Maxillofacial RadiologyDr Rince MohammedJR2 OMFSGovt Medical College Kottayam

Introduction

The anatomy of maxillofacial region is the most complex in the body. Injuries of this region range from isolated injuries to complex facial

injuries involving the entire facial skeleton. Diagnostic imaging has played a central role in providing information

essential in diagnosis and treatment of these injuries.

Common imaging modalities

Plain radiographs (conventional) Computed tomography (CT) CBCT (Cone beam computed tomography) Magnetic resonance imaging (MRI) Ultrasonography Contrast enhanced imaging

(sialography ,arthrography,angiography )

Plain radiographs (conventional)

1-Intra-oral radiograph :

Intra oral Periapical radiographs (IOPA) Bite-wing Occlusal radiograph :

Maxilla (occlusal view )Mandible (occlusal view )

Intra oral Periapical radiographs (IOPA)

Indications

To diagnose periapical pathology To determine root morphology To study eruption of teeth To find out impacted teeth,root stumps,fracture of teeth To evaluate root apex formation

Bite-wing radiograph

Used for• Early recognition of proximal

caries.• Proximal marginal integrity of

restorations and crowns.• Calculus accumulation in the

proximal regions.• To assess alveolar bone height

Occlusal radiographs

INDICATIONS

To locate roots and supernumerary,unerupted, and impacted teeth.

To localize foreign bodies in the jaws and stones in the ducts of salivary glands.

To aid in the examination of patients with trismus. To obtain information about the location, nature, extent, and

displacement of fractures of the mandible and maxilla To determine the medial and lateral extent of pathologies

(e.g., cysts, osteomyelitis, malignancies) and detect disease in the palate or floor of the mouth

Extra oral radiographs

Panoramic radiography (O.P.G) Lateral cephalometric projection True lateral skull P.N.S view P.A skull view P.A mandible Submento vertex Lat oblique Tmj imaging

Orthopantomography

A technique for producing a single tomographic image of the facial structures that includes both the maxillary and mandibular dental arches and their supporting structures.

pantomography is derived from two words – panorama and tomography

Ortho - straight Panoramic - An unobstructed or a complete view of the object in

every direction Tomography – An xray technique for making radiographs of layers of

tissue in depth, without the interference of tissue above and below that level

Principle

As the tubehead rotates around the patient, the x-ray beam passes through different parts of the jaws, producing multiple images that appear as one continuous image on the film (“panoramic view”).

Indications-

Evaluation of- Trauma Location of third molars Extensive dental or osseous disease Known or suspected large lesions Tooth development Retained teeth or root tips TMJ pain Dental anomalies etc.

Ext. Auditory meatus

Mandibular condyle

Articular eminence

Coronoid process

Zygomatic bone

Ptregomaxillary FissureInf. orbital rimFloor of Maxillary sinus

Ant. wall of Maxillary sinusHard palate

Nasal fossa

Inf. Orbital canal and foramen

Zyg. process of Maxilla

Lat. ptreg. plate

Man. fossa

Inf. border of Mandible

C- Spine

Mental foramen Hyoid bone Inf. Alveolar canalExt. oblique ridge

Hard Tissue

Advantages…

Broad anatomic coverage Low patient radiation dose Convenience of examination Used in patients unable to open mouth

Disadvantages

Does not show fine anatomic details Magnification Distortion Overlapped image of teeth Expensive

Lateral cephalometric projection

USES

• It helps in the classification of skeletal and dental abnormalities.

• Study of craniofacial growth

• Recognizing and evaluating changes brought about by orthodontic treatment

• Cephalometrics helps in predicting the growth related changes and changes associated with surgical treatment.

• Pathologic changes in the skull , jaws or cranial base can be observed.

Porion (P):most superior point of EAM

Sella(S): Centre of hypophyseal fossa

Nasion(N):Frontonasal suture

Orbitale(O): Most inferior point of IO rim

N S O

P

Lateral cephalogram-land marks

PT point: most posterior point of PM fissure

Basion(Ba):most antr point of F magnum

PNS: tip of Postr nasal spine

ANS: tip of Antr nasal spine

PTPNSBa

Lateral cephalogram

Point A: deepest point of antr border of maxillary alveolar ridge concavity

Point B: deepest point of antr border of mandibular alveolar ridge concavity

Pogonion(Po): most anterior point of symphysis

A

BPogonion

Lateral cephalogram

Gnathion(Gn): midpoint of symphysis outline between Po & M

Menton(M): Most inferior point of symphysis

Gonion(G): most convex point along the infr border of mand ramusGn

MG

Lateral cephalogram

TRACING

Cephalometric analysis

The major use of radiographic cephalometry is in characterizing the patient’s dental and skeletal relationships.

