Oral pathology/medicine/periodontology Flashcards
How thin are the sections cut of the tissue embedded in wax?
Microtome used to cut sections of 4um thickness
What are the three most common stain types?
- Haematoxylin and Eosin (H&E) routinely used
- Special histochemical stains e.g. Periodic Acid - Schiff (PAS), Trichromes, Gram
- Immunohistochemistry - antibodies
Hyperplasia vs hypertrophy
Hyper = increase
Plasia —> number of cells increased
Trophy —> size of cells increased
Metaplasia
Reversible change in which one adult cell type is replaced by another adult cell type
Hyperkeratosis
Thickening of the stratum corneum
Ulceration
Mucosal/skin defect with complete loss of surface epithelium
White lesions: developmental
fordyce granules
White lesion: normal variation
Leukoedema (stretch mucosa and it should disappear)
White lesions: Hereditary
White sponge naevus, Pachyonchia congenita, Dyskeratosis congenita
White sponge naevus
no tx required - thickened epithelium with marked hyperparakeratosis (mutation in keratin)
“basket weave” appearance
Pachyonchia congenita (genetic keratin mutation)
Dyskeratosis congenita (genetic keratin mutation)
Lichen planus
Lupus erthematosus
Leukoplakia
Leukoplakia
What causes Oral Hairy Leukoplakia?
Epstein-Barr virus (strongly associated with HIV infection in many cases)
oral hairy leukoplakia
What are the key pathological features of oral hairy leukoplakia?
Tx of oral hairy leukoplakia
none needed
Histopathology of frictional keratosis
hyperkeratosis
prominent scarring fibrosis within submucosa
Lichen planus description
Common chronic inflammatory disease of skin and mucous membranes —> if effected by skin lesions then 50% chance of having oral lesions too.
Aetiology unknown
What are the clinical features of lichen planus?
Bilateral and often symmetrical
What is the pathogenesis of lichen planus?
T cell-mediated immunological damage to the basal cells of the epithelium
Histopathology of lichen planus
What’s important to remember about the histopathology of lichen planus?
It is similar to lichenoid reaction to drugs, lupus erythematosus, etc
Management of lichen planus
manage symptoms - steriods occasionally
OMPD
Oral Potentially Malignant Disorder
What are some OPMDs?
Leukoplakia
white patch with questionable risk
LOW risk of malignant change
Proliferative Verrucous Leukoplakia
white patch with HIGH risk of progression to SCC
begins as a simple hyperkeratosis that in time becomes exophytic and wart-like
Median Rhomboid Glossitis
midline red patch
unknown - often associated w candida
Histopathology of median rhomboid glossitis
Treatment of median rhomboid glossitis
anti fungal medication
Erythroplakia
Erythroleukoplakia (speckled leukoplakia)
Cause of black hair tongue?
Papillary hyperplasia + overgrowth of pigment-producing bacteria
melanotic macule
Histopathology of melanotic macule
NOT an increased number of melanocytes
Melanoma - malignancy
Melanotic Neuroectodermal Tumour of Infancy
Left - aphthous ulcer
Right - traumatic ulcer
How can you differentiate between aphthous ulcer and traumatic ulcer?
Clinically - NOT histopathologically
Histopathology of ulcers
Histopathology of ulcers
Blister vs bulla
when the blister is greater than 10mm = bulla
Vesicles/bullae can be…(2)
1.Intrapithelial
2. Subepithelial
What are the two types of intraepithelial vesicles?
Non-acantholytic (death and rupture of cells)
Acantholytic (desmosomal breakdown)
Herpes simplex virus in primary herpetic stomatitis and herpes labialis is an example of what type of vesicle?
Intraepithelial non-acantholytic (CELL DEATH)
Pemphigus (and Pemphigus vulgaris) are caused by an autoimmune disease resulting in what type of vesicles?
