Extensive mandibular radiolucency with minimal expansion

§Chief complaint

Vague discomfort in the left lower jaw; lesion found on a routine radiograph

§Medical & dental history

• 01No basal cell carcinomas, no family history of naevoid basal cell carcinoma syndrome
• 02Otherwise healthy
• 03All teeth present and vital
• 04No previous surgery in the region

§Clinical examination

• 01Barely perceptible expansion of the left mandible despite a large radiographic lesion
• 02Mucosa intact; no discharge or tenderness
• 0334 to 38 all vital on electric pulp testing
• 04No paraesthesia of the lower lip; mouth opening normal

§ figuresFigures (4)

Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Odontogenic Keratocyst figures pending faculty review.

§Differential diagnosis

§Final diagnosis

Odontogenic keratocyst of the left mandibular body and ramus

Growth along the marrow spaces with disproportionately little cortical expansion, vital teeth, and aspiration of thick keratinaceous material with low soluble protein points to OKC; parakeratinised lining with a palisaded basal layer confirms it.

§Investigations

• 01Aspiration — thick, cheesy, keratin-containing material; total soluble protein below 4 g/dL
• 02Pulp testing of all teeth in the quadrant — vital
• 03Skin and skeletal survey to exclude naevoid basal cell carcinoma syndrome — negative
• 04Incisional biopsy before definitive surgery

§Radiology

• 01OPG — well-defined multilocular radiolucency 55 mm extending from 34 to the ramus with a scalloped corticated margin
• 02CBCT — cortical thinning without ballooning, lingual perforation at two points, minimal root resorption

§Treatment plan

• 01Incisional biopsy to confirm diagnosis
• 02Enucleation with peripheral ostectomy and Carnoy's solution application
• 03Preserve the inferior alveolar nerve and the dentition where possible
• 04Long-term radiographic surveillance for at least 5 years

§Surgical procedure

• 01Wide buccal flap exposure, careful enucleation of the friable lining in fragments
• 02Peripheral ostectomy 1-2 mm with a round bur under copious irrigation
• 03Chemical fixation with modified Carnoy's solution for 3 minutes, nerve protected with gauze
• 04Closure over a resorbable haemostatic dressing

§Histopathology report

Cyst lined by uniformly thin parakeratinised stratified squamous epithelium, 5-8 cells thick, with a palisaded, polarised hyperchromatic basal layer and a corrugated luminal surface. Daughter cysts present in the wall. No dysplasia. Odontogenic keratocyst.

§Follow-up & outcome

• 01Annual OPG for 5 years, then biennially
• 0212 months — progressive bony infill, no lucency at the margins
• 0336 months — no recurrence, lip sensation normal

Outcome: No recurrence at 3 years with preserved nerve function and dentition.

§Discussion

• 01OKC recurrence rates range from about 3% after resection to over 25% after simple enucleation, driven by satellite cysts and a friable lining.
• 02Multiple OKCs, especially in a young patient, demand a search for naevoid basal cell carcinoma syndrome (PTCH1).
• 03Marsupialisation followed by delayed enucleation reduces lesion size and morbidity in very large cysts.

§Clinical pearls / learning points

• 01Little expansion with a large radiolucency is the classic OKC signature.
• 02Enucleation alone is not enough — add peripheral ostectomy or a chemical adjunct.
• 03Multiple keratocysts should trigger a syndrome work-up.

§Viva questions

§MCQs

§Related diseases

§Similar cases