Examination (mouth and tongue)

Inspection of the mouth and tongue may yield important information:

Tongue:

• the tongue is blue in patients with central cyanosis
• the tongue is red and sore in iron- and B-vitamin -deficient patients
• the tongue is enlarged in:
  • acromegaly
  • amyloidosis
  • myxoedema
• the tongue is spastic in motor neurone disease

Gums:

• bleeding gums are characteristic of:
  • periodontal disease
  • leukaemia
  • scurvy
• hypertrophied gums may indicate chronic phenytoin use
• a blue line along the margin of the teeth indicates lead poisoning

Teeth:

• yellow teeth may indicate tetracycline use in early life
• caries may be cause local and systemic infection
• hypoplastic teeth may indicate dentinogenesis imperfecta
• Hutchison's teeth are seen in congenital syphilis

General:

• angular stomatitis is common in iron deficiency
• aphthous ulceration
• leukoplakia
• herpes simplex infection
• pigmented lesions of Peutz-Jeghers syndrome
• white reticular lesions of lichen planus
• the tight mouth of scleroderma
• oropharyngeal cancer may present as an ulcer or a mass