Intraepithelial acantholytic (desmosomal breakdown)
Treatment of pemphigus vulgaris
steroids
Histopathology of pemphigus vulgaris
Histopathological examination of pemphigus vulgaris
Direct immunofluorescene
Mucous membrane pemphigoid (subepithelial vescicles)
Autoimmune disease
Histopathology of mucous membrane pemphigoid
Direct immunofluorescene investigation
Epidermolysis Bullosa Acquisita (uncommon, autoimmune blistering dermatitis with subepithelial bullae)
Epidermolysis Bullosa
(formation of skin bullae which heal with scarring 3 variants; simplex, junctional and dystrophic)
Angina bullosa haemorrhagica
(spontaneous blood-filled bullae, bursts to form ulcers and heal uneventfully - secondary to trauma??)
Oral submucous fibrosis
an oral potentially malignant disorder —> HIGH risk of malignant transformation
WHO 2024 classification of epithelial dysplasia
Oral epithelial dysplasia (OED) is a spectrum of
architectural and cytological epithelial changes resulting from accumulation of genetic alterations, usually arising in a range of oral potentially malignant disorders (OPMD) and indicating a risk of malignant transformation to squamous cell carcinoma (SCC).
Histological features of epithelial dysplasia p
- funky shapes and sizes of cells and nuclei (pleomorphism)
- Nucleus getting bigger inside the cell (nuclei-cytoplasmic ratio effected)
- Darkened colouring of cells/nuclei (nuclear hyperchromatism)
- basal cell hyperplasia with loss of polarity
- abnormal keratinisation (dyskeratosis)
- drop-shaped retepegs i.e. wider at their deepest part
dysplasia; mild, moderate and severe
mild = bit disorganised
moderate = reaches suprabasal cells
severe = affects full thickeners of epithelium
How is epithelial dysplasia different to cancer (SCC)?
All the features of dysplasia may be seen in oral
squamous cell carcinoma, however in dysplasia
the atypical cells are confined to the
surface epithelium
In squamous cell carcinoma, the atypical cells
invade into the underlying connective tissue.
What percentage of oral cancers are SSCs?
> 90%
5 year survival rate for oral cancer is
55%
Highest risk factor for oral cancer
SMOKING.
TNM classification of malignant tumours
T- extent of primary Tumour
N- absence or prescence and extent of regional lymph Node metastasis
M- absence or presence of distant Metastasis
T1N0M0, T4aN2aM1
Which cancer is worse?
Each component is given a number, the higher the number the
more extensive the disease, poorer prognosis.
therefore = T4aN2aM1
Definition: Abscess
Abscess —> “cess”= puss; collection of pus i.e. infection.
Cyst—> sac of fluid encased partly or wholly by epithelial cells, painless unless grows too big
Histopathology: Acute periradicular periodontitis
Neutrophil, vascular dilation, neutrophils, oedema
Histopathology: acute periapical abscess
Central collection of pus (neutrophils, bacteria, cellular debris)
Adjacent zone of preserved neutrophils
Surrounding membrane of sprouting capillaries and vascular dilation and occasional fibroblasts (granulation
tissue)
histopathology: chronic periradicular periodontitis
histopathology: periapical granuloma
histopathology: periocoronitis
Acute and chronic inflammatory changes including
oedema, inflammatory cells, vascular dilation, fibrotic
connective tissue
What does a cyst have to be to be classified as an odontogenic cyst?
Derived from epithelial residues of tooth-forming organ
What are the two types of odontogenic cysts?
inflammatory
developmental
What are the four layers of the enamel organ
Development: what forms pulp?
ectomesenchymal cells
What are the types of inflammatory odontogenic cysts?
1 Radicular cyst
2 inflammatory collateral cyst (not necessarily from endodontic cause but by some breach of the oral mucosa which causes inflammation and proliferation of epithelial cells and thus a cyst forming - pericornitis)
What is the most common type of jaw cyst?
Radicular cyst (55%)
- mainly in the maxilla
What does this histopathology show?
Radicular cyst
Marsupialisation
Marsupialization is a surgical procedure used to treat large cysts by creating an opening in the cyst wall and suturing the edges to the surrounding tissue. This allows the cyst to drain and shrink gradually over time, preserving surrounding structures and avoiding complete excision, particularly in large or difficult-to-remove cysts.
