An impacted tooth has failed to erupt into its correct position within the dental arch by the expected time, remaining fully or partially embedded in the jawbone or soft tissue. This situation most frequently involves the upper canine teeth, which are important for the bite’s function and the smile’s appearance. When the tooth cannot emerge naturally, an orthodontist and an oral surgeon must combine efforts to guide it into place. This process is known as surgical exposure and orthodontic traction.
Understanding Surgical Exposure and Traction
The initial step is a minor surgical procedure performed by an oral surgeon to gain access to the crown of the unerupted tooth. This operation, often called an “expose and bond,” involves carefully lifting gum tissue and sometimes removing overlying bone to reveal the tooth crown. Once exposed, the surgeon bonds a small orthodontic bracket to the surface; this specialized bracket has a miniature gold chain or ligature wire attached, which allows the orthodontist to apply a controlled pulling force. The surgeon then repositions the gum tissue, leaving only the end of the chain accessible, typically attached to the existing orthodontic archwire, marking the beginning of the active orthodontic traction phase.
Key Factors Influencing the Movement Timeline
The duration required to successfully bring an impacted tooth into the arch depends on several specific anatomical and biological factors. One significant predictor is the orientation of the impacted tooth within the jawbone. Horizontally or severely angled teeth require longer treatment times compared to those positioned more vertically and closer to the intended path of eruption. The precise location also plays a role, as canines impacted on the palate side or those positioned closer to the central front teeth typically take longer to move.
A patient’s age influences the speed of movement because the bone surrounding the tooth responds more readily to orthodontic forces in younger individuals. The amount of space available in the dental arch is also a determining factor. If insufficient room exists, the orthodontist must first create the necessary space before active traction can begin. A thorough radiographic examination is necessary for an accurate prognosis due to these variables.
The Expected Duration of Active Tooth Movement
The period of active traction is measured in months, not weeks, due to the slow, biological nature of tooth movement through bone. For buccally impacted canines, the time until the tooth breaks through the gum line and becomes visible averages around six to seven months. Canines impacted on the palatal side take longer, often extending to sixteen months or more. The total time from the start of traction until the tooth is fully positioned and aligned with the other teeth is much longer, often averaging over two years. This range can span from four months up to three years in complex cases.
Orthodontic tooth movement relies on bone remodeling, where bone is broken down on the side of pressure and rebuilt on the side of tension. The applied force must be very light and continuous, typically 40 to 60 grams, to prevent damage to the tooth root or surrounding tissues. This light force dictates that the tooth only moves in fractions of a millimeter per month. The orthodontist adjusts the tension on the chain, often using an elastic or spring, at regular appointments every four to six weeks, to maintain this gentle, incremental movement.
Finalizing the Alignment
Once the impacted tooth has been guided down and the crown has emerged through the gum tissue, the focus shifts from traction to final integration. The chain and its attachment are often replaced with a standard orthodontic bracket, which is then connected to the main archwire alongside the other teeth. The newly erupted tooth is gently guided and rotated into its final, precise position within the dental arch. This phase of fine-tuning the alignment and bite relationship can take many additional months. The total duration of the entire orthodontic treatment is substantially longer than the time spent just pulling the tooth down with the chain.