A Review on Cone-Beam Computed Tomography and its Application in Dentistry

ABSTRACT

Cone-beam computed tomography (CBCT), which has benefits over traditional radiography in this age of cutting-edge technology, has become increasingly popular in oral radiology. The utilization of CBCT is experiencing significant growth in several dental specialties, mainly for diagnostic purposes and treatment planning. Image acquisition and 3D imaging have helped the clinical use of cone-beam technology. The equipment has a user-friendly interface, minimum image distortion, and images compatible with many planning and simulation software applications. The present literature review aims to discuss CBCT and its various applications in dentistry.

INTRODUCTION

CBCT has shifted the dental imaging paradigm from two-dimensional (2D) to three-dimensional (3D) for maxillofacial imaging. When diagnosing and treating oral and maxillofacial tumors, CBCT is quickly replacing conventional medical CT. Dentistry uses this imaging modality because it outperforms 2D and medical CT.[1]

In 1999, the first CBCT device sold for dental purposes was introduced in Europe. Several nations have started using CBCT for oral and maxillofacial imaging in the last ten years, but India has lagged behind because of the high cost of equipment. This technology is currently becoming more widespread across the nation’s dental clinics and diagnostic facilities. CBCT is used in orthodontics, airway studies, sleep disorders, Temporomandibular Joint (TMJ) issues, periodontics, endodontics, oral and maxillofacial surgery, and dental implantology.[2,3]

Basics of CBCT: A fan-shaped X-ray beam captures axial plane slices or spiral movements in traditional CT. Instead of slice-by-slice CT imaging, CBCT devices use a cone-shaped beam and a reciprocating solid-state flat panel detector to rotate 180–360 degrees around the patient to cover the required anatomical volume. This single scan (rotation) employs planned data (180-1024 2D images, identical to lateral cephalometric images, slightly offset) to reduce X-ray exposure by 6 to 15 times compared to CT.

Different manufacturers scan CBCT equipment in 5–40 seconds. A modified Feldkamp algorithm instantly reconstructs 2D images into the anatomical volume for 1:1 ratio viewing in the axial, coronal, and sagittal planes. It is easy to share and use with other imaging programs in Digital Imaging and Communications in Medicine (DICOM) format.[3]

Interpretation of CBCT: To make sure that no available diagnostic feature is overlooked when examining a CBCT scan, it is crucial to follow a systematic process. The imaging could be divided into multiple smaller portions depending on anatomical regions such as the maxilla and mandible, teeth, paranasal sinuses, TMJs, cervical spine, and skull base, among others, as an illustration of such an approach. The diagnostician should look for changes in the form, size, and density as well as any anomalies in the region of interest. In the axial section, structures may be seen from the most inferior slice to the most superior slice, and right and left can be compared. Additionally, decide whether the structure is pathogenic or anatomical. Coronal sections can be viewed from the most anterior to the posterior part, while sagittal sections can be viewed from one side to the other. On CBCT, lesions should be examined for the following characteristics: location, margin, form, internal structure, and effects on neighboring structures. After carefully assessing the aforementioned characteristics, the doctor must offer a radiographic diagnosis or differential diagnosis and decide on additional testing, a biopsy, extended observation, referral to another specialty, or therapy.[1]

APPLICATION OF CBCT IN DENTISTRY

CBCT in Endodontics: CBCT provides a comprehensive description of the tooth’s morphology, including the specific characteristics such as the quantity and arrangement of canals, the dimensions and level of calcification of the pulp chamber, the orientation and curvature of the root, the presence of fractures, any anomalies resulting from dental procedures, and the extent of dental decay. Identifying outcomes associated with periradicular and periapical illness encompasses assessing root resorption levels and the presence of periapical osteolysis characteristics.[4]

CBCT in Orthodontics: CBCT offers a three-dimensional evaluation of craniofacial anatomy, maxillary transverse dimensions, and alveolar border conditions. In craniofacial orthodontics, CBCT can assess skeletal and soft tissues in all directions, maxillary expansion, and cleft evaluation. CBCT can better visualize 2D imaging findings like panoramic radiographs. This helps the orthodontist assess pathology in three dimensions and its link to the teeth.[5]

