ORAL DERMATOLOGY: Part One
– Basic lesions
– Canker Sores and Aphthous Ulcers
– Oral cavity mycoses
I. TOPOGRAPHICAL ANATOMY OF THE ORAL CAVITY : The oral cavity opens anteriorly through the labial orifice and posteriorly into the oropharynx. It has a rigid architecture formed by the jaws and teeth. The entire oral cavity (except the teeth) is covered by a mucous membrane that protects the underlying structures. It is divided into:
* Lips
* Oral vestibule
* Gum
* Cheeks
* Language
* Buccal floor
* Palace
* Veil
* Dental arches
* Glandular apparatus of the oral cavity
II. HISTOLOGY : The oral cavity is entirely lined by a mucosa resting deep on the muscular and bony planes. This mucosa is made up of a squamous and multi-stratified Malpighian epithelium resting on a connective tissue called chorion. The base of the epithelium has reliefs, more or less numerous and pronounced, with epithelial crest surrounding connective papillae.
The basement membrane separates the epithelium from the underlying lamina propria . It is usual to describe three types of oral mucosa depending on the topography:
1. The bordering mucosa : it is thin, flexible and non-keratinized . It covers the inner surface of the lips and cheeks, the belly and floor of the tongue and the soft palate.
2. The masticatory mucosa : it includes the gingiva and palatine fibromucosa, it is keratinized .
3. The specialized mucosa : it covers the back of the tongue; it is an orthokeratinized mucosa and provided with papillae involved in the taste function.
4. Accessory salivary glands
III. CLINICAL EXAMINATION AND DIAGNOSTIC APPROACH : the diagnostic approach must be meticulous and includes a detailed history and interview, an exo and endo oral clinical examination, all accompanied by one or more additional examinations, depending on the lesion.
Clinical interview , an essential step for effective and quality care ; the practitioner must note age, profession, habits such as alcohol and tobacco consumption, take into account medical and surgical history and current drug treatments.
We must also look for the date and circumstances of the appearance of the lesion, their recurrence, the presence or absence of pain and even the existence of attitudes at risk of contracting sexually transmitted infections (STIs).
In the endo-oral , the lighting must be sufficient, the mouth wide open. The use of two mirrors to smooth the mucous membrane is necessary , the dental prostheses are kept in the mouth then removed . The examination of all the mucous membranes must be done as carefully as possible (inspection plus palpation).
All clinical data must make it possible to identify one (or more) type(s) of elementary lesion(s), the summary of which must be listed on an annotated diagram archived in the patient’s file.
IV. ADDITIONAL TESTS : they are guided by the pathology mentioned. We have:
1. Imaging (dento-maxillary panoramic)
2. Saliva tests
3. Biopsy
4. Cytological examination
5. Microbiological and serological examination.
ORAL DERMATOLOGY
V. MAIN ELEMENTARY LESIONS
In dermatology , the elementary lesion translates, on a morphological level, a lesion process and allows a rational classification of the pathology.
In the oral cavity , an attempt can be made to transpose elementary dermatological lesions, but the primitive elementary lesions of the oral mucosa are rapidly modified by the presence of saliva which dissociates the epithelial layers, and by the incessant movements of the tongue, lips and teeth. A bubble, for example, can lose its roof and appear in the form of an erosion or ulceration. This is then a secondary elementary lesion, corresponding to the evolution of the first.
1. Stains, spots and patches
1.1. Macules: they correspond to a change in the color of the mucous membrane over a limited surface (less than 0.5 cm in diameter), without relief (not palpable) or infiltration (or deep infiltration).
1.2. The beaches or plaques and veils: are more extensive than the macules (diameter greater than 0.5 cm ) and can extend to the entire oral cavity. These lesions, single or multiple, most often have clear limits and can be erythematous, white, pigmented (black), or on the contrary hypochromic or achromic (related to a decrease or total absence of melanin.
Erythema may appear as a macule or pink or red area. The characteristic sign is their disappearance on vitropression . On histological examination it responds to a dilation of the capillaries without extravasation of red blood cells .
