosis seal?
• FDA approval
• May be sought under less stringent standards for
  cosmetics
• Ingredients already approved as safe for human
  use
• Chlorine dioxide products
• May fall under the much weaker rules for dietary
  supplements
• Products containing zinc
• S. salivarius K12
• Manufacturers lack incentives to do the studies