Absorbed doses from temporomandibular joint radiography.

Area of Science:

• Radiology
• Medical Physics
• Radiation Dosimetry

Background:

• Temporomandibular joint (TMJ) radiography is crucial for diagnosing joint disorders.
• Different radiographic techniques expose various head structures to ionizing radiation.
• Understanding radiation dose distribution is essential for patient safety in diagnostic imaging.

Purpose of the Study:

• To quantify and compare radiation doses absorbed by head structures during TMJ examination using four distinct radiographic techniques.
• To identify which radiographic technique delivers the highest radiation dose to specific critical organs.

Main Methods:

• Thermoluminescent dosimeters (TLDs) were employed within a tissue-equivalent phantom.
• Radiation doses were measured for transcranial, transorbital, sigmoid notch (Parma), and lateral tomograph projections.
• Doses were assessed for various head structures, including the lens, pituitary gland, bone marrow, and parotid gland.

Main Results:

• Radiation doses at the x-ray entry point varied significantly, from 112 mrad (transorbital) to 990 mrad (sigmoid notch).
• The transorbital projection was the only technique delivering a measurable dose to the eye lens.
• The lateral tomograph yielded the highest doses to the pituitary gland and bone marrow; the sigmoid notch produced the highest parotid gland dose.

Conclusions:

• Radiographic technique selection for TMJ imaging directly impacts radiation dose distribution to critical head structures.
• The sigmoid notch projection results in the highest overall radiation dose, particularly to the parotid gland.
• Minimizing radiation exposure requires careful consideration of the specific radiographic technique used for TMJ evaluation.