Success Rate of Two-Piece Zirconia Implants: A Retrospective Statistical Analysis.

PURPOSE: About 10 years ago, one-piece zirconia implants were introduced to dentistry. The aim of the study was to evaluate the clinical success of two-piece zirconia implants regarding osseointegration using the manufacturers' warranty data. MATERIALS AND METHODS: Over a period of 4 years (2010-2014), the data of warranty replacements of 15,255 sold Zeramex implants were evaluated retrospectively and blinded. RESULTS: Three hundred forty-seven (2.2%) nonosseointegrated implants were sent back. Zeramex T showed an average success rate of 96.7%, whereas Zeralock implants exhibited an average success rate of 98.5%. Furthermore, Zeramex Plus implants exhibit an average success rate of 99.4% within the investigated period. Assuming, that 2% of the failed implants were unreturned, the above-mentioned values show no changes. Assuming 5% (10%) of unreturned nonosseointegrated implants, the average success rate of Zeramex T decreases from 96.7% to 96.6% (96.4%) and of Zeralock from 98.5% to 98.4% (98.4%), respectively. The success rate of Zeramex Plus implants remains unchanged at 99.4%. CONCLUSION: The results of this study imply that two-piece zirconia implants show competitive success rates, improved from >96.7% to >98.5% over three product generations.

Schneiderian membrane detachment using transcrestal hydrodynamic ultrasonic cavitational sinus lift: a human cadaver head study and histologic analysis.

PURPOSE: Recent studies have suggested the osteogenic layer of the periosteum at the base of the sinus membrane to play a key role in bone regeneration after sinus lift procedures. Thus, atraumatic detachment of the sinus membrane with an intact periosteum seems mandatory. The present histologic study of fresh human cadaver heads investigated the detachment behavior and histologic integrity of the detached periosteum after application of the transcrestal hydrodynamic ultrasonic cavitational sinus lift (tHUCSL-INTRALIFT). MATERIALS AND METHODS: A total of 15 sinuses in 8 fresh human cadaver heads were treated using tHUCSL-INTRALIFT. After surgery, they were checked macroscopically for damage to the sinus membrane and then processed for histologic inspection under light microscopy. A total of 150 histologic specimens, randomly selected from the core surgical sites, were investigated using hematoxylin-eosin (HE), Azan, and trichrome staining. RESULTS: None of the 150 inspected specimens showed any perforation or dissection of the periosteum from the subepithelial connective tissue and respiratory epithelium and were fully detached from the bony antrum floor. The connecting Sharpey fibers revealed to be cleanly separated from the sinus floor in all specimens. CONCLUSIONS: The results of the present study suggest tHUCSL-INTRALIFT should be used to perform predictable and safe detachment of the periosteum from the bony sinus floor as a prerequisite for undisturbed and successful physiologic subantral bone regeneration.

Randomized controlled trial: lip piercing: the impact of material on microbiological findings.

PURPOSE: The purpose of this study was to investigate whether there are microbiological differences in bacterial samples collected from labial piercings made of different materials. METHODS: Sterile piercings of 4 materials were randomly allocated to 80 pierced subjects. After 2 weeks, microbiologic samples were collected and processed by checkerboard DNA-DNA hybridization methods. Wilcoxon signed ranks and Mann-Whitney tests were used for statistical analysis (adjustment for multiple comparisons). RESULTS: There were no statistically significant differences between material groups in relation to baseline data. In samples from stainless steel piercings, the total microbial load was significantly higher than the other materials (P<.05). Ten (mainly periopathogenic) species were found at significantly higher levels (P<.001) on steel than on polypropylene and/or polytetrafluoroethylene piercings. CONCLUSIONS: Labial piercings made of stainless steel could promote the development of a pathogenic biofilm.

Rupture length of the sinus membrane after 1.2 mm puncture and surgical sinus elevation: an experimental animal cadaver study.

OBJECTIVES: To evaluate the rupture length of the sinus membrane after applying a defined 1.2 mm defect comparing 3 different techniques: Summers lift, balloon-assisted technique (BASL), and hydrodynamic ultrasonic cavitational sinus lift (HUCSL). STUDY DESIGN: Thirty fresh sheep heads (60 maxillary sinuses) were investigated. The sinus membrane was ruptured using a 1.2 mm pilot drill. Then Summers lift, BASL, and HUCSL were each performed on 20 sinuses, creating a 5 mm vertical lift of the sinus membrane. The length of the ruptured sinus membrane was measured before and after the experiment. The results of the different sinus lift techniques were compared using t tests. RESULTS: The t test showed that the Summers lift leads to a significantly higher rupture length (P = .05) than BASL. The comparison between Summers lift and HUCSL showed a significantly higher rupture length with the Summers lift (P < .005). The same significance (P < .005) was found when BASL was compared with HUCSL. Comparing the increasing rupture length of the sinus membrane during the experiment, the t test showed a significantly greater rupture using BASL or the Summers lift compared with HUCSL. CONCLUSIONS: The HUCSL technique yielded the lowest increase of rupture length compared with BASL and Summers lift. The technique therefore shows the lowest risk of a growing rupture of the sinus membrane in case of an iatrogenic puncture during preparation of the transcrestal approach.

