CBCT Interpretation & Radiographic Planning

01 — Indications & Anatomy

When 3D is justified and what to map

CBCT is not a routine substitute for 2D imaging. Under the justification principle, it is reserved for cases where conventional radiographs cannot answer the clinical question. When a scan is taken, systematically trace every vital structure in the field.

Decision

2D first-line

Periapical / panoramic for initial screening
Single anterior site, ample bone, low risk
Adequate width clinically and on 2D
No anatomical proximity concern

Decision

3D (CBCT) indicated

Cross-sectional dimension needed (true buccolingual width)
Proximity to IAN canal / mental foramen / sinus
Guided surgery or augmentation planning
2D findings equivocal or anatomy atypical

Map — Mandible

Mandibular structures

IAN canal — trace full course bilaterally
Mental foramen + anterior loop (may extend mesially)
Lingual / submandibular fossa concavity
Incisive canal continuation in anterior mandible

Map — Maxilla

Maxillary structures

Maxillary sinus floor, septa, membrane thickness
Incisive (nasopalatine) canal in anterior maxilla
Nasal floor and lateral nasal wall
Buccal plate thickness and concavities

02 — Decision Pathway

Interactive site-based interpretation selector

Select the planned site. Each pathway lists what to assess on the scan and the safety margins that govern implant length, diameter, and angulation.

Tap the implant site you are planning.

Step 1 — Where is the planned site?

POSTERIOR MANDIBLE

Premolar / molar mandible

IAN canal, mental foramen, lingual concavity dominate.

POSTERIOR MAXILLA

Premolar / molar maxilla

Sinus floor and residual height are limiting.

ANTERIOR MAXILLA

Esthetic anterior maxilla

Buccal plate, incisive canal, esthetic risk.

GENERAL

General checklist (any site)

Core read sequence for every scan.

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03 — Quick Reference

Minimum safety margins

Conservative working margins drawn from CBCT and consensus literature. Margins are minimums — increase them where measurement error, beam artefact, or planned drilling overshoot is a concern.

Relationship	Minimum margin	Note
Coronal to IAN canal	≥ 2 mm	Safety zone above superior cortex of canal; account for drill overshoot.
To adjacent tooth root	≥ 1.5–2 mm	Preserve periodontal ligament and interproximal bone.
Inter-implant (adjacent fixtures)	≥ 3 mm	At platform level; supports interproximal papilla/bone.
Buccal plate thickness	≥ 1–2 mm	≥2 mm preferred in esthetic zone to limit recession/loss.
To maxillary sinus floor	≥ 1–2 mm	Without lift; otherwise plan elevation. Avoid membrane perforation.
To mental foramen / anterior loop	≥ 2 mm	Identify anterior loop separately; it may extend mesial to the foramen.

Reference

Sources & clinical disclaimer

For licensed clinicians — educational use only. This algorithm summarizes published consensus and is not a substitute for individual clinical judgment, examination, or the standard of care in your jurisdiction. Imaging must follow the justification and ALARA principles; margins listed are conservative minimums and do not replace case-specific measurement on a calibrated scan.

SEDENTEXCT Project / European Commission. Radiation Protection No. 172: Cone Beam CT for Dental and Maxillofacial Radiology — Evidence-Based Guidelines. 2012. (Endorsed by EADMFR basic principles for CBCT use.)
Tyndall DA, Price JB, Tetradis S, et al. Position statement of the American Academy of Oral and Maxillofacial Radiology on selection criteria for the use of radiology in dental implantology with emphasis on cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012;113(6):817–826.
Bornstein MM, Scarfe WC, Vaughn VM, Jacobs R. Cone beam computed tomography in implant dentistry: a systematic review focusing on guidelines, indications, and radiation dose risks (ITI-related review). Int J Oral Maxillofac Implants. 2014;29(Suppl):55–77.

Last reviewed: June 2026 · Next review due: June 2027 · Version 1.0