Alexander Gaggl

Scanning electron microscopical analysis of laser-treated titanium implant surfaces—a comparative study

Design and surface qualities of titanium implants are of vital importance for long-term stability following implantation. Four different implant surfaces treated individually were analyzed with special attention focused on laser surface treatment. Surfaces with machine roughness, titanium spray coating, treated by aluminum oxide and treated by laser were examined individually. Evaluation of the surface was carried out by electron microscope examination and mechanical profilometry. The EDS analysis determined the degree of contamination of the implant surface. Electron microscope examination showed that the titanium plasma spray as well as the laser-treated implants have optimum surface qualities: a secondary and tertiary structure with micro-roughness of 10 mm and roughness ranging from 0.5 to 4 mm. The least contamination was found for machine rough surfaces as well as those treated by laser. The other implants showed contamination corresponding to the method of surface treatment. In summary the optimal surface structure with the least contamination was found for the laser-treated titanium surface. Similar surface purity was found for the machine rough surfaces. An optimal structure was also achieved by the titanium plasma spray method, however, at the cost of surface purity.

Vascularized Medial Femoral Trochlea Osteocartilaginous Flap Reconstruction of Proximal Pole Scaphoid Nonunions

PURPOSE The descending geniculate arterys branching pattern includes periosteal vessels supplying the cartilage-bearing trochlea of the medial patellofemoral joint. Previous cadaveric studies described anatomic similarities between the greater curvature of the proximal scaphoid and the convex surface of the medial femoral trochlea (MFT). We describe the technique and report our first 16 consecutive cases of vascularized osteocartilaginous arthroplasty for chronic scaphoid proximal pole nonunions using the MFT, with a minimum of 6 months of follow-up. METHODS Chart reviews of 16 consecutive cases of osteocartilaginous MFT flap transfers for scaphoid reconstruction were performed at 2 institutions. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months (range, 6-72 mo). Patient age and sex, duration of nonunion, number of previous surgical procedures, surgical technique, achievement of osseous union, preoperative and postoperative scapholunate angles, preoperative and postoperative range of motion, and pain relief were recorded. RESULTS Computed tomography imaging confirmed healing in 15 of 16 reconstructed scaphoids. Mean patient age was 30 years (range, 18-47 y). The average number of previous surgical procedures was 1 (range, 0-3). All patients experienced some wrist pain improvement (12/16 complete relief, 4/16 incomplete relief). Wrist range of motion at follow-up averaged 46° extension (range, 28° to 80°) and 44° flexion (range, 10° to 80°), which was similar to preoperative measurements (average 46° extension and 43° flexion). Scapholunate relationship remained unchanged with average scapholunate angles of 52° before surgery and 49° after surgery. CONCLUSIONS Osteochondral vascularized MFT flaps provide a reliable means of achieving resolution of difficult proximal pole scaphoid nonunions. These flaps allow resection of the proximal portion of the unhealed scaphoid and reconstruction with an anatomically analogous convex segment of cartilage-bearing bone. This technique provides the advantages of vascularized bone and ease of fixation. Early follow-up demonstrates a high rate of union with acceptable motion and pain relief. CLINICAL RELEVANCE Early follow-up suggests that the vascularized MFT osteocartilaginous flap is a valuable tool for treating challenging proximal pole scaphoid nonunions.

Free microvascular transfer of segmental corticocancellous femur for reconstruction of the alveolar ridge

In seven patients with deficiency of the alveolar ridge of the maxilla or mandible the defect was covered with the help of a microvascular corticocancellous transplant of femur. The defects to be corrected measured 3-10 cm long, 1.5-4 cm wide, and 1-1.5 cm high. The microvascular pedicle was between 4 and 10 cm long. The descending genicular artery was anastomosed to the facial or labial superior artery and the accompanying veins accordingly. There were no serious complications and no transplant was lost. In all patients the defect was covered by the correct size and design. All patients were treated with dental implants six months after successful reconstruction of the ridge. The microvascular osteoperiosteal femur transplant can be used successfully in individual reconstruction of segmental defects of the alveolar ridge.

