Interactive Differential Diagnosis

Dental Diseases · partial profile

Wedge-shaped cervical lesion thought to result from occlusal stress concentration at the CEJ.

Premalignant Disorders · partial profile

Chronic UV-induced degeneration of the vermilion of the lower lip; a potentially malignant disorder that may progress to lip SCC.

Odontogenic Tumors

Benign encapsulated odontogenic epithelial tumour with duct-like structures; classically presents as a pericoronal lesion around an unerupted maxillary canine in a young female — the 'two-thirds tumour'.

Pigmented Lesions · partial profile

Focal grey-black macule caused by iatrogenic implantation of amalgam particles into oral mucosa.

Odontogenic Tumors

Benign but locally aggressive odontogenic epithelial tumour; the most common clinically significant odontogenic tumour.

Developmental Disorders · partial profile

Group of inherited disorders affecting enamel formation resulting in hypoplastic, hypomature, or hypocalcified enamel.

Non-odontogenic Cysts

A rare, rapidly expanding, blood-filled, multilocular pseudocyst of bone — now recognised as a true neoplasm driven by USP6 gene rearrangements — that most commonly involves the posterior mandible of young patients.

Dental Diseases · partial profile

Physiological or pathological loss of tooth structure from tooth-to-tooth contact.

Ulcerative Diseases

Systemic vasculitis with recurrent oral and genital ulcers, uveitis, and multisystem involvement.

Malignant Tumors

Highly aggressive B-cell non-Hodgkin lymphoma driven by MYC translocation; jaw involvement is characteristic in the African endemic form.

Fibro-osseous Lesions

Benign non-neoplastic fibro-osseous lesion of tooth-bearing regions arising from the periodontal ligament; teeth remain vital.

Odontogenic Tumors

Benign true neoplasm of cementoblasts producing a radiopaque mass fused to the root of a vital tooth — the only true neoplasm of cementum.

Bone Diseases

Benign but sometimes locally aggressive intraosseous lesion containing multinucleated giant cells.

Maxillofacial Infections · partial profile

Chronic granulomatous suppurative infection by Actinomyces israelii producing woody induration, multiple sinuses and characteristic sulphur granules.

Maxillofacial Infections · partial profile

Rapidly progressive polymicrobial infection of subcutaneous tissue and fascia with high mortality; requires emergent surgical debridement and broad-spectrum antibiotics.

Malignant Tumors · partial profile

Malignant cartilage-producing mesenchymal tumour; in the jaws it favours the anterior maxilla and behaves aggressively despite indolent histology.

Maxillofacial Surgery · partial profile

Staged multidisciplinary reconstruction of orofacial clefts to restore lip continuity, palatal competence, speech, dental occlusion and facial aesthetics.

Developmental Disorders · partial profile

Congenital defect from failure of fusion of facial processes resulting in cleft lip, palate, or both.

Developmental Disorders · partial profile

Autosomal dominant skeletal dysplasia with clavicular hypoplasia, delayed cranial ossification, and multiple supernumerary teeth.

TMJ Disorders

Unilateral non-neoplastic overgrowth of the mandibular condyle producing progressive facial asymmetry, cross-bite and open-bite in adolescents.

Maxillofacial Infections · partial profile

Odontogenic infection can spread along fascial planes into potential spaces of the head and neck, threatening the airway, mediastinum and great vessels.

Dental Diseases · partial profile

Multifactorial biofilm-mediated demineralisation of dental hard tissues by acidogenic bacteria.

Dental Diseases · partial profile

Loss of tooth structure by chemical dissolution from non-bacterial acids.

Maxillofacial Surgery · partial profile

Placement of titanium or zirconia fixtures into alveolar bone to replace missing teeth via the biological phenomenon of osseointegration first described by Brånemark.

Odontogenic Cysts

Odontogenic developmental cyst that surrounds the crown of an unerupted tooth and is attached at the CEJ.

