radiographic techniques dr samy i al-agha a.professor of radiology al-azhar –gaza univercity

RADIOGRAPHIC TECHNIQUES

DR SAMY I AL-AGHAA.PROFESSOR OF RADIOLOGYAL-AZHAR –GAZA UNIVERCITY

RADIOGRAPHIC TECHNIQUES

CLASSIFICATION A-Periapical

B-Bite-wing

C-Occlusal

PERIAPICAL RADIOGRAPHIC TECHNIQUES

1-BISECTING ANGLE TECNIQUEA-Patient,s positionFor maxillary teeth>>>ala tragus line is parallel

to floorFor mandibular teeth>>>line from tragus to

corner of mouth is parallel to floor


B-Film placement:Tube side of the film packetis towards the tube.The film(short dimension) is parallel to occlusal

plane(For anterior region)The film (long dimension) is parallel to occlusal

plane(For posterior region)Avoid over-bending of film packetThe area of interest is in the center of film.


2-3mm of film packet should be left beyond the occlusal plane

The patient holds the packet with fingerAvoid movements of patient,film,or cone during

exposure.C-Cone,s position: 1-Central ray(C.R)angulation a-V.A b-H.A 2-Point of entry


Vertical angulationDenotes the angle between C.R&occlusal

planeVertical angle of maxillary teeth(+ve) Incisors>>>>>>55-60 Canines>>>>>>45-50 Premolars>>>>35-40 Molars>>>>>>25-30


V.A for mandibular teeth(-ve) Incisors>>>>>>15-20 Canines>>>>>>10-15 Premolars>>>>5-10 Molars>>>>>>0-5 Increase V.A 5 in a-shallow palate or floor of

mouth b-flat ridges(edentulous pt) c-inclined teeth


Decrease V.A 5 in case a-high palate b-deep floor of mouth

Horizontal angulationIt is the angle between CR&mid-sagittal planeIt control width(dimention of tooth)CR must project through interproximal

surfaces of examined teeth


H.A Incisor>>>>>zero Canines>>>>45-60 Premolars>>>60-70 Molars>>>>>>90Point of entryThe cone is positioned so that CR is directed

to apices of the teeth


For maxillary teeth>>>points of entry are located on ALA TRAGUS LINE

Incisors>>>>>tip of the nose Canines>>>>>0.2cm distal to ala of nose Premolars>>>vertical line from eye pupil to

ala tragus line 1st Molar>>>>vertical line from outer canthus to ala tragus line


2nd Molar>>>vertical line from 1cm distal of outer canthus to ala tragus line

3rd Molar>>>>vertical line from 2cm distal of outer canthus to ala tragus line

For mandibular teeth >>>the same as for maxillary teeth but located on a line 0.5cmabove inferior border of the mandible

Time of exposure depends on area of rediographed,KV,mA, film speed&age of Pt


Advantages of bisecting angle technique1-Easy,quick &comfortable2-Used in all patients3-short object-source distance>decrese exp time4-periapical area can be demonstrated5-Speed techniqueDisadvantages: 1-Not standerdized 2-error of

angulation>>>superimpositionof structures over the area of interest


2-The paralleling technique(long cone tech) or Right angle technique

C.R is perpendicular to both film &toothThe film is placed in mid of oral cavity to get

parallism between tooth&film>>>image magnification&unsharpness.

Target-object distance is increased to avoid unsharpness(16 inches)>>>increase KV,mA,s and fast film(increase exposure time 4times)

Film holders are used.


FILM HOLDERS: 1-Rinn instrument 2-Bite block3-hemostat 4-Cotton rolls5-Precision rectangular collimating instrumentAdvantages of film holders1-Provide parallism 2-Avoid exposure to Pt fingDisadvantages1-Closure of mouth before exposure2-Cannot examin the periapical structures3-Limited in small mouths or gagging sesation


ADVANTAGES OF PARALLELING TECHNIQUE1-Standerdized>>>used in research2-Accurate images3-Avoids superimposition on apices4-H.A&V.A detrmined by positioning devices5-No overbending of films


DISADVANTAGES OF PARALLELING TECHNIQUE1-Difficult to image all parts of the mouth2-Increased exposure time3-Need long cones &film holders4-Cannot image apical area in shallow palate5-Discomfort of film holder6-Time consuming

BITE-WING TECHNIQUE

Used mainly for posterior teeth.The wing is on the tube side of film backet.Film backet is parallel to long axis of coronal

portion of upper &lower teeth.CR is perpendicular to center of film

BITE-WING TECHNIQUE

TECHNIQUEMSP is perpendicular to floor&ala tragus line is

parallel to floorRemove any metallic objects.Patient should close mouth during exposure.For premolar teeth >>>the film bite should be

centered over the lower 2nd premolar &anterior border of the film extends anteriorly beyond the lower canine and 1st premolar.

BITE-WING TECHNIQUE

For molar teeth>>>the posterior border of film is behind the distal surface of most posteriorly erupted molar &the film bite is centered over the lower molar teeth.

The patient should close his mouth in centric occlusion when radiography of posterior teeth

In edentulous patient replace missing teeth by cotton rolls

BITE-WING TECHNIQUE

In anterior bitewing film we shoul use1-smaller film size2-short dimension is parallel to occlusal plane3-patient closes his mouth in edge to edge

position4-longer wing to avoid bending of film

BITE-WING TECHNIQUE

CONE POSITIONCR IS PERPENDICULAR to film packet.+ve 5 for premolar &10 for molar(short cone)+ve 6 for premolar &8 for molar (long cone)For posterior teeth use 2 filmsFor anterior teeth use 3 films

PANORAMIC RADIOGRAPHY

Produces radiographs for only one section (slice) of the patient.

Patient is placed so that dental arches are located in the middle of focal plane.

Patient places edges of incissors in bite block device.

MSP in midline position.Patient,s occlusal plane is lowered 20-30

degrees below horizontal plane.


Patient,s back is in erect position with extended neck.

Patient should hold tongue in contact with hard palate &keep lips closed during exposure

Patient,s breathing is shallow during exposure


INDICATIONS1-Evaluation of truama &3rd molars.2-Evaluation of teeth development.3-Evalution of developmental anomaly.4-Examination of maxillary sinuses.


ADVANTAGES:1.Imaging broad anatomic region.2.Relative low radiation dose.3.Convenient,easy &speedy.DISADVANTAGES:1.Fine anatomic details are not demonstrated.2.Magnification,geometric

distortion&overlapping of teeth.3.High cost.

EXTRA-ORAL TECHNIQUES

1-Lateral views: a-True lateral b-Lateral oblique2-PA views: a-True PA b-Sinus(Water,s view) c-Reversed Town,s view3-AP views: a-True AP b-Modified Town,s

c-SMV d-Frontal TMJ(transorbital)

LATERAL VIEW

LATERAL OBLIQUE

TRUE PA

TRUE PA FOR MANDIBLE

AP SKULL FOR TMJ

SINUS(WATER,S)VIEW

REVERSE TOWN VIEW

TOWN VIEW

SMV VIEW

PANORAMA

radiographic techniques dr samy i al-agha a.professor of radiology al-azhar –gaza univercity

Documents

ala tragus line slide

floor slide

periapical area

film speedage of pt

point of entry slide

periapical bbite

ala tragus line incisorstip

wing cocclusal slide