Enucleation vs marsupialisation of cysts
“enucleation” means completely removing the entire cyst lining, while “marsupialization” involves creating a pouch-like opening in the cyst wall, draining its contents, and then suturing the edges to the surrounding tissue, essentially turning the cyst into a “pocket” that gradually shrinks over time
Odontogenic Keratocyst (OKC)
Developmental cyst
3rd most common jaw cyst
MANDIBLE mainly (80%)
Where do OKCs arrise from?
Remnants of the dental lamina (Glands of Serres)
Why might OKCs be diagnosed late?
Symptomless, anterior-posterior expansion means they don’t show up and a swelling necessarily.
Neoplastic meaning
New growth
What syndrome may cause a patient to develop multiple odontogenic keratocysts at a young age?
Nevoid Basal Cell Carcinoma Syndrome
What is this histopathology characteristic for?
Odontogenic Keratocyst
What is the recurrence rate of OKC if incompletely removed?
25%
What is the 2nd most common odontogenic cyst?
Dentigerous cyst
Where are the dentigerous cysts attached to/derive from?
Amelocemental junction/associated with the crown of an unerupted tooth
Why might you not be able to diagnose a developmental cyst from it’s histopathological features?
These features can be lost if there is secondary infection - it will be indistinguishable from an inflammatory cyst.
What are these features of?
Dentigerous cyst
What is an eruption cyst?
A type of dentigerous cyst arising in extra-alveolar location.
Typically the tooth will naturally erupt through the cyst and no treatment is needed.
Botryoid odontogenic cyst
Botryoid = bunch of grapes (polycystic appearance)
Commonly in the MANDIBLE in premolar/canine region
Glandular odontogenic cyst
Very rare - anterior mandible
Gingival cyst
Calcifying odontogenic cyst
Very rare - GHOST CELLS
Nasopalatine duct cyst
Most common NON-odontogenic cyst
(epithelial remnants of the nasopalatine duct)
Unknown aetiology
Salty taste in mouth
Median palatine cyst, incisive canal cyst, median alveolar
cyst are now considered to represent different presentations
of ______________
nasopalatine duct cyst
Nasopalatine duct cyst
Surgical ciliated cyst
Nasolabial cyst
- can distort nostril
- derived from remnants of the embryonic nasolacrimal duct or lower anterior portion of the mature duct
Dermoid cyst
Lymphoepithelial cyst
- LYMPHOID tissue in cyst wall
Thyroglossal duct cyst
Why are non-epithelialised primary bone cysts not TRUE cysts?
not lined
Solitary bone cyst - no cyst contents
Aneurysmal bone cyst
blood-filled spaces separated by cellular fibrous tissue, no lining
Stafne’s Defect
Stafne’s Idiopathic Bone Cavity
• NOT a true lesion
• Developmental anomaly
• Due to part of submandibular gland indenting lingual
mandible
• Appears cyst-like on radiograph and be mistaken for
a cyst
WHO classification 2024: Odontogenic tumours
Benign (or malignant)
—»
1. Benign EPITHELIAL
2. Benign mixed EPITHELIAL & MESENCHYMAL
3. Benign MESENCHYMAL
Classifciation - Type of tumour: ameloblastoma
Benign epithelial odontogenic tumour
Ameloblastoma
POSTERIOR MANDIBLE commonly
- jaw swelling noted
Ameloblastoma
Tx of ameloblastoma
Complete excision with margin of uninvolved tissue, as this WILL recur if not completely excised.
What benign epithelial odontogenic tumour may mimic that of a dentigerous cyst as it arrises from an unerupted permanent tooth?
Adenomatoid odontogenic tumour
Adenomatoid odontogenic tumour
Classification of Odontoma
Benign mixed epithelial and mesenchymal odontogenic tumours
Odontoma types
“pound” = lots of coins —> lots of little tooth-like structures
“Pl(ex)”—> Plant = cauliflower appearance
Both contain enamel, cementum and dentine.
PAINLESS slow growing lesions.
Classification: Cementoblastoma
Benign mesenchymal odontogenic tumours
Cementoblastoma
- Formation of cementum-like tissue in connection with root of tooth.
- painful swelling
Cementoblastoma
- Formation of cementum-like tissue in connection with root of tooth.
