Other / Other / MRI

Mandibular torus

Mandibular tori are common benign bone outgrowths discovered incidentally on imaging, typically in asymptomatic patients or those presenting with difficulty eating or drinking.

Key Images

Look For First

Dense bony outgrowth from the inner surface of the mandible
Bilateral symmetric location above the mylohyoid line
Densely mineralized compact bone without central lucency

Key Image Findings

On CT, mandibular tori appear as dense bony exostoses arising from the inner aspect of the alveolar bone of the mandible, characteristically positioned above the origin of the mylohyoid muscle.
The lesions are composed of compact bone that is densely mineralized, typically lacking a central medullary cavity.
Mandibular tori are usually bilateral but can occur unilaterally, presenting as symmetric or asymmetric outgrowths depending on presentation.
The bony outgrowths originate from the lingual (inner) surface of the mandible, distinguishing them from other external mandibular bony lesions.
CT demonstrates the high density and well-defined morphology of these lesions, facilitating differentiation from other pathology.

Differential Diagnosis

Exostosis: distinguished by location on outer mandibular surface rather than inner surface
Osteoma: typically solitary and may show more central lucency or mixed density
Condensing osteitis: associated with dental pathology and adjacent tooth abnormality
Hyperostosis: typically more diffuse and less localized than discrete tori

Discussion

Mandibular tori have an unclear etiology but are thought to have a genetic component given their common familial occurrence and bilateral presentation.

These lesions are benign and typically grow slowly, with no invasive behavior or malignant potential.

Asymptomatic tori require no treatment; intervention is reserved for symptomatic cases that interfere with mastication, swallowing, or denture fitting.

Rare complications including fracture through the torus and osteomyelitis have been reported, though these are uncommon.

The lesions typically present after skeletal maturity and may progressively enlarge over time.

Reporting Pearls

Describe mandibular tori as "dense, well-mineralized bony outgrowths arising from the lingual mandibular cortex above the mylohyoid line, consistent with mandibular exostoses/tori" and note whether bilateral or unilateral, and whether they appear to cause mass effect on adjacent soft tissues.

Pitfalls

Mistaking mandibular tori for pathologic ossification or osteomyelitis due to their dense appearance, which may cause unnecessary clinical concern.
Overlooking bilateral tori by only evaluating one side of the mandible during routine screening.
Confusing mandibular tori with external mandibular exostoses or osteomas that arise from the outer cortical surface rather than the inner lingual surface.
Failing to correlate imaging findings with clinical symptoms, potentially recommending unnecessary treatment for asymptomatic incidental lesions.

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