Just can't get enough - Dr. Kim Gear


Article by: Dr. Kim Gear
MMedSci, MBChB, BDS, BSC (Hons)

Salivary glands are exocrine glands that are part of the digestive system that produce saliva as an essential and complex fluid in the oral cavity. There are three pairs of major salivary glands, the parotid, submandibular, and the sublingual glands, and many smaller minor glands in the oral cavity, pharynx, and larynx.

Submandibular glands contribute approximately two-thirds of unstimulated saliva volume, whereas parotid glands contribute the majority of stimulated saliva volume. Saliva flow is influenced by both the sympathetic and parasympathetic arms of the autonomic nervous system and the amount of saliva flow will be influenced by the functioning of the saliva glands in response to neural regulation and functioning acini.1 Disruption to this leads to significant morbidity for patients as evidenced in Anita Hart Balter’s reflections2 of the oral side effects of cancer treatment.

A fish hook lodges in my throat

Spittle, kindergarten paste, thickens everything- Even vision

Mouth, pocked with sores and blisters, swollen Ulcerated tongue.

Topside, sandpapered with number 7 coarsest grade.

Taste buds, saliva glands, seared. Cool water, corrosive acid now.

The tongue rests: teeth become enemies.

Coiled steel razored wire atop dentate prison walls. Only moans escape my lips. I cannot eat or speak.

Inside a howl festers. Pain lengthens time.

-    Anita Hart Balter

Why is saliva important?

Saliva is comprised of a number of constituents and physicochemical properties, important for the maintenance of not only oral health, but also general health. It plays a significant role in the protection of the intraoral structures against injuries caused by various pathogenic microbes, mechanical or chemical irritants. Under normal physiologic conditions, saliva acts as a buffer system with bicarbonate, phosphate and protein. It helps in maintaining the pH (6.0-7.5) and is oversaturated with calcium hydroxyapatite, preventing dental demineralisation. In addition, the salivary protein pellicle protects the teeth against irritants. Saliva also contains antibodies, ensuring a healthy balance of organisms in the mouth, and minimising infective processes. Lubrication of food supports swallowing alongside the digestive enzymes responsible for the initial stages of digestion.3-6

Xerostomia vs Hyposalivation

Xerostomia is the subjective feeling of a dry mouth, whereas hyposalivation is

the objective assessment of decreased salivary gland function. Not all people with xerostomia have hyposalivation, and not all people with hyposalivation have xerostomia.

Salivary gland hypofunction is a condition most often overlooked. The absence of subjective complaints of a dry mouth does not necessarily indicate an adequate level of saliva production, therefore measurement of saliva output is necessary to make an objective assessment (Table 1).

 

Table 1: Normal reference values for production of saliva

 

Normal flow

Pathological

Unstimulated Flow

0.3-0.4ml/min

<0.1ml/min

Stimulated Flow

1.5-2.0ml/min

<0.5-0.7ml/min

Sleep

<0.1ml/min

 

600-1500ml of saliva is produced over 24 hours. Salivary flow rates from minor salivary glands is independent of stimulation.7

There are a number of aetiologies affecting saliva secretion by not only disruption to salivary gland structure and function, but also neural regulation of salivary gland secretion. This results in hyposalivation and deleterious impact on the oral cavity. Patients with dry mouth may, or may not, present with dry mouth but report tingling, decreasing sense of taste and functional impairment with difficulty eating, speaking and sleeping. Clinically they may have oral malodour, increased dental caries rate, periodontal disease, oral ulceration, increase in opportunistic infections such as Candida albicans, salivary gland swelling, pain and fever (Table 2).

Table 2: Signs and symptoms associated with common chronic salivary gland hypofunction

Signs

Loss of clearance

Dry, chapped lips; desiccated, dry and fissured tongue

Salivary gland infections or swelling

Mucosal infections Angular cheilitis / pseudomembranous and erythematous candidiasis – decreased antibacterial properties)

Dental caries (cervical and root caries in particular) – decreased mineral content

Gingivitis/ Periodontitis

Symptoms (due to loss of lubrication)

None (often may be asymptomatic)

Difficulties in swallowing, chewing, speaking

Bad taste, breath

Sore mouth, lips, tongue

Burning sensations in the mouth, lips, tongue

Difficulty wearing removable intra-oral prostheses

Frequent need to sip water for food

Frequent awakenings at night with dry mouth

Dry mouth, nose, and throat

 

Causes of hyposalivation

In assessing hyposalivation, it is imperative to establish daily nutritional and fluid intake. A surgical sieve, outlining SOME of the iatrogenic or pathological entities contributing to dry mouth, is shown in Table 3.

