Mandibular tumors

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Mandibular tumours
Mandibular defect classification
Boyd’s HCL classification
 H defects are lateral and of any length including the condyle and do not cross the
midline.
 L defects are as above but don't involve condyle
 C defects consist of the entire central segment containing the four incisors and the
two canines
 Combination exist i.e. angle to angle defects LCL
 o- neither skin nor mucosal defect
 s - skin defect
 m - mucosal defect
 sm - skin and mucosa
Challenges
Soft tissue Reconstruction Only
 In the past, L and H defects were reconstructed with soft tissue closure
 Unopposed muscle pull on unresected remnant causes swing to the resected side,
leads to cross bite.
 This reduces the defect size but also leads to abnormal dental wear, caries, loss of
function or concave appearance on the unaffected side
Central Segment reconstruction
 Anterior arch defect - greatest aesthetic and functional problem and difficult surgical
challenge
 Frequently results in lip and chins ptosis in which the soft tissue slides of the
reconstructed arch producing eversion of the lower lip and salivary incontinence.
 Mandible tends to be pulled superiorly, especially in the edentulous which is not
limited by occlusion:
1. Unopposed masseter and pterygoid action
 The C segment has 4 mouth opening muscles (digastrics and geniohyoid)
attached to it. When c segment resected these muscle attachment is lost or
muscle lost in ablative procedure. . The mandible is then free of its
anterior muscular tethering and is pulled upward by the unopposed action
of the masseter and the pterygoids.
 When not possible to preserve the C segment it is occasionally feasible to
reattach the submental muscles to the reconstructed mandible
2. Chin Degloving
 Mentum soft tissue degloving should be reattached to avoid witch’s chin
deformity
3. Lower facial nerve paralysis
 Bilateral neck dissections often result in damage the lower branches of the
facial nerve on both sides and exacerbates the lip ptosis.
4. Soft tissue contraction

If during reconstruction the floor of mouth dead space is not adequately
filled with soft tissue the resulting contracture tends to distort the new
bony reconstruction or draw the soft tissue inferiorly thus resulting in
inferior displacement.
Mandibular pathology
Physiology
 Amoloblasts – secrete enamel
 Odontoblast – secrete dentin
 Cementoblasts – secrete cementum
 Fibroblast – periodontal membrane
 Neural crest forms nearly all components of teeth - dentin, pulp, periodontal ligament
and cementum, except enamel (develops from ectoderm)
 Enamel
o acellular (96% mineral), tapers off at the cementoenamel junction
o dependant on underlying dentin for support
 Dentin
o 70% mineral
o Occupied by odontoblasts which secrete matrix and also mediate sensation
 Pulp
o Odontoblasts to make dentin
o Nutrition
o Sensation
 Cementum
o Calcified connective tissue covering the anatomic root
o Anchors the periodontal ligament to the root of the tooth
o Continuous cementum deposition maintains length of the tooth as
compensation for occlusal wear
o May be acellular or contain cementoblasts
Symptoms and signs
1) Swelling (fibrous dysplasia, cherubim, cysts and cancer)
2) pain (osteoradionecrosis, osteomyelitis and invasive cancer)
3) Numbness (neoplastic invasion of the V3)
4) Loosening of teeth (weakness of the socket by disease processes)
5) Oral mucosal involvement (mandibular sarcomas breaking out, mucosal carcinomas
breaking in, osteoraionecrosis causing inflammation breakdown and bone exposure
Tumours of the mandible
Classification (Kramer)
1) Odontogenic
a. Cysts
i. Epithelial
1. radicular (periapical) cyst(55%)
2. dentigerous cyst (24%)
3. residual cyst (20%)
4. keratocyst (5%)
b. Benign Tumors
i. Epithelial
1. ameloblastoma (11%)
2. calcifying epithelial odontogenic tumor
3. adenomatoid odontogenic tumor
ii. Mesenchymal
1. myxoma (3%)
2. benign cementoblastoma
3. odontogenic fibroma
