Local and systemic conditions potentially compromising osseointegration. Consensus report of Working Group 3.
Explore the source record for details and available documents.
Alveolar Ridge Augmentation↗
Biomedical subjects
Friedrich W Neukam
Publications and source records attributed to Friedrich W Neukam.
Determination of facial symmetry in unilateral cleft lip and palate patients from three-dimensional data: technical report and assessment of measurement errors.
OBJECTIVE: To assess measurement errors of a novel technique for the three-dimensional determination of the degree of facial symmetry in patients suffering from unilateral cleft lip and palate malformations. DESIGN: Technical report, reliability study. SETTING: Cleft Lip and Palate Center of the University of Erlangen-Nuremberg, Erlangen, Germany. PATIENTS: The three-dimensional facial surface data of five 10-year-old unilateral cleft lip and palate patients were subjected to the analysis. Distances, angles, surface areas, and volumes were assessed twice. MAIN OUTCOME MEASURES: Calculations were made for method error, intraclass correlation coefficient, and repeatability of the measurements of distances, angles, surface areas, and volumes. RESULTS: The method errors were less than 1 mm for distances and less than 1.5 degrees for angles. The intraclass correlation coefficients showed values greater than .90 for all parameters. The repeatability values were comparable for cleft and noncleft sides. CONCLUSION: The small method errors, high intraclass correlation coefficients, and comparable repeatability values for cleft and noncleft sides reveal that the new technique is appropriate for clinical use.
Anthropometry↗
Neurophysiological monitoring of alveolar nerve function during sensor-controlled Er:YAG laser corticotomy in rabbits.
BACKGROUND AND OBJECTIVES: The sensor-controlled Er:YAG laser system may be a potent tool for tissue specific cutting in surgery. In order to investigate the impact of the laser on neural tissues, inferior alveolar nerve (IAN) function was monitored by the jaw-opening reflex (JOR) during specific corticotomy in rabbits. STUDY DESIGN/MATERIALS AND METHODS: Laser jaw corticotomy was performed in 13 anesthetized rabbits. During and after specific corticotomy the JOR was evoked by electric intraoral stimulation to monitor effects on IAN function. RESULTS: The JOR permanently abolished in one case and transiently failed immediately after surgery but largely recovered within days in another rabbit. In one experiment JOR threshold increased 7 days after corticotomy. Histology did not prove any objective nerve pathology. CONCLUSIONS: Monitoring IAN function by the JOR demonstrated the relatively low risk of nerve damaging during sensor-controlled laser corticotomy.
Animals↗
A clinical evaluation of the Zygoma fixture: one year of follow-up at 16 clinics.
PURPOSE: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement. MATERIALS AND METHODS: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered. RESULTS: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces. CONCLUSION: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.
Adult↗
Submental cutaneous sinus tract as a result of progressive peri-implantitis: a case report.
BACKGROUND: The aim of the present case report was to define diagnosis and treatment options of a submental cutaneous sinus tract as a result of a progressive peri-implantitis around mandibular dental implants in a patient with a history of oral squamous cell carcinoma. METHODS: Before the removal of the submental fistula, a panoramic radiograph and a computed tomography of the head and neck were assessed to identify the implants responsible for the cutaneous sinus tract and to exclude the presence of a tumor recurrence and lymph node metastases. The involved implants were removed, as there was a communication along them between the oral cavity and the cutaneous sinus tract resulting from progressive peri-implantitis. A histological examination of the excised fistula was carried out. RESULTS: The histological examination excluded a recurrence of the oral squamous cell carcinoma. The fistula completely consisted of granulation tissue without epithelialization. After affected implants were removed, the wound healing was uneventful. CONCLUSIONS: A panoramic radiograph is mandatory to identify the involved implants. Computed tomography, and excision of the fistula and a histological examination should be performed only in patients with a history of oral squamous cell carcinoma. Since the cutaneous sinus tract showed no epithelialization, it healed spontaneously after the removal of the responsible implants. Because of the large bony defect caused by progressive peri-implantitis leading to a communication of the oral cavity with the cutaneous sinus tract, more conservative treatment options with preservation of the implants could not be adopted in the present case.
Carcinoma, Squamous Cell↗
The effects of magnitude and frequency of distraction forces on tissue regeneration in distraction osteogenesis of the mandible.
