Understanding the science, biology, materials and technology behind carefully planned orthodontic treatment.
Explore the science
Teeth can become irregular for many different reasons. Crowding, spacing, rotations and bite problems are usually the result of a combination of factors rather than a single cause. Understanding these factors is the first step toward understanding how orthodontic treatment should be planned.
Genetics influence the size and shape of teeth, jaw dimensions and the development of the upper and lower jaws. When teeth are relatively large compared with the available jaw space, crowding may occur. Differences in jaw development can also contribute to various bite problems.
When there is not enough room for all the teeth to fit within the dental arch, teeth may become crowded, rotated, displaced or pushed out of their ideal positions. A mismatch between tooth size and available arch space is a common reason for irregular alignment.
The opposite can also happen. When the available space is greater than the space required by the teeth, gaps or spacing can develop. Missing teeth, smaller teeth or differences in jaw and tooth proportions can contribute to this
Teeth develop within growing jaws, so their final positions are influenced by how the jaws develop. Differences in the growth of the upper and lower jaws can affect how the teeth fit together and contribute to bite conditions such as overbite, underbite, crossbite or open bite.
Some habits, particularly when they continue over a long period during growth, can influence the position of teeth and the development of the jaws. Thumb or finger sucking and certain patterns of tongue posture and function are examples.
Teeth can also change position throughout life. Tooth loss, the eruption of other teeth and natural changes in the supporting tissues can gradually alter tooth alignment and the bite.
Therefore, orthodontic treatment is not simply about making teeth look straight. Before deciding where teeth should go, it is important to understand why they are irregular in the first place.
Understanding the cause is where orthodontic treatment begins.Teeth may look like solid structures fixed firmly in the jaw, but they are actually surrounded by living tissues that allow controlled movement. This biological process is the foundation of orthodontic treatment—whether braces or clear aligners are used.
Each tooth is held in its socket by a thin layer of tissue called the periodontal ligament. Around the tooth is the supporting bone. When a controlled orthodontic force is applied, compression occurs on one side of the periodontal ligament while tension develops on the other.
The body responds to these changes by remodelling the surrounding bone. Bone is gradually resorbed on the pressure side and formed on the tension side. This allows the tooth to move gradually within the surrounding bone.
This is why orthodontic tooth movement is not simply about pushing a tooth from one place to another. The force must work with the body's natural biology.
Different types of tooth movement require different amounts and directions of force. Tilting, rotation, bodily movement, intrusion and extrusion each involve different biomechanical requirements.
Applying excessive or poorly controlled force does not necessarily make treatment faster. The biological tissues need time to respond. Effective orthodontic treatment depends on appropriately controlled forces delivered through a carefully planned sequence.
Orthodontic treatment is a series of connected movements. Some teeth may need to move sequentially, while others may need to move together. The sequence matters because each stage creates the conditions required for the next.
This is where treatment planning and staging become important. The final result is achieved through the coordination of multiple movements over time., but by coordinating many smaller movements over time.
Clear aligners are designed to deliver forces to the teeth through their shape, fit and interaction with attachments where prescribed. Digital treatment planning allows these movements to be visualised and organised into stages before the aligners are manufactured.
But the digital plan represents what is intended to happen. The actual tooth movement depends on biological response, appliance design, clinical management and patient compliance.
Both braces and ODS Aligners can be used to correct a wide range of orthodontic problems. With proper diagnosis, treatment planning, staging and supporting mechanics, ODS Aligner treatment can address a wide range of orthodontic cases, including more complex movements, when clinically appropriate.
The fundamental principle is the same: apply controlled forces and guide teeth through their natural biological response.
Braces use brackets and wires to deliver forces, with adjustments made throughout treatment as the teeth respond.
ODS Clear Aligners take a digitally planned approach. Tooth movements are planned digitally in advance and divided into carefully sequenced stages using advanced treatment-planning software. Each aligner is designed to contribute to a specific stage of the planned tooth movement.
ODS Aligners are designed for comprehensive orthodontic treatment including bite correction, not just alignment of the front teeth.
Depending on the diagnosis and treatment objectives, ODS can support a wide range of tooth movements. When additional support is required, ODS Aligners can be combined with appropriate orthodontic auxiliaries, including elastics, temporary anchorage devices (TADs), expanders, distalizers and other orthodontic auxiliaries.
The aligner does not always have to work alone.
ODS Clear Aligners are part of a comprehensive orthodontic workflow, encompassing diagnosis, digital treatment planning, staging, aligner fabrication, auxiliary mechanics, monitoring and refinements.
From straightforward alignment to complex orthodontic movements, ODS treatment is not limited to the capabilities of aligners alone. They are designed to work with appropriate orthodontic mechanics. when the case requires them.
The goal is not simply to straighten teeth. The goal is to achieve the planned orthodontic result.