iii. Mixed
1. ameloblastic fibroma
2. ameloblastic fibroodontoma
3. odontoma
c. Malignant Tumors
i. Epithelial
1. malignant ameloblastoma
ii. Mesenchymal
1. ameloblastic sarcoma
2) Nonodontogenic
a. Cysts
i. Epithelial
1. fissural median mandibular cyst
ii. Nonepithelial
1. traumatic bone cyst
2. aneurysmal bone cyst
b. Benign Tumors
1. Fibrous dysplasia
2. cherubism
3. giant cell granuloma
4. osteoma
c. Malignant
i. Primary
1. osteosarcoma
2. chondrosarcoma
3. central mucoepidermoid carcinoma
4. Burkitt’s lymphoma
ii. Secondary
1. metastatic carcinoma
2. SCC
Odontogenic tumors radiographic features
Radiolucent Lesions
1. ameloblastoma
2. ameloblastic fibroma
3. odontogenic fibroma
4. odontogenic myxoma
5. squamous odontogenic tumor
6. clear cell odontogenic tumor
Radiolucent with or without Radiopacity Lesions
1. adenomatoid odontogenic tumor
2. calcifying epithelial odontogenic tumor
Radiopaque with or without Radiolucency Lesions
1. odontoma
2. ameloblastic fibro-odontoma
3. ameloblastic odontoma
Odontogenic Cysts
Radicular cysts (apical cyst)
 Most common cyst of jaw (55% of cysts)
 Response to apical inflammation
 may have sinus tract to oral mucosa or even skin
Radiographic features
 Pulpless nonvital tooth
 Small well defined periapical lucency
Treatment
 Extraction, root canal
 Low recurrence rate
Dentigerous cyst
 25%of odontogenic cyst
 Peak incidence in 2nd and 3rd decades
 Fluid between reduced enamel epithelium
and tooth crown
 Surrounds unerrupted second and third
molars. Cysts have epithelial lining and
vary from 2cm to expansible mass


May cause displacement of teeth and facial asymmetry
Can be locally destructive
Radiographic features
 well-demarcated radiolucent lesion
attached at an acute angle to the
cervical area of an unerupted tooth
Treatment and prognosis
 Enucleation or marsupialization.
 6% recur
 Possible malignant transformation
– 20% of ameloblastomas arise
from these cysts, also SCC and
mucoepidermoid tumor
Keratocysts
 5% of all jaw cyst
 third most common odontogenic cyst and belongs in the differential diagnoses of any
radiolucency of the jaws.
 Affect all ages with peak in 2nd 3rd decade
 M>F
 50 % around third molar and ascending ramus
 different from other cysts; they are aggressive and can be difficult to remove. OKCs
can grow quite rapidly, and recurrences are frequent - grow in a multilocular
bosselated fashion with daughter cysts that extend into the surrounding bone.
 cysts are formed with a stratified squamous epithelium
 5% have basal cell nevus syndrome, also known as Gorlin syndrome
 hypertelorism, midface hypoplasia, relative frontal bossing and prognathism,
mental retardation, multiple basal cell carcinomas, calcification of the falx
cerebri, bifid ribs, palmar pitting (the pits later develop into basal cell
carcinoma), and multiple OKCs.
 Multiple OKCs are diagnostic for basal cell nevus syndrome until proven
otherwise.
 autosomal dominant inheritance and high penetration
Radiographic features
 Mimics many cysts
 Multiloculated with scalloped
radiopaque borders
 Marked cortical thinning and root
resorption
Treatment
 Enucleation with curettage for small cyst
 aggressive and can be difficult to remove
 60% recurrence with incomplete excision
Residual cysts
Incidence and features
 Any odontogenic cyst that persists in bone after tooth is removed
 20 % of odontogenic cysts
Clinical
 Static or slowly enlarging asymptomatic or painful with inflammation
Etiology
 From epithelial remnant of periapical granuloma (root abscess)
Radiol
 Well circumscribed cyst in endentulous area
Treatment
 Enucleation with low recurrence rate
Non-odontogenic Cysts
Fissural: median mandibular cyst
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

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Rare; nonaggressive
thought to be derived from epithelium entrapped in the lines of fusion of the body
process that forms the jaw and face
Cysts are line with stratified squamous epithelium and respiratory epithelium.