- painful swelling
Tx of cementoblastoma
COMPLETE removal INCLUDING the tooth
Examples of malignant odontogenic tumours
Ameloblastic carcinoma
Odontogenic carcinosarcoma
Central giant cell granuloma (CGCG)
- mandible, female, under 30
- multinucleated giant cells
________ is histologically INDISTINGUISHABLE from cherubim’s, brown tumour of hyperparathyroidism, giant-cell tumour, aneurysmal bone cyst.
Central Giant Cell Granuloma
Cherubism (rare inherited disorder)
histologically the same as CGCG etc
What is a fibro-osseous lesion?
When normal bone (“osseous”) is replaced by cellular fibrous tissue.
- cannot be diagnosed by histology alone; need clinical/radiographic features
What is cemento-osseous dysplasia?
Fibro-osseous lesion occurring in tooth-bearing areas of the jaws (teeth can still remain vital)
Fibrous dysplasia
Fibrous dysplasia
fibro-osseous lesion of GROWING bones
Painless - rarely malignant change
Aesthetic surgery
Types of Ossifying fibroma
- Cemento(-ossifying fibroma)
- Juvenile trabecular (ossifying fibroma)
- Psammomatoid (ossifying fibroma)
Cemento(-ossifying fibroma)
(note this is the only one out of the three types categoried as a benign mesenchymal odontogenic tumour)
DEMARCATED nature is an important feature distinguishing it from fibrous dysplasia.
Juvenile trabecular (ossifying fibroma)
found in children and adolescents
Psammomatoid (ossifying fibroma)
“Psammomatoid” comes from the Greek word “psammos” meaning “sand,” and “-oid” meaning “like” or “resembling.” So, psammomatoid refers to something that looks like sand, often used to describe small, sand-like calcifications seen in certain tumors, such as psammomatoid ossifying fibromas.
Familial gigantiform cementoma
RARE (fibro-osseous lesion of jaws)
Segmental odontomaxillary dysplasia
RARE
Sporadic
Unilateral
Palatal-buccal expansion
Osteoma and Osteochrondroma are types of…?
Benign maxillofacial bone and cartilage tumours
Osteoma
- tumour slow-growing and made of bone.
- mandible
— multiple lesions associated with Gardner syndrome !
Two types of osteoma
- cancellous (inner spongey bone)
- compact (outer hard bone)
Depends which part of bone proliferates
Osteochondroma
• Bony projection with a cap of cartilage
• Continuous with underlying bone
• Rare in maxillofacial bones (occurs at sites of
endochondral ossification)
• Symptoms depend on site of lesion
Treatment
• Complete excision
Osteogenesis imperfecta
inherited disease (AD)
impaired collagen maturation - thus poorly developed bones.
Bones fracture easily, maybe associated w dentinogenesis imperfecta, malocclusion
Osteopetrosis (marble bone disease)
Rare genetic disease
Increase and bone density
Osteomyelitis is common (bone infection - V painful)
Cleidocranial dysplasia
Rare genetic disorder (AD)
No clavicles
Delayed eruption of teeth and many supernumeraries
Narrow high arched palate
Achondroplasia
Dwarfism
Retrusive maxilla = malocclusion
Abnormal endochondral ossification
Osteoporosis
NORMAL bone but just LESS bone there.
Seen in diseases that effect endocrine (cushing’ a hyperparathyroidism)
Post menopausal women
Rickets and Osteomalacia
Dry socket (clinical term)
Alveolar Osteitis
MRONJ definition
MRONJ defined as’ exposed bone, or bone that can
be probed through an intraoral or extraoral fistula, in
the maxillofacial region that has persisted for more
than eight weeks in patients with a history of
treatment with anti-resorptive or anti-angiogenic
drugs, and where there has been no history of
radiation therapy to the jaw or no obvious metastatic
disease to the jaws’
Pager’s disease of bone
Osteitis Deformans
Effects occlusion
May also see hypercemetosis or ankylosis
Paget’s disease
Exostoses
Localised bony protuberances e.g. torus
Completely fine to leave alone !
