A fixed orthodontic appliance, commonly known as braces, is a system of brackets and wires designed to apply gentle, continuous pressure to teeth. This controlled force gradually remodels the surrounding bone structure, allowing teeth to shift into more optimal positions. Orthodontic treatment focuses on correcting a range of dental and skeletal issues that affect alignment, bite, and overall oral function. The primary goal is to establish a harmonious relationship between the teeth and jaws.
Correcting Crowding and Spacing
One of the most frequent reasons people seek orthodontic treatment is to manage issues related to tooth placement. Dental crowding occurs when there is a mismatch between the size of the jaw and the size of the teeth, meaning there is insufficient space for all teeth to align properly. This lack of space causes teeth to overlap, become twisted, or erupt out of their ideal positions. The forces applied by the archwire and brackets work to unravel this misalignment, guiding the teeth into a uniform row.
The opposite issue, dental spacing, or diastema, results from an excess of space, causing noticeable gaps between teeth. This can be caused by teeth that are naturally too small for the jaw, congenitally missing teeth, or developmental habits like a tongue thrust. Braces effectively close these gaps by moving the separated teeth closer together, requiring precise control to ensure the roots are moved into their correct parallel positions within the bone.
Correcting these alignment issues often involves creating or eliminating space within the dental arch. In cases of severe crowding, the orthodontist may use techniques like palatal expansion to widen the jaw or recommend the extraction of a tooth to create room. Once the space is managed, the fixed appliance utilizes its components to translate, tip, and rotate teeth. This mechanical action achieves the precise alignment required for a stable and healthy dental structure.
Resolving Specific Bite Malocclusions
A primary function of braces is to correct malocclusions, which are problems with how the upper and lower teeth meet, often involving the underlying jaw structure. An overbite, also described as a deep bite, is a vertical misalignment where the upper front teeth overlap the lower front teeth excessively when the mouth is closed. While a slight overlap is normal, an excessive overlap can lead to the lower teeth biting into the gum tissue behind the upper teeth or causing abnormal wear on the lower incisors.
Conversely, an underbite occurs when the lower jaw or lower teeth protrude past the upper teeth. This results in the bottom teeth sitting in front of the top teeth, which often affects facial profile and can make chewing difficult. Treatment for an underbite may involve using rubber bands attached to the braces to reposition the dental arches or, in growing patients, the use of specialized appliances to modify the growth direction of the jaws.
A crossbite is a lateral, or side-to-side, misalignment where one or more upper teeth sit inside the lower teeth. This can happen with the front teeth (anterior crossbite) or the back teeth (posterior crossbite) and may involve a single tooth or an entire segment of the arch. If left untreated, a unilateral posterior crossbite can cause the lower jaw to shift to one side when closing, leading to uneven development and wear.
The open bite is characterized by a lack of vertical overlap, where a gap remains between the upper and lower teeth when the back teeth are together. This typically affects the front teeth, meaning the upper and lower incisors cannot touch, but it can also occur in the back. Open bites often interfere with speech and the ability to bite into food, and they are sometimes linked to habits like prolonged thumb sucking or a tongue thrusting pattern. Braces coordinate the movement of multiple teeth, ensuring the cusps and grooves of the molars and premolars interlock correctly for a balanced and stable bite.
Improving Overall Oral Health and Function
The alignment of teeth and correction of the bite lead directly to functional improvements. When teeth are straight and evenly spaced, the surfaces become far easier to clean effectively with a toothbrush and dental floss. This improved hygiene reduces the accumulation of plaque and bacteria, which in turn lowers the long-term risk of developing dental decay and periodontal disease.
A correctly aligned bite ensures that chewing is performed efficiently. A malocclusion often causes uneven distribution of biting forces, making it harder to break down food and placing excessive stress on certain teeth, jaw muscles, or the temporomandibular joints. By correcting the bite, orthodontic treatment distributes the force evenly across the entire dental arch, which reduces muscle strain and improves digestive preparation.
The proper meeting of the upper and lower teeth prevents abnormal wear patterns on the enamel surfaces. When teeth are misaligned, they can grind against each other, causing premature wear, chipping, or fracturing. Aligning the bite preserves the integrity of the tooth structure, reducing the risk of sensitivity and the need for restorative procedures later in life.
Finally, the precise positioning of teeth is necessary for clear speech articulation. Severe spacing or an open bite can allow air to escape incorrectly, sometimes contributing to a lisp or other speech impediments. By closing gaps and ensuring the front teeth meet properly, braces help the tongue and lips form the necessary contacts for accurate pronunciation, contributing to clearer communication.