Well-demarcated expansile mandibular lesion with downward bowing
33-year-old female
§Chief complaint
Painless firm swelling of the lower jaw for 18 months
§Medical & dental history
- 01No hyperparathyroidism; no family history of jaw tumours
- 02Teeth displaced but vital; no pain
§Clinical examination
- 01Firm, well-defined buccal and lingual expansion 35 mm over 34-36
- 02Overlying mucosa normal, no ulceration
- 0334-36 displaced, all vital, no mobility
- 04No paraesthesia
§ figuresFigures (5)
Fig. 1Well-defined fibrous connective tissue with calcified droplets and woven bone trabeculae, bordered by native lamellar bone.
“Ossifying fibroma 2” · Shqynq · CC BY-SA 4.0 · Wikimedia Commons
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Ossifying Fibroma figures pending faculty review.
§Differential diagnosis
§Final diagnosis
Cemento-ossifying fibroma of the left mandible
A sharply circumscribed, mixed radiolucent-radiopaque expansile lesion that bows the inferior border and shells out with a distinct capsule at surgery, with histology showing bone and cementum-like calcifications in a cellular fibrous stroma, is an ossifying fibroma — critically distinguishing it from fibrous dysplasia, which cannot be enucleated.
§Investigations
- 01Incisional biopsy
- 02Serum calcium, phosphate and PTH to exclude hyperparathyroid jaw tumour syndrome
- 03CBCT for surgical planning
§Radiology
- 01OPG — well-demarcated mixed-density lesion 35 mm with a thin corticated margin, bowing the inferior border downwards
- 02CBCT — concentric buccolingual expansion with intact but thinned cortices; roots divergent, no resorption
§Treatment plan
- 01Enucleation with curettage, exploiting the surgical plane provided by the capsule
- 02Preserve the dentition and the inferior alveolar nerve
- 03Resection reserved for large, recurrent or juvenile aggressive variants
§Surgical procedure
- 01Buccal flap with a bone window; lesion shelled out intact in its capsule
- 02Peripheral curettage; inferior alveolar nerve identified and preserved; primary closure
§Histopathology report
Well-demarcated fibrous lesion with a cellular stroma containing trabeculae of woven and lamellar bone with osteoblastic rimming and rounded cementum-like ossicles. Cemento-ossifying fibroma.
§Follow-up & outcome
- 016 weeks — healing uneventful, lip sensation normal
- 0212 months — progressive bone infill
- 0336 months — no recurrence, teeth vital
Outcome: Complete enucleation with preserved nerve and dentition; no recurrence at 3 years.
§Discussion
- 01The clinical value of separating ossifying fibroma from fibrous dysplasia is surgical: one enucleates cleanly, the other does not.
- 02Juvenile trabecular and juvenile psammomatoid ossifying fibromas are more aggressive, recur frequently and need wider excision.
- 03Recurrent multiple ossifying fibromas warrant screening for hyperparathyroidism-jaw tumour syndrome (CDC73).
§Clinical pearls / learning points
- 01A lesion that shells out has a capsule — that is ossifying fibroma, not fibrous dysplasia.
- 02Downward bowing of the mandibular lower border is a classic sign.
§Viva questions
How does ossifying fibroma differ from fibrous dysplasia?
Ossifying fibroma is encapsulated with sharp radiographic margins and shows osteoblastic rimming; fibrous dysplasia blends into adjacent bone and lacks rimming.
What are the juvenile variants?
Juvenile trabecular and juvenile psammomatoid ossifying fibroma, occurring in younger patients with rapid growth and higher recurrence.
§MCQs
Q1Which feature favours ossifying fibroma over fibrous dysplasia?
Q2Treatment of a conventional ossifying fibroma is:
§ evidenceReferences & Evidence
Current Classification
WHO Classification of Head and Neck Tumours
5th Edition — Volume 9
WHO Classification of Tumours Editorial Board · 2022
The authoritative international classification of head and neck, odontogenic and salivary gland tumours. Current terminology on this site follows this edition.
Evidence summary
Highest level of evidence linked to this page: WHO / Official Classification.
- L1 · Classification — 3
- L6 · Textbook — 3
1 linked source was published from 2024 onwards. Where guidance is limited or contested, rely on the higher-level sources above rather than this summary. Educational use only — not a substitute for clinical judgement.
Content last reviewed
September 2026
Evidence last reviewed
September 2026
Next scheduled review
September 2027
Review status
EVIDENCE REVIEWED
Search latest PubMed evidence
Last literature search: 7 September 2026
Current Classification
WHO Classification of Tumours Editorial Board. IARC / World Health Organization · 2022
The authoritative international classification of head and neck, odontogenic and salivary gland tumours. Current terminology on this site follows this edition.
Vered M, Wright JM. Head and neck pathology · 2022 · 16(1):63-75
Summary of odontogenic and maxillofacial bone tumour changes in the 5th edition WHO classification.
IARC / WHO. IARC · 2022
Continuously updated online edition of the WHO head and neck tumour classification.
Histopathology References
Barnes L. CRC Press · 2008
Detailed histopathological reference for head and neck diagnostic criteria.
Textbook References
Neville BW, Damm DD, Allen CM et al.. Elsevier · 2024
Standard reference textbook of oral and maxillofacial pathology used throughout this atlas.
Rajendran R, Sivapathasundharam B. Elsevier · 2020
Undergraduate and postgraduate oral pathology textbook widely used in BDS and FCPS curricula.
Additional sources cited on this page
- WHO Classification of Head and Neck Tumours, 5th edition, 2022.
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