Glossary

Dental uncovery is often described as tooth uncovery and is a specific type of dental procedure performed when an adult tooth is developed in the improper position and doesn’t properly erupt in the mouth. This condition is called tooth impaction and can cause a wide variety of problems for the patient if not treated. Healthy teeth can become crowded and new teeth are prevented from growing into their own correct positions, which can result in the need for more invasive dental procedures later on. Dental uncovery involves making a small incision into the gums where the tooth has failed to erupt to expose it. Then, orthodontic devices may be used to facilitate normal growth. Impacted teeth are most often caused by genetics or heredity, excess bone and gum tissue, the abnormal sequence of tooth eruption ankylosis (where the tooth root and bone become fused together), and crossbite.

An Underwood cleft or septum is a fin-shaped projection of bone that sometimes exists in the maxillary sinus on or near the floor of the sinus cavity and is often called a maxillary sinus septum or Underwood’s septa. Its name is derived from Arthur S. Underwood, the anatomist at King’s College in London who first discovered these bones in 1910. An Underwood septum is of special interest to dental professionals when performing surgical procedures designed to elevate the sinus floor, because it increases the likelihood of potentially serious complications like tearing of the Schneiderian membrane, or the thin lining of the maxillary sinus cavity. As many as 32% of patients have been reported to have an Underwood’s septa, and they can often be seen on dental x-rays without the need for additional imaging. Two types of septa exist; primary septa were originally described by Underwood and secondary septa can form after tooth loss.

For a dental implant to be successful, the alveolar ridge must have sufficient volume. When it doesn’t, periodontists can choose to use a unilateral subperiosteal implant, a type of dental implant that was specifically developed for patients who do not have enough residual bone in the alveolar ridge. This type of implant has survival/success rates similar to other modalities. Unilateral subperiosteal implants are contraindicated in patients with an overabundance of bone. The procedure involves two stages; first, a bone impression is taken and second, the custom dental implant is placed. A subperiosteal dental implant is made to rest on top of the bone under the periosteum instead of traditional implant hardware that is placed much deeper into bone. Instead, the implant disperses pressure over a larger surface area, much like a snowshoe. The implant is made from a custom metal casting that adheres to the bone with direct support and surrounding fibrous tissue.

The UCLA abutment has been around since the late 1980’s, however, many periodontists overlook this implant abutment in favor of others. This type of abutment is considered stronger than zirconia abutments because there is an internal connection via a secondary metal component. No matter the implant size, the UCLA abutment can be used with any dental implant system. In fact, UCLA abutments are often used in cases where a smaller implant is needed, because the smaller a zirconia abutment, the weaker it will be. Another benefit to the UCLA abutment is that it was created with ceramic applied and baked to the entire surface instead of just the sub-gingival area. This allows for a completely ceramic crown to be used. A UCLA abutment works particularly well with a bridge, however, crowns and other restorations can benefit from this abutment. Tooth color can be achieved for aesthetic purposes and healing time is similar to other abutment materials.