Biomedical subjects

Friedrich Wilhelm Neukam

Publications and source records attributed to Friedrich Wilhelm Neukam.

At least 19 recordsLinked to original sources

PubMed2006

Dynamic periosteal elevation.

The osteoinductive potential of the periosteum can be stimulated by raising the periosteum using a type of distraction. This was tested and confirmed in an animal experiment in 6 Goettingen minipigs. A titanium mesh was implanted beneath the periosteum and then raised. Bone formed underneath the mesh, with rows of micro-pillars similar to those found after osteodistraction. The main advantages of dynamic periosteal elevation are that invasion and morbidity are minimal. Clinically it might be applicable in craniomaxillofacial surgery, in augmentation before implantation, and in reconstruction of the skull.

Animals↗

PubMed2006

Nasolabial symmetry following Tennison-Randall lip repair: a three-dimensional approach in 10-year-old patients with unilateral clefts of lip, alveolus and palate.

AIM: To assess the degree of facial symmetry in patients suffering from unilateral cleft lip, alveolus and palate (UCLAP) by determining differences between the cleft and the non-cleft hemifaces from 3D surface data. PATIENTS AND METHODS: In twenty-two 10-year-old UCLAP patients, who had the lip repaired using the Tennison-Randall technique and did not undergo further revisional surgery, differences were determined between landmarks, surface areas of the upper lip vermilion and nostrils and virtual volumes of midface, nose and upper lip for cleft and non-cleft sides, separately, after having established a plane of symmetry calculated from optical 3D facial surface data. RESULTS: Statistically significant differences could be found between cleft and non-cleft sides for the nasal landmarks G(lat), G(sup) and La(med), the nostril angle and the virtual volume of the nose (p(Glat)=0.011, p(Gsup)<0.0005, p(Lamed)=0.002, p(nostril angle)=0.036 and p(nose volume)<0.0005, resp.). CONCLUSION: Analysis of 3D data shows that complete nasal symmetry is difficult to achieve with Tennison-Randall's lip repair without revisional surgery. Further trials on larger populations of patients will allow a more comprehensive and consistent analysis of the consequence of different methods for cp repair in order to identify the techniques with the best outcome in terms of facial symmetry.

Cephalometry↗

PubMed2006

Intraoperative noncontact, nonionizing, optical 3D exophthalmometry during repositioning of dislocated globes: first results.

PURPOSE: This study reports on the intraoperative use of noncontact, nonionizing, optical 3-dimensional (3D) exophthalmometry during the repositioning of dislocated globes as a result of trauma. PATIENTS AND METHODS: Ten patients (4 female, 6 male, 41.4+/-15.2 years) with a relative enophthalmos of the globe as a result of zygomatic fractures were included in the study. Preoperatively, en- and exophthalmometry data were assessed from axial CT slices and optical 3D imaging. 3D data were analyzed twice for the assessment of measurement errors. Intraoperatively, optical en- and exophthalmometry was carried out to control the globe position. Surgery was considered successful when the relative en- or exophthalmos no longer exceeded 2 mm. Optical 3D en- and exophthalmometry data were reassessed 5 days and 3 months after surgery. RESULTS: Method error was 0.184 mm for optical 3D en- and exophthalmometry. The preoperatively assessed en- and exophthalmometry data determined from axial CT scans and from optical 3D images did not differ significantly statistically (P=.538). When the preoperative en- and exophthalmometry data were compared to the values assessed at the end of surgery, a significant improvement in globe position was found (P=.005). Although a relative en- or exophthalmos of 2 mm was not exceeded in any of the patients 3 months after surgery, en- and exophthalmometry data differed significantly statistically from the data assessed at the end of the operation (P=.005). CONCLUSIONS: Intraoperative optical en- and exophthalmometry is an effective means to support the surgeon in objectively optimizing the globe position with small measurement errors.

Adult↗

PubMed2006

Is there a need for autogenous blood donation in orthognathic surgery?

