Oral Cavity: The Jaw and Teeth

10.1055/b-0034-87903

Oral Cavity: The Jaw and Teeth

**Table 4.41 Cystic lesions: dental**
Diagnosis	Findings	Comments
Periodontal/radicular cyst/periapical cyst	Radiograph (panorex): well-circumscribed radiolucency around apex of tooth surrounded by thin rim of cortical bone.	Most common cyst. Associated with carious teeth. If large may displace teeth.
Dentigerous/follicular cyst Fig. 4.149	Plain radiograph/panorex/CT: well-defined unilocular cyst, which incorporates the crown of the unerrupted tooth.	Vary in size. More common in mandible. If maxillary, may project into antrum.
Odontogenic keratocyst/primordial cyst Multiple indicates Gorlin syndrome	Radiograph/CT: expansile cystic lesion, uni-multiloculated, smooth/scalloped border, ± impacted tooth.	Characteristically in body/ramus of mandible. Often recurs. Aggressive.
Residual cyst		A cyst that remains or develops after surgical removal of a tooth.

**Fig. 4.149 Left dentigerous cyst** with opacification of adjacent maxillary sinus on coronal CT of face (bone window).

**Table 4.42 Cystic lesions: nondental**
Diagnosis	Findings	Comments
Fissural cyst	Radiograph/panorex: round or ovoid midline cyst near anterior palatine papilla.	Unusual in children. Developmental cyst in incisive canal. Often incidental.
Aneurysmal bone cyst	Radiograph/panorex: large, multiloculated. CT: cystic, expansile, multiple fluid-fluid levels.	More common in females. Rapidly growing, painless.
Giant cell granuloma	Plain radiograph/CT: Expansile, multilocular radiolu-cent lytic lesion with tiny bone septa traversing lesion. Contains intralesional mineralization. Enhances postcontrast. MRI: T1 and T2 hypointense, enhances postcontrast.	Rare, benign, slow-growing lesion in mandible/maxilla. Present with swelling and pain. Teeth and root displacement occurs.
LCH Fig. 4.150	Radiograph/CT: Lytic destructive bone lesion with resorption of lamina dura resulting in floating teeth appearance. Associated heterogeneously enhancing soft-tissue mass. MRI: T1 iso-/hypointense mass, T2 hyperintense, variable CE.
Hemangioma	Radiograph/CT: Radiolucent area traversed by t rabeculae forming various sized cavities. If trabeculae arranged in radiating pattern, then sunburst appearance.	Rare. Rapid proliferation phase followed by slower involution phase.
Metastasis	Radiograph/CT: fairly well-defined, lytic mass with soft-tissue component.
Bone cyst due to trauma/injury	Radiograph/panorex: slightly irregular cyst with poorly defined borders and scalloped margins between the roots.	Often incidental. May regress spontaneously.
Fibrous dysplasia Fig. 4.151	CT: Depends on fibrous vs osseous component. Varies from radiolucent to ground-glass. Uni-/multilocular lesion, well-defined margin. MRI: sharply demarcated mass, variable signal intensity, diffuse CE.
Pain, swelling, and displacement of teeth. Active growth in childhood. Malignant transformation in polyostotic variant described.

**Fig. 4.150** Right mandibular bone destruction with floating tooth characteristic of **Langerhans cell histiocytosis** on 3D CT reconstruction of face.

**Fig. 4.151** Axial CT of mandible (bone window) showing a diffuse, expansile, ground-glass bone lesion with large osseous component on left, which is characteristic of **fibrous dysplasia**.

