Orthodontists commonly recommend the removal of four teeth, often premolars, as part of a treatment plan for braces. This decision is highly specific and follows a comprehensive analysis of the patient’s dental and skeletal structure. While modern orthodontics increasingly favors non-extraction alternatives, tooth removal remains necessary for achieving stable, functional, and aesthetically pleasing results in certain complex cases.
The Primary Reasons for Extracting Teeth in Orthodontics
Extraction is primarily performed to resolve a significant discrepancy between the size of the teeth and the jawbones, known as tooth-size-arch-length discrepancy (TSALD). The first major reason is severe dental crowding, which occurs when the dental arch cannot comfortably accommodate all permanent teeth. Without creating space, attempting to straighten severely crowded teeth can push them forward, worsening protrusion or compromising bone and gum health.
The second reason for extraction is correcting significant protrusion, or “flaring,” of the front teeth, which results in a severe overjet. This condition can be characterized by the lips sticking out or difficulty closing them comfortably. Strategically removing teeth allows the orthodontist to move the anterior teeth backward into the newly created space. This retraction reduces the overjet, improves the relationship between the upper and lower jaws, and creates a more balanced facial profile.
Why Are Premolars Usually the Teeth Removed?
The teeth most frequently selected for removal are the first or second premolars, also known as bicuspids. Premolars are strategically located between the front teeth (incisors and canines) and the back teeth (molars). Removing them creates space precisely where it is needed to align crowded front teeth or retract protruding ones.
Choosing premolars minimizes the impact on chewing function because the molars remain to handle the majority of grinding forces. The typical recommendation involves removing one premolar from each of the four quadrants of the mouth. This symmetrical removal ensures the final bite is balanced and the dental midline remains centered.
Non-Extraction Techniques Used to Create Space
Orthodontics now utilizes several established methods to create space without resorting to extractions in many cases.
Interproximal Reduction (IPR)
One common technique is Interproximal Reduction (IPR), or “stripping,” where a tiny, controlled amount of enamel is shaved from the sides of the teeth. IPR is generally used for mild to moderate crowding and creates small amounts of space between multiple teeth.
Arch Expansion and Molar Distalization
Another approach is arch expansion, which involves widening the dental arch to create more room. In growing patients, a palatal expander can be used to physically widen the upper jaw. For adult patients, molar distalization involves pushing the back molars further backward in the jaw.
Molar distalization is often achieved using Temporary Anchorage Devices (TADs). These are small, temporary implants placed in the bone that act as fixed anchors. TADs allow the orthodontist to apply force to push the molars back without inadvertently moving the front teeth forward.
How Orthodontists Determine If Extraction Is Unavoidable
The decision to extract teeth is based on a comprehensive diagnostic process that looks beyond simple tooth alignment. Orthodontists utilize specialized X-rays, such as lateral cephalometric radiographs, to analyze the patient’s skeletal structure and growth pattern. These images help determine the relationship between the upper jaw (maxilla) and the lower jaw (mandible), classifying the patient into a skeletal Class I, II, or III malocclusion.
A thorough analysis of the patient’s facial profile is also a major factor in the decision-making process. The orthodontist measures the position of the lips relative to the nose and chin, assessing how tooth movement will impact the overall facial aesthetics. For example, if a patient has a protruding or convex facial profile, extractions may be necessary to retract the teeth and improve the soft tissue balance.
The final treatment plan integrates the severity of crowding, the degree of protrusion, the skeletal classification, and the desired long-term stability and facial harmony. Extraction is generally considered the most predictable path when the space required to correct the misalignment is too significant to be safely achieved by non-extraction methods alone.