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

Abstract

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.

Do cone‐beam computed tomography low‐dose protocols affect the evaluation of the temporomandibular joint?

“…The European Commission states that bone alterations, such as those found in osteoarthritis and rheumatoid arthritis, can be detected on conventional radiographs and CBCT 19 . In the practice of dentistry, panoramic radiographs often provide essential diagnostic information of the maxillofacial region and may aid in confirming or ruling out odontogenic causes of disease or gross bony alterations 20 . However, because CBCT allows inspection of the TMJ in a multiplanar way without overlapping structures, it has higher levels of reliability, sensitivity and specificity than panoramic radiographs or specific protocols for TMJ radiographs available in panoramic machines 4 .…”

“…19 In the practice of dentistry, panoramic radiographs often provide essential diagnostic information of the maxillofacial region and may aid in confirming or ruling out odontogenic causes of disease or gross bony alterations. 20 However, because CBCT allows inspection of the TMJ in a multiplanar way without overlapping structures, it has higher levels of reliability, sensitivity and specificity than panoramic radiographs or specific protocols for TMJ radiographs available in panoramic machines. 4 In addition, CBCT provides higher spatial resolution and lower cost when compared with CT scans.…”

Análisis Morfológico del Cóndilo Mandibular por Tomografía Computarizada de Haz Cónico en Relación al Sexo en Población Mexicana

“…Esta herramienta de diagnóstico por imágenes brinda a los médicos nuevas oportunidades y responsabilidades para un mejor diagnóstico de las estructuras que se muestran en las imágenes CBCT incluida la ATM. Varios estudios recientes sugirieron que es una herramienta prometedora para diagnosticar afecciones óseas de la ATM (Iskanderani et al, 2020). El objetivo de la presente investigación fue determinar las diferencias morfológicas del cóndilo mandibular por tomografía computarizada de haz cónico en relación con el sexo de la muestra integrada por individuos de población mexicana.…”

Dosimetric evaluation for temporomandibular joint cone beam computed tomography exams using different field of view

“…TMJ structures, for example, have the advantage of presenting a relatively high contrast in CBCT scans. Thus, such examinations allow a reduction in radiation exposure without the need for a high-resolution image [14].…”

“…The radiation dose absorbed varies according to the examination type, x-ray device, clinical settings, and patient age [14]. Moreover, the scan mode, size, and position of fields of view (FOVs) significantly influence the radiation dose [15].…”