The opaline veil of some leukoplakias is an example of a whitish patch.
2. Papules and plaques
Papular lesions are raised, circumscribed, solid lesions that do not contain fluid. Plaque is when the diameter of the lesion exceeds 0.5 cm in diameter.
They may be related to an increase in the thickness of the epithelium (leukoplakia and warts), an increase in the volume of the chorion (allergic edema), a cellular infiltrate (sarcoidosis) or a metabolic overload (amyloidosis). The papules may be chorioepithelial (lichen planus).
3. Nodules
These are round, prominent bumps, with a diameter greater than 1 cm , corresponding to a deep infiltration of the chorion by a cellular proliferation (benign or malignant tumors).
4. Vesicles and bubbles
4.1. Vesicles
These are small intraepithelial elevations containing a clear serous or hemorrhagic fluid of 0.5 to 5 mm . The etiology is generally viral (herpes). When bursting, these vesicles leave small rounded erosions whose bottom is covered with a flat fibrinous coating.
4.2. Bullous lesions
They are rounded or oval epithelial or subepithelial detachments of variable size (more than 5 mm in diameter). Like vesicles, they contain serous or hemorrhagic fluid.
Bullous conditions can be observed in isolation or associated with a skin rash (pemphigus). Their presence in the mouth is often ephemeral due to the fragility of the roof, oral humidity and dental trauma; they give way to erosions or rounded dark red ulcers, with a smooth base, bordered by flaps of epithelium often forming a peripheral grayish collar.
5. Erosions and ulcerations
Erosions and ulcerations correspond to a structural morphological alteration in loss of substance. Clinically, these lesions present for the most part with a characteristic yellowish fibrinous background, with variable contours. Their etiology is very varied:
* local: trauma, malignant tumors, canker sores, irradiation, chemicals, etc.
* general: systemic diseases (bullous), infectious diseases (tuberculosis, syphilis, mycoses, etc.), chemotherapy, etc.
5.1. Erosion: it can be primary or secondary . Histologically, erosions are defined by a loss of epithelial substance, leaving the underlying connective tissue more or less exposed. This is a loss of superficial substance, without necrosis of the underlying tissues (burst of bubbles and vesicles). The bursting of vesicles and bubbles gives way to erosions that can retain a collar.
Exp: herpes virus, pemphigus and erosive lichen planus.
5.2. Ulceration:
Histologically, it corresponds to a deep loss of substance with destruction of the entire epithelium and of the upper and/or deep part of the chorion.
Clinically, it is necessary to specify the location, appearance, size, shape, number of elements (single or multiple), color, limits, edges (cut steeply or everted, raised), base (clean or sanious), color, consistency. On palpation, we will look for the presence or absence of bleeding and the flexibility or induration of its base and periphery.
The interview specifies the date of appearance of the injury, absence or presence of pain, circumstances of appearance, current treatment and whether or not it is recurring.
These lesions can be single or multiple, of local or general origin; acute or chronic.
Examples of ulcers: aphthae, traumatic ulceration, squamous cell carcinoma (epithelial cancer), bullous lesions aphthae and aphthosis.
VI. OTHER ELEMENTARY LESIONS : We can cite
Vegetations, pustules, gums, pultaceous coatings and pseudomembranes, crusts, fissures, atrophy and scars.
VII. NORMAL ANATOMICAL VARIANTS
1. Linea alba or occlusal line of the cheek
2. Biting tics
3. Leukoedema
4. Marginal exfoliative glossitis or geographic tongue
5. Hairy tongue
6. Coated tongue
7. Scalloped tongue
8. Fissured tongue
9. Sublingual varicose veins or sublingual spider veins
10. Normal ethnic pigmentation of the oral mucosa
END
ORAL DERMATOLOGY
Wisdom teeth can cause infections if not removed.
Dental crowns restore the function and appearance of damaged teeth.
Swollen gums are often a sign of periodontal disease.
Orthodontic treatments can be performed at any age.
Composite fillings are discreet and durable.
Composite fillings are discreet and durable.
Interdental brushes effectively clean tight spaces.
Visiting the dentist every six months prevents dental problems.