CYSTS OF JAWS & ORAL SOFT TISSUES
Definition: 1. Pathological cavity lined lined wholly @ in part by epith. having fluid @ semi-fluid contents 2. Pathological cavity having fluid @ semi-fluid contents which not been created by accumulation of pus EPITHELIAL CYSTS ODONTOGENIC CYSTS Epith. lining derived from residue of tooth-forming organ RESIDUE TYPES Dental lamina rests/gland of Serres
Odontogenic keratocyst
GIVE RISE TO:
Reduced enamel epith. Rests of Malassez
Dentigerous cyst, paradental cyst Radicular cysts
TYPES OF: ODONTOGENIC CYST DEVELOPMENTAL INFLAMMATORY
Odontogenic keratocyst
Dentigerous(folli cular) cyst Eruption cyst Lateral periodontal cysts Gingival cyst Glandular odontogenic cyst
COMPONENT OF CYST: 1. Lumen 2. Epithelial lining 3. Fibrous capsule
Radicular cyst(dental cysts) -Apical -Lateral -Residual Paradental cyst
NON-ODONTOGENIC CYST
Nasopalatine duct (incisive canal) cyst
Nasolabial (nasoalveolar) cyst
Median cyst
NON-EPITHELIALIZED PRIMARY BONE CYSTS
SOLITARY BONE CYSTS (simple, traumatic, haemorrhagic bone cyst)
Aneurysmal bone cyst
Stafne’s idiopathic bone cavity
DEVELOPMENTAL ODONTOGENIC CYSTS DENTIGEROUS CYST
DESCRIPTIONS
CLINICAL & RADIOGRAPHIC FEATURES
Enclose part @ all of crown of unerupted tooth
Many detected in adolescent & young th adult - ↑ prevalence up to 5 decade
Unknown stimulus, unclear mechanism of cyst formation
Attached to amelocemental jxn.
Common in man, mandible
Cyst develop btwn crown of unerupted tooth & REE
Arise in follicular t. covering fully formed crown of unerupted tooth
Most involve teeth which are commonly impacted @ erupt late
Mechanism of expansion: same with RADICULAR CYST (unicentric ballooning)
Uncommon: associated with: Supernumerary teeth Complex & compound odontomes
Bone resorbing factor: Prostaglandin E2 Interleukin-1 Hypertonic content Rate of expansion: Rapid in child Slower in adult
rd
Mand. 3 M → max. perm. Canine → rd max. 3 M → mand. PM Pain is not a feature UNLESS there is second. Inflammation Well-defined unilocular radiolucency associated with crown of unerupted tooth
Central type: Cyst completely surround crown of associated teeth Lateral type: Cyst project laterally from side of tooth X completely enclose crown
ERUPTION CYST
PATHOGENESIS & EXPANSION
True dentigerous cyst
Involve both deciduous & permanent
Arise in extra-alveolar location
Fluctuant swelling on alveolar mucosa
MACROSCOPIC & HISTOPATHOLOGY
Thin, regular layer (2-5 cells thick) Non-keratinized stratified sq. @ low cuboidal epith. Resemble REE
Hypothesis(1): Compression of follicle by erupting impacted tooth ↓ ↑ venous pressure in follicle ↓ ↑transudation of fluid – pooling of fluid ↓ Separate follicle from crown – cyst formation Hypothesis(2): Proliferation of outer layer of REE ↓ Breakdown of cells within epith. islands ↓ Cyst formation Hypothesis(3): Spread of periapical inflam. from deciduous predecessor ↓ Involve follicle of permanent successor ↓ Accumulation of inflammatory exudates ↓ Cyst formation Same with dentigerous
Mucous cell metaplasia: Common ↑ with age Epithelial discontinuities observed Lining supported by fibrous connective t. capsule Free from inflammatory cell infiltration UNLESS there is second. inflam. Cholesterol clefts Island of odontogenic epith. Unicystic ameloblastoma: Lined by ameloblastomatous epith. Proliferate into cyst lumen Proteinaceous, yellowish fluid, cholesterol crystal
Same with dentigerous
Bluish in color
ODONTOGENIC KERATOCYST
uncommon lesion, unusual growth pattern
Haemorrhage into cyst cavity as result of trauma rd Envelop crown of impacted 3 molar Peak in 2
X DESCRIBE as any odontogenic cyst producing keratin Refers to specific clinicopathological entity Rarely produce keratin by metaplasia: Radicular cyst Dentigerous cyst Epith.lining usually orthokeratinized X show regular & ordered epith. differentiation X associated with NBCCS Tendency to recur
nd
rd
& 3 decade
Common in male, mand. st
Majority occur in post. to 1 PM Most common site: rd 3 molar Ascending ramus of mand. Few symptoms UNLESS become second. Inflam. Enlarge predominantly in ant.-post. direction Can reach large size without causing gross bony expansion
