Biometry of Aligners
Biometry of aligners sits at the intersection of biology, biomechanics, and biomaterials, turning aligners into measurable treatment sensors rather than passive plastic shells. From a biological standpoint, the rate and pattern of tooth movement reflect the patient’s individual response to force, so tracking fit, lag, and refinement needs over time provides indirect metrics of bone remodeling and periodontal adaptation. Biomechanically, planned versus achieved tooth positions, attachment engagem [...]
Attachments role in Translation
Attachments play a key role in achieving translation during canine retraction by modifying how forces are delivered to the tooth. By increasing the surface area and altering the geometry of the crown, optimally designed attachments (often vertical or optimized root-control shapes) allow the aligner to engage the tooth more effectively and apply a force system that includes both a distal force and a counter-moment. This shifts the effective line of action closer to the center of resistance and he [...]
Canine retraction with different angulations
When retracting canines into an extraction space, the required moment-to-force (M/F) ratio for good root control depends on the initial angulation of the tooth. For an upright canine, you use the “classic” M/F ratio for translation, generating a counter-moment just large enough to keep the root moving with the crown rather than tipping. If the canine is mesially angulated, the line of action of the distal retraction force tends to help upright the tooth, so a lower M/F ratio is often sufficient [...]
Force Driven vs Displacement Driven Movements-1
In orthodontics, a force-driven approach starts by prescribing the forces and moments you want at the tooth (e.g., 100–150 g of intrusion, a specific moment-to-force ratio for controlled tipping), and the resulting tooth movement is whatever the biology allows in response to that load. Classic fixed appliances, springs, and loops are essentially force-driven systems. A displacement-driven approach, by contrast, starts with the desired change in tooth position and orientation (for example, 0.25 m [...]
Segmentation of intraoral scans-2
Post-processing of intraoral scans becomes critical in cases of severe crowding, where overlapping teeth create complex, ambiguous geometries. After the initial acquisition, the raw point cloud or mesh is typically cleaned with noise reduction, hole filling, and mesh smoothing, but these steps must be applied cautiously to avoid blunting contact points or erasing subtle anatomy. In crowded segments, operators often use local re-meshing and refinement around contact areas, combined with manual or [...]
Segmentation of intra oral scans-1
Intraoral scan segmentation typically combines geometric, intensity-based, and increasingly machine learning–driven methods to isolate individual teeth and soft tissues from a 3D mesh, but it is neither trivial nor fully reliable. Classical approaches rely on curvature and surface normal analysis to detect tooth boundaries at gingival margins and interproximal embrasures, often using region-growing or watershed algorithms from seed points on each tooth. These methods are particularly prone to e [...]
Physics in Orthodontics Azerbajian
This is the link to the Azerbajian version of Physics in Orthodontics : Azerbajian Version [...]
Scientific and Physics of Aligners
Here is the link to download the free version of this pdf. Please comment and suggest changes to further improve the document. Thanks to all. https://discoverortho.com/wp-admin/upload.php?item=18686 Scientific and Physics of aligners March 2025 [...]