BACKGROUND: The present study sought to determine the frequency of blood transfusion and to evaluate the need for autogenous blood donations in patients undergoing bimaxillary orthognathic surgery. METHODS: According to an inclusion and exclusion protocol, 65 patients were selected for further analysis. Twenty-six patients donated a total of 45 units of autogenous blood; the remaining 39 patients did not. Medical records were reviewed retrospectively. RESULTS: Donors tended to have lower preoperative, intraoperative, and postoperative hemoglobin values, as well as lower hematocrit and leukocyte counts. Only the difference in mean preoperative leukocyte count, however, was statistically significant (donor: 6500/microl versus nondonor: 7400/microl; p = 0.021). The rate of transfusion was 2.5 percent for nondonors and 13 percent for donors of autogenous blood. Six donors had to be transfused a total of 8 units of autogenous blood, whereas only one of 39 nondonors received an allogenic blood transfusion. This difference turned out to be significant according to Fisher's exact test (p = 0.013). None of the donors received allogenic blood transfusion. CONCLUSIONS: In the authors' analysis, preoperative autogenous blood donation appears to be effective in reducing exposure to allogenic blood. Donors of autogenous blood, however, were transfused significantly more often than nondonors were. Neither intraoperative blood loss nor hematological values justify a preoperative donation of autogenous blood on a regular basis.

Adult↗

PubMed2006

Changes of mineralization of free autogenous bone grafts used for sinus floor elevation.

For augmentations before implant placement in areas of minor bone quantity, autogenous bone is considered the reference to all bone substitutes used alternatively. Autogenous bone transplants originate from various donor areas and can be prepared in different ways before augmentation. They may either be used as block grafts or may be milled to granules that can be used solitarily or in combination with a bone substitute. In a prospective study, 61 patients of the Maxillofacial Surgery Department of our University receiving two-stage sinus floor elevation because of insufficient bone supply were randomly selected. At first-stage surgery, the local augmentation procedure, monocortical probes were obtained on the site of bone harvesting. At second-stage surgery, the implant insertion 6 months after the elevation procedure, bone cores were harvested in the areas of implant placement. Donor regions were the following three areas: the posterior (N=28) and anterior pelvic region (N=15) and the chin region (N=18). The implanted bone in all three groups was particulated to granules of 2-3 mm(2) using a bone mill. All biopsies were analyzed by means of microradiography. The anterior pelvic bone grafts showed a mineralized tissue grade of 35.1+/-7.6% before milling and augmentation. The posterior pelvic bone grafts exhibited a mineralization of 30.7+/-9.5% and the chin bone grafts 74.6+/-8.6%. At second-stage surgery after 6 months, the mineralization was 36.1+/-7.59% in the areas where bone grafts from the anterior pelvic crest were used. Probes harvested from sites with posterior pelvic bone augmentations showed a mineralization rate of 34.5+/-6.5%, and sites were chin bone grafts were applied expressed a mineralization of 54+/-8.6% (P=0.003 compared with the pre-operative value). The comparison of the microradiographical results demonstrated significant differences in the mineralization grades depending on the origin of the graft. The origin of the grafts and their remodeling influenced the mineralization rates found at 6 months. How these data may influence the long-term clinical outcome considering implant survival and bone resorption has to be examined in further long-term studies.

Bone Density↗

PubMed2005

Enhanced bone regeneration with a synthetic cell-binding peptide--in vivo results.

This in vivo study compared the regenerative processes within defined defects of the porcine skull after delivery of a porous algae-derived hydroxyapatite (adHA), a similar, experimental adHA carrying the cell binding peptide P-15, used solely and in combination with 25% autogenous bone (AB). Particulated AB served as a control group. During an observation period of 26 weeks, microradiography and histology were performed at four specific times. Significantly higher mineralization rates (p=0.008) were found 4 weeks after application of the bioactive material in combination with AB. At 12 weeks there was a significantly higher mineralization (p=0.036) following the application of the bioactive form alone. This study showed significantly higher mineralization after use of a P-15 bioactivated material at early stages. Thus, it can be concluded that the application of the P-15 sequence to an hydroxyapatite accelerates the process of early bone formation, whereas no long-term effect was traced.

Animals↗

PubMed2005

Untreated 'blow-in' fracture of the orbital floor causing a mucocele: report of an unusual late complication.

BACKGROUND: Several severe complications have been described with blow-in fractures. Therefore, immediate surgical treatment of these fractures has been recommended. To date, there is only minimal knowledge on long-term complications of blow-in fractures that have remained untreated. The present case report describes a late complication of an untreated blow-in fracture of the orbital floor. CASE: A 37-year-old male was involved in a car accident 16 years before. At that time, a non-dislocated midfacial fracture was diagnosed and remained untreated because of the lack of clinical symptoms. Four months before surgery an exophthalmos of the left globe began to develop. CT examination revealed a consolidated blow-in fracture of the left orbital floor and an opaque mass around the dislocated bony fragments. By an infraorbital approach the bony fragments and the surrounding mass were removed. Histological examination of the removed material revealed a cystic structure lined with respiratory epithelium. Therefore, the diagnosis 'post-traumatic mucocele in the orbit caused by dislocated respiratory epithelium from the maxillary sinus' was made. CONCLUSION: Even if blow-in fractures do not cause complications immediately after trauma, late complications like mucoceles can occur after several symptom-free years. Therefore, early reconstruction should be intended even in asymptomatic cases of blow-in fractures with minimal displacement of the bony fragments.

