For more clinical information, readers may refer to my major book Color Atlas of Oral Diseases: Diagnosis and Treatment, 4th edition; Thieme, 2017.
George Laskaris, MD, DDS, PhD
Introduction to Oral Medicine
Oral medicine (stomatology) is an important, rapidly developing dental specialty in several countries of the world that recognizes and cultivates the close interplay between oral and systemic health. The spectrum of diseases of oral medicine is wide and includes diseases of the oral mucosa and the gingiva, lip disorders, salivary gland and jaw diseases, temporomandibular joint disorders, malodor, taste changes, orofacial pain, and oral manifestations of systemic diseases (see the schematic classification on the next page). Oral diseases may be local or systemic, acute or chronic, innocent or serious, painful or not, and life-changing or life-threatening. The oral medicine specialist (stomatologist or oral physician) should collaborate with several medical specialties (dermatology, gastroenterology, otorhinolaryngology, hematology, infectiology, immunology, oncology, pediatrics, neurology, psychiatry, internal medicine, pathology, imaging, and head and neck surgery) and with the dental specialties (general dentistry, oral surgery, periodontology, implantology, pediatric dentistry, oral pathology, and radiology).
The oral medicine specialist should have a dental and a basic medical background, particularly in internal medicine, dermatology, otorhinolaryngology, pediatrics, clinical pharmacology, therapeutics, histopathology, and others. The general dentist and the medical physician should also have the basic knowledge of oral diseases in order to recognize the primary lesions in the oral cavity and to direct the patient to the oral medicine specialist. The oral cavity, as an examination field, offers important clinical advantages: (a) it is an open cavity readily accessible to inspection and palpation, (b) it is easy to perform a biopsy here, (c) it is regularly examined by the dentist for tooth and gingival problems, and (d) it is accessible to self-examination by the patient. Several diagnostic difficulties exist due to: (a) the plethora of local and systemic diseases with similar lesions and (b) local factors, such as tooth, dentures, foodstuffs, or saliva, which may alter the morphology of the elementary lesions. Clinical diagnostic methodology should follow fundamental principles that we must adhere to in order to arrive at a correct diagnosis. Laboratory tests are a tool that must follow the clinical evaluation. Laboratory results should always be evaluated by the clinician in relation to the clinical features of the disease.
The goal of the oral medicine specialist should be the prevention, diagnosis, and treatment of oral diseases.
Schematic Classification of Oral Diseases
A guide, in the form of a tree, for students, residents, and specialists in oral medicine that offers a basic framework for the classification of oral diseases into four major groups: systemic, local, infectious, and neoplasms.
1 White Lesions
White lesions of the oral mucosa are a multifactorial group of disorders, the color of which is produced by the scattering of light through an altered epithelial surface. These lesions are classified into two groups: (1) attached to the oral mucosa and (2) scraped off from the oral mucosa. The diagnosis and differential diagnosis of oral white lesions should be made on the basis of the medical history, clinical features, and laboratory tests.
| Leukoplakia | Fordyce’s Granules |
| Hairy Leukoplakia | Leukoedema |
| Lichen Planus | White Sponge Nevus |
| Lichenoid Reactions | Dyskeratosis Congenita |
| Linea Alba | Pachyonychia Congenita |
| Nicotinic Stomatitis | Focal Palmoplantar and Oral Mucosa Hyperkeratosis Syndrome |
| Cigarette Smoker’s Lip Lesions | |
| Uremic Stomatitis | Mucosal Horn |
| Cinnamon Contact Stomatitis | Papilloma |
| Chemical Burn | Verrucous Carcinoma |
| Candidiasis | Squamous Cell Carcinoma |
| Chronic Biting | Skin and Mucosal Grafts |
| Material Alba of the Gingiva | |
| Epithelial Peeling |
1.1 Leukoplakia
Definition: Leukoplakia is a clinical term without any histologic significance. It is defined as a white patch or plaque that cannot be scrapped off and cannot be characterized, clinically and histologically, as any other disease entity. Leukoplakia is the most common potentially malignant disorder (precancerous lesion) and is characterized by biological heterogenicity.
Etiology: The exact etiology remains unknown. Smoking and alcohol consumption are the main environmental causative factors, followed by human papillomavirus (HPV) types 16 and 18, Candida species, chronic local friction, etc.
Clinical features: Based on the clinical criteria, leukoplakia is classified into two main groups: (1) homogeneous (common-low risk) and (2) nonhomogeneous, which is subdivided into speckled or nodular (less common-high risk) and verrucous (rare-high risk) forms. Clinically, homogeneous form is characterized by a, thin, flat uniform white plaque (▶ Fig. 1.1 and ▶ Fig. 1.2). The speckled form is characterized by a red surface with multiple, small, white macules or nodules (▶ Fig. 1.3 and ▶ Fig. 1.4). Verrucous form presents as an exophytic, irregular, wrinkled or corrugated white plaque (▶ Fig. 1.5). Proliferative verrucous leukoplakia is a subtype of verrucous form, which is characterized by multifocal location, tendency to recur, is usually HPV positive, and has a high rate of malignant transformation. The total risk of malignant transformation of leukoplakia varies between 3 and 6% independent of the form. The buccal mucosa and commissures, tongue, floor of the mouth, gingiva, and lower lip are more frequently affected. The lateral border of the tongue and the floor of the mouth represent areas of high risk for malignant transformation.
Laboratory tests: Biopsy and histopathologic examination must be done to determine the risk of malignant transformation of oral leukoplakia. The oral clinicians should remember that the histologic results represent exclusively the site of biopsy taken in a specific time frame and do not have a long-term value.
Differential diagnosis: Lichen planus, lichenoid reaction, hairy leukoplakia, cinnamon contact stomatitis, nicotinic stomatitis, candidiasis, chronic biting, chemical burn, leukoedema, uremic stomatitis, lupus erythematosus, white sponge nevus, dyskeratosis congenita, pachyonychia congenita, skin, and mucosal grafts.
Treatment: The treatment of choice is surgical excision and smoking cessation. Electrosurgery and laser may also be used as alternative procedures. A follow-up program every 6 months for 3 to 5 years is recommended.
Fig. 1.1 Homogeneous leukoplakia on the upper gingiva.
Fig. 1.2 Homogenous leukoplakia on the floor of the mouth.
Fig. 1.3 Speckled leukoplakia on the buccal mucosa.
Fig. 1.4 Speckled leukoplakia on the buccal mucosa.