Decoronation is a dental procedure performed to address ankylosed teeth, particularly in children and adolescents. It involves surgically removing the crown of an ankylosed tooth while leaving the root within the jawbone. The goal is to preserve the surrounding alveolar bone, which supports jaw development and prepares the site for future tooth replacement.
Understanding Ankylosed Teeth
An ankylosed tooth has fused directly to the surrounding jawbone, preventing its normal eruption or movement. This condition often results from severe dental trauma, such as avulsion (tooth knocked out) or intrusive luxation (tooth pushed into the bone), which damages the periodontal ligament that normally connects the tooth to the bone. When this ligament is compromised, the bone can directly attach to the tooth root.
Ankylosis presents problems, especially in children and adolescents, because their jawbones are still growing. An ankylosed tooth will not move with the developing bone, leading to infraocclusion, where the tooth appears sunken compared to adjacent teeth. This can cause aesthetic concerns, interfere with the eruption of neighboring teeth, and lead to localized bone defects.
While extraction might seem straightforward, removing an ankylosed tooth in a growing individual can result in substantial loss of both vertical and horizontal alveolar bone. This bone loss can complicate future prosthetic rehabilitation, such as dental implant placement. Decoronation is chosen over extraction to avoid these bone deficiencies, as it helps maintain the volume and width of the alveolar ridge for future tooth replacement.
The Decoronation Procedure
The decoronation procedure begins with an assessment, often including radiographs, to confirm the diagnosis of ankylosis and plan the surgical approach. Local anesthesia is administered. A small incision may be made to elevate a mucoperiosteal flap, providing access to the ankylosed tooth and surrounding bone.
The dental crown is then carefully removed at the cementum-enamel junction, which is the natural border between the crown and the root. This is done using a high-speed dental bur. For permanent teeth, the root canal filling is removed from the remaining root portion.
The empty root canal is then irrigated to encourage bleeding from the surrounding tissues. This encourages a blood clot to form within the canal, promoting bone-forming cell ingrowth. The exposed root surface is then reduced below the marginal bone crest or gingival margin.
The mucoperiosteal flap is then repositioned and sutured over the remaining submerged root. The goal is for the remaining root to undergo replacement resorption, where it is gradually resorbed and replaced by new bone.
Recovery and Long-Term Outlook
Following decoronation, patients can expect some discomfort, swelling, and minor bruising. Applying a cold compress, such as an ice pack, for 20-minute intervals during the first 24-48 hours helps minimize swelling. Keeping the head elevated also assists in reducing swelling.
Dietary recommendations involve consuming soft foods for a few days to a week, avoiding extremely hot foods, and refraining from using straws to prevent dislodging the blood clot. Maintaining good oral hygiene in unaffected areas is important, while the surgical site should be gently cleaned as instructed by the dentist. Follow-up appointments are scheduled to monitor the healing process, assess bone regeneration, and plan for future restorative treatments.
The long-term benefits of decoronation include preserving alveolar bone volume. This procedure helps maintain both the height and width of the jawbone, which is important for future prosthetic options like dental implants, often avoiding complex bone grafting. The submerged root acts as a scaffold for new bone development, allowing for natural vertical bone growth over time. This continuous bone apposition contributes to a more favorable aesthetic outcome. Root resorption and bone regeneration can take several years, with monitoring extending for at least 4 years to confirm successful bone integration and vertical growth.