Pullout strength of a biodegradable free form osteosynthesis plate.

The Inion(®) Free Form Plate is a newly designed biodegradable plate. After drilling through the plate and tapping, a biodegradable screw can be inserted, followed by removal of the screw head. As an alternative a countersink screw can be used. Aim of the study was to compare the mechanical properties of the 1.4 mm Free Form Plate with the 2.0 mm conventional shaped plate. Mechanical testing of the plate pullout strength was conducted for the Inion(®) Free Form Plate fixed with an Inion OTPS™ 2.0 × 20 mm Screw. In addition, the failure mode was reported. Overlapping confidence levels were found with regard to the yield load, first peak load and maximum load, when comparing the Free Form Plate and the conventional 4-hole plate. The Free Form Plate fixed with a screw with head and countersink showed the highest stability at maximum load. The results of the mechanical stability testing showed no significant differences between the tested plates. The main failure mode was a failure of the screw shaft. The results of the current investigation imply that the 1.4 mm Free Form Plate could be used as an alternative to the 2.0 mm conventional shaped plate.

Hydrodynamic ultrasonic sinus floor elevation--an experimental study in sheep.

PURPOSE: The aim of the present study was to evaluate the pressure forces appearing to elevate the sinus membrane by comparing the hydraulic and pneumatic pressure. Also, the relation between the time and volume of the applied liquid and the achieved lift-volume were determined. MATERIALS AND METHODS: A total of 190 fresh, half sheep heads were used for the present investigation. An ultrasound surgical device (Piezotome; Acteon, Bordeaux, France) was tested to evaluate the pressure increase at different flow rates. The elevation volume at different flow rates and activation times of the ultrasound hand piece were measured. RESULTS: To detach the sinus membrane pneumatically from the sinus floor, a mean average pressure of 29.54 millibars was required. Using the hydraulic technique, a mean average pressure of 19.8 millibars was determined. Comparing the different flow rates, the elevated volume increased to 0.52 mL when a flow of 60 mL/minute was used. Using an activation time of 20 seconds, a lifted volume of 3.92 mL could be measured on average. If the flow was set to a maximum of 60 mL/minute, the created volume increased to 5.58 mL. A comparison using the chi(2) test showed a significant correlation (P = .03) between the application time and the created sinus lift volume. Even at high flow rates of 60 mL/minute of the activated Piezotome for a 20-second period, no rupture of the sinus membrane of the sheep heads occurred in 190 experiments. CONCLUSION: From these results, we have concluded that hydrodynamic ultrasound could be used as an alternative method for sinus floor elevations of any size and volume with a mere 3-mm-diameter transcrestal approach, if findings from clinical investigations confirm the results of the present animal study.

Facial trauma: how dangerous are skiing and snowboarding?

PURPOSE: The aim of this study was to investigate maxillofacial injuries sustained in both skiing and snowboarding accidents and correlate injury mechanisms and patterns evaluating a large population. MATERIALS AND METHODS: Between 1991 and 2003, all patients with maxillofacial injuries due to skiing and snowboarding accidents (1,393 cases) were reviewed and statistically analyzed according to age, gender, type of injury, cause of accident, location of trauma, and associated injuries. RESULTS: Skiing accidents resulted in a total of 1,250 injuries, and snowboarding resulted in 143. In this study 686 skiers presented with 1,452 facial bone fractures and 80 snowboarders sustained 160 fractures of the face. Skiers had dentoalveolar trauma in 810 cases and 1,295 soft tissue injuries, whereas snowboarders had 88 dental injuries and 187 soft tissue lesions. Mechanisms of injury included 542 cases due to skiing and 85 falls due to snowboarding (a 1.79-fold higher risk for snowboarders). The gender distribution showed a male-female ratio of 3:1 in skiers and 5.5:1 in snowboarders. In both groups male patients were more prone to have a facial bone fracture than female patients. Snowboarders aged between 10 and 29 years had a 2.14-fold higher risk of sustaining a maxillofacial injury than skiers. CONCLUSIONS: In both groups facial bone fractures occurred more often in male patients, and they were more likely to result from falls and collisions with other persons. Young snowboarders had a higher risk of maxillofacial injuries (especially soft tissue lesions) than skiers, whereas for children and old persons, skiing posed a much higher risk. Wearing a helmet while skiing and snowboarding should be mandatory to prevent serious trauma to the head.

