International Journal of Periodontics & Restorative Dentistry, 01/2001

Two case reports demonstrate a new orthodontic method that offers short treatment times and the ability to simultaneously reshape and increase the buccolingual thickness of the supporting alveolar bone. A 24-year-old man with a Class I severely crowded malocclusion and an overly constricted maxilla with concomitant posterior crossbites and a 17-year-old female with a Class I moderately to severely crowded malocclusion requested shortened orthodontic treatment times. This new surgery technique included buccal and lingual full-thickness flaps, selective partial decortication of the cortical plates, concomitant bone grafting/augmentation, and primary flap closure. Following the surgery, orthodontic adjustments were made approximately every 2 weeks. From bracketing to debracketing, both cases were completed in approximately 6 months and 2 weeks. Posttreatment evaluation of both patients revealed good results. At approximately 15 months following surgery in one patient, a full-thickness flap was again reflected. Visual examination revealed good maintenance of the height of the alveolar crest and an increased thickness in the buccal bone. The canine and premolars in this area were expanded buccally by more than 3 mm, and yet there had actually been an increase in the buccolingual thickness of the overlying buccal bone. Additionally, a preexisting bony fenestration buccal of the root of the first premolar was covered. Both of these findings lend credence to the incorporation of the bone augmentation procedure into the corticotomy surgery because this made it possible to complete the orthodontic treatment with a more intact periodontium. The rapid expansive tooth movements with no significant apical root resorption may be attributed to the osteoclastic or catabolic phase of the regional acceleratory phenomenon. Instead of bony "block" movement or resorption/apposition, the degree of demineralization/remineralization might be a more accurate explanation of what occurs in the alveolar bone during physiologic tooth movement in these patients.

This article presents a histologic evaluation of three hydroxyapatite (HA)-coated root-form implants retrieved from humans after being in function for 3.5 to 11 years. If the coronal portion, where bone loss was observed clinically and radiographically, is excluded, all implants appeared to be well osseointegrated, with intimate contact between the surrounding bone and the coating. There was no sign of resorption or dissolution of the HA coating. The coating had a uniform thickness (50 µm) equal to the thickness originally provided by the manufacturer. In the few areas where there was no bone contact, the HA coating appeared to line the implant with no sign of dissolution. The few detached particles had tight contact with the bone, demonstrating the biocompatibility of the HA. The observations from the three reported cases suggest that the HA coating of dental implants may not be susceptible to resorption or dissolution under long-term function.

The biologic principle of guided tissue regeneration has been expanded to mucogingival surgery, using resorbable barrier membranes for the treatment of gingival recessions. Space provision is one of the main problems in non-space making defects, considering the softness of resorbable membranes. In this study, we tested the possibility to create and maintain a secluded space using a slow, long-lasting resorbable suture so that a resorbable dome device could support the barrier and immediately become a space-making device. Ten purely mucogingival recessions in ten patients were treated. At 12 months, the results were evaluated. In five subjects the gingival margin was within 1 mm of the cementoenamel junction, in four patients it was within 2 mm, and in one case a residual gingival recession was present (where the membrane became exposed). The mean root coverage obtained was 70.4%, while the mean gain of clinical attachment was 3.3 mm.

Although dental implants have become an effective treatment modality for the replacement of missing teeth, their predictability relies on successful osseointegration during the healing period. The purpose of this pilot study was to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on early bone formation within the perforations of dental implants in beagle dogs. Histologic sections were evaluated for the extent of new bone formation within a 1-mm diameter of through-and-through perforations. Data indicated that significantly more bone formation occurred with rhBMP-2-treated sites within the implant perforation (P 0.01) compared to sites treated with the vehicle alone. This pilot study indicates that rhBMP-2 increases the rate and extent of bone formation in combination with dental implants.

Tissue engineering is an emerging discipline that applies engineering principles to create devices for the study, restoration, modification, and assembly of functional tissues and organs from native or synthetic sources. In the field of guided bone regeneration (GBR), cellular matter engineering has been applied, more or less successfully, to the development of biodegradable and bioresorbable devices with chemical, physical, or mechanical properties, structure, or form that permit active tissue integration with desirable cell types and tissue components. The employment of synthetic and naturally occurring polymers as well as sophisticated manufacturing technologies allow the tissue engineering of matrix configurations so that the biophysical limitations of mass transfer can be satisfied. The configuration of such a hybrid matrix can also be manipulated to vary the surface area available for cell attachment, as well as to optimize the exposure of the attached cells to nutrients. A biodegradable and bioresorbable device made of synthetic and natural polymers was engineered specifically for GBR procedures. The degradation and resorption kinetics as well as the mechanical properties give the device the potential to function as a carrier for bone growth factors. This innovative device was applied as a GBR membrane in a clinical investigation inseven patients.

A restorative design is introduced in preference to the implant-supported bar, clip, or ball-type removable prosthesis. It has been necessary to develop an alternative treatment approach to the placement and restoration of implants in the posterior mandible or maxilla. In an examination of the available therapeutic choices and their rationales, this treatment option offers greater function, esthetics, and comfort. Four maxillary and one mandibular arches were reconstructed with anterior implant-supported fixed bridges/splinted restorations and a precision partial denture design posteriorly, using an extracoronal universal ball attachment. These cases have demonstrated minimal maintenance up to 7 years in function.

The importance of gingival augmentation to increase the amount of keratinized tissue is a controversial subject. In this case report, an acellular dermal matrix was used to obtain an increase in the amount of keratinized tissue around four implants. In this case, the acellular dermal matrix was placed on bone. The surgical procedure resulted in an increase in the amount of keratinized tissue. Therefore, it met the clinical goals of the surgical procedure. However, the clinical findings and patient pain levels during the healing seemed to resemble a denudation procedure. Additionally, the histologic evaluation of the tissue that formed around the implants showed that the acellular dermal matrix was not incorporated into the result. Based on this case, the use of an acellular dermal matrix placed on bone does not seem to be a good technique to increase the amount of keratinized tissue.

Techniques for surgical root coverage have been continuously revised over the past few decades. With increased knowledge on the etiopathogenesis of gingival recessions and on the repair/regeneration mechanisms of deep and superficial periodontal tissues, procedure simplification has been possible, and more predictable and stable results have been obtained. The maintenance of maximal blood supply has brought major changes in flap design. The coverage of contiguous recessions on the maxillary central incisors using a conservative technique for the incision of the recipient site is presented, along with the 11-month follow-up from surgery. A supraperiosteal tunnel was performed for the insertion and stabilization of a connective tissue autograft.

A retrospective study was conducted on all cases of pemphigus vulgaris occurring on oral mucosal surfaces in the files of the Oral Pathology Laboratory at Temple University from 1974 to 1996. A total of 35 biopsies from 33 patients were reviewed, 25 female and eight male. Patient ages ranged from 27 to 79 years; the mean age was 56.5. The most common clinical complaint was of painful ulcers that failed to resolve within several weeks. Thirty patients had no known history of pemphigus, while in three patients a history of pemphigus was known. The most common clinical impression was that of mucous membrane pemphigoid, but the differential diagnosis included other vesiculoerosive conditions.