radiology of maxillary sinus

Radiographic appearance of maxillary sinus

Prepeared by :Zara khasrow balakiPrepeared by :Zara khasrow balaki

Maxillary sinus Maxillary sinus is an air containing cavity lined by mucous membrane

The sinus may be considered as a three sided pyramid its three sides are:

Maxillary sinus are largest sinuses amongst the other paranasal sinusesMaxillary sinus are largest sinuses amongst the other paranasal sinuses

Intraoral periapical radiograph :

In these radiograph the roots of the maxillary teeth may appear to project directly into the sinus and may produce conical elevations on the floor of the sinus ,yet there is always a layer of bone and mucosa covering these roots

In periapical radiograph one must remember that:

*a radiopaque band of tissue following the contour of the sinus indicate generalized inflamatory reaction of the sinus mucosa leading to hyper plasia

*a localized opaque thickening adjacent to the source of inflammation as in severe periodontal disease indicated localized mucosites

*most antral changes caused by pathosis are radiopaque

aaOn the periapical radiograph of canine the floors of the sinus and nasal cavity are often superimposed and maybe seen crossing each other forming an inverted Y in the area

On the periapical radiograph of canine the floors of the sinus and nasal cavity are often superimposed and maybe seen crossing each other forming an inverted Y in the area

the anterior maxillary occlusal projection, the cross sectional maxillary anterior projection and the lateral maxillary occlusal projection are excellent techniques to visualize maxilla from the palatal aspect

Standard radiograph1. the caldwell view(occepito frontal)1. the caldwell view(occepito frontal)

2.water’s view (occepitomental view)2.water’s view (occepitomental view)

3.The lateral view 3.The lateral view

this is an ideal view when opaque foreign bodies are being looked for in the maxillary sinus

4.Submentovertex view 4.Submentovertex view

Panoramic view (orthopantomography)

Gives a good display of the lower aspects of antrum

On the panoramic radiograph maxillary sinus appear as paired radiolucent areas located above the apices of maxillary premolars and molars .the floor of the maxillary sinus is composed if dense cortical bone and appear as a radiopaque line

Most of the anterior and posterior walls of the maxillary sinus are superimposed upon the medial wall in the pantomogram.

Computerized tomography and magnetic resonance imaging

Provide multiple section through the sinus at different planes

MRI of the paranasal sinuses is a comlimentary imaging technique to CT

MRI can image intra cranial complications of inflammatory disease

MRI can readily separate tissues oof similar densities better than CT which is useful to diffrentiate tumors from inflammatory disorders as well as haemorrhage and inflammatory secretions

MRI is unable to image bone and air ,so evaluation of bony anatomy and pathology is difficult hence MRI is mainly usefull to determine spread of disease ,especially intracranially and intraorbitally

MRI can readily separate tissues oof similar densities better than CT which is useful to diffrentiate tumors from inflammatory disorders as well as haemorrhage and inflammatory secretions

MRI is unable to image bone and air ,so evaluation of bony anatomy and pathology is difficult hence MRI is mainly usefull to determine spread of disease ,especially intracranially and intraorbitally

Antral diseases and their radiographic appearanceAntral diseases and their radiographic appearance

Antroliths These are small bodies of varying sizes generally found in the base of sinus

Generally They are homogeneous density and rarely they may have a more radiopaque area around

They usually have irregular border

Thickining of the sinus mucosa and the accumulation of secretions that accompany sinusites reduce air content of the sinus and cause it to become increasingly radiopaque

Acute right side maxillary sinusitis and chronic left side maxillary sinusitis

Irregular thickining of the radiopaque lining on the inner side of sinus because of mucosal hypertrophy

Shrinkage of the radiolucent cavity of the sinus

Acute right side maxillary sinusitis and chronic left side maxillary sinusitis

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