reactive lesions of the oral mucosa Flashcards
What type of epithelium is found in the oral mucosa and what is under this
The oral mucosa is made of stratified squamous epithelium and lamina propria.
Name the different types of mucosa in the mouth
Lining
Masticatory
Gustatory
Describe the difference between non-keratinised and keratinised mucosa and give examples of each
Non-keratinised mucosa is redder and examples include the buccal mucosa, floor of mouth, soft palate, and ventral surface of the tongue
Keratinised tissue is paler, with examples including the hard palate
What are the layers of the non-keratinised epithelium?
Superficial
Intermediate
Progenitor
What are the reactions of oral epithelium?
Keratosis
Acanthosis
Elongated rete ridges
Atrophy
Erosion
Ulceration
Oedema
Blister
What is the difference between orthokeratosis and parakeratosis?
Parakeratosis contains dark dots in the keratin - the remains of nuclei of squamous cells
Only seen microscopically, not clinically
What are the layers of the epithelium?
Stratum corneum - most superficial
Stratum granulosum
Stratum spinosum
Stratum basale
Lamina propria is deep to this
In what layer of the epithelium does cell division occur?
Basal and suprabasal cells
What is keratosis?
The formation of a keratin layer
In a non-keratinised site this is always parakeratosis
What is acanthosis?
Hyperplasia of the stratum spinosum
How will the epithelium appear in keratosis and acanthosis and why is this?
White as it is thickened and is blocking the underlying blood vessels
What is elongated rete ridges?
Hyperplasia of basal cells
What is atrophy and how does it appear?
Reduction in viable layers
Appears as red lesion as thinner epithelium causes blood vessels to show through
What is erosion and how does it appear?
Partial thickness loss
Generally appears red
What is ulceration and how does it appear?
Full thickness loss with fibrin on the surface, exposing the underlying lamina propria
May appear yellow as fibrin is yellow
What is oedema?
A build up of fluid, can be intracellular or intercellular (spongiosis)
How are blisters categorised?
If small then called a vesicle
If larger then called a bulla
Define dysplasia in the context of oral epithelium.
Disordered maturation or growth in a tissue
It is microscopic and cannot be seen clinically
The more severe the dysplasia, the more likely to become malignant
What is atypia?
Changes in cells at a cellular level
What are the common causes of oral tissue atrophy?
Commonly progresses with age
Nutritional deficiencies - haematinics
What determined the oral mucosa reaction to trauma?
Irritation
Time
Person
How may the oral mucosa react to trauma?
Inflammation
Keratosis
Ulceration
Fibrous tissue formation
Formation of vesicles and bullae
Other
What are epulides and what causes them?
Soft tissue swellings on the gingiva only
Caused by a reaction to chronic inflammation or chronic trauma
Can reoccur after removal is the stimulus persists
Why should unexplained tooth mobility be investigated?
In case of a malignancy
Describe localised gingival hyperplasia histologically?
Metaplastic bone formation over granulation tissue
Describe localised gingival hyperplasia clinically?
Mostly in posterior teeth
Can get a fibrous epulis
Can be removed but may persist if stimulus is not removed
What is a pyogenic granuloma?
Granulation tissue on any mucosal site
A response to trauma
What is a giant cell lesion?
Fused macrophages caused by either unphagocytosable material, chronic infection, infective agents or hormonal stimulation of osteoclasts
Describe a giant cell epulis histologically?
Bleeding into the granulation tissue
No capsule present
What is a traumatic fibroma and where are they commonly seen?
Also called fibroepithelial polyp
Fibrous tissue covered in epithelium
Often seen in the lip, cheeks and tongue
What different fibrous overgrowths are associated with dentures?
Denture induced hyperplasia (can be a flabby ridge)
Leaf fibroma - fibroepithelial polyp that gets squashed under patients denture
Papillary hyperplasia of palate
Describe papillary hyperplasia of the palate?
Also called pseudo-epitheliomatous hyperplasia
A reaction to trauma, infections and other pathogens
A candida infection
What drugs commonly cause fibrous overgrowths?
Anti-hypertensives - calcium channel blockers
Anti-epileptics - phenytoin
Immunosuppressants - cyclosporin
Describe pregnancy gingivitis
A hormonal condition - not just seen in pregnancy
Caused by increased progesterone levels
Responds to oral hygiene measures
What is a haemangioma?
Fibrotic growth generally present at birth
Becomes more fibrotic and less likely to bleed as child ages
What is Sturgeon weber syndrome?
A large haemangioma that runs along a reticular nerves
Unilaterally affects a patient
Describe vascular malformations
Very common coloured lesion
Becomes evident in adult life
Considered to be a hamartoma
Microscopically there are two types - capillary and cavernous
What is a hamartoma?
Normal tissue structure but number increased or in different location in body