Changes in soft tissue profile after sagittal split ramus osteotomy and retropositioning of the mandible

PURPOSE The prediction of profile changes as a result of orthognathic surgery remains a problem during preoperative planning because of the different relative movements of the hard and soft tissues. This study analyzed the changes in soft tissue profile after sagittal split ramus osteotomy and mandibular setback. PATIENTS AND METHODS Soft tissue changes relative to hard tissue references were recorded by means of computer-supported measurements of preoperative and postoperative standardized lateral skull radiographs of 60 Class III patients. RESULTS An average backward transposition of the osseous pogonion of 7.1 mm was recorded. Relative to movements of this reference point in the sagittal plane, the soft tissue pogonion moved 83.9%, the soft tissue menton moved 98.9%, the labrale superior moved 32.0%, the stomion moved 45.2%, and the labrale inferior moved 79.6%. The same measurements were performed in the vertical plane, and changes in soft tissue references were analyzed. There was a marked difference in soft tissue changes after mandibular retropositioning when compared with results after mandibular advancement reported in the literature. CONCLUSION It was concluded that it is of great importance to consider both the direction and the surgical method when predicting profile changes in the vertical as well as sagittal plane after orthognathic surgery.

Periodontal disease associated with interdental osteotomies after orthognathic surgery

PURPOSE One of the main reasons for orthodontics and orthognathic surgery is the prevention of dental loss caused by periodontal disease. Until now there have been no published data describing the periodontal situation near interdental osteotomies after orthognatic surgery. The purpose of this study was to evaluate this situation. PATIENTS AND METHODS Thirty patients with Class II malocclusions were studied 4 to 10 years after segmental orthognathic surgery, analyzing the periodontal condition near osteotomies with the aid of periapical and panoramic radiographs. RESULTS Fifty-one pathologic periodontal lesions were found in the 74 segmental osteotomy sites. There were 35 segmental areas with osseous periodontal defects and 16 segmental areas with missing teeth. CONCLUSION A high incidence of dental and periodontal trauma occurs in the region of segmental osteotomies after orthognathic surgery.

Stability of dental implants in microvascular osseous transplants

&NA; Microvascular iliac crest and scapula transplants have been used in reconstruction of the lower jaw following tumor surgery. It has only been with the insertion of dental implants that a satisfactory prosthetic rehabilitation of the patient has been achieved. For this study, a follow‐up of 38 patients with lower jaw tumors was carried out. The patients had been treated with partial resection of the lower jaw and neck dissection with microvascular iliac crest transplants (n = 20) or microvascular scapula transplants (n = 18); this was followed with dental implants (n = 143) in the region of the transplants or the local lower jaw. One hundred thirty‐nine of the 143 dental implants were loaded by prosthetic superstructures. In all patients, the implant situation was evaluated on average 2 years 5 months after implantation. Periotest values, periimplant probing depths, and contact bleeding were registered, and the extent of periimplant bone loss was defined radiographically. The clinical situation in the region of the implant was compared for both types of implants and also with the nonresected lower jaw. The average Periotest values were within the normal range for all groups. In one scapula implant, however, a better average of Periotesting, ‐ 3.3, was found compared with implants of the iliac crest with Periotest values of ‐0.7. A measurement of ‐2.1 was found for the local lower jaw, similar to that of scapula implants. Pathologic probing depths were found for all three compared groups. The radiographically determined vertical loss of bone was the same for all three groups, on average 1 mm at 27 months postoperatively. The highest incidence of sulcus bleeding was found in the scapula implant group. Thus, it can be stated that the scapula transplants provide a similar transplant site to local lowerjaw bone, whereas implants in iliac crest transplants show lesser bony stability. Periimplant soft‐tissue conditions are worse for both types of transplants compared with local tissue of the lowerjaw. (Plast. Reconstr. Surg. 109: 916, 2002.)

The Microvascular Osteocutaneous Femur Transplant for Covering Combined Alveolar Ridge and Floor of the Mouth Defects: Preliminary Report

In this preliminary report, the surgical technique of an oral defect coverage using the microvascular osteocutaneous flap from the distal medial femur is described and three clinical cases are reported. The new flap was used for covering combined defects of the alveolar ridge and the neighboring floor of the mouth after tumor surgery and irradiation. The bone part of the flap was supplied by the descending genicular artery and the soft tissue part by their first emission-the saphenous artery. Anastomoses were performed between the common part of the flap pedicle and cervical arteries or veins. There were no severe complications or transplant loss. All patients were successfully treated with dental implants (n = 12) 4 to 6 months after ridge reconstruction. The microvascular osteocutaneous femur transplant can be used successfully in individual reconstruction of the alveolar ridge and the neighboring floor of the mouth after tumor resection.