William. B. Downs developed the first cephalometric analysis. This was later followed by other analyses by Steiner (1952), Tweed

(1953), Ricketts (1958), Sassouni (1969), etc

True lateral skull

To survey skull and facial bone for trauma or pathology.Nasopharangeal soft tissue, paranasal sinus and hard

palate.Condition affecting sella turcica, such as tumour of pitutary

gland in acromegaly.

Indications

Submandibular sialolith

35

05/03/2023

PA WATERS (P.N.S),(0.M)PROJECTION

Occipito Mental 30° (OM30) View Standard occipitomental (0° OM)

39INDICATIONS

Fractures of the cranium and the cranial base Middle third facial fractures, to show possible downward and

backward displacement of the maxilla Investigation of the frontal, sphenoidal and maxillary sinuses Conditions affecting the skull vault,

Paget’s disease Multiple myeloma Hyperparathyroidism

Conditions affecting the sella turcica, Tumor of pituitary gland in acromegaly

Posteroanterior skull (PA) projection:

Asymmetry

This projection shows the skull vault, primarily the frontal bones and the jaws.

The beam passes through the skull in a posterior to anterior direction.

Purpose: Asymmetry , Developmental abnormalities ,fracture of the skull vault.

Conditions affecting the cranium, particularly:Paget's diseaseMultiple myelomaHyperparathyroidism

Postero-anterior of the jaws (PA jaws/PA mandible)

Indications Fractures of the mandible lesions such as cyst or tumor in post 1/3 of

body & in ramus of mandible. condylar hypoplasia or hyperplasia

Posteroanterior radiographic view of a fracture of the left body and angle.

• The PA view is used to evaluate the entire mandible. However, the symphysis is often obscured by the cervical spine, and the condyles can be superimposed over the mastoid process and occipital bone.

• A Waters view or a basal view should be obtained to better evaluate the symphysis to negate the overlap of the cervical spin.

44 Submentovertex (base) projection

45 indications

Help to s tudy dest ruct ive les ion affect ing the pa late , pterygo id reg ion or base o f the sku l l , spheno ida l s inus .

Fractures o f zygomat ic arches ( JUG HANDLE) .

Lateral oblique

Left angle fracture on a left oblique radiographic image

47

Lateral Oblique Views - Largely replaced by panoramic views

Indications:  Impacted third molars  fractures of the ramus, body,condyle coronoid of the mandible.

48

49 Transcranial View

50

Indications• Arthritic changes on the articular surface.• To evaluate the joint’s bony relationship.

• Closed view- size of joint space, position of head of condyle, shape & condition of glenoid fossa & articular eminence.

• Open view- range & type of movement Comparison of both sides

Disadvantages :Superimposition of ipsilateral petrous ridge over the condylar neck

51

Transpharyngeal view

52 Indications

• Fracture of condylar head and neck of the mandible

53 Transorbital /ZIMMER view

54 Indications

The anterior view of the temporomandibular joint Medial displacement of fractured condyle Fracture of neck of condyle. There is minimum superimposition.

55

Reverse-towne projection(open mouth)

56

INDICATIONS:

• Suspected fracture of the condylar neck.

• Intracapsular fracture of the TMJ

• Shows posterolateral wall of maxillary sinus

57 Drawbacks of extra oral techniques

Magnification occurs due to the greater object to film distance used.

Details are not well defined.Contrast is reduced as the secondary

radiation produced by the soft tissues is more.

It is a 2- D image of 3- D structure.

CONCLUSION Thorough knowledge of the indications

of various extra oral techniques allows accurate and timely diagnosis of various maxillofacial pathologies. Further, we can arrive at a diagnosis with minimum number of x-rays there by reducing patient exposure to radiation.

DR ANKIT GOEL, SUBHARTI.