Cyst enlargement involve: Focal area of active growth of cyst wall Extension of proliferating area along cancellous spaces Production of bone resorbing factors
Rough, corticated keratinized layer Cyst wall: Thin, folded, regular continuous layer of st. sq. epith. Basal cell layer: Well-defined Palisaded columnar @ cuboidal Suprabasal cell: Same of stratum spinosum Parakeratinized predominate Cells desquamate into cyst lumen
multiple cyst: associated with NAEVOID BASAL CELL CARCINOMA SYNDROME(GORLIN SYNDROME): autosomal dominant mutation of tumour suppressor gene on chromose 9q(ptch gene) → important in normal growth & development of tissue n organs
X depend on hydrostatic & osmotic & intracystic pressure Arise sporadically Present in solitary lesions
↑mitotic activity Found in BASAL & SUPRABASAL LAYER Fibrous capsule: Thin Free from inflam. cell Epith. residue + satellite cyst
Well-defined radiolucency, unilocular@ multilocular rd
Associated with unerupted 3 M MANIFESTATIONS: SKIN multiple NBCCS, occur anywhere, appear around puberty age
Crown of teeth separated from cyst cavity
ORAlmultiple odonto. keratocyst
Pericoronal t. continuous with cyst capsule
SKELETALrib anomalies, vertebral
May also present as developmental
If become second. Inflam: Epith. lining lose its character. Histology Resemble RADICULAR CYST Tendency to recur related to difficulty of surgical removal
deformities, polydactyly, cleft lip/palate CNScalcified falx cerebri, brain tumours
LATERAL PERIODONTAL CYST
-
NOT DIAGNOSTIC: Odontogenic keratocyst Unicystic ameloblastoma
-
Thin, easily ruptured wall Projections into cancellous spaces easily torn Satellite cyst in capsule
Contain thick, grey/white cheesy material consist of keratinous debris, little free fluid GINGIVAL CYST
Common in neonates Rare in adult Referred to as Bohn’s nodules @ Epstein’s pearls
LATERAL PERIODONTAL CYST
Disappear spontaneously by 3months of age Uncommon lesion Associated with vital teeth (differ from LATERAL RADICULAR CYST)
Arise from rest of dental lamina – proliferate to form small keratinizing cyst Most common in: Females Interpremolar region of mand. Mainly in: Canine Premolar region of mand.
Derived either from REE @ rests of dental lamina
Lined by thin non-keratinized sq. @ cuboidal epith. Resemble REE
Present with expansion Arise alongside root of tooth (differ from ODONTOGENIC KERATOCYST)
Well-defined radiolucent area with sclerotic margin
Focal, plaque-like thickening, contain glycogen
Multilocular
GLANDULAR ODONTOGENIC CYST
Rare
Botyroid→ resemble to bunch of grapes Unilocular @ multilocular radiolucency
Most occur in ant. part of mand.
Lined by epith. varying thickness
Potentially aggressive
Superficial layer of columnar @ cuboidal cell
Locally invasive nature
Cluster form of mucous cell
↑Tendency to recur
Crypts @ small cyst-like present within thickness of epith.
Slow-growing Painless
INFLAMMATORY ODONTOGENIC CYST RADICULAR CYST
DESCRIPTIONS
Most common lesion: APICAL (70%) Associated with non-vital teeth
CLINICAL & RADIOGRAPHIC FEATURES Expansion of alveolar bone (due to deposition layer of new bone by overlying periosteum)→ discharge through sinus
PATHOGENESIS & EXPANSION
Proliferation of rest of Malassez within chronic periapical granulomas
Lined wholly @ in part by nonkeratinized st. sq. epith
X all granulomas progress to cyst
Irregular lining, vary thickness (newly formed cyst)
Rare in deciduous dentition Most common: 20-60 yrs old RESIDUAL CYST: (20%) Remained in jaw
Failed to resolve following extraction of involved tooth LATERAL CYST: Very uncommon
Extension of inflammation from pulp into lateral periodontium along lateral root canal Cyst content: Watery, straw-coloured fluid → semi-solid, brownish material
Cholesterol crystal → shimmering appearance Hypertonic content
Rate of expansion tend to outstrip rate of subperiosteal deposition Progressive thinning of cortex Can be deformed on palpitation Produce ‘oil-can bottoming ’ & ‘egg-shell crackling’
Common finding: Strands & sheets of sq. epith. from proliferation of the rest Mechanism(1): Degeneration & death of central cells within proliferating epith.
