Sarcoidosis

Sarcoidosis is a multisystem non-necrotizing granulomatous disease of unknown cause that preferentially involves the lungs and intrathoracic lymph nodes but can affect virtually any organ.[1][2] In the oral and maxillofacial region it is uncommon: clinically apparent oral involvement occurs in only about 1% to 2% of patients with systemic disease, and intraosseous jaw disease is rarer still.[3][4] Two distinct oral patterns exist—soft-tissue mucosal lesions and destructive intraosseous (alveolar) disease.[5] Pathogenesis reflects an exaggerated, Th1-polarized CD4+ T-cell response to an unidentified antigen in genetically predisposed individuals, culminating in granuloma formation.[6]

The signature maxillofacial finding is ill-defined, lytic/permeative alveolar bone loss that mimics rapidly progressive periodontitis, often with mobile teeth and without the bony expansion seen in small-bone disease.[7][8] Because oral lesions may be the first manifestation of systemic sarcoidosis, recognition triggers biopsy and systemic evaluation; management ranges from observation to corticosteroids and steroid-sparing immunosuppression.[3][9]

Sarcoidosis is the accepted term. The historical eponym Besnier–Boeck–Schaumann disease is obsolete and should be avoided except to resolve older references. Lesions confined to the mouth are described as oral sarcoidosis, subdivided into mucosal (soft-tissue) and intraosseous (jaw) sarcoidosis.[5][10] Non-necrotizing (non-caseating) granuloma is the preferred histologic descriptor; "noncaseating" persists in clinical use.[11]

Several defined syndromes carry maxillofacial relevance:

• Heerfordt syndrome (uveoparotid fever): uveitis, parotid/salivary enlargement, fever, and cranial (usually facial) nerve palsy.[12][13]
• Löfgren syndrome: erythema nodosum, bilateral hilar adenopathy, and polyarthralgia—an acute phenotype with good prognosis but no direct oral component.[14]

Sarcoidosis affects all ages, sexes, and ancestries, with a female predominance and peak onset in adulthood. Annual incidence ranges roughly 1 to 15 per 100,000 depending on region, highest in Scandinavia and lowest in East Asia.[15] In the United States, incidence is substantially higher among Black Americans (reported near 18 per 100,000) than White, Hispanic, or Asian Americans.[11][15] Average age at diagnosis is approximately 45 to 55 years; men tend to peak earlier (30s–40s) and women later (50s–60s).[15][16]

Oral and jaw involvement follows the same demographic skew but presents somewhat younger:

• Pooled oral-sarcoidosis data give a mean age near 43 years with female predominance in both soft-tissue and bone-involved cases.[5]
• Clinically overt osseous sarcoidosis of any site is reported in roughly 0.5% to 13% of patients, with jaw involvement a small subset.[17][18]
• Anatomically, intraosseous jaw disease shows a predilection for the anterior maxilla and posterior mandible, though generalized bilateral involvement occurs.[4][10]

Oral sarcoidosis presents as two clinically distinct entities—mucosal soft-tissue lesions and destructive intraosseous disease—and in a large fraction of patients the oral finding precedes a systemic diagnosis.[5] Oral lesions were the first evidence of disease in a majority of reported cases, and detection may precede established systemic sarcoidosis in up to roughly 62%.[3]

Mucosal (soft-tissue) disease

• Firm submucosal nodules, plaques, or swellings; less often ulceration; color may be normal, erythematous, or violaceous.[3][7]
• The buccal mucosa, gingiva, lips, tongue, and palate are most often involved; depapillation and macroglossia are described on the tongue.[3][10]
• Most lesions are asymptomatic; some cause soreness, dysarthria, or dysphagia.[3]

Intraosseous (jaw) disease

• Presents with loose teeth, localized alveolar bone loss, pain (sometimes radiating to the ear), non-healing extraction sockets, and occasionally nasal obstruction.[5][10]
• Clinically indistinguishable from aggressive/rapidly progressive periodontitis and, around implants, from peri-implantitis.[4][8][19]

Salivary and neural involvement

• Salivary gland involvement occurs in an estimated 5% to 10%, typically bilateral painless parotid enlargement with xerostomia; it may mimic Sjögren syndrome.[13][20]
• Facial nerve palsy is the most common neurologic manifestation and may be unilateral or bilateral; within Heerfordt syndrome it accompanies parotid swelling, uveitis, and fever.[13][21][22]

Red flags prompting referral include rapid unexplained alveolar bone loss discordant with plaque/calculus, persistent atypical mucosal nodules, bilateral parotid swelling, and facial weakness.[3][8]

Intraosseous jaw sarcoidosis characteristically produces ill-defined, lytic/permeative radiolucency of the alveolar bone that resembles severe periodontitis, typically without the expansion seen in phalangeal disease.[7][8] Findings are nonspecific, so imaging supports rather than establishes the diagnosis.

