Watch a tooth move under a force system — step by step — through a validated periodontal-ligament model. See the center of resistance, the center of rotation, the crown and apex paths, live PDL stress, and root-resorption risk. Compare uncontrolled tipping vs controlled bodily movement from first principles.
No install · No signup · Runs in your browser. Educational and research tool — not a medical device.
Every output traces to a named equation and a published source — this is a transparent model, not a black box.
Located for any root geometry — the point where a single force gives pure translation. See it shift as the root changes.
Watch it migrate as you change the moment-to-force ratio — from tipping, to controlled tipping, to bodily movement and root torque.
Dial the moment-to-force ratio and see the movement type resolve live — the core of orthodontic force-system design.
Per-patch periodontal-ligament stress against the optimal-pressure threshold — see where the ligament is overloaded.
A risk index from the PDL stress field, step by step — see why uncontrolled tipping concentrates stress at the apex.
Trace where the crown and root apex actually travel through the movement — the geometry behind the clinical outcome.
From a force system to a moving tooth in three steps — no setup.
Choose the force, the moment, and the appliance — or start from a preset. A bracket-applied force with a chosen M/F ratio.
The validated PDL model applies the load, moves the tooth by its initial ligament displacement, and recomputes until the force decays.
Play or scrub through the movement and read CRes, CRot, PDL stress, resorption risk, and the crown/apex paths at every step.
The model recovers the textbook results before it draws anything: center of resistance at ~0.40 of root length, the M/F → center-of-rotation relationship following Burstone, and ~0.17 mm initial crown mobility. Uncontrolled tipping leaves the root tipped with peak apical stress; controlled bodily movement spreads the load — exactly as the literature predicts.
Biomechanics is abstract on paper. This makes it something you can change and watch.
Build intuition for force systems before the clinic. See why a moment changes the movement, instead of memorizing M/F ratios.
A fast sandbox to reason about anchorage, tipping, and resorption risk from first principles — concept-level, never patient-specific.
A transparent, citable model for teaching and study. Every value traces to a published equation; the engine is available as a citable library.
The center of resistance is the point at which a single force produces pure translation (bodily movement) with no rotation. For a single-rooted tooth it sits roughly 40% of the root length apical to the alveolar crest. The simulator locates it for any root geometry and shows how it shifts.
The moment-to-force ratio determines the type of tooth movement: a low ratio tips the tooth, around 10:1 produces controlled tipping, and roughly 12–15:1 produces bodily translation. The simulator shows the resulting center of rotation live as you change it.
It's completely free, with no signup, and runs entirely in your browser — nothing is downloaded or installed.
No. It is an educational and research simulation of general biomechanics using generic, user-entered parameters. It does not use patient data and is not intended for the diagnosis or treatment planning of individual patients.
A validated periodontal-ligament / rigid-body tooth model, part of the open Ortho-Biomechanics engine. Every output traces to a named equation, author, and year.
Free, in your browser, right now. Change a force, watch the mechanics respond.
Launch the Tooth-Movement Simulator →