Article
Specialist referral may be indicated if the Practitioner feels:
Odontogenic diseases may be related to the tooth or tooth germ.
Odontogenic infections
Caries, periodontitis or pericoronitis are the common oral pyogenic infections. Depending on the bacterial load and host immunity, dental pulpal infection may lead to apical periodontitis, abscess and fascial space infection, or granuloma or periapical (radicular) cyst.
Odontogenic cysts
Most jaw cysts arise from odontogenic epithelium. Odontogenic cysts (and tumours) arise from ectoderm, mesenchyme or a combination (ectomesenchyme) involved in tooth germ formation and they may be related to the site of a tooth germ, or may be associated with a tooth. There is an overall male predominance and the mandible is affected three times as commonly as the maxilla.
Clinical features
Jaw cysts are often asymptomatic presenting as an incidental finding, on radiographs, as a well-defined, corticated radiolucency owing to their benign, slow-growing nature. They may reach a large size before they give rise to:
Occasionally carcinomas may arise within some cysts.
Diagnosis
Most cysts are discovered on intra-oral radiography or on dental panoramic tomography. In the mandible they, by definition, arise above the inferior alveolar canal. Unless the lesion is very large, advanced imaging is rarely required. Cross-sectional imaging allows bucco-lingual expansion to be assessed more easily, especially in the maxilla. CBCT is now the imaging of choice if required (Figures 1 and 2: Nasopalatine duct cyst; CBCT panoramic and sagittal.)
Other investigations may include pulp vitality testing, aspiration and analysis of cyst fluids, and histopathology.
Management
Enucleation (complete removal of the cyst) makes all tissue available for histological examination, the cavity usually heals uneventfully with minimal aftercare, but may render adjacent teeth non-vital. Marsupialization (partial removal) requires considerable aftercare and co-operation in keeping the cavity clean – the patient syringing the cyst cavity after meals. Healing may take up to 6 months and not all cyst lining is available for histopathology.
Odontogenic cysts are relatively common – most are inflammatory (55% of all) or dentigerous (22%) (Table 1). Odontogenic cysts that can be problematical, because of recurrence and/or aggressive growth, include especially the calcifying odontogenic and glandular odontogenic cysts.
Odontogenic | Non-odontogenic | Pseudocysts | |
---|---|---|---|
Inflammatory | Developmental | ||
Apical radicular |
Dentigerous cyst |
Nasopalatine cyst | Haematopoietic |
Characterized by its position at the apex of a non-vital tooth (pulp necrotic because of caries, trauma or deep restoration), there is a round or pear-shaped, well-defined radiolucent lesion with sclerotic borders, larger (often >20 mm) than a periapical granuloma, with a rounder contour, and more well-defined border. It often involves a maxillary incisor or canine.
Any cyst that remains after surgery is termed a residual cyst – most arise from periapical cysts.
A hyperplastic follicle, in contrast, is <2–3 mm, and neither displaces the tooth nor causes cortical expansion.
The main odontogenic cysts are listed in Table 2.
Type | Decade at Presentation | Commonest Location | Usual Management |
---|---|---|---|
Dentigerous | 3rd and 4th | Lower third molars, maxillary canines | Enucleation or marsupialization |
Eruption | 1st | Anterior to permanent molars | Nil unless impeding eruption |
Radicular | 3rd and 4th | Anterior maxilla | Enucleation |
Residual | 4th and 5th | Anterior maxilla | Enucleation or marsupialization |