Polypharmacy

Polypharmacy is one of the greatest contributors to hyposalivation. There are at least fourty-two drug categories and fifty-six subcategories of medications inducing hyposalivation. The most common types of medication with xerogenic potential are those with anticholinergic and sympathomimetic actions.8

Unfortunately, many patients who take xerogenic medications  may not know that they are at risk of oral complications such as dental disease and fungal infections. The main drug classes which influence these include antidepressants, antihypertensives, opiates, bronchodilators, proton pump inhibitors, antipsychotics, antihistamines, diuretics, and antineoplastics.

The synergistic effects of combinations of medications also contribute to hyposalivation. There has been increased prescribing of xerogenic medications in children and adolescents for ADHD and ADD (Ritalin (methylphenidate)), anxiety and depression.9 In the elderly, although saliva flow does not necessarily decrease with increasing age, they are likely to have drier mouths due to the side effects of pharmacological management of chronic illnesses.

Drug-induced hyposalivation is generally reversible, however the beneficial effects of the medications may outweigh the associated risks and therefore as Dental Practitioners’ we have a role working alongside Medical Practitioners’ in minimising the effects on the Oral Cavity.

Radiotherapy to the head and neck

Xerostomia and dysphagia are the main acute and late complications resulting in decreased Quality of Life during and after radiotherapy of the head and  neck. Radiation-induced hyposalivation is thought to be multi-factorial, with resultant damage to major and minor salivary glands and associated nerves and endothelium. Intensity Modulated Radiotherapy (IMRT) is one example of advanced RT working toward organ sparing treatment.10-11


Figure 1: Resultant dental decay following salivary gland damage from Radiotherapy.

 

Connective tissue disease 

Autoimmune conditions such as Sjögren’s syndrome, damage the saliva- producing cells. These can be further differentiated into primary and secondary Sjögren's, depending on presence/absence of other Connective Tissue Disorders. Other differential diagnoses include Rheumatoid Arthritis, Systemic Lupus Erythematosus, Granulomatosis with Polyangiitis and IgG4-related disease12.

 

Table 3: Differential diagnoses and the surgical sieve : vitamin ABCDEFG 

The examples below include but are not limited to dry mouth aetiology.

Vascular

Vasculitis

Inflammatory

Sarcoidosis

Traumatic /Iatrogenic

Previous Surgery Irradiation

Chemotherapy

Autoimmune

Sjögren’s syndrome, RA, SLE, autoimmune thyroid disease, scleroderma, GvHD, Primary Biliary Cirrhosis

Metabolic

Haemochromatosis

Infective

Viral: HIV, Hep C, Mumps, HTLV-1, CMV

Bacterial: Tuberculosis, Syphilis

Fungal: Aspergillus

Neoplastic Benign

 

 

 

Malignant

 

Pleomorphic adenoma Warthin's tumor Papillary cystadenoma

Oncocytoma (potentially malignant) Mucoepidermoid carcinoma Adenoid cystic carcinoma

Acinic cell tumor

Squamous cell carcinoma

Lymphoma (greater risk in Sjögrens syndrome)

Acquired

Salivary gland stones

Behavioural/Lifestyle

Alcoholism, obesity, malnutrition, dehydration

Congenital

Hereditary amyloidosis

Drugs

Xerogenic medications

Endocrine

Uncontrolled diabetes, Renal disease

Functional

Chronic fatigue syndrome and fibromyalgia (may be related to medications)

Genetic

Ectodermal dysplasia, Salivary gland aplasia

 

Assessment

The Xerostomia Inventory: Subjective Assessment13

This is an eleven item summated rating scale combining the responses to eleven individual items in a single continuous scale score. This represents the subjective severity of chronic xerostomia; higher scores represent more severe symptoms. It allows for comparisons of subjective symptoms after instituting management options.

The following statements refer to the patient’s experiences of mouth dryness during the last four weeks. For each statement, the patient circles the response which applies to them.

 

My mouth feels dry NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
I have difficulty in eating dry foods NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
I get up at night to
drink
NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
My mouth feels dry when eating a meal NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
I sip liquids to aid in swallowing food NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
I suck sweets or cough lollies to relieve dry mouth  NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
I have difficulties swallowing certain foods NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
The skin of my face feels dry NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
My eyes feel dry NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
My     lips feel dry NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS
           
The inside of my nose feels dry NEVER HARDLY EVER OCCASIONALLY FREQUENTLY ALWAYS

 

To validate the questionnaire, the following global question needs to be placed somewhere else in the consultation or questionnaire.

