This page is for dentists, specialists, lab technicians and students who work on a Mac and need to open a CBCT scan, panoramic or intraoral X-ray that arrived as DICOM files. Many dental imaging suites and the popular Windows viewers do not run on macOS, so the question comes up every time a disc or USB stick lands on a Mac desk.
The short answer: install Horos or Weasis. Both are free, open source and native on Apple Silicon and Intel Macs, and both build a panoramic-style view with cross-sections from a CBCT. Choose Weasis if your practice also has Windows or Linux computers, and Horos if you want STL export from a Mac-only setup. If the scan came from a Planmeca unit, the free Planmeca Romexis Viewer has a macOS version too. None of these is a certified diagnostic system; use them for review, referral, teaching and research.
The short list
| Program | Best for | Licence | Mac support | Status |
|---|---|---|---|---|
| Horos | Mac-only practices: CBCT review, curved MPR, STL export | Free, open source (LGPL 3.0) | macOS only; Apple Silicon (4.0.1) and Intel builds | Maintained, infrequent releases |
| Weasis | Any-vendor CBCT and X-rays, PACS, mixed Mac/PC teams | Free, open source (EPL 2.0 / Apache 2.0) | macOS 12+ on Apple Silicon, macOS 11+ on Intel | Active (4.7.3, August 2026) |
| Planmeca Romexis Viewer | Scans exported from Planmeca Romexis | Free (proprietary) | macOS and Windows versions in one package | Active (6.4.8) |
| VolView | 3D viewing with nothing to install | Free, open source (Apache 2.0) | Runs in Safari, Chrome, Edge or Firefox | Active (4.5.1) |
| 3D Slicer | Automatic tooth and jaw segmentation, STL models | Free, open source (BSD-style) | macOS 14+, Intel and Apple Silicon | Active (5.12.4) |
| InVesalius | Simple CBCT-to-STL conversion | Free, open source (GPL v2) | Intel and Apple Silicon builds | Last stable 2022, nightly builds since |
Horos
Horos is the best-known free DICOM viewer for Mac. It is a community fork of the OsiriX code, licensed under LGPL 3.0, and runs only on macOS. Drag a CBCT folder into its database, open the series and you have window/level, length, angle and area tools, oblique MPR and 3D rendering. Its curved MPR lets you trace the arch on an axial slice and read a straightened, panoramic-style reformation with cross-sections. It can export a rendered surface as STL, OBJ or VRML, query a PACS and burn studies to disc. Use the 4.0.1 build on Apple Silicon Macs and the Intel build on older ones. Limits: releases are infrequent, there is no FDA or CE claim, and the project warns against keeping the Horos database in iCloud.
Weasis
Weasis is the choice when a practice mixes Macs and PCs, because the same free viewer runs on macOS, Windows and Linux. On the Mac, install the PKG that matches your processor or use brew install --cask weasis; current builds bundle their own Java. It opens compressed DICOM (JPEG, JPEG-LS, JPEG 2000, JPEG-XL), DICOMDIR discs and ZIP archives, and its curved MPR is documented for tracing the dental arch on a CBCT. PACS query/retrieve, DICOMweb and export to a disc image with the viewer embedded make it useful for referrals. Development is active, with several releases a year. Limits: no STL export of 3D models, no implant planning, and the open-source build is not a certified medical device (CE or FDA).
Planmeca Romexis Viewer for Mac
Yes, there is a Romexis Viewer for Mac. Planmeca Romexis Viewer is free and the current public package, 6.4.8, contains both the macOS and Windows versions. It does not need to be installed: unpack it, keep the viewer in the same folder as the exported images and start the Mac version. If macOS blocks the first launch, Control-click the app and choose Open, or allow it in System Settings, Privacy & Security. You get slices with a 3D view, a panoramic layout along a curve over the arch, cross-sections with a nerve canal tool, and measurements. Limits: Planmeca positions it for Planmeca 2D and 3D images, the package is close to 0.9 GB, and it has no implant planning. For scans from other manufacturers, use Horos or Weasis.
