Vascular calcification

Vascular calcification in the maxillofacial region encompasses two principal forms of arterial wall mineralization—intimal atherosclerotic calcification and medial (Mönckeberg) arteriosclerosis—as well as venous calcification in the form of phleboliths.[1][2] These are incidental, non-neoplastic findings detected on panoramic radiographs, intraoral radiographs, and CBCT during routine dental imaging.[1][3] Intimal calcification occurs within atherosclerotic plaques and is driven by endothelial dysfunction, lipid accumulation, and chronic inflammation.[4][5] Medial calcification involves hydroxyapatite deposition within the tunica media through osteogenic transformation of vascular smooth muscle cells, independent of lipid-mediated atherosclerosis.[2][6] Phleboliths are calcified thrombi arising within low-flow venous malformations.[7] Recognition and accurate characterization of these calcifications on dental imaging is clinically important because they may signal undiagnosed systemic vascular disease, and appropriate referral can facilitate cardiovascular risk assessment.[8][9]

• Calcified carotid artery atheroma (CCAA): The most widely used term for intimal atherosclerotic calcification detected at the carotid bifurcation on dental imaging.[3][10]
• Carotid artery calcification (CAC): Broader synonym encompassing any calcification in the carotid artery region on panoramic radiographs.[11][12]
• Mönckeberg medial arteriosclerosis (MMA): Also termed medial arterial calcification (MAC) or medial arterial calcinosis; refers specifically to calcification of the tunica media. The eponym "Mönckeberg sclerosis" remains in common use.[2][13]
• Phlebolith: A calcified thrombus within a vein, most often associated with venous malformations.[7]
• Arteriosclerosis is a general term for arterial wall hardening and should not be confused with atherosclerosis, which specifically denotes intimal plaque disease.[1]

• Calcified carotid artery atheroma is the most commonly reported vascular calcification on dental imaging. A meta-analysis of 34 cross-sectional studies found a pooled incidence of approximately 7% on panoramic radiographs. On CBCT, prevalence is higher, with approximately 30% of scans demonstrating calcified atheromas when both intracranial and extracranial sites are assessed.[3][14]
• Prevalence increases with age; calcifications are most common in patients older than 50–60 years. Male sex and cardiovascular risk factors—hypertension, hyperlipidemia, diabetes, and prior myocardial infarction—are significantly associated with calcified atheromas.[14][15][16][17]
• Mönckeberg medial arteriosclerosis is less commonly recognized on dental imaging. In a cohort of medically compromised dental patients, MMA was identified in approximately 6% on panoramic radiographs, with a strong association with chronic kidney disease (OR 31.84).[1]
• Phleboliths in the maxillofacial region are uncommon; they are encountered occasionally within venous malformations of the head and neck, which themselves represent approximately 40% of all venous malformations.[18][19]

Vascular calcifications in the maxillofacial region are almost always asymptomatic and discovered incidentally on dental imaging.[1][3]

Atherosclerotic calcification (CCAA)

• Patients are typically asymptomatic from the calcification itself. The clinical significance lies in its association with systemic atherosclerotic disease and elevated risk of stroke, transient ischemic attack, and myocardial infarction.[8][9]
• Bilateral vessel-outlining calcifications carry the highest cardiovascular risk; in a 10-year follow-up, bilateral CCAAs were independently associated with increased cardiovascular events and mortality (HR 1.67–1.96).[9]
• Patients with CCAAs are very likely to harbor unrecognized vascular risk factors, including hypertension and dyslipidemia.[20]

Mönckeberg medial arteriosclerosis

• Also clinically silent on oral examination. Its significance is as a marker of systemic disease, particularly chronic kidney disease, diabetes mellitus, and hyperparathyroidism.[1][6][21]
• Unlike atherosclerotic calcification, MMA does not narrow the vessel lumen; rather, it causes arterial stiffness, contributing to elevated pulse pressure and cardiovascular morbidity.[2][5]

Phleboliths

• When present in the maxillofacial region, phleboliths are typically associated with a clinically evident venous malformation—a soft, compressible, nonpulsatile mass with blue-purple discoloration.[18]
• Phleboliths may cause localized pain due to venous stasis and localized intravascular coagulation.[18][22]