Accidents, Traffic↗

PubMed2005

Hemoglobin value reduction and necessity of transfusion in bimaxillary orthognathic surgery.

PURPOSE: It has been the aim of the present clinical study to assess the reduction of the hemoglobin value and the frequency of blood transfusions during bimaxillary orthognathic surgery and to discuss the clinical consequences. PATIENTS AND METHODS: Fifty-six patients (31 female, 25 male; mean age, 28.6 +/- 13.0 years; range, 14 to 66 years) were operated on. Twenty-nine patients predeposited blood before surgery. As a threshold for intraoperative or postoperative transfusion, a hemoglobin value of 7.5 g/100 mL was chosen. RESULTS: Perioperatively, the hemoglobin values of the patients who predeposited blood decreased significantly after blood donation. The hemoglobin value reduced postoperatively by 2.6 +/- 1.4 g/100 mL in the non-donors and by 2.6 +/- 1.1 g/mL in the donors. None of the patients who did not predeposit blood received homologous blood transfusions intraoperatively or postoperatively. In the group of patients who predeposited blood, 3 were transfused intraoperatively. They received 1 or 2 units of autologous blood. CONCLUSION: The individual statistics of the department show that there was only a limited reduction of the intraoperative and postoperative hemoglobin values as a consequence of bimaxillary orthognathic surgery. The increased safety of homologous blood and the minimal transfusion rates support abandonment of routine predepositing of autologous blood and the acceptance of homologous blood in the rare case of transfusion in bimaxillary surgery.

Adolescent↗

PubMed2005

The bone-metal interface of defect and press-fit ingrowth of microwave plasma-chemical vapor deposition implants in the rabbit model.

PURPOSE: The histological differences between the defect and contact areas of the implant surface to bone were tested in 35 New Zealand White rabbits in a standardized model. Microwave plasma chemical vapor-coated implant probes were tested in control and uncoated materials. MATERIAL AND METHODS: In each femur of 35 rabbits, cylindrical implant rods with a planed side were inserted. Three groups, divided in coated and uncoated material at half, were observed 42, 84 and 168 days. The probes were examined histologically for bone-implant contact in the curved and plane (defect area) sides. RESULTS: Generally the bone-implant contact seems to be nearly constant in time in the curved area of coated and uncoated probes. Here the implant was inserted in the press-fit mode. Diamond-coated probes showed similar bone-implant contact (51.9% (42 days), 62.5% (84 days), 56.1% (168 days)) compared to uncoated material (56.2%, 65.4%, 62.9%). The defect area (plane side) had no bone-implant contact at the time of insertion and showed increasing values on longer observation times with only significant differences in the 42-day group between coated (17.85%, 35.2%, 47.7%) and uncoated materials (35.5%, 40.55%, 51.81%). CONCLUSION: The evaluation of the curved side of the implant probe showed no great variation of bone-implant contact within the described observation times. This model simulates the usual implant insertion situation. The diamond-coated material becomes osseointegrated at a later time point. The bone-implant contact was only statistically relevant in one group in comparison to uncoated material.

Alloys↗

PubMed2004

Sensor-based laser ablation for tissue specific cutting: an experimental study.

The interaction of laser light and tissue causes measurable phenomenons. These phenomenons can be quantified and used to control the laser drilling within a feedback system. Ten halves of dissected minipig jaws were treated with an Er:YAG laser system controlled via a feedback system. Sensor outputs were recorded and analyzed while osteotomy was done. The relative depth of laser ablation was calculated by 3D computed tomography and evaluated histologically. The detected signals caused by the laser-tissue interaction changed their character in a dramatic way after passing the cortical bone layer. The radiological evaluation of 98 laser-ablated holes in the ten halves showed no deeper ablation beyond the cortical layer (mean values: 97.8%). Histologically, no physical damage to the alveolar nerve bundle was proved. The feedback system to control the laser drilling was working exactly for cortical ablation of the bone based on the evaluation of detected and quantified phenomenon related to the laser-tissue interaction.

