Radiopacities in Soft Tissue on Dental Radiographs PDF

Soft Tissue Calcification and Ossification Head and neck soft tissues calcifications can result from physiological or pathological mineralization. Some of these calcifications may be found on panoramic radiography because of their proximity to the focal trough and their superimposition over hard and...

Soft Tissue Calcification and Ossification Head and neck soft tissues calcifications can result from physiological or pathological mineralization. Some of these calcifications may be found on panoramic radiography because of their proximity to the focal trough and their superimposition over hard and soft tissue structures.  The deposition of calcium phosphate, usually occurs in the skeleton. When it occurs in an unorganized fashion in soft tissue, it is referred to as heterotopic calcification. Heterotopic calcifications may be divided into three categories: Dystrophic calcification : refers to calcification that forms in degenerating, diseased, and dead tissue with normal serum calcium and phosphate levels. The soft tissue may be damaged by blunt trauma, inflammation, injections, the presence of parasites, soft tissue changes arising from disease. This calcification usually is localized to the site of injury. Such as calcification of a focus of necrosis of tuberculosis, necrotic tumour tissue or of atheromatous plaque.  Idiopathic calcification: results from deposition of calcium in normal tissue with normal serum calcium and phosphate levels, such as chondrocalcinosis and phleboliths (calcification within a vein). Metastatic calcification: results when minerals precipitate into normal tissue as a result of higher than normal serum levels of calcium (e.g., hyperparathyroidism, hypercalcemia, of malignancy) or phosphate (e.g., chronic renal failure). Metastatic calcification usually occurs bilaterally and symmetrically. Calcified lymph nodes : occurs in LNs that have been chronically inflamed because of various diseases such as tuberculosis, necrotic metastatic malignant deposit which frequently occurs post chemo- or radio therapy, and metastases from thyroid carcinoma. Clinically: asymptomatic unless infected, discovered on OPG, affects mostly submandibular and superficial and deep cervical nodes. When palpated, they are hard, lumpy, round masses. Radiographic Features: LN calcifications may affect a single or a linear series of nodes ( LN chaining). The periphery is irregular, having a lobulated appearance similar to the outer shape of cauliflower. This irregularity is of great significance in distinguishing node calcifications from other soft tissue calcifications. Differential Diagnosis : A-Sialolith in the hilar region of the submandibular gland but sialolith has a smooth outline, whereas a calcified LN is usually irregular and sometimes lobulated. The differentiation can be made by: 1.Symptoms related to the submandibular salivary gland. 2. Sialography may be necessary to make the differentiation. B- Phlebolith; they are usually smaller and multiple, with concentric radiopaque and radiolucent rings, and their shape may mimic a portion of a blood vessel. Phlebolith Tonsilloliths (calcified tonsils): develop due to chronic inflammation of the tonsils. If large, they protrude from the tonsillar crypts and manifest clinically as yellow or white stones. Radiographicaly: multiple small radiopacities superimposed on the mid- ramus and angle of the mandible often below the inferior alveolar canal. Well-defined, round to oval, irregular, small and multiple (cluster) or single and larger (rare),radioaque cortical density. on OPG. If uncertain, CBCT examination can be performed which will confirm the location. Myositis Ossificans: is dystrophic calcification within a muscle and is induced by trauma and haemorrhage and can be localized when affecting only one muscle or generalized when affecting several muscles. The muscles of mastication can be involved and the condition is therefore seen in their anatomical locations Myositis ossificans of the distal fibres of the temporalis muscle and its tendon at its attachment at the lower part of the coronoid process. Synovial Osteochondromatosis : is a rare disorder which more commonly affect major joints than the TMJ. Synovial osteochondromatosis is usually characterized by unilateral osteo- cartilagenous nodules in the synovium of the joint and may be associated with pain and swelling, Irregular large calcifications associated with the left TMJ. The lesions were palpated as firm nodules in the capsule of the TMJ, surgically removed and confirmed microscopically. Elongated styloid process and ossified stylohyoid ligament: The styloid process is a cylindrical bony projection, of approximately 20 to 30 mm in length, located in the temporal bone.Ossification of the styloid process can create a radiographic image of an elongated styloid process. The stylohyoid ligament is attached at the lesser horn of the hyoid bone and therefore stabilizes it. Patients with an ossified stylohyoid ligament may manifest with headaches, pain with swallowing, yawning and with moving the head laterally, referred (TMJ) pain or recurrent throat pain due to impingement of the elongated process on adjacent structures. A symptomatic ossified stylohyoid ligament is referred to as Eagle syndrome and OPG showing a length of 3cm or more is sufficient to confirm the diagnosis. The radiopaque outlines of an ossified stylohyoid ligament (open arrow), passing the angle of the mandible, are present in this radiograph of a 77- year-old female. A calcification within Stensen’s duct of the parotid gland can also be seen projecting onto the upper part of the ramus (solid arrow) Ossified stylohyoid ligament Arterial Calcification A: Arteriosclerosis: is the fragmentation, degeneration, and eventual loss of elastic fibers followed by the deposition of calcium within the medial coat of the vessel. Clinically: are asymptomatic initially, but in the course of the disease may have cutaneous gangrene, peripheral vascular disease, and myositis as a result of vascular insufficiency. Radiographicly: It affects the facial artery or, less commonly, the carotid artery, which may be viewed on OPG.The calcified vessel appears as a parallel pair of thin, radiopaque lines that may have a straight course or a tortuous path and is described as a pipe stem or tram-track appearance. In cross-section as a circular or ring like pattern.  Cropped OPG image showing calcification of a blood vessel, probably the facial vein (arrows). Management : Evaluation of the patient for occlusive arterial disease and peripheral vascular disease may be appropriate. hyperparathyroidism may be considered because medial calcinosis frequently develops in patients with this condition. B: Calcified Atherosclerotic plaque Atherosclerosis develops at arterial bifurcations as a result of increased endothelial damage from shear forces at these sites. When calcification has occurred, these lesions may be visible in OPG in the soft tissues of the neck either superior or inferior to the greater cornu of the hyoid bone (where the common carotid artery splits into the external and internal carotid arteries) and adjacent to the cervical vertebrae C3, C4, or the intervertebral space between them. Cropped OPG: The arrows indicate two radiopaque roughly parallel lines which are evidence of calcified carotid atheromatous plaque (CAC) in the bifurcation between the external and internal carotid arteries in this 76-year- old female.  Idiopathic Calcification Sialolith (salivary stones) : Submandibular sialoliths: on or below body- and mesial to angle of mandible, above hyoid bone or on apices of mandibular premolars. Parotid sialoliths: on upper third of ramus or anterior or posterior of it. Regular but may be irregular if close to hilus of gland, smooth, round or oval, single or multiple. Radiopaque, frequently laminated or stippled according to degree of calcification. Maxillary Antrolith: is a rarely found calcified mass in the maxillary sinus formed by exogenous or endogenous origin. Stones arising in the antral cavities are uncommon. Their development is similar to that of a sialolith as these may form around a nidus or concentrated mucus, which continues to grow because of the precipitation of calcium salts in concentric layers. The origin of the nidus of calcification may be extrinsic (foreign body in sinus) or intrinsic (stagnant mucus and fungal ball). Such radiopacities may also represent exostoses arising from the antral wall, it shows no change in position over time