Midline symphyseal
Controversial from trapped epithelial remnants of mandibular arch fusion vs. peri
odontal cyst
Nucleation; uncertain of prognosis due to rarity of lesion
Traumatic bone cyst
Features and incidence
 Empty or fluid filled cavity associated with jaw trauma(50%)
Location
 Mostly anterior mandible but also
molar area
Clinical Presentation
 Size extremely variable
aymptomatic and found on routine
associated with labial or buccal
expansion teeth remaining vital
Etiology
 Trauma with intramedullary
hematoma
Radiographic
 Smooth radiolucency with scalloped borders extending roots
Treatment and Prognosis
 May resolve spontaneously curettage with possible bone grafting of low recurrence
rate.
Aneurysmal bone cyst
Incidence
 Rare in mandible benign expansile lytic lesion
Location
 Body of mandible
Clinical presentation
 Pain and swelling growth rate variable
Etiology
 Possibly traumatic origin with localized alteration in hemodynamics or persistent
connection between damaged vessels and hematoma possibly AV fistula
 Expansile eccentric cyst with thin cortices; soap bubble or honeycomb appearance
 Large vascular sinusoids (no bruit)
Radiographic
 Multilocular radiolucency with cortical expansion
Treatment
 Curettage or excision.
 Recurrence rare
Odontogenic epithelial tumours
Ameloblastoma
 may develop from any of the epithelial elements (e.g. dentigerous cyst, enamel organ,
peridontal membranes)
 benign but locally invasive
 most common odontogenic tumor (11%)
 peak incidence 4th – 5th decade
 Propensity for rapid disfiguring growth and late recurrence
Location
 80% in mandible, 20% in maxilla
 Most commonly in molar area
 Often associated with unerupted third molar
Clinical features
 Slow growing painless swelling with or without a soft tissue mass
 Size range from 1-16 cm
 Large lesions can cause facial asymmetry or displaced teeth and malocclusion
 Can expand bone erode through it or produce pathological fracture
Radiology
 Classic appearance – multilocular (soap bubble) radiolucency of posterior mandible
 3 types
1. Unilocular (13%)
o Round or ovoid appearance with no calcified or radioopaque components
distinct border with slight marginal sclerosis, may have scalloped margins ;
no periosteal reaction.
o Often confused with odontogenic cysts
2. Multilocular (86%)
o Honeycomb or soap bubble appearance ; marked expansion with cortical
thinning and bony destruction
3. Peripheral (extraosseous – 1%)
Treatment
 Curettage or enucleation not recommended due to 90 % recurrence
 partial mandibulectomy or segmental resection with margins of normal bone
recommended( recurrence rate -5% )
 Radiotherapy palliative for unresectable tumours
 Mets rare
Calcifying epithelial odontogenic tumours(Pindborg tumour)
Incidence /Features
 Rare, locally aggressive tumour;
 2% of odontogenic tumours
 Bimodal incidence
 Occurs in third to fourth decades
Location
 Usually in Premolar and Molar area (in
contrast to ameloblastoma)
 Many associated with unerupted teeth
Radiology
 Chief sign is cortical expansion in all directions
 Radiolucent; poorly defined, noncorticated
borders
 Unilocular, multilocular, or “moth-eaten”
 Driven-snow” appearance from multiple
radiopaque foci
Treatment


Similar to ameloblastoma
Up to 14% recurrence reported
Adenomatoid odontogenic tumour
 A well-circumscribed lesion derived from odontogenic epithelium that usually occurs
around the crowns of unerupted anterior teeth of young patients
 consists of epithelium in swirls and ductal patterns interspersed with spherical
calcifications.