Callus distraction has become an accepted treatment procedure to lengthen hypoplastic mandibles in humans. For this purpose, extraoral and intraoral devices have been applied successfully. The effects of the distraction vector, distractor stability, and rate and frequency of callus distraction on the regenerating tissues have been examined in various studies. In an experimental animal trial on pigs (n = 12), a newly developed microhydraulic osteodistractor was tested. The animals were evenly assigned to two groups to perform a continuous and noncontinuous osteodistraction of the mandible. Initially, the forces necessary to distract the pig mandibles were recorded from a noncontinuous distraction procedure; the results were then used to perform continuous bone distraction. Besides testing the new distractor, the study proved that in continuous osteodistraction, intramembranous bone regeneration occurred, whereas in noncontinuous osteodistraction the bone regeneration process followed a chondroid ossification. In continuous osteodistraction, the bone regeneration proceeded at a higher speed with the lower distraction forces compared with noncontinuous distraction, thereby reducing the consolidation period. Clinical and microscopical results are presented.
Animals↗
The endoscopically controlled osteotome sinus floor elevation: a preliminary prospective study.
PURPOSE: It was the aim of the present prospective study to quantify the gain in height of implant sites by endoscopically controlled osteotome sinus floor elevations (ECOSFE) with simultaneous implant placement and to report the number of sinus membrane perforations. MATERIALS AND METHODS: From October 1999 to December 2000, of 92 sinus floor elevations, 18 were carried out endoscopically controlled with an osteotome technique. As augmentation material, beta-tricalcium phosphate (beta-TCP) or autogenous bone was used; 22 implants were placed. RESULTS: The residual height of the alveolar crest in the posterior maxilla was 6.8 +/- 1.6 mm on average. The implant lengths ranged from 10 to 16 mm (mean implant length 12.2 +/- 1.4 mm). They were significantly larger than the residual height of the alveolar crests (P < .0005). Elevation of the sinus floor with an osteotome had to be supported by conventional sinus floor elevation instruments after a mean elevation of 3.0 +/- 0.8 mm to prevent perforation of the sinus membrane. However, 1 perforation occurred, which was repaired with a periosteal patch. At stage 2 surgery, 2 implants were removed because of mobility. Endoscopic control revealed one case in which beta-TCP could be found within the sinus; another case showed areas of polypoid mucosa on the sinus floor. DISCUSSION: With the ECOSFE, perforations of the sinus membrane can be visualized; however, they cannot be avoided. Although this technique is less invasive than the lateral window technique, it cannot be recommended as a standard procedure in the posterior maxilla because of the large amount of additional equipment needed and the technically demanding procedure. CONCLUSION: The use of the ECOSFE should be confined to scientific trials.
Adult↗
Examination of the bone-metal interface of titanium implants coated by the microwave plasma chemical vapor deposition method.
PURPOSE: Diamond layers can be plated with microwave plasma chemical vapor deposition (MWP-CVD) treatment on metal bases such as titanium-aluminum-vanadium alloy (Ti-6Al-4V). The bonding strength of the diamond layer to the metal base is very high, so that no fissures and partial loss of coating take place-well known phenomena that may occur with other coatings in tribologic material testing. In an experimental study using 40 New Zealand White rabbits, a new method for coating implant material was tested for stability of the bone-metal interface. MATERIALS AND METHODS: The results of histomorphometric and biomechanical evaluation of coated and uncoated probes implanted in the distal femur of 40 rabbits were compared. The animals were divided into 3 groups, with observation times of 42, 84, and 168 days. RESULTS: The bone-implant contact was 5% to 18% less in coated than in uncoated probes. Only the early group, with 42 days healing time showed significant differences. Values for the pull-off force of uncoated material were about 3 to 4 times higher than coated material (diamond layer = 2.7 microm). The force increased 2 to 3 times when 200-nm coatings were tested. Electron microscopy detected undercuts of the rough surface that were obturated by diamond when the coating was too thick. DISCUSSION: Diamond-coated material seems to have no corrosion problems in contrast to all other known implant material. CONCLUSION: An inert diamond layer on a metal base can become osseointegrated. Biomechanical stability increased by thinning the diamond coating.
Alloys↗
Are factor V and prothrombin mutations associated with increased risk of oral cancer?
BACKGROUND: Methylenetetrahydrofolate reductase is associated with pathogenesis of both thrombosis and oral cancer. Therefore, a search for a similar association of other thrombosis-related factors with oral cancer is justified. PATIENTS AND METHODS: In order to investigate whether the coagulation factor V Leiden and prothrombin G20210A mutations increase the risk of oral cancer, we searched for these mutant alleles by RFLP analysis in DNA samples of 102 patients with oral cancer and 120 healthy controls. RESULTS: Neither the Leiden nor the G20210A alleles were found in statistically different frequencies in the two groups. In addition, no statistical difference was observed in parameters such as sex, age and positive family history for cancer. Nevertheless, a significant difference was observed for Leiden in patients with a positive history for thrombophilia (p < 0.001). CONCLUSION: There seems to be no association of prothrombin, and possibly a minor contribution of factor V, in oncogenesis in the oral region.
Adult↗