Animals↗

PubMed2004

Reconstruction of skull bone defects using the hydroxyapatite cement with calvarial split transplants.

PURPOSE: We sought to present a new method for primary reconstruction of traumatic or tumor calvarial defects. PATIENTS AND METHODS: Forty-one patients underwent reconstruction of calvarial bone defects between October 1998 and December 2001. Among them were 19 patients who needed reconstruction of the calvaria due to traumatic bone loss. Five of these trauma cases had insufficient primary reconstruction of the calvaria. Tumor resection caused calvarial defects in 22 patients. For primary reconstruction of the skull bone defects, calvarial split grafts were used to cover the defect as accurately as possible. The monocortical layers of the calvaria were fixed with titanium miniplates. Irregular defects surrounding the transplanted regions were filled with hydroxyapatite cement. In one case of posttraumatic bone loss, hydroxyapatite cement alone was sufficient to reconstruct the defect. RESULTS: The follow-up of each patient was at least 6 months; the longest period was 38 months. Evaluated clinical and radiologic results are stable, showing no measurable side effects. CONCLUSION: Hydroxyapatite cement alone or in combination with calvarial split grafts gave clinically and aesthetically stable results in the reconstruction of skull bone defects. The cement can be used for many reconstruction possibilities in craniofacial surgery.

Adult↗

PubMed2004

Evaluation of quality of life of patients with oral squamous cell carcinoma. Comparison of two treatment protocols in a prospective study.

BACKGROUND AND PURPOSE: In recent years, various therapeutic concepts have been developed for treating oral cancer, these include preoperative simultaneous "neoadjuvant" radio-chemotherapy and one-stage-surgery with tumour ablation and reconstruction. When considering long-term survival, there is substantial evidence that the neoadjuvant therapy is superior to the primary surgical approach with postoperative radiation. Both treatment concepts, however, have a strong impact on the quality of life. PATIENTS AND METHODS: This study prospectively evaluates and compares quality of life in 53 patients with oral cancer treated according to a neoadjuvant concept or primarily surgically, using the questionnaires QLQ C-30 and H and N35 by the EORTC. RESULTS: Initially both groups showed a marked reduction in the quality of life. Despite a clear improvement in the first postoperative year baseline values were not reached in most of the scores. Specific long-lasting impairments in the symptom scales concerning oral functions were found in both treatment arms. In the neoadjuvant therapy group, however, especially global health and the emotional status were reduced to a higher degree than in the other group. This was particularly noticeable in the early treatment phase. CONCLUSIONS: Following an initial deterioration of quality-of-life after 3 months a gradual improvement of physical and psychological function was observed in the course of the first post-treatment year in both groups. Severe side effects can be observed. These side effects vary strongly in their individual expression. Limitations in the quality of life can be justified, if the more aggressive therapy resulted in a better disease free survival.

Adult↗

PubMed2004

Life-threatening thrombotic thrombocytopenic purpura associated with dental foci. Report of two cases.

OBJECTIVES: Thrombotic thrombocytopenic purpura (TTP) is a rare haematological disease of unknown aetiology. This thrombotic microangiopathy is characterized by microvascular lesions with platelet aggregation. It is found in adults and can be associated with pregnancy, cancer, autoimmune diseases, bone marrow transplantation, drugs and bacterial as well as viral infections. The therapy requires a multi-disciplinary team approach involving dentistry. Even if TTP is immediately treated in an adequate manner, it still shows a mortality of up to 20%. AIM: To define a specific treatment concept for periodontal disease and decayed teeth in patients suffering from TTP based on the experiences gained from two cases. CONCLUSION: The two patient cases revealed a possible association of TTP with dental foci. Because of the severity and mortality of this disease, both prognosis evaluation and treatment standards of periodontologically compromised or decayed teeth have to be strictly followed in patients suffering from TTP. In order to avoid recurrence of TTP, it seems important to remove radically teeth of questionable prognosis.

Adult↗

PubMed2003

Lengthening of the reconstructed mandible using extraoral distraction devices: report of five cases.

