Low-dose Cone-beam Computed Tomography for Assessment of Alveolar Clefts, a Randomized Controlled Trial in Image Quality

Radiographic imaging is an integral part of diagnostics, therapy planning and post-surgery assessment. Cone beam computed tomography (CBCT) was introduced in the late 90s and is now widely accepted. The technique utilizes a cone shaped X-ray beam to directly create a volumetric data, with predefined fields of view (FOV). CBCT provides 3D information with excellent spatial resolution, enabling assessment of anatomical variations and pathological changes in bone.

Cleft lip and palate disorder are among the most common birth defects, with the reported incidence in the Stockholm region of 1.7/1000 live births. The malformation can involve the lip, the alveolar process and the palate. When the alveolar process is involved CBCT can be indicated to assess the local anatomy prior to and after bone augmentation.

Minimizing the radiation dosage is especially important for children since the estimated risk for cancer formation or hereditable effects is approximately 3 times higher than for an adult aged 30.

Therefore the developments of low dose protocols within CBCT techniques are progressing rapidly. By applying more sensitive detector and a sophisticated image processing algorithm, the manufacturer Planmeca claimed that with Ultra Low Dose (ULD) protocol the effective patient dose may be reduced by up to 76%. A consequence of dramatically reduced exposure is the decreased signal-noise ratio, in other words reduced image quality, which results in increased diagnostic uncertainty of detailed structures. Since the accepted diagnostic image quality is highly associated with diagnostic tasks, clinical studies on evaluation new diagnostic feature are important.

HYPOTHESIS/RESEARCH QUESTION Will Promax 3D Mid CBCT with ULD normal dose protocol provide adequate information in order to assess necessary clinical questions in the region of the maxillary alveolar cleft compared to normal dose protocol?