Fixation properties of a biodegradable "free-form" osteosynthesis plate with screws with cut-off screw heads: biomechanical evaluation over 26 weeks.

OBJECTIVE: The aim of this study was to compare the postoperative fixation properties of a biodegradable osteosynthesis "free-form" plate achieved with countersunk screws with those provided by screws with cut-off screw heads. STUDY DESIGN: Acrylic pipes were fixed together to simulate fracture fixation for tensile testing. Additional plates were fixed to a polyurethane block with a single screw for plate-screw pullout testing. Specimens were incubated in phosphate buffer solution at 37 degrees C, and testing was conducted at various time points during hydrolytic degradation of 26 weeks. In both tests the specimens were loaded at a speed of 5 mm/min until failure. The yield load, maximum load, and stiffness were recorded, and failure mode was visually determined. RESULTS: Both countersunk screws and screws with cut-off screw heads provided similar plate fixation properties over degradation time. CONCLUSION: According to these results, fixation of the biodegradable osteosynthesis free-form plate with screws with cut-off screw heads seems to be feasible.

Identification of the rare EGFR mutation p.G796S as somatic and germline mutation in white patients with squamous cell carcinoma of the head and neck.

BACKGROUND: Somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) are involved in tumorigenesis and response to targeted therapies in distinct cancer types. Squamous cell carcinomas of the head and neck (HNSCC) show an incidence of EGFR mutations varying from 7% in Asians to 0% to 4% in white patients. Mutational screening predominantly focuses on the analysis of hotspot regions of EGFR (exons 19 and 21). METHODS: In a follow-up study, we screened for mutations in exons 18 to 21 of the EGFR gene in 127 patients. RESULTS: In this cohort, a mutation frequency of 2.4% (3/127) was detected. In addition to the previously reported mutation p.K745R, the otherwise rare EGFR mutation p.G796S occurred in 2 patients with HNSCC (2/127). CONCLUSION: EGFR kinase mutations are rare in white patients with HNSCC. Extension of mutational screening to exon 20 may clarify the frequency and impact of the mutation p.G796S.

Fixation properties of a biodegradable "free-form" osteosynthesis plate.

The Inion FreedomPlate, a "free-form" osteosynthesis plate, is a biodegradable plate with just pilot holes for drilling. The construction of the plate allows the surgeon a placement of screws in optimal position. The screw heads can either be countersunk into the plate or cut off. Furthermore, the plate can be cut and contoured to match the bone. The aim of this study was to determine the mechanical properties of the Inion FreedomPlate compared to a conventional biodegradable plate. Acrylic pipes were fixed together with plates and screws. Tensile and cantilever bending tests were performed to measure the fixation properties. In the tensile test, the samples were loaded with a constant speed of 5 mm/min until failure of fixation. The yield load, maximum failure load, and initial stiffness were recorded, and the failure mode was visually determined. In the cantilever bending test, the samples were loaded with a constant speed of 50 mm/min (with a moment arm of 45 mm) until failure of fixation. The yield bending moment and initial stiffness were recorded, and the failure mode was determined. The results of the study show that the new free-form plate provides at least as strong fixation as the tested conventional biodegradable plate. No clinically relevant difference was found between free-form plates fixed with into-the-plate countersunk screws and those fixed with screws without heads.

Sonographic investigation of the temporomandibular joint in patients with juvenile idiopathic arthritis: a pilot study.

OBJECTIVE: To evaluate whether there are any correlations between the clinical parameters of temporomandibular joint (TMJ) arthritis and pathologic ultrasound (US) findings of the TMJ in patients with juvenile idiopathic arthritis (JIA). METHODS: We conducted prospective clinical and US investigations of the TMJs of 48 patients with JIA. The US investigation was performed by a 12-MHz high-resolution transducer, which was positioned parallel to the ramus of the mandible overlying the zygomatic arch in a closed-mouth position and maximum open-mouth position. RESULTS: Patients with > or = 5 peripheral affected joints showed significantly more sonographically diagnosed destructive changes in the TMJ than did patients with <5 affected joints. There was no significance between the number of affected peripheral joints and disc dislocation in the closed-mouth position. In the maximum open-mouth position, there was a significant correlation between the number of affected peripheral joints and disc dislocation. Patients with a JIA duration >23 months had a significantly higher rate of disc dislocation and destructive changes. Patients with a JIA duration >60 months had a significantly higher rate of destructive changes of the TMJ than patients with a disease duration <60 months, but no statistical significance was found concerning disc dislocation. CONCLUSION: The significant correlation between pathologic sonographic findings, duration of JIA, and the number of affected peripheral joints make the technique interesting for use as a diagnostic screening method.