Fibular and scapular osteocutaneous free-tissue transfer represents the workhorse procedure in the reconstruction of large oromandibular defects. However, transplanted bone segments for mandibular reconstruction may be too short for a correct interarch alignment, which is a prerequisite for further functional rehabilitation. Extraoral distraction osteogenesis was performed in the neomandible of five patients after tumor resection following neoadjuvant radiotherapy-chemotherapy. The neomandible was distracted bilaterally in two patients and unilaterally in three patients. Gradual distraction was applied at a rate of 0.5 mm twice a day after osteotomy in the region of vascularized fibular and scapular reconstruction. An average sagittal bone gain of 11 mm was achieved following active distraction. In three patients, the distraction procedure rendered good results with full compensation of the deficit; in one patient, the sagittal bone gain did not compensate for a lateral deviation of the mandible; and in another patient, the fixation pins loosened and had to be reaffixed. Osteodistraction is a treatment option in patients in whom vascularized bone grafts have been used for mandibular reconstruction, but due to contractures or lack of hard and soft tissues, no satisfactory interarch alignment could be achieved. Distraction procedures in irradiated and reconstructed neomandibles bear a higher risk of failure and complications than those in nonirradiated tissues. A correct and stable intermaxillary relation always has to be attempted in the first surgical approach, as osteodistraction cannot be suggested as a routine procedure in this special group of patients.

Bone Transplantation↗

PubMed2003

[Evaluation of quality of life of patients with oral squamous cell carcinoma. Comparison of two treatment protocols in a prospective study-first results].

BACKGROUND: The treatment of oral cancer has a strong impact on the quality of life. In recent years different therapeutic concepts have been developed, these include preoperative simultaneous "neoadjuvant" radiochemotherapy (RCT) and one-stage surgery with tumor ablation and reconstruction. When considering long-term survival, there is substantial evidence that evidenced modality treatment including neoadjuvant RCT is superior to the primary surgical approach with postoperative radiation. PATIENTS AND METHODS: This longitudinal study prospectively evaluates quality of life in two groups consisting of 53 neoadjuvant and primarily surgically treated patients with oral cancer, using the quality-of-life core questionnaire (QLQ-C30) and the head and neck cancer module (H and N 35) of the European Organization for Research and Treatment of Cancer (EORTC). RESULTS: Postoperatively both groups showed a marked reduction in quality of life. 1 year later quality of life had equalized between the two groups to such an extent that the quality of life scores had almost reached the preoperative level. Both groups showed specific impairments in the symptom scales. In the neoadjuvant therapy group however, global health and the emotional status were reduced to a greater degree than in the other group. CONCLUSION: Temporary limitations in quality of life can be expected after tumor treatment of oral cancer as presented here. Neoadjuvant therapy concept is more aggressive and might result in a longer disease-free survival, but the restriction in quality of life is more severe. Primary goal is the eradication of the tumor. Nevertheless preservation or reconstruction of a maximum of function is essential for a high level of quality of life.

Adult↗

PubMed2003

Relative en- and exophthalmometry in zygomatic fractures comparing optical non-contact, non-ionizing 3D imaging to the Hertel instrument and computed tomography.

AIM: It is the aim of the present study to introduce non-contact, non-invasive optical 3D imaging to relative exophthalmometry and to compare the resulting data to exophthalmometry values assessed by the Hertel instrument and computed tomography. PATIENTS AND METHODS: 20 patients (3 female, 17 male, 44.4+/-16.6 years) without orbital pathology, who were examined by computed tomography of head and neck for the exclusion of different diseases, and seven patients (1 female, 6 male, 40.1+/-14.4 years), who received routine orbital computed tomography because of zygomatic fractures, were included in the study. Optical 3D images of the facial surface were assessed and Hertel exophthalmometry was carried out to determine the relative globe position. In patients with zygomatic fractures the assessment of optical 3D images and Hertel values was repeated 5 days after surgery. RESULTS: For patients without orbital pathology relative exophthalmometry data were 1.4+/-1.1 mm for the Hertel instrument, 0.9+/-1.0 mm for computed tomography and 0.5+/-0.5 mm for optical 3D imaging. The values for Hertel exophthalmometry and computed tomography did not differ statistically significantly (p(Herteldifferencepreop/CTdifferencepreop)=0.284), while there was a significant difference between Hertel exophthalmometry and optical 3D imaging (p(Herteldifferencepreop/opticaldifferencepreop)=0.008). In the cases of zygomatic fractures, Hertel exophthalmometry revealed less pronounced relative differences in globe position than CT and optical 3D imaging data (Hertel 0.7+/-1.1 mm, CT 1.9+/-1.0 mm, optical 3D imaging 1.9+/-1.0 mm). Postoperatively, relative Hertel exophthalmometry showed an increased value revealing a more pronounced enophthalmos (1.7+/-1.0 mm), while the corresponding value of the optical 3D images decreased as a sign for normalization of the globe position (1.1+/-0.7 mm). CONCLUSION: Because of its reliance on the lateral orbital rims Hertel exophthalmometry can lead to an under- or overestimation of enophthalmos, when soft tissue oedema or a dislocation of the orbital rim are present. The combination of computed tomography as baseline measurement and optical 3D imaging for the follow-up examinations reveal more realistic data in cases of zygomatic fractures. Therefore, they should be preferred to the determination of Hertel values especially in more complex cases.

