Skin Doses on the Lens for Temporomandibular Joint Exam in Cone Beam Computed Tomography

Oliveira, Marcus; Andrade, Marcos Ely Almeida; Batista, Wilson Otto; Campos, Paulo Sérgio Flores

doi:10.1590/s1516-89132015060233

Cited by 4 publications

(3 citation statements)

References 16 publications

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“…12 Several studies have measured doses absorbed during radiographic TMJ examinations by using thermoluminescent dosimeters (TLDs). [13][14][15][16][17] In organ dose measurements, TLDs are associated with limited spatial resolution; this is a disadvantage in situations with steep dose gradients. 18 Gafchromic film has been suggested as a more feasible tool for radiation measurements, 12,19,20 but only 1 report has described the use of Gafchromic film in TMJ dosimetry.…”

Section: Statement Of Clinical Relevancementioning

confidence: 99%

Dose distributions in adult and child head phantoms for panoramic and cone beam computed tomography imaging of the temporomandibular joint

Iskanderani

Nilsson

Alstergren

et al. 2020

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology

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Objectives. The aim of this study was to map and compare the distributions of absorbed doses with Gafchromic film for panoramic radiography and cone beam computed tomography (CBCT) examinations of the temporomandibular joint (TMJ) by using adult and child phantoms. Study Design. Gafchromic films were placed at 5 selected levels of anthropomorphic head phantoms of an adult and a child. Clinical protocols for panoramic and CBCT imaging of the TMJ were used for three 2-dimensional or 3-dimensional dental x-ray units. Mean absorbed doses in a set of radiosensitive tissues within the oral and maxillofacial regions were estimated. Results. The absorbed doses varied considerably among and within radiosensitive tissues. The bone surface and the salivary glands received the highest absorbed doses compared with other tissues, in both panoramic and CBCT examinations of the TMJ. The radiation burden to the adult phantom was generally higher than that to the child phantom. Small right and left fields of view were associated with lower amounts of radiation, in contrast to a single larger field of view. Conclusions. The absorbed dose within all radiosensitive tissues varied considerably in relation to examination type, x-ray unit, clinical settings, and patient age. The mean doses were smaller when using 2 (bilateral) 4 £ 4 cm volumes than with use of one 14 £ 5 cm volume.

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Section: Statement Of Clinical Relevancementioning

confidence: 99%

Dose distributions in adult and child head phantoms for panoramic and cone beam computed tomography imaging of the temporomandibular joint

Iskanderani

Nilsson

Alstergren

et al. 2020

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology

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show abstract

“…Alternatively, another study showed that the doses absorbed by the lens of the eye were not reduced when a limited FOV for the TMJ was used. These authors also used different devices (CS 9000, Gendex GXCB 500 and i-CAT classic) to obtain different FOVs (16). Comparing the results obtained with different CBCT units creates a bias because factors that differ from one unit to the other, such as energy parameters, may affect the radiation dose.…”

Section: Discussionmentioning

confidence: 99%

“…However, it is unclear whether the use of a smaller FOV reduces radiation dose to patient, since two exposures would be necessary to scan both TMJs. A direct comparison of doses delivered by different FOV sizes for assessment of bilateral structures has not been performed yet, since previous studies compared doses delivered for TMJ exams produced by different devices (15,16). That drawback was secondary to the use of equipment without large FOV settings; since the devices operated with different energy factors, therefore it is not precise to attribute any dose variation to FOV size alone.…”

Section: Introductionmentioning

confidence: 99%

Dosimetry in CBCT with Different Protocols: Emphasis on Small FOVs Including Exams for TMJ

Nascimento

Andrade

Frazão³

et al. 2017

Braz. Dent. J.

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This study aimed to estimate the absorbed dose in cone beam computed tomography (CBCT) exams according to different exposure parameters and size and position of the field of view (FOV). In addition was compared the absorbed dose of two smaller FOV scans with that of a larger FOV scan for evaluation of temporomandibular joint (TMJ), as it is a bilateral structure. CBCT scans were obtained on OP300 Maxio unit varying scanning mode (standard, high and endo) as well as size (5x5, 6x8 and 8x15 cm) and positioning of FOV. With a small FOV, different areas were scanned (maxilla or mandible, anterior or posterior and TMJ). Absorbed doses were determined using thermoluminescent dosimeters on the skin surface of sensitive organs of an anthropomorphic phantom. Endo mode showed the highest dose, followed by the high and standard modes in all FOV positions. With small FOV, doses were higher in the posterior region, especially in the mandible. Dose reduction occurred when small FOVs were used, but it was not proportional to FOV size reduction. For TMJ, the dose in a single acquisition with large FOV was greater than two acquisitions with small FOV, but lower than two acquisitions with medium FOV (6x8 cm). In conclusion, scanning mode, size and FOV position have great influence on the absorbed dose. Small FOV decreases the dose, but there is no linear relation between FOV size and dose. For bilateral exams of TMJ, double acquisition with small FOVs produces decrease in absorbed dose relative to a large FOV.

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Association between condylar position and vertical skeletal craniofacial morphology: A cone beam computed tomography study

Paknahad

Shahidi

2017

International Orthodontics

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Skin Doses on the Lens for Temporomandibular Joint Exam in Cone Beam Computed Tomography

Abstract: The aim of this study was to evaluate the kerma at the surface of the lens in TMJ CBCT

Cited by 4 publications

References 16 publications

Dose distributions in adult and child head phantoms for panoramic and cone beam computed tomography imaging of the temporomandibular joint

Dose distributions in adult and child head phantoms for panoramic and cone beam computed tomography imaging of the temporomandibular joint

Dosimetry in CBCT with Different Protocols: Emphasis on Small FOVs Including Exams for TMJ

Association between condylar position and vertical skeletal craniofacial morphology: A cone beam computed tomography study

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