Developmental Disorders · partial profile

Autosomal dominant disorder of dentin causing opalescent, amber-discoloured teeth prone to fracture.

Trauma · partial profile

Injuries involving teeth, periodontium and alveolar bone; management is time-critical and follows IADT 2020 guidelines.

Maxillofacial Surgery · partial profile

Gradual mechanical lengthening of bone through an osteotomy that stimulates new bone formation in the distraction gap — powerful for severe hypoplasia.

Soft Tissue Lesions · partial profile

Hyperplastic fibrous tissue folds in the vestibule caused by ill-fitting denture flanges.

Vesiculobullous Diseases · partial profile

Acute, self-limiting mucocutaneous hypersensitivity reaction commonly triggered by HSV or drugs, with target lesions and haemorrhagic oral crusting.

Red Lesions · partial profile

A red, painful form of oral candidiasis presenting as diffuse or focal erythematous mucosal patches, often on the palate, dorsum of tongue or beneath dentures.

Red Lesions

A red velvety patch that cannot be attributed to any other definable lesion — the highest-risk oral premalignant disorder.

Fibro-osseous Lesions

Benign fibro-osseous lesion in which normal bone is replaced by cellular fibrous tissue with immature woven bone; due to GNAS mutation.

Red Lesions · partial profile

A common, benign, chronic inflammatory condition of the tongue characterised by migrating, well-demarcated red patches with raised white serpiginous borders, producing a map-like appearance.

Benign Tumors

Benign vascular tumour of endothelial proliferation; presents in infancy with proliferation then involution — distinct from vascular malformations which never regress.

Developmental Disorders · partial profile

Second most common craniofacial anomaly; unilateral underdevelopment of mandible, ear, and soft tissues from first and second arch defects.

Oral Cancer · partial profile

A biologically and epidemiologically distinct SCC of the tonsil and base of tongue driven by high-risk HPV-16; better prognosis than tobacco-related SCC and staged separately in AJCC 8.

Malignant Tumors · partial profile

Low-grade vascular malignancy caused by HHV-8 (KSHV); oral involvement is a defining lesion of AIDS, typically as purple palatal macules or nodules.

Odontogenic Cysts

Uncommon developmental odontogenic cyst located along the lateral root surface of a vital tooth, most often in the mandibular premolar–canine region.

Trauma · partial profile

Three classical transverse patterns of midface fracture described by René Le Fort (1901) — each separates the maxilla from the cranial base at a different level.

White Lesions · partial profile

A benign, developmental variation of the oral mucosa presenting as bilateral, diffuse, grey-white opalescent buccal mucosa that disappears when the tissue is stretched.

White Lesions

Predominantly white lesion of oral mucosa that cannot be characterised as any other definable lesion. A potentially malignant disorder.

Maxillofacial Infections

Rapidly spreading bilateral cellulitis of the submandibular, sublingual and submental spaces — an airway emergency.

Trauma

Most commonly fractured facial bone after nasal bones. Often multiple fractures due to arch geometry.

Red Lesions · partial profile

A well-demarcated, rhomboid-shaped, red or pink depapillated area in the midline of the dorsum of the tongue, anterior to the circumvallate papillae, now considered a form of chronic erythematous candidiasis.

Bone Diseases

Exposed necrotic jaw bone persisting >8 weeks in a patient on antiresorptive or antiangiogenic therapy without prior head-and-neck radiotherapy.

Soft Tissue Lesions

Dome-shaped, fluctuant swelling from extravasation or retention of saliva in minor salivary glands, most common on lower lip.

Salivary Gland Disorders

The most common malignant salivary gland tumour; composed of mucous, intermediate and epidermoid cells with CRTC1/MAML2 fusion driving pathogenesis.

Vesiculobullous Diseases · partial profile

Chronic autoimmune subepithelial blistering disease affecting mucous membranes with scarring potential, especially in eyes.

