Crest Expander

The Crest Expanding distractor is used to widen a narrow alveolar crest which has sufficient height so as to prepare the ridge for implantation. With this technique, bone augmentation is avoided, implant is placed in the correct lateral position and sufficient attached gingiva is obtained. In addition the expander can be used to allow easy distal or mesial orthodontic movements of the molars.

The Crest Expander consists of 4 arms, 2 on each side connected with guiding pins and an activating screw. The Crest Expander is inserted through the incisions without stripping the bone after cutting and splitting the narrow crest. By rotating the activating screw, each pair of arms move apart from the other 2 arms, thus pushing the buccal cortical bone apart. Activating starts 5 - 7 days (latency period) after the insertion of the device. By separating the cortical plates, new bone is created in between, and the attached gingiva will be distracted simultaneously (Distraction Histiogenesis).

The procedure is conducted under local anesthesia in one or two stages.

Implantation is possible after extremely short period (5-8 weeks post-op).

Advantages

• Mucosal Distraction leads to sufficient attached gingiva and soft tissue cover (Distraction Histiogenesis).
• Transport bone is not stripped from periostium, therefore - no post-operative bone resorption.
• Simple, short, minimally traumatic procedure.
• No pain or morbidity at donor site.
• Less technique-sensitive.
• Implant placement possible after extremely short post-operative period (5-8 weeks).
• Procedure is easily performed in a dental office.
• Minimally compromised aesthetics.
• Encourages ideal lateral implant placement when needed.
• Facilitates easy orthodontic movements of molars.

Indications

• Preparing the narrow alveolar crest for implantation as an alternative to bone augmentation.
• Distraction of the attached gingiva prior to implantation (Distraction Histiogenesis).
• Preparing the crest for orthodontic mesialisation or distalisation of molar teeth.

Contra-indications

In cases where the alveolar ridge has insufficient vertical height, or there is an absence of cancellous bone between the two crestal cortical bones.

Recommendations for the surgeon

• Avoid unnecessary stripping of the periostium to reduce bone resorption.
• Attempt to perform the crestal bony cut on the lingual/palatal cortical bone, since these are thicker and more compact than the buccal bone.
• Either the scalpel reciprocating saw, the thin long tungsten fissure bur or the Piezo machine can be used for the bony cuts.
• The Piezo machine is the recommended technique for this procedure under local anesthesia, since it is the most comfortable for the patient.
• Impaired dental aesthetics in the anterior segments can be avoided with an Omnivac Vacuum Egg Shell with denture teeth as provisional bridge.
• After tapping the Crest Expander, always ensure that the bone fragment is loosened by activating the distractor 2 full anti-clockwise turns and 1 clockwise turn. The stability of the device is increased when it is activated.
• If the bone fragment is not loosened, then use a thin osteotome to free it.
• Always secure the distractor to an adjacent tooth with the titanium wire or 4/0 black silk or nylon suture.
• If the distractor is loosened after activation is stopped, remove the distractor and insert the implants.
• Antibiotic cover is recommended.

Instructions to communicate to the patient

• Cold soft food and drinks for 24 hours.
• Avoid chewing on the distracted side.
• Antiseptic mouth rinsing and gentle brushing of the distractor and the widened region.
• Self activating of the device 1/4 of an anti-clockwise rotation, twice a day.
• One day rest after every 4 days of activation.
• Once a week, the device has to be checked by the surgeon.
• If the device is loosened after the activation is stopped, patient has to see the surgeon as soon as possible.
• Slight pressure might be felt at the beginning of the activation and towards the completion.