Break in lining – common
Perforate cortex
Mechanism(2): Degeneration & liquefactive necrosis of granulation t.
Chronically inflamed fibrous tissue capsule
Present as bluish, fluctuant, submucosal swelling Pain is seldom UNLESS here is acute exacerbation → rapidly progress to abcess formation Round @ ovoid radiolucency at root apex Lesion well circumscribed Surrounded by peripheral radiopaque margin
Serum protein Breakdown product (epith. & inflammatory cell, connective t. component)
HISTOPATHOLOGY
Continuous with lamina dura of involved tooth
Cyst expansion: Expand equally in all direction, rather than balloon
Rate of expansion = rate of local bone resorption As bone resorbed = ↑hydrostatic pressure cause cyst to enlarge Key point: Bone resorption allow cyst expansion due to hydrostatic pressure created by osmotic gradient
Lining more regular, even thickness (established cyst)
Metaplasia of lining – give rise to mucous cell
Pocket cyst: Cyst surround root apex Heal after endodontic treatment
Hyperplasia – predominant feature Result in anastomosing cords of epith. Forming complex arcades extend into surrounding capsule Connective t. capsule become more fibrous with time Less vascular Reduction in density of inflammatory cell infiltration Deposit of cholesterol crystals – common
Mural cholesterol cleft – associated with foreign-body giant cell In periapical granuloma: Cholesterol derived from breakdown of RBCs Result of haemorrhage into cyst capsule Deposits of haemosiderin commonly associated with clefts (Perl’s rxn) PARADENTAL CYST
Cervical enamel expansion Arise alongside partly erupted 3 molar Involved by percoronitis
All occur in mand. rd
Teeth show enamel spur extend from buccal cervical margin → root furcation
Most are bucally @ distobucally located
Extension of inflammation stimulating proliferation
Well-defined radiolucency Related to neck of tooth & coronal 3 of root
rd
Cystic change in REE covering unerupted part of crown
Resemble RADICULAR CYST
NON-ODONTOGENIC CYSTS NASOPALATINE DUCT (INCISIVE CANAL) CYST
CLINICAL & RADIOGRAPHIC FEATURES Most common type
HISTOPATHOLOGY St. sq. epith., pseudostratified ciliated columnar(respiratory) epith.
Arise from epithelial remnant of nasopalatine duct – connect oral & nasal cavity in embryo
Collection of mucous gland Scattered chronic inflammatory cell infiltrate
Unknown stimulus Common in: th th 5 & 6 decade Males
Epith. supported by connective t. capsule Prominent neurovascular bundles
Asymptomatic Slowly enlarging swelling in ant. region of midline of palate Discharge into mouth when patient complain of salty taste If second. Inflam. → pain may occur Most common originate in lower pt. & entirely within soft t. of incisive papilla (CYST OF PAPILLA PALATINA) X bony abnormalities Well-defined round, ovoid, heart-shaped radiolucencies Sclerotic rim NASOLABIAL CYST
Rare lesion
Lined by pseudostratified columnar epith.
Arise in soft t. of upper lip just below ala of nose
Stratified sq. epith, mucous cell, ciliated cell also present
Traditionally grouped with jaw cyst
Unknown aetiology
Slowly enlarging soft-tissue swelling obliterating nasolabial fold Distorting nostril
Suggested: Arise from remnant of lower pt. of embryonic nasolacrimal duct
Maybe arise bilaterally th
MEDIAN CYST
Majority present in 4 decade in women Rare lesion Occur in palate / mand. Represent displaced nasopalatine duct cyst It’s very likely that Median cyst of mand. are of odontogenic origin
NON-EPITHELIALIZED PRIMARY BONE CYSTS SOLITARY BONE CYST
CLINICAL & RADIOGRAPHIC FEATURES
Other terms: Simple bone cyst Traumatic bone cyst Haemorrhagic bone cyst Unicameral bone cyst
PATHOGENESIS
Clinical diagnosis surgical exploration Rapid healing Rough bony-walled cavity devoid of any detectable soft t. lining Cavity either empty @ little clear @ blood-stained fluid
Common in: Children & adolescent nd Peak incidence in 2 decade Premolar & molar region of mand.