Location and distribution

• CCAA: Characteristically located in the soft tissue of the neck, projected anterior to the C3–C4 vertebral bodies on panoramic radiographs, at or near the carotid bifurcation. Calcifications may be unilateral or bilateral.[1][10]
• MMA: Detected along the course of external carotid artery branches, including the facial, lingual, maxillary, ascending pharyngeal, and superficial temporal arteries. On panoramic radiographs, these appear in the soft tissue spaces between the mandible and hyoid bone, between the ramus and cervical vertebrae, and around the condylar region. MMA may also be visible on periapical and bitewing radiographs in the molar region as calcified facial or maxillary arteries.[1][21]
• Phleboliths: Located within the soft tissue mass of a venous malformation; in the maxillofacial region, common sites include the muscles of mastication, lip, tongue, and buccal space.[7][18]

Periphery and shape

• CCAA: Appears as irregular, patchy, or "cauliflower"-shaped radiopacities. The morphology reflects focal intimal plaque calcification and is characteristically heterogeneous.[1]
  • Four morphologic categories have been described on panoramic radiographs: single, scattered, vessel-width-defining, and vessel-outlining. All categories correlate with ultrasound-confirmed carotid plaque, but vessel-outlining calcifications show the strongest association with advanced cardiovascular disease.[11][12]
• MMA: Presents as thin, parallel, linear radiopacities along the vessel wall, producing a characteristic "tram-track" pattern. This appearance results from circumferential calcification of the tunica media along the elastic laminae.[1]
• Phleboliths: Appear as small, round to ovoid, well-defined radiopacities, often with a characteristic concentric laminated (target-like) internal pattern reflecting successive layers of calcified thrombus.[7]

Internal architecture

• CCAA: Heterogeneous density; may contain areas of dense calcification interspersed with less calcified plaque.[1]
• MMA: Uniformly dense, linear calcification conforming to the vessel wall; the tram-track pattern is the hallmark internal feature.[1]
• Phleboliths: Concentric laminations are characteristic when visible; smaller phleboliths may appear homogeneously radiopaque.[7][23]

Effects on adjacent structures

• Vascular calcifications do not cause displacement, resorption, or alteration of teeth, alveolar bone, or adjacent osseous structures. They are entirely extraskeletal soft tissue findings.[1]
• On panoramic radiographs, CCAA may be superimposed on the cervical vertebrae, hyoid bone, or mandibular angle, requiring careful differentiation from osseous pathology.[24]

Extent and cortical involvement

• These calcifications have no relationship to cortical bone. Their extent is determined by the severity and distribution of the underlying vascular disease.[1][2]
• CBCT allows three-dimensional localization of calcifications to specific vascular structures and can distinguish intracranial from extracranial atheromas, which is not possible on panoramic radiographs. CBCT also permits differentiation of vascular calcifications from other soft tissue calcifications (tonsilloliths, sialoliths, calcified lymph nodes) by confirming their anatomic relationship to the vessel course.[14][15][19][25]

Variants

• Coexisting intimal and medial calcification: Both types may occur simultaneously in the same patient, particularly in those with diabetes or chronic kidney disease.[1][5]
• Intracranial carotid calcification: Detectable on CBCT within the cavernous segment of the internal carotid artery; more common in females as an isolated finding, while males more often demonstrate combined intracranial and extracranial calcification.[14]

Ultrasound

Carotid duplex ultrasonography is the standard confirmatory study following detection of suspected CCAA on dental imaging. It directly visualizes carotid plaque, measures intima-media thickness, and quantifies luminal stenosis.[11][12][26] All morphologic categories of CAC on panoramic radiographs correlate with ultrasound-confirmed plaque, with vessel-outlining calcifications associated with the most severe disease (mean luminal reduction 24.1% vs. 3.5% in controls).[11] Ultrasonography is also the initial imaging modality for suspected venous malformations containing phleboliths, demonstrating compressible hypoechoic channels with echogenic foci representing calcified thrombi.[18][27]

MRI

MRI is the gold standard for characterizing venous malformations associated with phleboliths. Venous malformations appear hyperintense on T2-weighted sequences, while phleboliths appear as foci of low signal on all sequences.[18][27] MRI delineates lesion extent and relationship to critical structures, guiding treatment planning.