How often does your mouth feel dry? (circle the appropriate response)

NEVER   OCCASIONALLY    FREQUENTLY   ALWAYS

 

Table 4: Clinical examination (objective history and assessment)

Patient Details

Patient Name:

Address:

Date of Birth:

Gender:

Ethnic Group patient identifies with: Hospital Number:

Date of examination:

 

History

Presenting Complaint Review of Systems Further Questioning
Age at onset CVS, Could you eat a cracker without water?
Symptoms and duration Respiratory,
Initiating / precipitating factors Gastrointestinal,  Sore mouth
Genitourinary,  Dysarthria
Past history of salivary gland disease Musculoskeletal,  Dysphagia
Integumentary/Breast,  Dysaesthesia
Past history of salivary gland surgery Neurological, Rhinitis Reflux
Past history of Radiation Treatment to the Head and Neck region?  Psychiatric,  Nutritional status/Weight loss
  Endocrine,  Dehydration
Past history of xerogenic medications? Haematologic/ Lymphatic,  Nocturia/polyuria Constipation/Diarrhoea
Corrective treatment Allergic/Immunologic, Fatigue and Raynaud’s phenomenon
  Constitutional symptoms Nasal or genital mucosa dryness
    Rash
    Arthralgias
    Gritty and dry eyes
    Salivary swelling
     
     
Medical History Medications Allergies/Adverse Reactions
Current Medical problems Identify xerogenic medications Allergy to medications
Allergy to other substances
Surgical history    
Past illnesses    
     
     
Dental History Social History Family History
Regular Dental Practitioner Employment/ Occupation Relevant family medical history
Current dental care regimen, dental appliances, toothpastes, mouthrinses, flossing Dependents/ living arrangements  
Caries history, Periodontal history, orthodontic history Diet Alcohol
  Smoking, tobacco use, e-cigarettes
Oral Malodour/Halitosis Recreational drug use  
Recurrent oral infections    
Taste disturbance    

 

CLINICAL EXAMINATION

Extraoral Examination

The first step in the extraoral examination is a quick general examination of the patient, ability to mobilise, swelling of joints, obvious skin rashes, finger nail changes.

Salivary glands

Inspect swelling

Palpate: parotid and submandibular salivary glands using a bilateral technique.

(Enlargement, induration, tenderness, masses require further investigation)

Lymphadenopathy

Palpate head and neck for masses or lymphadenopathy

Cranial nerves

Particularly facial nerve VII and Trigeminal Nerve V

Facial symmetry and swelling

 

Presence of scars and previous surgical sites

 

 

Intraoral examination 

Utilise the Challacombe scale designed to produce a clinical oral dryness score (CODS).14 The first step in the intraoral examination is a quick general examination of the buccal mucosa, hard palate, tongue, gingiva and floor of mouth.

 

Oral cavity

Lips

Oral Malodour/Halitosis Signs of dehydration

Mucosa

Mucosa – Presence / absence of mucosal lesions

Lobulate tongue Sialadenitis

Presence/ absence of candida

Saliva

milk the ducts: Stensen’s and Wharton’s duct

Description of saliva: serous, mucous, ropey

Hard and soft tissue dental examination

Atypical dental caries (particularly cervical decay) periodontal disease

Salivary flow assessment and function, laboratory tests and referrals are performed as necessary. The patient then needs to be given a definitive diagnosis and aetiology where possible, as well as prognosis of the salivary dysfunction.

 

Table 5: Investigations

Non Invasive

Bloods

Imaging

 

Salivary Gland flow:

Collect Saliva by spitting into a tube over 5 minutes (mls/min)

  1. Unstimulated saliva
  2. Stimulated saliva - chew a piece of wax or similar to increase yield.

CBC LFT’s

U and E’s HbA1c sACE ANA/ ENA

Viral Screen

Ultrasound CT

MRI

MR sialography

Radioisotope salivary function test

Salivary Gland Biopsy

 


Figure 2: The Caries Balance15

 

Shows the balance between biological caries risk factors (pathological factors) and protective factors. The balance can either be toward progression or reversal of the disease.


Figure 3: The Caries Imbalance15
Featherstone Community Dentistry Oral Epidemiology, 1999

Shows the imbalance when risk factors exceed protective factors and lead to caries progression.

 

Table 6: Considerations in the management of hyposalivation and xerostomia15-16

Management of the condition, depending on the diagnosis and severity, include oral moisture and comfort, oral disease prevention strategies and therapies, prevention of recurrent caries and other conditions, controlling soft tissue

infections and pain, and referral where appropriate.

  • Keep water at hand to keep the mouth moist
  • Small spray bottle with bland cooking oil to lubricate tissue
  • Sugar free chewing gums or sweets (may provide adequate lubrication between meals for talking and normal activities)
  • Use paraffin moisturiser regularly on the lips. Avoid fragrances.

PERSONAL ORAL HYGIENE

Dentate

  • The oral cavity should be rinsed immediately after meals.
  • Brush at least twice a day and before bedtime with a soft toothbrush and high fluoride toothpaste.

(It is controversial about when to brush, but if brushing after a meal, wait 30 minutes to prevent further demineralisation in the presence of an acidic environment.)