High EGFR expression predicts poor prognosis in patients with squamous cell carcinoma of the oral cavity and oropharynx: a TMA-based immunohistochemical analysis.

This retrospective study was designed to investigate the prognostic significance of EGFR overexpression in human oral squamous cell carcinoma on a long-term follow-up. EGFR expression was examined immunohistochemically on a tissue microarray (TMA) of paraffin embedded tissue specimens from 109 patients who underwent surgical treatment for squamous cell carcinoma of the oral cavity and oropharynx in the period between 1980 and 1997. High EGFR expression was found in 80 (73.42%) of the tumour samples. Kaplan-Meier curves showed that EGFR overexpression was significantly related to decreased overall survival (p=0.05). Multivariate analysis showed that EGFR overexpression is an independent prognostic marker in these patients (p=0.02, RR 3.6). These results confirm that EGFR overexpression is an independent prognostic marker in patients with squamous cell carcinoma of the oral cavity and oropharynx. The EGFR antigen represents an attractive target for targeted therapies with monoclonal antibodies or specific tyrosine-kinase inhibitors in these patients.

A reason for the use of toluidine blue staining in the presurgical management of patients with oral squamous cell carcinomas.

Verification of oral cancer relies on histopathological diagnosis of suspect or malignant lesions. There is evidence for further pre-surgical screening procedures to localize tumor borders and define other malignant lesions. Important methods are: visual examination, including pan-endoscopy, fluorescence imaging, and brush biopsy, as well as radiologic techniques such as conventional radiography, computed tomography, magnetic resonance imaging, scintigraphy, and ultrasonography, which may reduce the mortality rate associated with oral cancer. In addition, toluidine blue staining is a simple, inexpensive, and excellent diagnostic tool. Herein we show that the clinical use of in vivo staining is effective to define the superficial tumor borders and to detect malignant or pre-malignant cells in the surrounding area of the tumor following detection of a malignancy of the oral cavity. In our reported case, the main tumor mass was surrounded by layers of an intact mucosa, yet in a distance of more than 1 cm a group of malignant or pre-malignant cells in the surrounding area required a resection of the tumor in a size that would have been unaddressed during visual examination alone followed by clinical routine program of presurgical examinations after the detection of a malignancy of the oral cavity.

Intrarater reliability in the ultrasound diagnosis of medial and lateral orbital wall fractures with a curved array transducer.

PURPOSE: The aims of the study were to document the effectiveness of ultrasound (US) in diagnosing orbital wall fractures when compared with computed tomography (CT) and to measure the intraobserver reliability of US using a curved array transducer. MATERIALS AND METHODS: From December 2003 to March 2004, 13 patients with the clinical diagnosis of an orbital trauma were investigated prospectively by CT (reference) and 2 US investigators. Both orbits were investigated. Sensitivity, specificity, accuracy, and positive and negative predictive value were calculated. The statistical difference between the 2 US investigators was calculated by a chi-square test. The interrater reliability was calculated using the lambda coefficient. Values below 0.4 represent poor reliability, between 0.4 and 0.75 represent fair to good reliability, and a score > 0.75 is graded as excellent reliability. RESULTS: The comparison of the results of the 2 US investigators by the chi-square test showed P values of .385 for the medial orbital wall and .638 for the lateral orbital wall, which shows no significant difference. The lambda-value for the investigation of the medial orbital wall reached 0.429, 0.714, and 0.750. The lambda-value for the investigation of the lateral orbital wall yielded 0.647, 0.750, and 0.882. These values show a good and excellent inter-rater reliability. CONCLUSION: The US investigation does not yet reach the diagnostic quality of CT. US could be a helpful diagnostic imaging tool in cases with clear clinical symptoms. The results of the current study and the previously published results imply that US has the potential to reach the same diagnostic quality as CT in the future, but further studies must be performed to improve the diagnostic quality of the method.

Interrater reliability of sonographic examinations of orbital fractures.