Cephalometric and occlusal outcome in adults with unilateral cleft lip, palate, and alveolus after two different surgical techniques

OBJECTIVE To assess differences in the aesthetic and functional long-term results of one-stage and two-stage surgical and orthodontic treatment in patients with cleft lip, palate, and alveolus. DESIGN Sixty adult patients who were operated on as children for unilateral cleft lip, palate, and alveolus were examined. In every patient the lip was closed using Tennisons technique. Thirty patients had soft and hard palate closure in two stages and 30 patients in a single stage. Lateral cephalometric and model analyses were conducted at a mean age of 18.4 years. RESULTS In the model analysis, transverse narrowing was seen in all patients after two-stage operations and in three patients after one-stage operations. The deficit was more severe in the molar region in the two-stage group and nearly similar in the premolar and molar region in the one-stage group. A sagittal deficiency in the anterior maxilla was found in 26 patients after two-stage operations and in 16 patients after one-stage operations. In the lateral cephalometric analysis, the mean sella-nasion-point A angle in the one- and two-stage group was 78.2 degrees and 76.8 degrees, respectively. The ANB angle was normal in both groups. In both groups the inclination of the midface was low. There was a low posterior facial height. Minor scarring was seen in the single-stage group. CONCLUSION A more severe impairment of growth of the maxilla in the sagittal and frontal plane was observed after two-stage operations on the cleft palate.

Biomechanical properties in titanium implants with integrated maintenance free shock absorbing elements

Good functional properties are essential in dental implantology. Bio-kinetic elements are imitating dental resilience. In this study a new kind of implants with maintenance free shock absorbing elements will be introduced and their bio-mechanic properties reported. The mobile implant (SIS Inc., Klagenfurt, Austria) is a self-cutting conical screw implant with an integrated bio-kinetic element. The shock absorber is a central part of the implant and a titanium ring closes the shock absorbing unit within the implant. The resilience of the implant was tested by axial and horizontal loading in a special testing unit. Furthermore, a survival test of the elastic titanium ring in the most exposed cervical part of the implant was performed. The region was examined by electron microscopy after 12 million movements in the axial and horizontal direction. A progressive shock absorption was registered during horizontal and axial movements. The maximum movements were 0.06 mm in the axial and 0.16 mm in the horizontal direction. There were seen no signs of material destruction in the electron microscopic analysis. A maintenance-free bio-kinetic implant with progressive shock absorbing qualities was registered.

Aesthetic and Functional Outcome of Surgical and Orthodontic Correction of Bilateral Clefts of Lip, Palate, and Alveolus

OBJECTIVE To assess the aesthetic and functional long-term results of surgical and orthodontic treatment of patients with bilateral cleft lip, palate, and alveolus. DESIGN Long-term follow-up study. SETTING Teaching hospital in Austria. PATIENTS Twenty adult patients who had been operated on as children for bilateral cleft lip, palate, and alveolus. INTERVENTIONS Lateral cephalometric and model analysis. The sum of all mesiodistal tooth diameters in the maxilla and mandible were compared with standard Bolton tracings. MAIN OUTCOME MEASURES Aesthetic and functional results. RESULTS (MODEL ANALYSIS): The upper arch was too wide in 12 patients and the mandibular arch was too wide in 4 patients. In 11 patients, the lateral teeth were crowded, and all had a persistent transverse space deficit and a reduction in sagittal measurements. Fifteen patients had alveolar midline displacement of the maxilla as well as of the mandible. RESULTS (LATERAL CEPHALOMETRIC MEASUREMENTS): The lateral cephalograms showed a mean sella-nasion-A point angle of 77 degrees and a maxillary baseline-nasion-sella line angle of 9 degrees, indicating a tendency toward maxillary retrognathia. An anterior facial height index of 42% (compared with the standard 58%) indicated a slight reduction in midface height with consequent increase in the height of the lower face. CONCLUSION There is specific growth impairment of the midface in adults who were treated as children for bilateral clefts of lip, palate, and alveolus. An optimal result can be achieved only by additional orthognathic surgery (Le Fort II osteotomy).