EXTRAORAL PERIAPICAL RADIOGRAPHY : A TECHNIQUE

UNVEILED

STUDY

• Michael E. Newman and Seymour Friedman first proposed in 2003 in patients having complication to films and sensor in endodontic therapy.

Journal of Endodontic volume:29 issue:6 June 2003

• An Aiming Device for an ExtraoralRadiographic Technique - Chia-Hui Chen

Journal of Endodontics—Volume 33, Number 6, June 2007

• Extraoral Periapical Radiology-A Technique Unvieled – S Reddy and A Kaushik

JIAOMR , JULY –SEPTEMBER 2011 S NO: 336-339

• Extraoral periapical radiography: an alternative approach to intraoral periapicalradiography - R Kumar, N khambete and E Priya

US national Library of Medicine NCBI december 2011 volume 41(4)

Extraoral periapical radiography is a technique where the film is placed extraorally overlying the tooth of interest and the x-ray beam is directed from the opposite side of the face.

• Intraoral radiograph serves as valuable diagnostic tool in dental disease’s such as caries , periodontal disease , periapical disease etc .

• For the patients with severe gag reflex, paediatric dental patients, patients with restricted mouth opening IOPAR cannot be done with great result.

POSSIBLE INDICATION FOR EOPAR

• Exaggerated Gag reflex

• Shallow palate

• Developmental anomalies of floor of the mouth

• Maxillary and Mandibular tori

• Painful mucosal conditions

> Ulcer

> Infection and intraoral diseases

• Endodontics procedure

• Ridge resorption in edentulous patients

• Pediatric patients

• Impacted third molars

• Patients with low pain threshold

• Differently abled patients

• Dental phobia patients

MATERIALS AND METHOD

The aiming devices consist of :

1. Two locator rings

2. Two straight metal supporting indicator

3. A bite block

4. A rubber tube or acrylic splint of 2 mm

A: locator rings

B: Metallic rod

C: Bite block

D: Rubber tube

COMPONENTS OF THE AIMING DEVICES

ASSEMBELING THE AIMING DEVICE

• The two metal indicator rods are inserted into two locator rings .

• The bite block is attached on one end and the film/PSP sensor is placed firmly into slot of the bite block with exposing surface directed into the cone

• The two indicator rods are connected together using the rubber tube or acrylic splint.

PARAMETERS FOR PREMOLAR AND MOLARS

• Radiographic film or sensor on the bite block is placed parallel to premolars and molars such that the tooth of interest must come in centre of film or sensor

• The central ray is projected such that the beam is diverted through the opposite side buccal soft tissue without opposing the crown of opposite side teeth.

• Angulations is made -20 to -30 degree for maxillary teeth and -10 to -15 degree for mandibular teeth.

Film / sensor placed Parallel to the maxillary tooth.

The centre ray beam

The EOPAR parameters for maxillary teeth

The EOPAR parameters for mandibular teeth

Film / sensor placed Parallel to the mandibular tooth

The centre ray beam

CASE REPORTS

Chia-Hui Chen

• Using extraoral technique took images of 12 volunteers aged between 26 to 65 years

• Volunteers were asked to firmly hold the aiming device with angulation of -20 to -30 degree for upper teeth and -10 to -15 degree for lower teeth

• Standard intraoral sensor ( 30 x 40 mm ) was used

• X- ray source 7mA 60 KV was used

• Exposure time of 0.5 sec for the lower teeth and 1.0 sec for upper teeth.

(A) Taking an image of the right lower third molar area using theextraoral radiographic technique under the guidance of the aiming device

(B)The resultant image shows the right lower second molar. No third molar is noted, but the alveolar canal can be seen (arrow)

Journal of Endodontics—Volume 33, Number 6, June 2007

A) Taking radiograph of left upper third molar

B) The resultant image shows third and second left upper molar with implantPlacement mesial to second molar.

Journal of Endodontics—Volume 33, Number 6, June 2007

Application in the patient with limited mouth opening

• Age – 35/ male

• Chief complaint – Pain and swelling in maxillary left posterior region

• Examination – Masseteric space abscess secondary to carious maxillary left first and second molar

- Restricted mouth opening 25mm.

A) Intraoral radiograph and B) Radiograph taken by extraoralmethod was found to have adequate diagnostic value.

US National Library of Medicine NCBI December 2011 volume 41(4)

Application in pediatric patients :

• Age – 7 yrs/ male

• Chief complaint – Severe pain in maxillary deciduous second molar region

• Examination – Deciduous maxillary second molar was grossly carious

Patient was highly reluctant to intraoral sensor Hence ; EOPAR technique was used

Angulation -20 degree

Exposure time 0.35-0.40 second

The radiograph provided the essential diagnostic details of the deep carious lesion extending into bifurcation, and it was decided to extract the tooth followed by placement of a space maintainer.

US National Library of Medicine NCBI December 2011 volume 41(4)

• Even though conventional intraoral radiography has been used widely in dental field, sometimes there are problems in taking the radiographs in pediatric patients, disabled patients, obtaining third molar radiographs, and obtaining radiographs in endodontics.

• Extraoral radiography technique is not intended as a substitute for conventional intraoral radiography but it can be used as a supplement.