VolView: nothing to install
VolView from Kitware runs in the browser, so it works on any Mac, and also on an iPad. Open it in a current Safari, Chrome, Edge or Firefox, drag the DICOM folder onto the page and you get slices plus a cinematic 3D rendering. Kitware states that data you load is processed locally and never leaves your machine. Rulers, labelled annotations and saved .volview.zip sessions make it handy for case discussions and for showing patients a scan. Limits: Kitware states it is not FDA approved for any purpose, it has no panoramic curve or nerve tracing, and the documentation does not describe STL export. Drag in the DICOM folder itself, not the whole disc with its bundled Windows viewer.
3D Slicer with dental extensions
3D Slicer is not a day-to-day viewer but a research platform, and it runs natively on macOS 14 Sonoma or later on both Intel and Apple Silicon. Install the DentalSegmentator extension from the Extension Manager and it segments the maxilla, mandible, upper and lower teeth and the mandibular canal from a CBCT automatically, then exports STL. On a Mac without an NVIDIA GPU, expect the AI step to be slow, and check every result slice by slice. The interface takes a few hours to learn. Limits: the project states that Slicer is not approved for clinical use, and the core application has no implant planning or guide design. Pick it for models, teaching and research.
InVesalius
InVesalius, from Brazil’s CTI Renato Archer, is the simplest free route from a CBCT to an STL file on a Mac. The 3.1.99998 release has separate Intel and Apple Silicon builds; if Gatekeeper blocks the first launch, right-click the app and choose Open. Import the DICOM folder, start from the Bone or Enamel threshold preset, keep the largest connected region and export STL for cleanup in a mesh editor. Limits: the last stable release dates from April 2022, with newer code only in nightly builds; CBCT grey values are not calibrated like CT, so thresholds need manual adjustment; and there is no automatic tooth segmentation. Pick it for printed demonstration models and teaching.
What about OsiriX and RadiAnt?
OsiriX is the commercial Mac viewer from Pixmeo that Horos was forked from. OsiriX MD is a paid product; Pixmeo states that it is FDA cleared as a Class II medical device and complies with the European medical device directive as a Class IIa product. OsiriX Lite is its demo version, so it counts as shareware (conditionally free). Pixmeo’s FAQ says Lite has limited features and opens only about 800 images at a time (512×512 matrix), and the Lite download page states that it is not certified as a medical device for primary diagnosis. OsiriX runs only on macOS.
RadiAnt DICOM Viewer is Windows only. Medixant does not offer a Mac version; it describes an unsupported workaround with CrossOver and warns that some features may fail. It is also shareware (conditionally free). On a Mac, Horos or Weasis does the same job natively and for free.
How to choose
- Is it a Planmeca export with the viewer included? Start the Mac version of Romexis Viewer from that folder.
- Everything else, Mac-only practice: Horos, especially if you want STL export.
- Macs and PCs in the same clinic, or a PACS: Weasis on every computer, so staff learn one tool. See Weasis vs Horos for a task-by-task comparison.
- A borrowed Mac, an iPad, or no admin rights: VolView in the browser.
- You need a 3D model: InVesalius for a quick STL, 3D Slicer for automatic segmentation.
- Implant planning: none of these does it; see free dental implant planning software. For the wider picture, see free dental imaging software.
FAQ
What is the best free DICOM viewer for Mac?
Horos for Mac-only practices and Weasis for clinics that also use Windows or Linux. Both are free, open source and native on Apple Silicon.
Is the Horos DICOM viewer for Mac free?
Yes. Horos is free and open source under LGPL 3.0. The project accepts donations, but you do not have to donate to use it. Paid training and a detailed user guide are optional services from its sponsor, Purview.
Is there a Romexis Viewer for Mac?
Yes. Planmeca’s free viewer package includes a macOS version alongside the Windows one. Keep it in the same folder as the exported images.
Does Weasis work on Mac?
Yes. There are separate packages for Apple Silicon (macOS 12 or later) and Intel Macs (macOS 11 or later), and it installs with Homebrew as well.
Is there RadiAnt DICOM Viewer for Mac?
No. RadiAnt runs only on Windows. Medixant describes an unsupported CrossOver workaround, but Horos or Weasis is the simpler answer on a Mac.
Can a Mac open a dental CBCT disc made for Windows?
Usually, yes. Ignore the Windows viewer on the disc, copy the DICOM folder to the Mac and import it into Horos or Weasis, or drag it into VolView.
Last updated: 26 September 2026 · DentIIT editorial team. Licence, version and platform details are checked against each developer's official documentation; none of the tools listed here should be treated as a certified medical device unless its vendor says so.