Salivary Gland Disorders · partial profile

Acute contagious viral infection by paramyxovirus causing bilateral non-suppurative parotitis; now uncommon due to MMR vaccination.

Non-odontogenic Cysts

A rare, extra-osseous, developmental soft-tissue cyst of the upper lip and nasal alar base, historically thought to arise from entrapped epithelium of the nasolacrimal duct or the fusion line of embryonic facial processes.

Non-odontogenic Cysts

The most common non-odontogenic developmental cyst of the oral cavity, arising from epithelial remnants of the embryonic nasopalatine duct within the incisive canal.

Odontogenic Cysts

Developmental odontogenic cyst arising from dental lamina remnants; notable for aggressive behaviour, high recurrence, and association with Gorlin–Goltz syndrome.

Odontogenic Tumors

Benign but locally infiltrative odontogenic mesenchymal tumour composed of stellate cells in a myxoid stroma; notable for finger-like invasion of medullary bone and 'tennis-racket' radiographic pattern.

Odontogenic Tumors

The most common odontogenic tumour — a hamartomatous developmental malformation of odontogenic tissues classified as compound (denticles) or complex (disorganised mass).

White Lesions

Opportunistic fungal infection of the oral mucosa, most commonly caused by Candida albicans, presenting as wipeable white plaques (thrush), erythematous patches or angular cheilitis.

White Lesions

Chronic T-cell mediated mucocutaneous inflammatory disease with characteristic reticular white striae and, in erosive forms, painful ulcerations. Considered an oral potentially malignant disorder.

Benign Tumors · partial profile

Benign tumour of mature adipocytes; the commonest mesenchymal soft-tissue neoplasm but comparatively rare in the oral cavity.

Systemic Diseases · partial profile

Chronic renal failure produces a distinctive constellation of oral findings — uraemic fetor, mucosal pallor, renal osteodystrophy of the jaws and bleeding tendency.

Systemic Diseases · partial profile

Uncontrolled diabetes produces a spectrum of oral findings; oral health worsens glycaemic control (bidirectional).

Systemic Diseases · partial profile

The oral cavity is an early sentinel of HIV disease; classical lesions include pseudomembranous candidiasis, oral hairy leukoplakia, Kaposi sarcoma and necrotising periodontitis.

Systemic Diseases · partial profile

Acute leukaemias, especially AML M4/M5, present with striking oral signs — gingival enlargement, spontaneous bleeding, pallor and ulceration — often the presenting complaint.

Pigmented Lesions

Rare, aggressive malignancy of melanocytes in oral mucosa with poor prognosis.

Pigmented Lesions · partial profile

Benign, flat, well-circumscribed brown macule on oral mucosa due to increased melanin production without melanocyte proliferation.

Pigmented Lesions · partial profile

Benign melanocytic neoplasm of oral mucosa; less common than cutaneous nevus.

Benign Tumors · partial profile

Benign encapsulated tumour of Schwann cells arising from peripheral nerve sheath; solitary, slow-growing and eccentric to the parent nerve.

Oral Cancer

Malignant epithelial neoplasm; > 90% of all oral malignancies. Sixth most common cancer worldwide.

Premalignant Disorders

Chronic, progressive, scarring disease of oral mucosa strongly associated with areca nut chewing; a WHO-recognised potentially malignant disorder.

Ulcerative Diseases · partial profile

Rare oral manifestation of TB, typically presenting as a chronic, painful, non-healing ulcer.

Maxillofacial Surgery · partial profile

Surgical correction of dentofacial deformities to restore functional occlusion, facial aesthetics and airway.

Fibro-osseous Lesions

Benign well-demarcated encapsulated fibro-osseous neoplasm of tooth-bearing regions of the jaws; unlike fibrous dysplasia, it can be shelled out.

Bone Diseases

Inflammation of medullary and cortical bone, most often of the mandible, secondary to odontogenic infection or trauma; classified as acute, chronic suppurative, chronic non-suppurative and specific forms.

