Third molars are the final set of teeth to emerge, typically appearing between the ages of 17 and 25. Their late arrival often coincides with orthodontic correction using braces. Whether these molars must be removed for successful teeth straightening is a common concern. While removal is frequent, it is not a universal prerequisite for starting or completing orthodontic treatment. The decision is always made on a case-by-case basis after evaluation by an orthodontist and an oral surgeon.
Primary Reasons for Third Molar Extraction
The primary justifications for removing third molars center on preventing structural damage and maintaining the stability of the final alignment. A common reason is the concern that eruption will compromise the space created by braces, potentially leading to a condition known as relapse. While scientific literature debates how much third molars cause late-stage crowding, many orthodontists view their presence as a risk factor for misalignment after braces are removed.
This mechanical concern is relevant when the jaw size is inadequate to accommodate all 32 teeth. If third molars attempt to erupt in an already crowded arch, the lack of space may undermine the stability of the corrected bite. Proactive removal ensures the dental arch has the necessary room to remain stable long-term.
A definitive reason for extraction involves pathological risks associated with impaction. An impacted tooth is trapped beneath the gum line or bone, often growing at an angle. If the tooth grows horizontally, it can exert pressure on the adjacent second molar, potentially leading to root damage or bone loss. Impactions can also create pockets where bacteria accumulate, leading to chronic infection or pericoronitis. Extraction is medically necessary in these instances to preserve the health of the surrounding teeth and jaw.
Scenarios Where Extraction is Not Required
Many patients can keep their third molars if their anatomy allows for retention. If the jaw is sufficiently large, it can comfortably accommodate the full eruption without compromising the alignment achieved by braces. In these cases, the third molars erupt vertically and align properly with the rest of the teeth.
A healthy eruption angle, where the molars are growing straight up, indicates a high likelihood of emerging into a functional position. If the tooth is positioned vertically with adequate space, it poses minimal risk to adjacent teeth or the overall orthodontic result. A fully erupted third molar can sometimes serve as a stable anchor point during the movement of other teeth.
The concern is eliminated entirely if the third molars never develop, a condition known as agenesis. For patients who do not require removal, the orthodontist monitors development through periodic X-rays during and after treatment. If the teeth remain asymptomatic, are free of pathology, and do not threaten the stability of the occlusion, they can safely remain.
The Timeline for Removal in Orthodontic Treatment
If the removal of third molars is deemed necessary, the timing of the procedure is coordinated with the orthodontic treatment plan. There are three primary timeframes for extraction.
Pre-Braces Removal
This timeframe is often recommended when severe impaction or crowding is present before treatment begins. Removing the teeth first ensures the orthodontist has the maximum space available to align the rest of the teeth efficiently. Patients typically wait two to six weeks after surgery before braces are placed, allowing for initial healing and soft tissue stabilization.
During Treatment
Removal can occur during treatment if new issues arise, such as a sudden change in the angle of an erupting tooth or the onset of pain or infection. In this situation, the oral surgeon and orthodontist communicate closely to ensure the extraction does not interfere with the active movement of the teeth.
Post-Braces Removal
Some orthodontists opt for post-braces removal, choosing to monitor the third molars throughout treatment. They are only removed if late-stage crowding or damage becomes evident. This allows the orthodontist to use the existing teeth as part of the overall alignment structure for as long as possible.