The answer to whether braces work is a definitive yes. Braces are precision orthodontic devices designed to apply controlled, continuous mechanical force to the teeth. This force is calibrated to gradually guide teeth into new, predetermined positions within the jawbone. Their primary purpose is twofold: to achieve an aesthetically pleasing alignment and, more importantly, to establish a functional, stable bite. These devices initiate a complex, natural biological response that allows for the physical movement of teeth through the surrounding bone structure. The success of this treatment depends on leveraging the body’s capacity for cellular change.
The Biological Mechanism of Tooth Movement
Braces function by harnessing the body’s innate ability to remodel bone tissue. The application of a light, continuous force initiates a biological cascade within the periodontal ligament (PDL), the specialized connective tissue that anchors the tooth root to the alveolar bone. The PDL translates the mechanical pressure from the brace wire into biochemical signals. This mechanical stress creates two distinct zones around the moving tooth root: a compression side and a tension side.
On the compression side, specialized cells called osteoclasts are recruited to dissolve the bone matrix, creating a path for the tooth to follow. Simultaneously, on the tension side, osteoblasts are activated to deposit new bone material into the space left behind the moving root. This coordinated breaking down and building up of bone is known as bone remodeling, which is the foundational process for all orthodontic tooth movement. The careful balance between resorption and deposition allows the tooth to migrate slowly and permanently through the jawbone.
Correcting Alignment and Bite Issues
The clinical applications of this biological mechanism are broadly categorized into fixing alignment problems and correcting bite discrepancies, known as malocclusions.
Alignment Problems
Alignment problems include issues where teeth are incorrectly positioned relative to one another within the same arch. Common examples are crowding, where there is insufficient space for all teeth, causing them to overlap or twist, and spacing, where excessive gaps exist between teeth. Braces can also correct rotations by applying torque to the tooth, gradually twisting it into the correct orientation. Addressing these alignment issues is important for more than just appearance; properly aligned teeth are significantly easier to clean, which reduces the long-term risk of developing tooth decay and periodontal disease.
Bite Issues (Malocclusions)
Bite issues, or malocclusions, involve the improper relationship between the upper and lower dental arches when the mouth is closed. An overbite, for instance, occurs when the upper front teeth overlap the lower front teeth excessively in a vertical direction. Conversely, an underbite is a condition where the lower jaw protrudes, causing the lower front teeth to sit in front of the upper teeth. A crossbite is a misalignment where some upper teeth sit inside the lower teeth when biting down. Correcting these bite problems is necessary to ensure efficient chewing function, prevent abnormal wear patterns on the tooth surfaces, and alleviate potential strain on the temporomandibular joints.
Maintaining the Results After Treatment
The success of treatment is measured by the stability of that result over time, not just the final alignment upon removal of the braces. Relapse, the tendency for teeth to shift back toward their original positions, occurs because the periodontal ligaments and the gingival fibers surrounding the teeth require time to fully reorganize and adapt to the new tooth positions. The retention phase, which follows the active treatment, is mandatory to counteract this tendency. Retainers are passive devices that hold the teeth in their corrected positions while the surrounding bone and soft tissues stabilize. These include removable retainers (such as the Hawley or clear Essix models) and fixed retainers (a thin wire bonded to the tongue-side surface of the front teeth); retention is often required indefinitely to ensure long-term stability.