The Bitewing Technique

Reference reading: Chapter 19

Show interproximal caries

Show pulp changes

Show overhangs

Display improperly fitting crowns

Shows recurrent caries beneath restorations

Show resorption of alveolar bone

Objectives for Bitewings:

Alveolar Bone

Contact Areas

Diagnostic Image

Caries on #30 D

Crestal Bone Height

Alveolar Bone Loss

Crown Margins

Overhanging Amalgam and Crown

Recurrent Caries #29 M

Pulp Stone

Is a method used to examine the inter-proximal surfaces of the teeth (where the explorer doesn’t reach).

Considered a method of preventive dentistry.

Is a radiographic exam that is used the most frequently in conjunction with dental exams and cleanings.

The Bitewing Technique

X-ray beams pass through teeth at a 90 degree angle, which creates a more accurate image of structures.

The use of paralleling technique creates the illusion of open contacts, giving the appearance that there are spaces between the teeth.◦ Appears radiolucent (BLACK)

Show the crowns of both upper and lower teeth, as well as the supporting alveolar bone, on a single film.

How it works:

Vertical Angulation

The film is placed in the mouth parallel to the crowns of both the upper and the lower teeth

The film is stabilized when the patient bites on the bite-wing tab or film holding device.

The central ray of the x-ray beam is directed through the contacts of the teeth, using vertical angulation of +10 degrees

Principles of Bite-wing Technique:

The Bite-wing tab: this is a sticky tab that is placed on the tube side of the film packet.

The patient bites directly on the tab, and therefore establishes a better image because the teeth are fully closed, and there is no bite-block interference.

The Bite-wing Tab

Bite-wing Tab

Film Holding Devices - Rinn Rinn XCP Bitewing

instrument:◦ Just like the Rinn for

periapical films, the Rinn bite-wing holder will position the film, stabilize it, and align the PID for a good diagnostic film.

Premolar view: ◦ angle the PID at +10 degrees vertically; ◦ horizontally aim toward center of film, between

the premolars and the occlusal plane◦ Center tab on 2nd premolar

Molar view: ◦ angle the PID at +10 degrees vertically,◦ horizontally aim at contacts of 1st and 2nd molars◦ Center tab on 2nd molar

Bite-Wing Radiograph Views

Posterior Teeth

Premolar Curvature

Premolar Placement and Image

Molar Area

Molar Placement and Image

Size 0 = pediatric patient with primary dentition

Size 1 = children with mixed dentition

Size 2 = teens and adult patients

Size 3 = horizontal bitewings only; not recommended due to overlapped contact results

Four sizes of film are used for BWX

Vertical Bite-wings Can be used to

examine the level of supporting bone in the mouth.

The bite-wing is placed in a vertical, up and down, direction.

Mainly used for periodontal patients.

A total of 7 projections are used to cover all areas.

Modified CMRS using Vertical Bite-wings

Image of Anterior Vertical Bitewing

The whole purpose of the bitewing examination is to see the interproximal areas of the teeth.

If horizontal angulation is incorrect, the contacts will be overlapped, and produce a film of poor diagnostic quality. To avoid overlap, direct the CR through the interproximal areas of the teeth.

If the vertical angulation is incorrect, the image will be distorted, and also of poor diagnostic quality

The importance of angulation:

Open Contacts: Desirable Image

Overlapping: non-diagnostic

Negative Angulation: non-diagnostic

Edentulous Areas◦ A cotton roll must be placed in the area of the

missing teeth to support the bite-wing tab.◦ Failure to support the BW tab results in a tipped

occlusal plane on the radiograph. Bony Growths (tori)

◦ Mandibular tori may cause a problem in film placement.

◦ The film must be placed between the tori and the tongue, not on the tori.

Modifications to the BW Technique

BEFORE PLACING FILM IN PATIENT’S MOUTH: Set exposure factors

◦ (kVp, mA, exposure time) Ask patient to remove all intraoral objects

and eyeglasses Check the oral anatomy

◦ Tori? Shallow or narrow palate? ◦ Limited opening?

Attempt to retract cheeks and tongue to gauge difficulty during film placement.

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