Adult↗

PubMed2003

Er:YAG laser osteotomy directed by sensor controlled systems.

BACKGROUND: Great efforts have been taken in the past to develop laser systems suitable for bone cutting. Laser systems emitting light in the infrared spectrum (2.9, 3.0 microm) have been found to be ideal for efficient bone ablation with very little carbonization. AIM: To evaluate a new laser bone cutting system enabling the automatic detection of different tissue qualities by an integrated sensor to avoid damage to sensitive structures such as blood vessels or nerves. MATERIAL: An Erbium:YAG laser containing an integrated closed-loop control system, was constructed and tested on dissected bone. Process emissions such as resonance changes caused by the interaction of laser light and various tissue structures can be used for a controlled system. Sensor signals from a photodiode and a piezo-electric accelerometer were received and processed to guide the laser osteotomy. METHODS: Tests were performed on dissected bone specimens from rabbit femur (14) and minipig jaw (6). After laser application, the bone specimens were evaluated macroscopically and histologically. RESULTS: The specimens were evaluated histomorphometrically for the depth of cortical bone ablation when the closed-loop control system switched off the laser. Mean courses of 97.45% (pig) and 97.83% (rabbit) showed that the systems work with precision. CONCLUSION: After penetrating the cortical bone layer, the laser beam was promptly interrupted due to extreme changes of the signal character received by the sensor system. The in vitro tests of this new laser closed-loop control system were successful.

Aluminum Silicates↗

PubMed2003

Implant stability and histomorphometry: a correlation study in human cadavers using stepped cylinder implants.

The aim of the present study was to determine the correlation between the primary stability of dental implants placed in edentulous maxillae and mandibles, the bone mineral density and different histomorphometric parameters. After assessing the bone mineral density of the implant sites by computed tomography, 48 stepped cylinder screw implants were installed in four unfixed human maxillae and mandibles of recently deceased people who had bequeathed their bodies to the Anatomic Institute I of the University of Erlangen-Nuremberg for medical-scientific research. Peak insertion torque, Periotest values and resonance frequency analysis were assessed. Subsequently, histologic specimens were prepared, and bone-to-implant contact, the trabecular bone pattern factor (TBPf), the density of trabecular bone (BV/TV) and the height of the cortical passage of the implants were determined. The correlation between the different parameters was calculated statistically. The mean resonance frequency analysis values (maxilla 6130.4+/-363.2 Hz, mandible 6424.5+/-236.2 Hz) did not correlate with the Periotest measurements (maxilla 13.1+/-7.2, mandible -7.9+/-2.1) and peak insertion torque values (maxilla 23.8+/-2.2 N cm, mandible 45.0+/-7.9 N cm) (P=0.280 and 0.193, respectively). Again, no correlations could be found between the resonance frequency analysis, the bone mineral density (maxilla 259.2+/-124.8 mg/cm(3), mandible 349.8+/-113.3 mg/cm3), BV/TV (maxilla 19.7+/-8.8%, mandible 34.3+/-6.0%) and the TBPf (maxilla 2.39+/-1.46 mm-1, mandible -0.84+/-3.27 mm-1) (P=0.140 and 0.602, respectively). However, the resonance frequency analysis values did correlate with bone-to-implant contact of the oral aspect of the specimens (maxilla 12.6+/-6.0%, mandible 35.1+/-5.1%) and with the height of the crestal cortical bone penetrated by the implants in the oral aspect of the implant sites (maxilla 2.1+/-0.7 mm, mandible 5.1+/-3.7 mm) (P=0.024 and 0.002, respectively). The Periotest values showed a correlation with the height of the crestal cortical bone penetrated by the implants in the buccal aspect of the implant sites (maxilla 2.5+/-1.2 mm, mandible 5.4+/-1.2 mm) (P=0.015). The resonance frequency analysis revealed more correlations to the histomorphometric parameters than the Periotest measurements. However, it seems that the noninvasive determination of implant stability has to be improved in order to give a more comprehensive prediction of the bone characteristics of the implant site.

Aged↗