Vascular calcifications must be distinguished from other soft tissue radiopacities in the maxillofacial region. Location relative to known vascular anatomy, morphology, and multiplicity are the primary discriminators. The tram-track pattern of MMA and the irregular patchy appearance of CCAA at the carotid bifurcation are usually diagnostic, but overlap with other calcified entities can occur, particularly on two-dimensional imaging.[26][28]

The highest-risk diagnostic pitfall is misidentifying a CCAA as a benign calcification (tonsillolith, calcified lymph node) and failing to refer for cardiovascular evaluation, particularly in patients with unrecognized vascular risk factors.[8][9] When the nature of a cervical calcification is uncertain on panoramic radiography, CBCT or carotid duplex ultrasonography can confirm the diagnosis.[12][26]

Intimal atherosclerotic calcification

• Characterized by calcium phosphate deposition within atherosclerotic plaques of the tunica intima.[4][5]
• Microscopic features include lipid-laden macrophages (foam cells), fibrofatty plaque, chronic inflammatory infiltrate, and dystrophic calcification within the necrotic core.[5][31]
• Microcalcifications may be present in the fibrous cap, potentially contributing to plaque instability.[4][31]
• Advanced lesions show dense, sheet-like calcification with minimal residual inflammation.[31]

Mönckeberg medial arteriosclerosis

• Calcium phosphate (hydroxyapatite) deposits within the tunica media, initially as fine granulations near the internal elastic membrane, progressing to large sheaths replacing the media.[2]
• Absence of lipid deposits and macrophage infiltration distinguishes MMA from intimal atherosclerosis.[5][32]
• Vascular smooth muscle cells undergo osteogenic differentiation, expressing bone-related markers (Runx2, osteopontin, osteocalcin, alkaline phosphatase).[6][32]
• In advanced stages, fragmentation of the internal elastic membrane and, occasionally, ectopic osteogenesis with true bone and cartilage formation may occur.[2]
• Both intimal and medial calcification may coexist in the same vessel, particularly in patients with diabetes or chronic kidney disease.[5]

Phleboliths

• Organized thrombus within a venous channel that undergoes progressive dystrophic calcification, producing concentric laminations of calcium salts.[7][22]

Referral and workup

• Detection of suspected CCAA on dental imaging warrants referral to the patient's primary care physician or a vascular specialist for cardiovascular risk factor assessment, particularly in patients not currently managed for cardiovascular disease.[8][9][10]
• Patients already receiving treatment for atherosclerotic disease may not benefit from additional investigations based solely on panoramic findings.[8]
• Bilateral vessel-outlining CCAAs carry the highest prognostic significance and should prompt urgent referral.[9][12]
• Detection of MMA should prompt evaluation for chronic kidney disease, diabetes mellitus, and disorders of calcium-phosphate metabolism.[1][13][21]

Management of the calcification itself

• Vascular calcifications are not treated locally by the dental practitioner. Management is directed at the underlying systemic disease.[6][10]
• For CCAA with significant carotid stenosis confirmed by duplex ultrasonography, management follows established vascular surgery or interventional guidelines (carotid endarterectomy or stenting for symptomatic high-grade stenosis).[10]
• No effective pharmacological treatment currently exists to reverse medial arterial calcification; management focuses on controlling contributing metabolic derangements.[6]
• Phleboliths within venous malformations are managed as part of the overall malformation treatment, which may include sclerotherapy, surgical excision, or medical therapy with sirolimus for refractory symptoms.[18]

Prognosis

• The presence of bilateral CCAAs on panoramic radiographs is independently associated with increased 10-year cardiovascular morbidity and mortality.[9]
• MMA is a marker of advanced systemic vascular disease; its presence correlates with arterial stiffness and elevated cardiovascular risk, particularly in patients with chronic kidney disease.[2][6]
• Phleboliths themselves are benign, but the associated venous malformation may require ongoing management for pain, coagulopathy, or functional impairment.[18][22]

Dental treatment considerations

• Routine dental treatment can proceed when the patient is medically stable, with appropriate coordination with the patient's medical team regarding anticoagulation status and cardiovascular risk.[13]

Chronic kidney disease

Patients with chronic kidney disease and end-stage renal disease are at markedly elevated risk for both medial and intimal vascular calcification due to hyperphosphatemia, hypercalcemia, and secondary hyperparathyroidism.[4][33] MMA prevalence in kidney disease patients is substantially higher than in the general population, and its detection on dental imaging may precede clinical recognition of renal disease.[1] Dental practitioners should inquire about renal history when MMA is identified and facilitate nephrology referral when appropriate.

Diabetes mellitus

Diabetes is a shared risk factor for both intimal and medial calcification.[5] Although diabetes status alone was not an independent predictor of panoramic soft tissue calcifications after adjustment for age and sex in one study, the coexistence of diabetes with kidney disease markedly accelerates vascular calcification.[6][13][17]