Something can only be classified as an epulis if…
located on the gingiva
Fibrous Epulis
Even though pyogenic granulomas and pregnancy epulis are technically the same thing; how would you treat them differently?
Pyogenic granuloma - local excision
Pregnancy epulis - good OH and should resolve post-partum
Giant cell epulis vs pyogenic granuloma
While both Giant-Cell Epulis (also known as Peripheral Giant-Cell Granuloma) and pyogenic granuloma are benign oral lesions that appear as soft tissue growths, the key difference lies in their microscopic appearance, with a Giant-Cell Epulis being characterized by a large number of multinucleated giant cells, while a pyogenic granuloma typically has a more vascular structure with fewer giant cells, and often presents with a brighter red color compared to the more bluish-purple hue of a Giant-Cell Epulis; both are usually caused by local irritation or trauma
Fibroepithelial polyp
—> buccal mucosa, lip, tongue
Papillary hyperplasia of the palate
Fibrosarcoma
Malignant (rare)
A fibrous tissue tumour
Lipoma or Liposarcoma
Adipose tissue tumour
Lipoma - benign
Liposarcoma - malignant
Lipoma
Haemangioma
Benign neoplasm
tx - often regress on own
Lymphangioma
Excise
Kaposi’s Sarcoma
Locally aggressive tumour of endothelial cells
Associated w HHV-8 infection
tx - antiretroviral therapy/chemotherapy
Rhabdomyoma
Painless growing mass
Lobules of closely packed mature MUSCLE cells.
Pleomorphic adenoma (accounts for approx 60% of all parotid tumours)
benign, painless, rubbery
genetic mutation
Pleomorphic adenoma
HIGH CHANCE of malignant transformation
Warthin Tumour
Malignant epithelial tumours
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Acinic cell carcinoma
Adenoid cystic carcinoma —> NEURAL INVASION
Mucoepidermoid carcinoma
Acini Cell carcinoma
Management of asymptomatic oral lichen planus
no treatment required
Management of symptomatic oral lichen planus
Match treatment to symptom severity
- “STAD”
- Steroids (topical)
- Toothpaste = SLS free
- Analgesic (topical)
- Diet modification
Oral lichen planus & recurrent aphthous stomatitis - topical steroids
Betamethasone (500mg as a mouthwash)
Oral lichen planus & Recurrent aphthous stomatitis - topical analgesic
Benzydamine (mouthwash or spray)
Potential for malignant transformation of oral lichenoid reaction vs lichen planus
Higher for oral lichenoid reaction than lichen planus
What is recurrent aphthous stomatitis (RAS)?
Recurrent bouts of one or more painful, rounded or ovoid ulcers.
Most aphthous ulcers last for 10-14 days.
It is a common mouth condition affecting up to 20% of the population at any given time.
The severity and frequency of RAS tends to decrease with age.
behcet disease
Aphthous ulceration and sores also on genitalia etc
Pemphigus Vulgaris - screening
Autoantibody: Desmoglein 3 —> seen w immunofluorescene
Management of pemphigus vulgaris
Systemic steroids = Prednisolone (1mg/kg)
+ topical analgesics and steroids
Aciclovir
Antiviral medication used to treat herpes simplex virus
An example of orofacial pain attributed to lesion or disease of the cranial nerves
Trigeminal neuralgia
Trigeminal Neuralgia
- Recurrent, one-sided, brief (up to 2 mins) SEVERE electric shock-like pains.
- Specific to one or more divisions of the trigeminal nerve.
Classical trigeminal neuralgia
Nerve has been compressed by blood vessel (this can be seen surgically or from an MRI)
“ with Concomitant continuous pain
—> pain in the background in that area existing between the main shocks.
Secondary trigeminal neuralgia
caused by a known underlying disease (multiple sclerosis, lesion etc).
tends to cause bilateral trigeminal neuralgia
First line management of Trigeminal Neuralgia
Carbamazepine
Perio: to proceed to subgingival instrumentation “step 2”
you must have an engaged patient
Three types of periodontal surgery
Resective, reparative and regenerative
When is surgical interventions recommended for periodontitis patients?
