Dental CBCT Field of View: Selecting the Appropriate Scan Volume

A concise clinical guide to selecting the appropriate CBCT field of view for the diagnostic question.

Dr. Anna Liakh, DMD, Oral and Maxillofacial Radiologist at Insight Dental Radiology

Nov 11, 2026

3 min

Field of view (FOV) selection in dental CBCT should be driven by the clinical indication. The objective is to select the smallest volume that adequately includes the anatomy required for diagnosis and treatment planning, rather than simply the smallest volume available on the CBCT system.

What Is Field of View?

Field of view (FOV) is the three-dimensional anatomical volume included in a CBCT acquisition.

FOV should not be confused with spatial resolution or overall image quality, which depend on additional acquisition and reconstruction factors.

Think of FOV as a box. The box must be large enough and positioned correctly to capture all the anatomy relevant to the diagnostic question.

Small, Medium, and Large FOVs

FOVs are commonly described in three general categories based on anatomical coverage:

General CBCT Field of View Categories and Common Clinical Applications
FOV	Typical Coverage	Common Applications
Small or limited	1-3 teeth and surrounding dentoalveolar structures	Endodontics, localized pathology, single implant site assessment
Medium	A single dental arch, both arches, or a larger region of the jaws	Multiple implant sites, impacted teeth, pathology involving a larger region of the jaws
Large	Extensive maxillofacial or craniofacial anatomy	Orthodontic and craniofacial assessment, bilateral TMJ evaluation, extensive pathology and trauma cases

Available FOV dimensions vary among CBCT systems. Small, medium, and large are descriptive categories rather than standardized sizes.

Limiting the FOV to the anatomy necessary for the diagnostic task is an important measure for reducing unnecessary radiation exposure, although the actual dose also depends on the CBCT system and acquisition protocol.

Match the FOV to the Clinical Question

Both the size and positioning of the FOV determine whether the required anatomy is adequately captured. Proper patient positioning is essential to avoid excluding relevant structures and potentially requiring repeat imaging.

Endodontics

For endodontic CBCT, a limited FOV centered on the tooth or teeth of interest is generally preferred. The volume should include the entire tooth, periapical region, and adjacent anatomical structures relevant to the diagnostic question.

Implant Planning

The FOV should include the proposed implant site and adjacent anatomical structures relevant to treatment planning, such as the mandibular canal, mental foramen, maxillary sinus, nasal cavity, and neighboring teeth.

When CBCT is used for guided implant surgery, sufficient anatomical landmarks should also be captured to support accurate registration with intraoral scans.

Impacted Teeth

The FOV should include the entire impacted tooth, adjacent teeth, and relevant anatomical structures. Adequate coverage is needed to assess tooth position, orientation, root morphology, and proximity to structures such as the mandibular canal, maxillary sinus, or nasopalatine canal, as applicable.

TMJ, Orthodontic, and Craniofacial Assessment

Orthodontic and craniofacial assessment may require a larger FOV to evaluate relevant skeletal relationships. For TMJ imaging, both joints should be evaluated, either within a single FOV or through separate acquisitions, depending on the clinical indication and available imaging protocols.

The selected volume should provide adequate coverage without unnecessarily including additional anatomy.

Pathology and Trauma

The FOV should encompass the entire abnormality or injured region and sufficient surrounding anatomy to assess its extent and relationship to adjacent structures. Including the contralateral side may be helpful when comparison with unaffected anatomy is relevant to the diagnostic assessment.

Avoid an Overly Restricted FOV

An overly restricted FOV may exclude part of a lesion, omit critical anatomical structures, or prevent accurate assessment of the extent of an abnormality. When the boundaries of a lesion or its relationship to adjacent structures cannot be fully evaluated within the acquired volume, additional imaging may be necessary.

Remember the Entire Volume Must Be Interpreted

Regardless of the selected FOV, the entire acquired CBCT volume must be systematically interpreted, not just the region of clinical interest. Larger volumes include additional anatomical structures and increase the potential for incidental findings that may require further evaluation.

Selected References:

FAQ

Does FOV size affect radiation dose?

Yes. A smaller FOV generally exposes a smaller volume of tissue to radiation and can reduce patient dose. Patient dose from CBCT depends on the FOV, CBCT system, and acquisition parameters, including kVp, mA, and exposure time. Approximate dose ranges for small, medium, and large volumes are presented in the dental radiation dose chart.

Is the region of interest the same as the field of view?

No. The region of interest is the specific anatomy or abnormality being evaluated, while the FOV is the entire anatomical volume acquired during the CBCT examination.

Does a larger FOV increase the likelihood of incidental findings?

Yes. Incidental findings are generally reported more frequently in larger FOV scans because more anatomical structures are included. Their prevalence also tends to increase with patient age. Some findings may require further evaluation, referral, or treatment.