Incidence
 Rare nonaggressive tumour
 F>M 2:1
 age <20
Location
 anterior to canines and frequently associate with
impacted or unerupted teeth
 may be associated with cortical expansion
Clinical Presentation
 low growing asymptomatic mandibular swelling
 small 1.5 - 3 cm painless anterior tumour
Radiology
 well-demarcated mixed radiolucent / opaque lesion often surrounds the crown of an
impacted tooth
Treatment and prognosis
 Conservative excision; low recurrence rate
Odontogenic mesenchymal tumours
Myxoma (fibromyxoma)
 Locally aggressive - 3% of odontogenic tumours
 primarily consisting of a mucoid ground substance with widely scattered
undifferentiated spindled mesenchymal cells.
 Peak incidence in second and third decades
 Painless slow jaw enlargement
Location
 Usually posterior mandible but rarely in condyle
 progressive swelling with bony expansion; can cause
malposition of teeth
Radiology
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Margins variably demarcated
multilocular radiolucency soap bubble or honeycomb appearance
Treatment and prognosis
 En bloc excision; recurrence rate - 25%
Odontogenic mixed tumours
Odontoma
Features and incidence
 composed of aberrant tissue of all the dental elements likely a harmartoma
 Common
 All ages but mostly second decade
Location
 Posterior mandible
 Usually less than 1cm +/- larger
Clinical
 Most are symptomatic but swelling may interfere with tooth eruption
 From odontognic apparatus(i.e. Enamel, dentin and cementum)
Radiology
 solid unilocular radiopaque mass surrounded by a thin radiolucent zone
Treatment
 Early enucleation to prevent interference with tooth eruption
 Low recurrence rate
Compound Odontoma
Malignant Epithelial odontogenic tumors
Compound Odontoma
Malignant ameloblastoma
Incidence and features
 Rare tumour classified as an odontogenic carcinoma
 Any age after first decade
 Most commonly in men >50 years
Location
 Generally same as ameloblastoma
Clinical Presentation
 History of multiple unsuccessful treatments of benign but persistent odontogenic
epithelial lesion
 Pain swelling ulceration and paresthesia
 Regional lymphadenopathy with mets to lung, liver vertebrae
Etiology
 Arises from residual odontogenic apparatus or from transformation of an odontogenic
cyst or ameloblastoma
Radiology
 Poorly defined radiolucency with gross expansion and thinned cortices
Treatment
 Full ontological screening, radical excision
 Rare tumour thus ideal treatment difficult to define
 radiorx and chemo rx are used
 Poor prognosis
Non Odontogenic Benign tumors
Fibrous Dysplasia
 Found in membranous facial bones of younger individuals and becomes less active
with maturity
Incidence
 Uncommon
 First and second decades
Features
 Fibro osseous lesion
 Developmental derangement due to undiffentiated mesenchymal bone forming cells


replacing normal lamellar by woven bone
Monostotic and polyostotic variants
Polyostotic associated with Albrights Syndrome
Location
 Common in maxilla
 Angle of mandible
 Usually progressive unilateral swelling with variable facial asymmetry
 Pain and decreased function with progressive deformity
 Dentition can be shifted
 Burns out after puberty
Radiology
 Ground glass or orange peel appearance
 Poorly circumscribed with diffuse borders
 Pagetoid or cyst like appearance
Treatment
 If required, definitive reconstruction when disease has burned out
 Earlier intervention with partial resection, ,curettage or bony contouring indicated for
pain and functional loss.
 Rare malignant change post radio rx - thus not recommended
 Prognosis generally good
Cherubism
Features and incidence
 autosomal-dominant disorder of variable penetrance (100% penetrance in males)
 Bilateral symmetrical maxilla and mandible swelling
 Usually begins with eruption of secondary dentition (age 2-4)
 stabilizes after the growth period, usually leaving some facial deformity and
malocclusion.