CBCT in Periodontics: Comparing intraoral periapical radiography and CBCT for detecting intrabony defects has demonstrated that the latter is significantly more accurate. Images from a CBCT can help better visualize periodontal tissue morphology. CBCT also provides high accuracy for identifying the involvement of the furcation. This method is beneficial for more intrusive treatments.[1]

CBCT in Pediatric Dentistry: CBCT should only be used in pediatric patients when conventional radiography fails to offer significant information. CBCT pictures detect proximal carious lesions better than digital intraoral methods. CBCT should examine impacted supernumerary teeth to reduce danger to nearby anatomical tissues and cortical bone.[6]

CBCT for TMJ Imaging: CBCT is cheaper and safer than CT for TMJ evaluation. Assessing osseous TMJ problems is more advanced than older imaging techniques like radiography and MRI.[6]

CBCT in Oral and Maxillofacial Surgery: CBCT is routinely used to detect oral and maxillofacial cancers. Oral and maxillofacial fracture assessment and therapeutic planning prefer CBCT. It reduces the need for multiple 2D radiographs to find a similar thing. Benign jaw lesions have numerous radiological presentations. CBCT imaging determines the disease’s location, expansion, size, extent, and involvement of nearby vital structures.[1,2]

CBCT in Implantology: CBCT is best because oral implants only require localized radiation exposure to the oral and maxillofacial region. CBCT scans help plan oral implants by measuring the distance between the alveolar crest and mandibular canal to prevent inferior alveolar nerve impingement, posterior lingual undercut perforation, and bone quality and density. They help plan maxilla oral implants, focusing on the nasopalatine canal and maxillary sinus.[7]

CBCT in Forensic Dentistry: Age estimation is a crucial element within the field of forensic dentistry. The dental pulp, pulpo-dentinal complex, and cementum undergo physiological and pathological alterations. To quantify morphological changes, extraction and sectioning are usually needed. However, the feasibility of employing this method may be limited in certain cases. Nevertheless, CBCT presents a noninvasive alternative.[2]

Advantages and Disadvantages of CBCT are mentioned in Table 1.

Table 1.

Advantages and Disadvantages of CBCT[6,8,9]

Advantages	Disadvantages
Precision of images.	Poor soft tissue contrast.
The duration of scanning is characterized by a rapid pace.	Cost of the equipment.
The phenomenon of image artifact reduction.	Production of scattered radiation.
Concept of minimizing radiation exposure.
Concept of X-ray beam limiting refers to the process of restricting the size and shape of the
X-ray beam used in medical imaging.

Future Prospective of CBCT: The diagnostic efficacy of CBCT has been demonstrated to be significantly higher than that of other modalities in accurately detecting complex oral and maxillofacial disorders. Modifying beam form, focused spot size, detector efficiency, exposure, and image reconstruction settings may improve CBCT efficacy.

The integration of CBCT with modern optical scanners could improve treatment planning due to recent improvements in diagnosis accuracy. CBCT is useful for implant surgery because it provides 3D cross-sectional images of the jaws but cannot duplicate the surface features and occlusal morphology of teeth. The use of conventional impression materials may soon become obsolete as intraoral scanners capture digital impressions of the occlusal surfaces of teeth. To do this, a stone cast is first placed in an optical scanner and then transferred to a CBCT machine set up with the same parameters as those used for the patient’s scan. In the context of preparation for minimally invasive surgery, digital technologies play a crucial role in facilitating the clinician’s ability to accurately visualize the patient’s anatomical structures.[8]

CONCLUSION

CBCT and its 3D imaging technology help dentists overcome the limits of standard radiography. The limits of 2D imaging were overcome by CBCT imaging, which gave clinicians submillimeter resolution, great quality, fast scanning, and low radiation. The patient and dentist will benefit from replacing practice-based guess-estimates with this dental assistant. The potential for further applications is huge from dental procedure diagnostics to visual guidance.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.