OBJECTIVE: The purpose of this study is to determine whether there are statistically significant variations among different observers when examining fractures of the orbital walls. MATERIAL AND METHODS: From December 2003 to April 2004, 28 patients with clinically suspected orbital fractures were examined by ultrasound prospectively. The US images of the infra-orbital margins, the orbital floors, the medial and lateral orbital walls of each patient were reexamined by two independent investigators. RESULTS: Computed tomography revealed fractures of the orbital floor in 28 out of 31 patients (90.3%). The infra-orbital margins showed fractures of 14 of 31 patients (45.2%). The ultrasound examinations of the orbits by the three examiners presented satisfactory correlation regarding sensitivity and specificity. There were no significant differences between investigators. There was good agreement among the ultrasound examiners regarding the infra-orbital margins. This was not the case for the orbital floors. CONCLUSIONS: If there are clear cut clinical findings ultrasound examination could represent an alternative to computed tomography. If the clinical findings were indeterminate, computed tomography was essential as implicated by this study. Accordingly, further evaluation of ultrasound examinations of fractures of the orbital margins and floors are necessary.

Effectiveness of ultrasonography in determining medial and lateral orbital wall fractures with a curved-array scanner.

PURPOSE: The purpose of the study was to evaluate the diagnostic value of ultrasonography to determine medial and lateral orbital wall fractures. MATERIALS AND METHODS: Sixty-two patients with the clinical diagnosis of an orbital trauma underwent coronal computed tomography (CCT) and ultrasonographic investigation (US). Inclusion criteria were clinically suspected orbital injuries defined by reduced bulbus motility, diplopia, or additional traumatic injuries of the orbit or the globe. US and CCT were used as imaging diagnostic methods. RESULTS: Ultrasonography showed a sensitivity of 56%, a specificity of 95%, and an accuracy of 88% at the medial orbital rim. Regarding the lateral orbital rim, ultrasonography showed a sensitivity of 92%, a specificity of 88%, and an accuracy of 90% using CCT as a reference method. CONCLUSION: Ultrasonography with a curved-array scanner seems to be a valuable method in the detection of lateral orbital wall fractures. Further studies have to be done to improve sensitivity in the interpretation of medial orbital wall fractures.

Ultrasound versus computed tomography in the imaging of orbital floor fractures.

PURPOSE: The aim of the study was to investigate whether orbital ultrasonography (US) with a curved-array transducer could be an alternative imaging method to computed tomography (CT) to detect orbital wall fractures and fractures of the infraorbital rim. MATERIALS AND METHODS: Fifty-eight patients with the clinical ophthalmologic or radiologic diagnosis of an orbital trauma were investigated prospectively by US and CT. The reference method was the intraoperative findings. RESULTS: CT evaluation of the infraorbital rim yielded a sensitivity of 79%, a specificity of 90%, and an accuracy of 94%. The positive predictive value (PPV) and the negative predictive value (NPV) of the infraorbital rim reached 69% and 83%, respectively. CT evaluation of the orbital floor showed a sensitivity of 96%, a specificity of 71%, and an accuracy of 96%. PPV and NPV resulted in 71% and 93%, respectively. US investigation of the infraorbital rim yielded a sensitivity of 77%, a specificity of 89%, and an accuracy of 97%, whereas PPV and NPV reached 65% and 83%, respectively. US investigation of the orbital floor reached a sensitivity of 94%, a specificity of 57%, and an accuracy of 96%, whereas PPV and NPV yielded 57% and 91%, respectively. No significant difference was found between US and CT in the investigation of the infraorbital rim (P =.809) and the orbital floor (P =.729). CONCLUSIONS: US with a curved-array transducer appears to be a useful alternative method in the investigation of orbital floor fractures. Further studies have to be conducted to reduce the presence of false-negative results.

Clinical signs of orbital wall fractures as a function of anatomic location.

OBJECTIVE: The objective of this study was to see whether clinical signs of medial orbital wall fractures distinguished these fractures from fractures of the lateral orbital wall and the orbital floor. STUDY DESIGN: The orbital fractures of 424 patients were analyzed. The patients were divided into 2 groups: (1) patients with orbital fractures with a medial orbital wall component and (2) patients with orbital fractures without a medial orbital wall component. RESULTS: Orbital fractures with involvement of the medial orbital wall showed a significantly higher incidence (P =.001) of diplopia and exophthalmos (P =.039) than fractures without involvement of the medial wall. CONCLUSION: Posttraumatic orbital clinical signs are associated with a higher incidence of medial orbital wall component fracture. Apparent lack of involvement of the medial orbital wall should not be an exclusion criterion for a surgical intervention when clinical orbital signs exist.