By: Dr. Abhishek Kumar Pandey, Asstt. Editor-ICN

LUCKNOW: In the past, dental disease and lesions involving the jaw were either evaluated by plain radiography or tomography. The advent of spiral computed tomography (CT) and Denta Scan is changing the imaging trend.

Denta scan is a computed tomography (CT) software program that allows the mandible and maxilla to be imaged in three planes: axial, panoramic and cross-sectional. It is an interactive CT imaging software that combines the power and detail of CT imaging with the convenience of interacting with the images on a desktop.

As an adjunct for treatment planning before implant placement.Clinical success of dental implants is influenced by both the volume (quantity) and density (quality) of available bone. Bone quality and quantity varies from site to site and from patient to patient. After determining the appropriate cross-sectional images, one can measure the height and width of alveolar ridge and asses the bony contour and density in the desired region.

Dentascan offers not only excellent comprehensive assessment of bone morphology for implants but also aids in diagnosis of other pathologies related to oral cavity. Most masses within the oral cavity, both benign and malignant, are amenable to direct clinical examination. The primary purpose of imaging is to detect deep or sub mucosal extent and adjacent osseous involvement.

Bony erosion is better characterized by multi-planar CT Unlike standard pantomography; there is no super- imposition of other osseous structures in Dentascan. The image quality is sharp and clear, providing better tissue contrast resolution. Anatomic structures such as the inferior alveolar canal, mental foramen, mandibular foramen, buccal and lingual cortical margins, and the wall of the maxillary sinus can be clearly identified and evaluated. It is essential to evaluate the mandible in Dentascan in these cases as it affects patient management. On cross-sectional views in Dentascan, buccal and lingual cortical involvement is clearly identified. These views provide the surgeon with better pre- operative information in relation to the extent of resection.

Utility of Dentascan is not only confined to preoperative assessment of bone but it also find its usage in endodontology as extra canals are a common findings and missing these canals leads to endodontic treatment failure. Intra oral radiographs are a two dimensional imaging modality of a three dimensional structure. Hence, anatomy in the third dimension cannot be assessed on radiographs. Because root canals tend to lie one behind the other in buccolingual plane, they get superimposed onto each other on periapical panoramic radiographs and easily go undetected. Dental CT is reformatting software used along with spiral / helical CT and allows assessment in all three dimensions.

A dental scan can be prescribed as part of the evaluation before extracting mandibular wisdom teeth when a suspected proximity of the mandibular canal is seen on the initial x-rays (dental panorama and/or retroalveolar or occlusal negatives). This could lead to a more complicated surgery. The Dentascan allows the clinician to perfectly locate the tooth on the dental arch, together with its position and in relation to adjacent teeth. It guides the surgical approach by indicating the vestibular or lingual position of either the tooth or the bud. It gives the exact position of the mandibular canal with regards to the apexes.

Preparation made for Dentascan-

The examination is very simple and painless, and can easily be performed in a matter of minutes. Wear loose comfortable clothing without metal snaps or zippers, such as a cotton sweat suit. Do not wear any makeup jewellery Remove any dentures, wigs, hairpins and hearing aids. Notify the radiologist if the patient is pregnant or breastfeeding Patients who are allergic to iodine and shellfish should be medicated prior to the examinations.

The CT scan in addition with Dentascan reconstructions gives a very good performance that should not be limited to a pre-implant evaluation. There are several indications in general dentistry even if it should not replace classical radiographs: panoramic, retro-alveolar and occlusal x-rays. As CT is widely available, Dentascan can play a wider role in evaluating lesions of the mandible and maxilla. It provides valuable information in the assessment of oral cavity tumours (pre-and post-operative, post-radiotherapy); lesions of the jaw (benign and malignant, infection) and bony anatomy before and after implant surgery.