Bony walls covered by delicate layer of loose, vascular fibrous t, containing RBCs & deposits of haemosiderin pigment X epithelial lining
Majority are asymptomatic Unknown pathogenesis Radiolucency of variable size & irregular outline Relationship to trauma – evidence not convincing Prominent feature: scalloping around & btwn roots of standing teeth Well-defined margin of lesion Rarely multilocular ANEURYSMAL BONE CYST
Rare in jaws
Non-endothelial lined
May occur alone @ be associated with other disorder of bone
Blood-filled spaces separated by cellular fibrous t.
Primary cyst: Arise in post pt of body @ angle of mand. Occurred in children @ young adults Present as firm expansile swelling causing facial deformity Maybe associated with pain Unilocular @ multilocular radiolucency Ballooned-out appearance due to gross cortical expansion
Multinucleated giant cell
Secondary cyst: Associated with fibro-osseous lesion + central giant cell granuloma
STAFNE’S IDIOPATHIC BONE CAVITY
Lingual bone defect Symptomless Round @ oval, well-demarcated radiolucency btwn premolar region &
Evidence of old & recent haemorrhage – common in fibrous septa Unknown pathogenesis Associated with haemodynamic disturbance in medullary bone (like SOLITARY BONE CYST)
angle of jaw Usually beneath inferior dental canal Bilateral anomaly Saucer-shaped depression @ concavity Contain ectopic salivary t. in continuity with submandibular salivary gland Sialography – identify salivary inclusions
CYSTS OF SOFT TISSUES
SALIVARY MUCOCELES Arise in connection with minor salivary glands EXTRAVASATION MUCOCELES: Mucous outside ruptured duct
70% arise in lower lip→cheek→floor of mouth Uncommon in upper lip (salivary tumour occur in upper lip) Pt. <30 yrs old Bluish, translucent submucosal swelling History of repeated rupture, collapse, refilling Mucin-filled cystic cavity @ cavity lined by inflamed granulation t No epithelial lining – have granulation t.
DERMOID & EPIDERMOID CYSTS X filled with fluid
LYMPHOEPITHELIAL CYSTS Branchial cysts @ pharyngeal pouches
Intraoral @ submental swelling
Majority occur deep to: sternomastoid ant. border at level of angle of mand.
Arise from enclavement of epith. in midline Lined by regular layer of orthokeratinized st. sq. epith resembling epidermis
THYROGLOSSAL CYSTS Derived from residue of embryonic thyroglossal duct
Intraoral cyst, midline of tongue @ floor of mouth (very rare)
Unusual lesion, Arise in floor of mouth
Most thyroglossal duct arise in region of hyoid bone
Lined by stratified sq. epith.
Treatment: should be aggressive!
Lumen contain keratinous debris Dermoid: skin appendages (hair follicles, sebaceous, sweat gland, erector pili muscle)
Wall contain well-organized lymphoid t. & germinal centre in wall Aetiology:
Developmental origin If in midline → developmental origin Uncertain pathogenesis
Epidermoid: absence of skin appendages acquired lesion result of traumatic implantation of epith. into deeper tissue
If other location → traumatic origin Salivary origin- becomes entrapped by lymphoid t. Yellowish color
Torn duct be seen running into lesion RETENTION MUCOCELES: Mucous inside duct – no surrounding chronic inflammatory rxn.
Salivary contain inside duct Pt. > 50 yrs old Never found in lower lip Derived from cystic dilatation of duct Lined by epith. of ductal type Unknown pathogenesis Ballooning of partially obstructed duct Spontaneous cystic change RANULA: Bluish color (filled with fluid)
Swelling of floor of mouth Resemble frog’s belly X pathological diagnosis Mucous extravasation cysts Extend through mylohyoid muscle Present in submandibular area @ neck Referred to clinically as plunging ranula
