OMFS-0206Benign jaw lesionsPathologybeginnerLeft mandibular body

Incidental scalloped radiolucency between vital premolar roots

17-year-old male

Draft — educational study aid, pending faculty review.

§Chief complaint

No symptoms — lesion seen on a radiograph taken before orthodontics

§Medical & dental history

01Healthy, plays contact sport
02No pain, no swelling, all teeth vital

§Clinical examination

01No facial asymmetry or expansion
02Mucosa normal; no tenderness on percussion of 34-36
03All teeth vital on electric pulp testing
04No paraesthesia

§Figures

Verified clinical, radiology and histopathology images not yet available

§Differential diagnosis

Simple (solitary) bone cystScalloping up between vital tooth roots, no expansion, empty cavity

Odontogenic keratocystMore defined cortication, may expand, keratin on aspiration

Central giant cell granulomaExpansion and multilocularity

Cemento-osseous dysplasia (early)Periapical, teeth vital, becomes mixed with time

§Final diagnosis

Simple (traumatic/solitary) bone cyst of the left mandible

A radiolucency scalloping up between the roots of vital teeth without expansion, confirmed at exploration as an empty or minimally serous-filled cavity with no epithelial lining, is diagnostic; the surgical finding is the diagnosis.

§Investigations

01Pulp sensibility testing of 33-37 — all vital
02Surgical exploration with curettage of the bony walls and biopsy of any lining tissue

§Radiology

01OPG — well-defined radiolucency 30 mm scalloping between the roots of 34-36, no root resorption
02CBCT — no cortical expansion or perforation; intact lamina dura

§Treatment plan

01Surgical exploration, curettage of the bony walls to induce bleeding
02No tooth extraction; orthodontics may proceed after healing

§Surgical procedure

01Small buccal window under local anaesthesia
02Empty cavity confirmed; walls curetted to produce a blood clot, flap closed

§Histopathology report

Scanty fragments of fibrovascular tissue and reactive bone with no epithelial lining. Consistent with a simple bone cyst.

§Follow-up & outcome

013 months — early infill
029 months — near-complete ossification
0318 months — radiographically normal bone

Outcome: Complete spontaneous healing after exploration; no recurrence.

§Discussion

01The simple bone cyst is a pseudocyst — no epithelial lining — and heals after the clot organises.
02Cemento-osseous dysplasia can coexist with simple bone cysts, especially in the posterior mandible of middle-aged women.

§Clinical pearls / learning points

01Vital teeth, scalloped outline and no expansion: think simple bone cyst.
02Do not extract teeth — surgical exploration alone is both diagnostic and therapeutic.

§Viva questions

Why is it called a pseudocyst?

It has no epithelial lining; it is a bony cavity, usually empty or containing serosanguinous fluid.

What is the treatment?

Exploration and curettage of the walls to induce bleeding and clot formation; healing follows within 6-12 months.

§MCQs

Q1A hallmark radiographic feature of a simple bone cyst is:

Q2At surgery, a simple bone cyst is typically:

§ evidenceReferences & Evidence

Current Classification

WHO Classification of Tumours Online — Head and Neck

IARC / WHO · 2022

Continuously updated online edition of the WHO head and neck tumour classification.

View official source

Evidence summary

Highest level of evidence linked to this page: WHO / Official Classification.

L1 · Classification — 1
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

Open PubMed

Current Classification