**Table 4.43 Tumor/tumorlike lesions**
Diagnosis	Findings	Comments
Burkitt lymphoma Fig. 4.152	Radiograph: Poorly-defined destructive, mottled bone lesion with root resorption and loss of lamina dura of developing teeth. Associated cortical loss. CT: destructive soft-tissue mass with extension into surrounding soft tissue. MRI: diffuse infiltration, heterogenous mass with CE.	African variant most common childhood malignancy in Africa. African Burkitt strongly associated with Epstein-Barr virus (EBV).
LCH Fig. 4.150, p. 387	Radiograph/CT: Lytic destructive bone lesion with resorption of lamina dura resulting in floating tooth appearance. Associated heterogeneously enhancing soft-tissue mass. MRI: T1 iso-/hypointense mass, T2 hyperintense, variable CE.
Osteosarcoma	Radiograph/CT: lytic bone destruction with ill-defined margins (osteolytic type) or areas of sclerosis (o steoblastic type) with aggressive periosteal reaction, ± sunburst effect, ± cortical breakthrough, and ± calcification/osteoid formation. MRI: heterogeneous mass. NM: increased uptake, identifies other bone lesions.	Prone to recurrence and metastases.
Rhabdomyosarcoma	CT: Soft-tissue mass with variable but diffuse CE, ± bone erosion. May extend to involve mandible depending on site. MRI: T1 isointense, T2 hyperintense, variable but diffuse CE.	Forty percent occur in head and neck. May extend intracranially.
Leukemia	Radiograph/CT: loss of lamina dura, varying degree of lytic bone destruction.
Odontoma Fig. 4.153	Radiograph/panorex: initially radiolucent then calcified, with the calcified portion separated from expanded cortex by a radiolucent zone ± impacted, unerrupted tooth.	Benign tumor made up of various components of teeth (enamel, dentin, cementum, pulp). Located between roots of teeth. May be associated with unerupted tooth.
Metastasis	Radiograph/CT: fairly well-defined, lytic mass with soft-tissue component.
Cementoma: cementifying fibroma	Radiograph/panorex: Early—well-circumscribed, well-demarcated radiolucent lesion with no internal radiopacities. Late—contains internal radiopacities.	Slow growing: 1–2 cm.
Benign cementoblastoma (true cementoma) Fig. 4.154	Well-defined, dense radiopaque material attached to tooth root with surrounding radiolucent zone.	Rare. Mandibular first molar most frequently involved.

**Fig. 4.152 Burkitt lymphoma** with floating tooth and loss of lamina dura and cortical resorption on oblique radiograph of mandible.

**Fig. 4.153** Oblique radiograph of mandible showing expanded radio-lucent lesion with calcification and unerupted tooth consistent with an **odontoma**. Note how the calcified portion is separated from the cortex by a radiolucent zone.

**Fig. 4.154** Well-defined dense radiopaque material attached to tooth root is characteristic of a **true cementoma** on panorex view of the right mandible.

**Table 4.44 Floating teeth**
Diagnosis	Findings	Comments
LCH Fig. 4.150, p. 387	Radiograph/CT: Lytic destructive bone lesion with resorption of lamina dura resulting in floating tooth appearance. Associated heterogeneously enhancing soft-tissue mass. MRI: T1 iso-/hypointense mass, T2 hyperintense, variable CE.
Metastasis	Radiograph/CT: aggressive bone destruction, no periosteal reaction/calcification.
Leukemia	Radiograph/CT: loss of lamina dura, varying degree lytic bone destruction. CT: permeative bone destruction. MR: T1—leukemic infiltrate of low signal replacing normal fatty marrow. T2—increased signal.
Burkitt lymphoma Fig. 4.152	Radiograph: Poorly defined destructive, mottled bone lesion with root resorption and loss of lamina dura of developing teeth. Associated cortical loss. CT: destructive soft-tissue mass with extension into surrounding soft tissue. MRI: diffuse infiltration, heterogenous mass with CE.	African variant most common childhood malignancy in Africa. African Burkitt strongly associated with EBV.
Desmoplastic fibroma	Radiograph/CT: destructive, expansile mass, contains lacelike calcification.	Aggressive, high recurrence rate.

