Ridge augmentation is a procedure that can shore up dents and other abnormalities in your gum line. People who lose a tooth, for example, may eventually develop a small indentation where the original tooth was located; this sometimes creates an uneven or unsightly gum line. Even if the tooth is replaced, the preceding shrinkage of the gum may cause the replacement tooth to look longer than the others.



If a loss of contour has already occurred, a hard tissue ridge augmentation can be done to rebuild the jaw bone, or a soft tissue ridge augmentation can be done to rebuild the contour and appearance of the gum. A hard tissue augmentation creates the bone necessary to support a dental implants, and both hard and soft tissue procedures create a natural looking soft tissue contour where teeth are missing.

Alveolar distraction osteogenesis is simply another clinical tool used to augment (rebuild) deficient alveolar bone. The concept of distraction osteogenesis (bone creation) derives from Gavril Ilizarov, the famous Russian orthopedic surgeon who demonstrated that long bones (found in the arms and legs) could be lengthened if an osteotomy (deliberate fracture) was done and the bone fragments moved slowly apart during the callus stage of bone healing. He found that when bone separation was too rapid or too frequent, callus formation was disturbed and bone healing did not occur. However, when bone movement was done “physiologically,” bone formed in the distraction zone and the bone was successfully lengthened. Ilizarov made several recommendations that are applicable for alveolar (jaw bone) “lengthening.” These include use of a latency period prior to distraction of about 1 week, use of very small increments of movement on the magnitude of 0.5 mm to 1 mm, and a frequency of movement limited to once or twice per day as long as 1 mm is not exceeded in a 24-hour period. Unique to alveolar distraction is the investing oral tissues that must be preserved on the transport segment. As the segment of bone is moved away from basal bone, the segment is “pulled” lingually or palatally by the pedicle, such that the vector of distraction becomes problematic.


For leg lengthening, Ilizarov used opposing distractors to counterbalance distraction force. For alveolar distraction, an opposing device cannot be placed as it would disturb the blood supply to the segment. One solution for this vector problem is to use a “biphase” device, such as the Mommaerts/Laster crest distractor illustrated here in Figures 1, 2, and 3. With this device a vertical movement is made and then followed by horizontal movement to compensate for lingual or palatal deflection.

This is a 34-year-old woman with missing upper premolar teeth due to trauma from a motor vehicle accident. She desired implants. The defect appears to be minimal at first glance. However, a critical appraisal of bone morphology reveals nearly complete loss of the facial plate of bone, a 4-mm to 5-mm horizontal defect, combined with a 3-mm alveolar vertical deficiency. This diagnostic conclusion discards the previous notion of “sufficient bone to restore” in favor of a desire to “recover alveolar anatomy,” a re-establishment of orthoalveolar form.


In this setting the maxillary segment was distracted vertically 3 mm, then horizontally about 5 mm (Fig 6). Following distraction healing, which in animals is about 2 months (but in humans can take 4 to 6 months), the device was removed and dental implants placed.


The patient was restored with a 3-tooth bridge on 2 implants (Fig 3). Resonance frequency analysis (RFA) was used to help determine the viability for single tooth restoration. A splinted restoration was done.