Dental Implant Planning on iPad: A CBCT Site-Assessment Workflow
Updated July 2026 · 8 min read
Most of what makes an implant case succeed is decided before any surgery: is there enough bone, what quality is it, and where are the structures you must not touch. All three questions are answerable from a CBCT volume, chairside, on an iPad — while the patient is still in the chair and the treatment conversation is happening. This guide walks the assessment sequence in MedScan from import to documentation. One thing stated up front and repeated at the end: this is a planning aid. Final implant selection, prosthetically driven positioning, and guide fabrication belong in dedicated planning software, and every decision belongs to clinical judgment. Not medical advice.
Step 1: Import the CBCT
MedScan accepts the export formats dental CBCT units actually produce: patient CDs, ZIP archives, DICOMDIR structures, and plain DICOM folders from Carestream, Planmeca, Vatech, Sirona/Dentsply, Morita, and other standards-compliant machines. Transfer via AirDrop, Files, or a cloud drive — or pull the study directly from your imaging center's PACS over DICOMweb. Everything renders on-device and works fully offline; nothing is uploaded anywhere. Verify patient name, scan date, and voxel size before measuring — an old pre-extraction scan will happily lie to you about today's ridge.
Step 2: Trace the Arch, Get Cross-Sections
Open the volume and scroll the axial stack to a level where the arch form is clear — typically mid-root. Trace the dental arch with the CPR tool: MedScan generates a panoramic reformat along your curve plus perpendicular cross-sections with millimeter rulers at every position along the arch. Tooth numbering keeps you oriented; step through cross-sections to the edentulous site. Take a few seconds to trace accurately — the panoramic reformat and the cross-section geometry are only as good as the curve, a point discussed in the CBCT reading guide.
Step 3: Measure the Ridge
On the cross-section at the planned position, measure with the mm ruler:
- Ridge width — buccolingual, at the crest and at 2–3 mm apical to it (crestal knife-edges are common; the usable width is often subcrestal). Budget at least 1–1.5 mm of bone buccal and lingual of the planned implant diameter.
- Ridge height — from crest to the limiting structure: IAN canal roof in the posterior mandible, sinus floor in the posterior maxilla, nasal floor anteriorly.
- Angulation — the angle tool shows how far the ridge axis diverges from the ideal prosthetic axis; severe divergence flags an angulated abutment or grafting conversation early.
Measure on cross-sections only. Panoramic-style images — whether a true OPG or a CBCT reformat — collapse the buccolingual dimension and carry magnification assumptions; the panoramic vs CBCT comparison covers why.
Step 4: Check Bone Density (Misch D1–D4)
On the same cross-section, tap the planned osteotomy path with the Misch HU probe: MedScan reads the value and reports the D-class at that point. Sample crest, mid-body, and apex, or draw an HU ROI over the trabecular compartment for a mean value. The class informs your drilling protocol (undersize in D3/D4, full sequence with irrigation discipline in D1) and loading expectations. Keep the CBCT caveat in mind — gray values are not calibrated HU, so treat the classification as comparative guidance; the full argument, plus D1–D4 protocol details, is in the Misch classification guide.
Step 5: Verify Safety Margins
Trace the IAN canal through consecutive cross-sections in the posterior mandible — including any anterior loop mesial to the mental foramen — and measure the crest-to-canal distance at the planned site. Subtract your implant length plus margin from the available height. In the posterior maxilla, measure to the sinus floor and decide explicitly: stay short, engage the floor cortex, or plan an elevation as its own procedure.
| Structure | Commonly cited margin | Notes |
|---|---|---|
| IAN canal (posterior mandible) | ≥ 2 mm | From implant apex to canal roof; the most widely cited safety figure |
| Mental foramen | ≥ 2 mm, mind the anterior loop | Loop can extend mesial to the visible foramen |
| Maxillary sinus floor | Engage or stay clear per plan | Intentional membrane elevation is a distinct, planned procedure |
| Adjacent tooth root | ≥ 1.5 mm | Preserves interproximal bone and papilla |
| Adjacent implant | ≈ 3 mm | Commonly cited inter-implant distance |
| Buccal / lingual plate | ≥ 1–1.5 mm each side | Thin buccal plates predict recession and thread exposure |
These figures are widely cited conventions, not statutes — published recommendations vary, and individual anatomy, surgical technique, and guide accuracy all move the numbers. Also check for lingual concavities in the posterior mandible: an implant that looks safe on height alone can still perforate the lingual plate through a submandibular fossa undercut visible only on cross-sections.
Step 6: Document and Export
Annotated measurements persist with the study, so the site assessment — ridge dimensions, density class, canal distance — is available at the next visit or for the surgical record. Export annotated views to share with the surgeon, the referring colleague, or the patient's chart, and keep the numbers alongside the eventual plan from your guide-design software. A patient looking at their own cross-section with a measured 2 mm nerve margin understands the treatment plan faster than any verbal explanation.
Where MedScan Ends and Planning Software Begins
To be precise about scope: MedScan gives you diagnostic-quality viewing and measurement — MPR, arch cross-sections, density probing, distances, angles — which covers the site assessment phase of implant planning. It does not place virtual implants from manufacturer libraries, design surgical guides, or simulate prosthetics; those tasks belong to dedicated planning platforms. MedScan is not a medical device, and no measurement on any screen replaces clinical examination and the clinician's final judgment. For the general toolset, see the dental CBCT viewer guide.
FAQ
What safety margin should I keep to the inferior alveolar nerve canal?
A minimum clearance of 2 mm between the implant apex and the roof of the IAN canal is the most commonly cited figure in the literature, intended to absorb drill overshoot, measurement error, and slight positional deviation. Some clinicians plan more conservatively. Whatever margin you choose, measure it on a cross-section perpendicular to the arch, never on a panoramic image.
How much ridge width do I need for an implant?
A widely used rule of thumb is at least 1–1.5 mm of bone on both the buccal and lingual aspects of the implant, so a standard 4 mm diameter implant wants roughly 6–7 mm of ridge width. Narrower ridges push toward narrow-diameter implants, ridge augmentation, or expansion techniques.
Can I plan implants entirely on an iPad?
You can perform the diagnostic site assessment — ridge dimensions, bone density, distances to the IAN canal, sinus floor, and adjacent roots — on an iPad with a CBCT viewer like MedScan. Prosthetically driven planning with virtual implant libraries, surgical guide design, and final treatment decisions belong in dedicated planning software combined with clinical judgment. MedScan is a planning aid and measurement tool, not a medical device.
How do I measure bone density at the implant site?
Navigate to the site on an arch-perpendicular cross-section and tap with the Misch HU probe to get a D1–D4 classification, or draw an HU ROI over the trabecular compartment and read the mean. Remember that CBCT gray values are not calibrated Hounsfield units — use the result comparatively and expect confirmation from drilling resistance at surgery.
What distance should an implant keep from adjacent teeth and implants?
Commonly cited guidance is at least 1.5 mm between an implant and an adjacent natural tooth root, and roughly 3 mm between two adjacent implants, to preserve interproximal bone and papilla. Verify root positions and angulations on cross-sections, since roots frequently tilt into edentulous spaces.
Does the CBCT need to be recent for implant planning?
Yes — the scan should reflect current anatomy. Bone remodels substantially after extractions (most change occurs in the first months), so a volume acquired before an extraction or graft can materially misrepresent today’s ridge. If healing, grafting, or pathology has intervened since acquisition, re-image before finalizing a plan.