Recent advances in imaging technologies in dentistry

Abstract

Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools, specially imaging methods, have become mandatory. From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation (brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry.

Keywords: Cephalogram; Dental X-rays; Dental cone beam computed tomography; Intraoral X-rays; Panoramic radiograph.

Figure 1

X-ray. A: An intraoral periapical X-ray helps to view the number and morphology of roots and root canals, periapical status and alveolar bone support interdentally. In this case, a grossly carious lower molar with diffuse radiolucency around both the root apices, denoting a chronic abscess is seen; B: An occlusal view of maxilla is useful to evaluate suture line of maxillary processes and extent of large pathological lesion such as a cyst and for location of impacted teeth. In this X-ray an impacted left maxillary canine can be seen; C: A bitewing X-ray is useful to examine a segment of upper and lower arch simultaneously to detect inter-proximal caries. In this X-ray, distal proximal surface of the lower 1st molar shows a carious defect; D: A panoramic radiograph gives a bird‘s-eye view of upper and lower jaws with excellent view of temporo-mandibular joint and maxillary sinuses. In this X-ray, a large, multi-locular cystic lesion, involving an impacted and inverted 3rd molar, extending up to the premolar region can be seen.

Figure 2

Cephalometric radiographs show the entire side of the head and help to evaluate the spatial relationships between cranial and dental structures. A: A lateral cephalometric X-ray is useful to determine cranio-facial structures and their relationship with position of the jaws and teeth; B: Different landmarks used to evaluate the planes and angles formed, to arrive at a diagnosis and treatment planning for orthodontic treatment/orthognathic surgery. Serial cephalograms can give the amount and direction of growth of facio-maxillary complex.

Figure 3

Cone beam computed tomography. A: A cone beam computed tomography scan gives a three-dimensional view of the area of interest. In this case, the periapical lesion is being evaluated; B: The image gives values in Hounsfield unit of cementum and alveolar bone density to measure post-treatment healing. CBCT: Cone beam computed tomography.