Location and distribution

• Predilection for the anterior maxilla and posterior mandible; disease may be unifocal, multiquadrant, or generalized and bilateral.[4][10]
• Most jaw lesions are centered on tooth-bearing alveolar bone, producing the periodontitis-like pattern, although condylar, temporomandibular joint, and non–tooth-bearing involvement are occasionally reported.[8][19]

Relationship to teeth and the alveolar process

• Horizontal and vertical alveolar bone loss producing mobile teeth, frequently out of proportion to local plaque burden.[8][19]
• Loss of lamina dura and widening of the periodontal ligament space may be seen, mimicking periodontitis and other systemic osteolytic conditions.[23]

Periphery and shape

• Margins are typically ill-defined and non-corticated; a permeative edge reflecting granulomatous marrow infiltration is characteristic.[7][24]

Internal architecture

• Predominantly radiolucent/lytic with coarsened, disrupted trabeculation, analogous to the "lacework/latticework" pattern described in small bones.[17][24]
• A mixed cotton-wool (focal sclerotic/granular) appearance has been reported in generalized mandibular disease; purely sclerotic jaw lesions are rare and tend to be late.[8]

Effects on teeth and adjacent structures

• Progressive alveolar resorption, tooth mobility, non-healing sockets, and bone loss around implants.[4]
• Cortical erosion can occur, but frank expansion is uncommon, helping distinguish it from expansile odontogenic lesions.[7]

Growth pattern, cortical involvement, and extent

• Slowly progressive but destructive; cortical thinning or erosion without periosteal new bone.[17][24]
• Extent is best appreciated on a panoramic survey, which can show generalized severe alveolar resorption across both jaws.[10]

Recognized variants

• Spectrum from focal punched-out radiolucency to diffuse permeative marrow infiltration, with the uncommon mixed cotton-wool variant at the sclerotic end.[8][24]

Extraoral imaging is central to confirming that jaw disease is part of a systemic process and to staging, because the oral lesion is frequently the sentinel finding.[3][7]

Thoracic imaging

• Chest radiography and chest computed tomography commonly reveal bilateral hilar lymphadenopathy with a perilymphatic micronodular pattern, features highly supportive of sarcoidosis and guiding accessible biopsy.[14]

Whole-body metabolic and marrow imaging

• Fluorodeoxyglucose PET/CT detects occult osseous and marrow involvement far more often than radiographs and identifies active, biopsy-amenable sites; much skeletal disease is radiographically occult.[20][25]
• On magnetic resonance imaging, osseous lesions are T1-hypointense and T2/STIR-hyperintense with variable enhancement and cannot be reliably distinguished from metastases, an important caveat when a destructive jaw lesion is found.[18][25]

Salivary gland imaging

• Imaging of salivary involvement is nonspecific, showing diffuse glandular infiltration or enlargement; correlation with histology is required.[13][26]

Jaw sarcoidosis is a clinical and radiographic mimic: its ill-defined alveolar lytic pattern overlaps with periodontitis, histiocytic and metabolic bone disease, malignancy, and other granulomatous disorders. The highest-yield alternatives are distinguished chiefly by biopsy and targeted laboratory testing rather than imaging alone.

The dominant pitfall is treating rapid alveolar bone loss as ordinary aggressive periodontitis and proceeding to extraction without tissue diagnosis; incisional bone/soft-tissue biopsy with microbial stains, plus PTH/calcium and chest imaging, should precede definitive dental surgery.[4][8]

The diagnostic hallmark is the well-formed, discrete non-necrotizing (non-caseating) granuloma composed of epithelioid histiocytes and multinucleated giant cells surrounded by a sparse rim of lymphocytes.[11][29] Granulomas tend to remain compact and discrete and may coalesce; peripheral lamellar hyaline fibrosis is characteristic, and chronic lesions become progressively fibrotic.[29]

• Giant cells characteristically contain asteroid and Schaumann (conchoidal) bodies; Hamazaki–Wesenberg bodies are a further characteristic but nonspecific inclusion, classically identified in nodal sinus histiocytes rather than giant cells. None is specific for sarcoidosis.[11][29][32]
• Necrosis is typically absent or minimal; significant necrosis should prompt reconsideration of infection or vasculitis.[11][30]
• Sarcoidosis is a diagnosis of exclusion: histochemical stains and cultures for mycobacteria and fungi must be negative, because granuloma morphology alone cannot separate sarcoidosis from other granulomatous diseases.[30]

Radiologic-pathologic correlation is essential—the permeative radiolucent bone pattern corresponds to granulomatous marrow infiltration with trabecular resorption, while the surrounding destructive change explains tooth mobility.[17][24]

Management begins with tissue confirmation and systemic staging, then is individualized from observation to systemic immunosuppression based on symptoms and organ risk.[3][14] An oral or jaw lesion showing non-necrotizing granulomas mandates evaluation for pulmonary, cardiac, ocular, and neurologic involvement, with referral to pulmonology and, as indicated, rheumatology or ophthalmology.[3][14]

Local and systemic treatment

• Asymptomatic or mild oral disease may be observed; many lesions remit.[9][31]
• Corticosteroids are first-line systemic therapy, with steroid-sparing agents (methotrexate most studied; azathioprine, leflunomide, mycophenolate) added early when prolonged suppression is needed; hydroxychloroquine is useful for cutaneous, mucosal, and hypercalcemic disease.[11][14]
• Local dental measures—oral hygiene, scaling/root planing, splinting, extraction of non-restorable mobile teeth, and curettage of intraosseous lesions—are adjuncts; definitive dental surgery should follow diagnosis and systemic control.[4][19]

Outcome and surveillance

• Oral and jaw lesions generally respond well, with most achieving complete or partial remission, though relapses occur.[9]
• Prognostic weight lies in systemic involvement: most non-Löfgren patients remit, about one-third follow a chronic course, and cardiac, neurologic, renal, and progressive pulmonary fibrotic disease drive morbidity and mortality; all-cause 5-year mortality was about 7% in one UK cohort (versus 4% in matched controls), and fewer than 10% of patients die from sarcoidosis itself.[2][14]
• Because the oral lesion may be the earliest sign, long-term dental and medical surveillance is warranted after diagnosis.[5]