The material of an aligner plays an important role in how forces are delivered throughout treatment. Single-layer and multilayer materials have different characteristics, uses and performance, and the choice should complement the movement being planned.
| Comparison | Single-Layer Material | Multilayer Material |
|---|---|---|
| Structure | Made from one homogeneous material | Combines different material layers with different properties |
| Force delivery | Provides a relatively consistent force profile | Can provide a more controlled and sustained force response |
| Uses | Suitable for many routine orthodontic movements | Particularly useful where greater control, resilience or sustained force delivery is desired |
| For the Orthodontist | Simple and predictable material behaviour | Allows material characteristics to support different treatment requirements and stages |
| For the Patient | Comfortable, removable and discreet | Can offer improved comfort, sustained force delivery and potentially more efficient, predictable progression when appropriately planned |
For the orthodontist, material selection is an important part of biomechanics. An aligner must deliver the intended forces while maintaining its shape throughout the prescribed wear period. Properties such as flexibility, elasticity, resilience and durability influence its mechanical performance.
Multilayer materials combine different material characteristics within the same aligner, offering a balance of flexibility, resilience and sustained force delivery.
For the patient, these properties can contribute to a more comfortable wearing experience and support effective tooth movement. When combined with appropriate treatment planning and patient compliance, they can support efficient and controlled treatment progression.
Ultimately, better material works alongside better planning. Material selection, treatment staging and aligner design must work together to achieve the intended orthodontic results.
The right material supports the right movement at every stage of treatment.
The right material is the one that supports the movement the treatment requires.A treatment-stage approach to aligner material selection, guided by the treating doctor.
An aligner is more than a tray that fits over the teeth. Its material influences flexibility, stiffness, force delivery and how those forces change during wear.
Laboratory research indicates that material composition and thickness affect the forces produced and distributed by clear aligners. Material relaxation during use is also important when selecting an appliance and wear protocol. These findings concern aligner biomechanics in general, rather than proven clinical outcomes of the ODS Dual Aligner System.1, 2
Different stages of orthodontic treatment can call for different force characteristics. Material choice should therefore follow the planned tooth movement, aligner design, attachments or other auxiliaries, prescribed wear interval and the patient's clinical response. A material change is a treatment-planning decision, not an automatic way to improve results.
ODS Premium Aligners use a Co-PU composite material. Its relevant characteristics, including stiffness, flexibility, shape recovery and force retention, need to be considered alongside aligner thickness and design. Within an ODS treatment protocol, Premium Aligners provide one material option that the treating doctor may select when its characteristics are suitable for the movement being planned.
The decision to use Premium at a particular stage should follow the clinician's assessment of the case and the approved digital set-up. The available general studies do not establish that ODS Premium produces a specific clinical benefit over another ODS material. Product-specific test data would be needed for such a comparison.
ODS FLX Aligners use a multilayer material construction. Combining different material layers allows complementary mechanical properties to be engineered within the same aligner, offering greater versatility in flexibility, resilience and force response.. However, the direction and size of those differences depend on the exact layers, thickness and manufacturing conditions.
FLX may be considered where its measured mechanical characteristics suit the intended movement or stage of treatment. The treating doctor should make that selection based on case requirements, staging and any supporting mechanics. Multilayer construction alone does not demonstrate greater comfort, faster movement or a superior clinical outcome.
The ODS approach allows the treating doctor to consider different aligner materials at different stages where clinically appropriate. The purpose is to match material characteristics to treatment requirements, rather than to switch materials routinely or assume that two materials are always better than one.
The treating doctor remains responsible for diagnosis, movement objectives, treatment staging, selecting and approving the plan, and monitoring the clinical response.
With ODS, material selection becomes part of the treatment strategy:
Material selection follows the clinical plan and the treating doctor’s approval.
The treating clinician assesses the case and defines the intended tooth movements, biomechanics and treatment objectives.
The treatment protocol considers material characteristics alongside the planned movements and supporting mechanics.
Selection is case-dependent. These materials are not automatically alternated, and switching does not itself establish faster or better outcomes.
The treating clinician reviews and approves the digital set-up before aligners are manufactured to the approved plan.
The doctor directs case selection, planning and monitoring. The material descriptions above are not claims of ODS-specific superiority; refer to the research and evidence limitations below.
Published laboratory studies highlight the influence of material composition and thickness on force generation, distribution and decay in clear aligners. A 2024 in-vitro study compared several commercially available single-layer and multilayer materials and found differences in force generation and distribution; the authors noted that a proposed exchangeable-material protocol still needs clinical testing.1 Separate laboratory work documents force decay in PET-G specimens under simulated wear conditions.2
Evidence limitation: These publications do not directly evaluate the ODS Premium and FLX combination or demonstrate that switching between them improves treatment speed, predictability or patient outcomes. ODS-specific material testing and clinical studies would be required to support those claims.