**Table 4.45 Hyperostosis/sclerosis/destruction**
Diagnosis	Findings	Comments
Osteomyelitis	Radiograph: sclerosis or mixed sclerotic/lucent.	Primary chronic osteomyelitis: nonsuppurative, noninfectious. Actinimycosis occurs in mandible.
Infantile cortical hyperostosis (Caffey disease) Fig. 4.155, p. 390	Radiograph: periosteal thickening, dense laminated subperiosteal new bone formation of mandible, may cause mandibular asymmetry.
Fibrous dysplasia Fig. 4.151, p. 387	CT: Depends on fibrous vs. osseous component. Varies from radiolucent to ground-glass. Uni-/multilocular lesion, well-defined margin. MRI: sharply demarcated mass, variable signal intensity, diffuse CE.
Camurati-Engelmann disease	Radiograph: sclerosis of base of the skull (BOS) ± cranial vault and facial bones.
Van Buchem disease	Radiograph: osteosclerosis and hyperostosis of mandible, endosteal sclerosis of cranium.

**Fig. 4.155** AP radiograph of mandible shows diffuse periosteal thickening of mandible with dense laminated subperiosteal new bone formation, which is characteristic of **Caffey disease**.

**Table 4.46 Congenital abnormalities: affecting size and symmetry**
Diagnosis	Findings	Comments
Down syndrome	Radiograph: hypoplasia of the facial bones and sinuses, short hard palate, hypotelorism, dental abnormalities (delayed tooth eruption, anodontia).
Pierre Robin syndrome Fig. 4.156	Radiograph: mandible hypoplasia, obtuse mandibular angle, cleft palate.
Alcohol embryopathy	Radiograph: mandible hypoplasia, microcephaly.	Growth retardation.
DiGeorge syndrome	Radiograph: mandible hypoplasia, hypertelorism. Thymic aplasia.
Crouzon syndrome	Radiograph: premature closure any/all sutures, hypoplasia of the maxillomalar facial mass, recession malar bone, short and distorted zygomatic arches.
MPS (Hurler syndrome)	Radiograph: short wide mandible with obtuse angle, short rami, and flat/concave condyles. Premature closure of sutures, thickened calvarium at base, J-shaped sella.
Mandibulofacial dysostosis	Radiograph: hypoplasia/agenesis of malar bones, cleft palate.	Abnormality of first and second pharyngeal pouch, groove and arch structures.
Seckel syndrome	Radiograph: hypoplasia maxilla and mandible, microcrania, hypertelorism.	“Bird-headed appearance.”
Acrofacial dysostosis	Radiograph: mandible hypoplasia, craniosynostosis.
Melnick-Needles syndrome	Radiograph: mandible hypoplasia, BOS sclerosis.
Goldenhar syndrome	Radiograph: hypoplasia maxilla ± mandible and temporal bones.	Usually unilateral.
Caffey disease Fig. 4.155	Radiograph: periosteal thickening and dense, laminated, subperiosteal new bone formation of mandible causing mandibular asymmetry.	Mandible, clavicles, and ribs most commonly involved.
Trisomy 13/15	Radiograph: mandible hypoplasia.
Trisomy 17/18	Radiograph: mandible and maxilla hypoplasia, J-shaped sella, thin calvaria.
Pyknodysostosis Fig. 4.157	Radiograph: mandible hypoplasia, obtuse or absent angle of mandible, wormian bones, dental abnormalities.	Generalized osteosclerosis.
Hallermann-Streiff syndrome	Radiograph: mandible hypoplasia, anterior displacement of temporomandibular joint, brachycephaly.
Campomelic dysplasia	Radiograph: mandible hypoplasia, antegonal notching of mandible, macrocephaly.
Metaphyseal chondrodysplasia (Jansen type)	Radiograph: mandible hypoplasia with irregular mineralization, brachycephaly, platybasia.
Russell-Silver syndrome	Radiograph: mandible hypoplasia.	Two-thirds have partial or total asymmetry of face, small triangular face.
Rubenstein-Taybi syndrome	Radiograph: mild retrognathia, mandible hypoplasia, cleft palate.