15.1 Oral Manifestations of Systemic Disease

Why This Is a Separate Blueprint Topic

"Oral aspects of human disease" appears in the Paper A blueprint as a topic distinct from "human disease relevant to dentistry". The distinction is deliberate. The first asks how systemic disease changes your dental management; the second asks what the mouth tells you about the patient's general health. A substantial minority of systemic diseases produce oral signs before the patient consults a physician, and Preparing for Practice outcome 1.10.1 requires registrants to "recognise the responsibilities of a dentist as an access point to and from wider healthcare".

Haematological Disease

Any patient with recurrent oral ulceration deserves a haematinic screen — full blood count, ferritin, vitamin B12 and folate — because deficiency is found in roughly 5% to 10% of cases and is fully correctable.

Gastrointestinal Disease

• Crohn's disease produces mucosal tags, cobblestoning of the buccal mucosa, linear ulcers in the buccal sulcus and diffuse lip swelling. Orofacial granulomatosis may be the presenting feature, particularly in children, and a proportion later develop intestinal disease.
• Coeliac disease presents with recurrent aphthae, enamel defects in a symmetrical, chronological distribution, and delayed eruption.
• Ulcerative colitis is associated with pyostomatitis vegetans, a "snail-track" pustular eruption on the gingivae and buccal mucosa.
• Gastro-oesophageal reflux produces palatal erosion of the upper anterior teeth, as covered in the human disease chapter.
• Peutz-Jeghers syndrome gives perioral and intraoral melanotic macules with intestinal polyposis.

Endocrine and Metabolic Disease

• Diabetes mellitus presents orally with periodontitis out of proportion to plaque, recurrent periodontal abscesses, candidiasis, xerostomia, burning mouth and delayed healing. Undiagnosed diabetes is sometimes first suspected in the dental chair.
• Addison's disease causes generalised mucosal and skin hyperpigmentation from ACTH-driven melanocyte stimulation. New, diffuse oral pigmentation in a patient with fatigue and postural hypotension is a red flag.
• Hyperparathyroidism produces loss of lamina dura, a ground-glass trabecular pattern and brown tumours — giant-cell lesions that are histologically identical to central giant cell granuloma, which is why serum calcium and parathyroid hormone must be checked before that diagnosis is accepted.
• Acromegaly causes mandibular prognathism, spacing of the teeth, macroglossia and an increased interdental distance developing in adulthood.

Connective Tissue and Autoimmune Disease

• Sjogren's syndrome is covered in detail in the salivary chapter; the oral hallmark is objective hyposalivation with rampant cervical and root caries.
• Systemic lupus erythematosus produces oral lesions resembling lichen planus, often on the palate, together with the classic malar rash.
• Systemic sclerosis causes microstomia, a rigid perioral skin, widening of the periodontal ligament space on radiographs without mobility, and severely restricted mouth opening that makes routine dentistry difficult.
• Rheumatoid arthritis may involve the temporomandibular joint and limits manual dexterity for oral hygiene, which is a reasonable adjustment issue under the Equality Act 2010.

Infectious and Immunosuppressive Conditions

HIV produces a well-defined set of oral lesions covered in the immunology chapter: pseudomembranous and erythematous candidiasis, oral hairy leukoplakia, linear gingival erythema, necrotising periodontal disease and Kaposi sarcoma. Because these may be the presenting feature, a dentist who recognises them and refers appropriately is performing a genuine public health function.

Referral principle. When an oral sign suggests undiagnosed systemic disease, the dentist's duty is to document the finding clearly, explain the reason for referral in terms the patient understands, and write to the general medical practitioner with the specific findings and the differential being considered. Sending a patient away with "see your doctor" and no letter is not an adequate discharge of that duty.

Using Oral Signs to Trigger the Right Investigation

The point of this topic is that a dentist may be the first clinician to detect systemic disease, so each sign should be linked to an investigation rather than to a treatment. Recurrent aphthous ulceration or a sore, depapillated tongue leads to a full blood count with ferritin, vitamin B12 and folate. Spontaneous gingival bleeding with petechiae or unexplained bruising leads to a full blood count and clotting screen and, if acute leukaemia is suspected, to same-day referral. Symmetrical, painless parotid enlargement leads to consideration of sialosis in diabetes, alcohol dependence, bulimia or acromegaly. Rapidly progressive periodontitis in a young adult leads to screening for diabetes. Orofacial granulomatosis with cobblestone mucosa, lip swelling and mucosal tags leads to investigation for Crohn's disease. Unexplained mucosal pigmentation leads to consideration of Addison's disease and to measurement of blood pressure and electrolytes.