All-on-4 Planning Calculator

Cantilever and angulation planning index.

Arch length (mm)

Posterior cantilever (mm)

Anterior implant angle (deg)

Posterior implant angle (deg)

Tab to move between fields

A-P spread (mm)

Cantilever ratio0.41

Cantilever acceptable (0/1)1

Max cantilever (mm)43.5

Teeth in prosthesis11

Tilted implant length (mm)15

How to Use This Calculator

Enter Arch length (mm), Posterior cantilever (mm), and Anterior implant angle (deg).
Set Posterior implant angle (deg).
Review the A-P spread (mm) result.
Use Cantilever ratio and Cantilever acceptable (0/1) to inform your decision.

How the result changes with Arch length (mm)

Arch length (mm): Anterior-posterior distance of the edentulous arch.
Posterior cantilever (mm): Length of distal cantilever extension beyond last implant.
Anterior implant angle (deg): Angulation of anterior implants (typically near-vertical).
Posterior implant angle (deg): Angulation of posterior implants (typically 30-45 degrees).

A-P spread (mm): Anterior-posterior spread between outermost implants.
Cantilever ratio: Cantilever length relative to A-P spread (should be <=1.5).
Cantilever acceptable (0/1): 1 = cantilever within acceptable biomechanical limits.
Max cantilever (mm): Maximum recommended cantilever for this A-P spread.
Teeth in prosthesis: Recommended number of teeth in the full-arch prosthesis.
Tilted implant length (mm): Effective bone engagement length of the tilted posterior implants.

Identify Input Parameters
4 parameters
Arch length (mm) = 55, Posterior cantilever (mm) = 12, Anterior implant angle (deg) = 0, Posterior implant angle (deg) = 30 = 4 input(s) provided
Calculate A-P spread
A-P spread
29 = 29
Calculate Cantilever ratio
Cantilever ratio
0.41 = 0.41
Calculate Cantilever acceptable
Cantilever acceptable
1 = 1