A hemisection is a specialized dental procedure where half of an injured natural tooth is removed. A hemisection can only be performed on molars, which are the larger, flatter teeth at the rear of the mouth. Hemisections cannot be performed on smaller teeth because they lack the strength and stability required to remain functional after the procedure.
There are many advantages to a hemisection. Preserving as much natural tooth as possible is of paramount importance to dental professionals. There are plenty of prosthetic teeth restorations available, but none is preferable to a healthy natural tooth. Another advantage of a hemisection is that it is a cost-effective and highly predictable procedure. When a tooth is extracted, a dental implant, bridge or other prosthetic is placed to fill the gap. Though these alternatives are effective under the right circumstances, they can be expensive to implement.
When a hemisection is performed, the tooth is essentially cut in half. The root and crown on the affected side are removed completely. There are a wide variety of circumstances that favor a hemisection, including:
Root canal therapy failure – During root canal therapy, the pulp and inner workings of the tooth are removed. The resulting space is packed with dental filler and the tooth is sealed with a crown. If this procedure is unsuccessful, the next step can involve a hemisection to save as much tooth structure as possible.
Vertical fractures – When a healthy molar has sustained a vertical injury either due to trauma or decay, a hemisection may be performed to save the healthy section of the tooth.
Vertical bone loss – If a significant amount of bone has been lost in an area adjacent to the tooth, the resulting lack of adequate attachment can jeopardize the whole tooth structure. A hemisection can save the firmly affixed portion, and a partial crown can be placed to add stability.
Damage to the pulp chamber – When the floor of the pulp chamber is punctured or perforated, the inner mechanisms of the tooth are susceptible to oral bacteria. Partial tooth removal and reconstruction on the affected side saves the healthy part of the tooth and seals it from bacterial colonization.
Bifurcation – Sometimes, gum disease or periodontitis affects the area between two tooth roots. To halt the progression of the disease and to prevent the recession of the jawbone, part of the tooth may be removed through a hemisection.
Hemisections are becoming less common, as recent technological advances mean that root canal therapy fails less frequently. However, to determine candidacy for a hemisection, the dentist will first examine teeth to look for signs of disease and decay. X-rays will be taken to determine the exact nature of the problem below the gumline. The procedure itself will be performed under local anesthetic and generally takes around 30 minutes.
To split the tooth, the dentist makes a tiny incision in the gum to expose the structure below. The roots of the tooth are examined and separated into two sections. At this point, the dentist can definitively determine whether one of the roots can be saved, or if both should be discarded.
If one root is deemed to be healthy, the dentist removes the corresponding root and thoroughly cleanses the gap with saline solutions. A temporary crown will be placed to fill the gap. Arrangements will then be made to construct a permanent custom crown, which will be fitted with dental cement at a later date to strengthen the tooth.
If you have any questions or concerns about hemisections, please contact your dentist.