  • Use high fluoride toothpaste or mouthrinse. Do not rinse out after brushing, spit out foam.If high risk of decay, apply prescription strength fluoride gel at bedtime or use fluoride mouthrinse.
  • Clean interproximally with floss, interproximal brushes or waterpick.
  • ATTEND DENTIST AND HYGIENIST SIX MONTHLY UNTIL DECAY RATE AND PERIODONTAL CONDITION IS STABLE.

Prostheses

  • Dentures need to be brushed and rinsed after meals
  • Use denture adhesive as retention can be challenging with loss of surface tension of saliva.

PROFESSIONAL INTERVENTION

Oral Hygiene instruction; technique, equipment (Avoid rinses containing alcohol)

  • Lifestyle advice:
  • Avoid liquids and foods with high sugar content, strongly acidic Alcohol and coffee cessation or reduction, Smoking cessation, Avoid recreational drugs
  • Prescription for Fluoride Treatments and consideration of Salivary Substitutes and Sialogogues
  • Consider alteration of Xerogenic medications with General Medical Practitioners.
  • Refer where appropriate

PRESCRIPTION AND OTC

  • PROBIOTICS BLIS K12 AND M18
  • SIALOGOGUE 16
    Pilocarpine is a useful salivary stimulant, but there are side effects and it is crucial to ensure there is no concurrent heart disease, diabetes and drug interactions.
  • SALIVA REPLACEMENTS

Usually produced from methylcellulose. Designed to mimic saliva as much as possible.

 

 

Management

The basic principles of management are the elimination or correction of

accessible aetiological factors and the stimulation of natural salivary flow. If this is not possible, replacement with artificial saliva, together with other measures for the prevention  of dental disease is necessary.  Often, however,  the cause   is multifactorial and therefore a number of management strategies need to be considered with a multidisciplinary team. Providing appropriate therapy in time will help patients with their mental health, decrease anxiety and depression, maintain a better quality of life and wellbeing in addition to optimising systemic health.

Symptomatic management of hyposalivation is required when saliva production cannot be stimulated effectively in the form of sipping water or chewing gum. Saliva substitutes can also be considered as treatment alternatives. Artificial saliva preparations are available in different forms such as sprays and gels and are used as a replacement of natural saliva and to mimic its functions. Sialogogues (drugs that promote saliva secretion) can also play a role, but require careful management. Multidisciplinary management of systemic disease is necessary as there are steroids and biologics which may be of benefit in autoimmune conditions, and antibiotics, antifungals and antivirals for infective causes.

Additional referrals may be necessary for second opinions in cases with suspicion of neoplasms or blockage due to stones.

 

Treatment of fungal infection

 

 

Caution

Topical Antifungal

Nystatin

Amphotericin B (Fungilin) Miconazole 2% gel

Contains sucrose

 

Be aware of interaction with cholesterol lowering agents and blood thinners

Xerogenic medications – liaise with general medical practitioner

All treatment should be undertaken in collaboration with the General Medical Practitioner and xerogenic medications reviewed and altered where possible.

  • Consider modifying patient medication schedules to minimise impact of hyposalivation and xerostomia
  • Consider easy to take formulas
  • Avoid sublingual medications


 

Dietary considerations

Dietary guidance is important for overall management as people try to compensate for their dry mouth with drinking fruit juices and carbonated beverages, therefore increasing the risk of dental caries. The patient should be seen by a dietitian and encouraged to eat moistened foods, and reduce foods that induce diuresis (including coffee and alcohol). This should be followed by dietary advice aimed at reducing the intake and frequency of sugars including glucose and fructose which are often used as sucrose substitutes in food and drinks.

 

Conclusion

The role of the General Dental Practitioner is paramount in the control and maintenance of oral health in a patient with a dry mouth. Optimal oral care is achieved with a multifactorial approach (Table 6). The Patient’s current oral health status, hygiene regime, and compliance should be considered while making a treatment plan for patients with xerostomia. The quality of conservative dentistry must be of a high standard as patients are vulnerable to caries and intolerant of dentures. The patient should then be given a clear and concise account of the effect of xerostomia on the teeth and gingival tissues so that the need for good personal oral hygiene is appreciated.


Figure 5: Illustration of the factors involved in caries development17
\Selwitz RH, Ismail, AI, Pitts NB. Dental Caries, Lancet 2007, 369:51-59 
Adapted from Fejerskov and Manji 1990

This paper provides a practical evidence-based update for the clinician to use in

practice for patients aged six through adult.

Caries Management by Risk Assessment (CAMBRA): An Update for Use in Clinical Practice for Patients Aged 6 Through Adult John D.B. Featherstone, MSc, PhD; Pamela Alston, DDS, MPP; Benjamin W. Chaffee, DDS, MPH, PhD; and Peter Rechmann, DMD, PhD

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