Malignant Tumors

Malignant mesenchymal tumour producing osteoid; jaw osteosarcoma presents later than long-bone counterparts.

Bone Diseases

Chronic disorder of accelerated, disorganised bone remodelling; jaw involvement causes progressive symmetrical enlargement, hypercementosis and denture non-fit.

Vesiculobullous Diseases

Autoimmune intraepithelial blistering disease with IgG autoantibodies against desmoglein-3 (and desmoglein-1).

Dental Diseases · partial profile

Localised collection of pus at the root apex resulting from pulp necrosis and bacterial infection.

Soft Tissue Lesions

Reactive exophytic gingival lesion containing multinucleated giant cells, arising only from attached gingiva or alveolar ridge.

Salivary Gland Disorders

Commonest benign salivary gland tumour; slow-growing painless mass composed of epithelial, myoepithelial and mesenchymal-like elements; recurrence risk if incompletely excised or capsule breached.

Vesiculobullous Diseases · partial profile

Acute, self-limiting primary infection with HSV-1 causing widespread oral vesicles, ulcers, and gingivitis in children.

Dental Diseases · partial profile

Inflammation of the dental pulp, classified as reversible or irreversible, commonly caused by caries, trauma, or restorations.

Benign Tumors

Common reactive vascular proliferation of skin and mucosa; despite the name, neither pyogenic nor a granuloma.

Odontogenic Cysts

The most common inflammatory odontogenic cyst; a sequela of pulp necrosis stimulating epithelial cell rests of Malassez at the apex of a non-vital tooth.

Soft Tissue Lesions

Mucocele arising in the floor of mouth from sublingual gland, appearing as a blue, translucent swelling resembling a frog's belly.

Ulcerative Diseases

Recurrent, painful, self-limiting oral ulcers on non-keratinised mucosa in otherwise healthy individuals.

Salivary Gland Disorders

Calcified concretion within salivary gland ducts; most common disease of salivary glands.

Salivary Gland Disorders · partial profile

Chronic autoimmune exocrinopathy targeting lacrimal and salivary glands, producing xerostomia and xerophthalmia; carries a 15–20× increased risk of MALT lymphoma.

Pigmented Lesions · partial profile

Diffuse brown mucosal pigmentation, particularly on anterior labial gingiva, caused by tobacco smoking.

Non-odontogenic Cysts

A pseudocyst of the jaws lacking an epithelial lining, presenting as an empty or serosanguineous cavity most often in the posterior mandible of adolescents; the leading theory relates to trabecular bone haemorrhage that fails to organise.

TMJ Disorders · partial profile

Heterogeneous group of musculoskeletal & neuromuscular disorders involving TMJ, masticatory muscles and associated structures.

TMJ Disorders

Bony or fibrous fusion of the mandibular condyle to the glenoid fossa producing limited or absent mouth opening; a paediatric-onset case causes 'bird-face' deformity.

Benign Tumors

Benign, non-neoplastic bony exostoses of the midline hard palate or lingual mandible; usually incidental but may interfere with denture construction.

Soft Tissue Lesions

The most common reactive soft-tissue lesion of the oral cavity, arising from chronic low-grade trauma.

Ulcerative Diseases · partial profile

Painful mucosal ulcer resulting from mechanical, thermal, or chemical injury with identifiable cause.

Oral Cancer

Well-differentiated low-grade variant of oral SCC with warty exophytic architecture, pushing (not infiltrating) margins and excellent prognosis when adequately excised.

White Lesions · partial profile

A rare autosomal dominant genodermatosis presenting from childhood as bilateral, thick, spongy, folded white plaques of oral (and other mucosal) surfaces.

Trauma · partial profile

Fracture of the zygoma at its four articulations (frontal, temporal, maxillary, sphenoid) producing malar flattening, diplopia, infraorbital paraesthesia and trismus.