Residual deep sites (>6mm)
Infrabony defects >3mm
Furcation involvement (class II)
OHI NEEDS to be good —> otherwise failure likely!
Periodontal surgery: flap design
Avoid vertical relieving incisions, consider horizontal extension.
If absolutely necessary, extend just past mucogingival junction and avoid cutting over bulbosity such as canine eminence.
Sutures opted for
Synthetic mono-filament
While sutures present post-op…
No brushing in the region
Use chlorohexidine mouthwash to reduce plaque formation
Periodontal dressings
not really opted for…
Probing/instrumentation post perio surgery
No probing or instrumentation of site for 3 months (minimum)
Effectiveness of periodontal surgery
only more effective for deep pockets (>6mm).
Resective surgery
Pocket elimination procedures which establish a morphologically normal attachment but with apical displacement of the dento-gingival complex
Gingivectomy
Type of resective surgery for gingival overgrowth
Overgrowth can be due to inflammation, drugs, systemic conditions.
Electrosurgery for gingival
Resective surgery
For smaller areas of recontouring
Contraindications: pacemakers
Surgical crown lengthening
A surgical procedure which apically repositions the soft tissue and alveolar bone to expose more tooth structure, and increase the length of the clinical crown.
MAINTAIN BIOLOGICAL WIDTH WHILST APICALLY REPOSITIONING THE GINGIVAL LEVEL.
Open flap debridement
Aims of surgery
- Open flat debridement
- Modified Widman flap
Open flap debridement vs modified widman flap
A modified Widman flap is a specific type of open flap debridement technique, known for its more conservative approach with minimal tissue manipulation, aiming primarily to reattach the existing tissue rather than aggressively removing bone to eliminate deep pockets
Open flap debridement advantages
Sites >6mm with BoP or suppuration
Regenerative surgery
Recreation of the complete attachment apparatus of bone/cementum/functionally orientated PDL against previously exposed root surface.
What cases warrant regeneration periodontal surgery?
Infrabony defect associated with periodontal pocket of >6mm (>3mm vertical defect).
Class II furcation in mandibular molars.
Single class II furcation in maxillary molars.
Guided tissue regeneration
Use of mechanical barrier (membrane) to selectively enhance the establishment of PDL and peri vascular cells in osseous defectors to initiate periodontal regeneration.
Different types of bone grafts: auto, allo, xeno, alloplast
auto = donor from SAME person
allo = different person, human
xeno = animal
alloplast = synthetic
Emdogain
90% amelogenins + propylene glycol alginate (PGA)
= mimics the development of tooth supporting apparatus during tooth formation
Management of furcation involved teeth: Grade 1
NSPT
Odontoplasty
Management of furcation involved teeth: Grade 2
Odontoplasty
Open flap debridement
Regenerative procedures
Management of furcation involved teeth: Grade 3
Tunnelling procedures
Odontoplasty
Reduces plaque accumulation by reshaping tooth surface with a bur
Can aid in treatment of grade 1 and shallow grade 2 lesions
Surgical procedure involving raising a flap buccal and lingual to the site
Can result in hypersensitivity and caries
Regeneration for furcations
good for class 2 defects, but limited evidence for class 3 lesions.
Root resection
“hemisection”
Severe bone loss on 1 or more roots
Tunnel preparation
Used in mandibular molars with deep Degree 2 and Degree 3 lesions
Frenectomy
Removal of local muscle insertion to stabilise tissues, improve access for OH, aid recession cases.
Pedicle flap vs graft
Pedicle = single site surgery, local tissue maintaining own blood supply, limited by local anatomy
Grafts = material from distant donor site, TWO surgeries, larger quantities of connective tissue, more demanding technically
Free gingival graft
Graft from palate formed of epithelium and small amount of underlying connective
tissue is placed into a region with localised recession
Aims:
To create a band of keratinised mucosa
Remove frenal attachments
Prepare site for second procedure to increase root coverage
Connective tissue grafting
Surgical procedure where a split thickness flap is raised, released and then replaced
in a more coronal position
Can be combined with a connective tissue graft from the palate, especially when:
Limited attached gingivae apical to recession
Shallow sulcus
Buccally placed root
Interdental CAL
