Braces are a common orthodontic treatment designed to straighten teeth and improve bite alignment. Tooth movement with braces is a carefully orchestrated biological response to gentle, continuous forces applied to the teeth. This gradual process unfolds within the jawbone, transforming a misaligned smile into a properly aligned one.
The Fundamentals of Orthodontic Movement
Braces apply light, consistent pressure to teeth, initiating bone remodeling. Brackets, archwires, and sometimes elastics or other auxiliary components work together to deliver these forces.
When pressure is applied, it creates compression and tension within the surrounding periodontal ligament, a tissue connecting the tooth root to the jawbone. On the compression side, cells called osteoclasts break down bone, creating space for the tooth to move.
Simultaneously, on the tension side, cells called osteoblasts deposit new bone, filling the space as the tooth moves forward. This continuous cycle of bone resorption and deposition allows teeth to gradually shift through the bone, achieving the desired alignment. The forces must be gentle and continuous to stimulate this biological response without causing damage to the tooth or surrounding structures.
The Initial Stages of Tooth Movement
When braces are first applied, the initial focus of orthodontic treatment is on general leveling, alignment, and correcting rotations. During this phase, the front teeth, specifically the incisors and canines, begin to show noticeable movement first. These teeth are often the most visibly misaligned or crowded, making them primary targets for initial straightening and space creation.
The archwires used in these early stages are flexible and light, guiding teeth into a more aligned position. These wires derotate teeth and begin to level the arch, reducing overcrowding. This initial movement of the anterior teeth helps establish a foundation for subsequent treatment phases.
Molars often serve as stable anchors, providing a firm base against which other teeth can be moved. Sometimes, molars may be moved backward to create additional space in the arch. The specific sequence and timing of tooth movement depend on the patient’s orthodontic needs and the treatment plan developed by the orthodontist.
The Progression of Orthodontic Treatment
After initial alignment and leveling, orthodontic treatment progresses into subsequent phases, each designed to achieve precise tooth positioning and bite correction. One phase involves space closure, systematically closing any gaps created by tooth extractions or previous movements. Stiffer, more rectangular archwires are used to provide greater control over individual tooth movements.
Correction of bite discrepancies, known as occlusion, also occurs in later stages. This involves meticulously adjusting how the upper and lower teeth fit together when biting, aiming for a stable and functional relationship. Auxiliary appliances, such as interarch elastics, springs, or power chains, are used to apply specific forces for these refined movements, helping achieve proper intercuspation and alignment of the dental arches.
The final stages focus on achieving root parallelism and refining each tooth’s precise position. This meticulous detailing ensures teeth are not only straight but also stable within the bone. After braces are removed, the retention phase begins, where retainers are worn to maintain the new tooth positions and prevent relapse, preserving the long-term results of orthodontic treatment.