Location
 Entire body and ramus with sparing of condoles
 Extends into alveolar process
Clinical presentation
 Painless rapid early growth
 Alveolar involvement causes shedding of deciduous teeth
 Delayed eruption and malocclusion
 maxillary fullness produces retraction of the lower eyelids increasing scleral show
causing “cherubic Appearance”
Radiographic features



Bilateral well defined multilocular expansile radiolucenices
Becomes ground glass at end of growth
Cortical thinning or absence
Treatment
 Generally resolves with age
 Treatment individualized on amount of regression or deformity
 Good prognosis if limited to mandible
Giant cell granuloma
Incidence and features
 Uncommon
 3-5% of benign jaw tumours
 Neoplastic like reactive proliferation - locally aggressive
 Multinucleated giant cells on histology
 Younger age groups
Location
 Typically symphyseal and bicuspid regions
Clinical
 Intermittent variable growth
 Pain may be dominant symptom
Radiology
 Unilocualted or multiloculated well circumscribed
Treatment
 Curettage of excision
 Recurrence rare with complete excision
Osteoma
 exophytic nodular growth of dense cortical bone on or within the mandible or maxilla
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in locations other than those occupied by exostoses.
benign skeletal neoplasm of unknown etiology that is composed
of osteoid and woven bone.
hamartomatous proliferation
restricted to the craniofacial skeleton located either superficially
or intraosseously
classic presentation is that of focal bone pain at the site of the
tumor. The condition worsens at night and increases with
activity, and it is dramatically relieved with small doses of
aspirin.
often associated with Gardner syndrome
Treatment
 surgically reducing osteoma to the level of the surrounding bone
Gardners Syndrome
 Autosomal dominant with multiple osteomas, epidermal cysts, colon polyposis and
pigmented lip macules
Location
 Commonly lingual surface of mandibular body
 Attached to cortical bone by a stalk
Treatment and prognosis
 Usually not required
 If symptomatic , local excision is sufficient with no
risk of recurrence
Non odontogenic Malignant (Primary)
Burkitts Lymphoma
Features and incidence
 Poorly differentiated B cell lymphoma
 Most common childhood malignancy in east Africa
 Mean age 7-9 yrs
 Rare in north America with mean age 11-12 yrs
 Fastest growing neoplasm
Location
 80% of tumours found in all four jaw quadrants

Jaw less commonly involved in north American cases
Clinical presentation
 Enlarges very rapidly shifting and exfoliating the teeth
 Associated with adrenal , kidney and gonadal masses
 Lymphadenopathy rare
Aetiolgy
Related to EBV
Genetic association
Link to malaria
Treatment and Prognosis
Chemotherapy
50 % relapse rate
Poorer prognosis if gonadal involvement
Non odontogenic malignant(secondary)
Squamous cell Carcinoma
Features and Incidence
 30 % of head and neck cancers
 M:F 2:1
 Increasing female incidence due to smoking
Morphology
1. exophytic (best prog)
2. Ulcerative
3. Mixed
Histological variants
1. Basiloid (worst variant)
2. Verrucous - 5% of oral SCCs (better prognosis)
Location
 Commonly arises in mucosa of posterior alveolar ridge, but can spread from any part
of the oral cavity including the lips
 35 -50 % have bone invasion histologically and radiographically at the time of
diagnosis
 Spread is through occlusal surface (gingiva and tooth socket) since the periosteum is
considered an effective barrier to tumor spread
 May extend along inferior alveolar nerve
 10 %of oral sccs arise at alveolar ridge
Clinical
1. May present as an incidental finding or as advanced disease
2. Present with non healing ulcer, pain, loose tooth, poorly fitting dentures, difficulty
with mastication or numbness in the inferior alveolar region
3. Weight loss common
Risk factors
1. Smoking 6x risk
2. Betel chewing increased risk when combined with tobacco
3. Alcohol 6x risk
4. Alcohol plus tobacco 15x risk
5. Malnutrition, iron, vitamin a and C deficiencies
6. Solar exposure - lips
7. Viral
8. Poor dentition
9. Genetic
Treatment
Initial screening
Hx and Ex
Bx
CXR and LFT
Ct for nodal and distant disease
MRI useful for soft tissue and perineural involvement
Bone scan if bone pain
Pan endoscopy
Consultation
1. H and N team
2. Oncologist
3. Nutritionalist
Modalities of treatment
1. Surgery
2. Radiotherapy
3. Chemotherapy
4. 50 % reduction in cure rate with nodal involvement
5. Prognosis generally poor
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