Peri-implant health after microvascular head and neck reconstruction-A retrospective analysis.

INTRODUCTION: Prosthodontic rehabilitation after reconstruction with microvascular revascularized free flaps following ablative tumor surgery is challenging due to the altered anatomical and functional conditions. The aim of this retrospective study was to determine whether the type of graft and the type of peri-implant tissue have an effect on peri-implant inflammatory parameters and implant survival. MATERIALS AND METHODS: Patients who received a free flap reconstruction with subsequent implant-prosthetic rehabilitation between 2010 and 2022 were retrospectively included. The primary outcome variable was the probing depth (PPD) at a minimum of 1 year after completion of prosthetic restoration. Predictive variables were type of free flap, emergence profile, and history of radiation. RESULTS: Seventy-one patients after free flap reconstruction were included in the analysis. At a minimum of 24 months after implant insertion the primary outcome, PPD showed no clinically relevant differences between the types of free flaps used. The emergence profile through a skin island resulted in an increase in BOP compared to native mucosa in the descriptive analysis (p-value > .05). The analysis showed a 5-year implant survival of 96.2% (95% CI: 0.929-0.996) in cases without irradiation and 87.6% (95% CI: 0.810-0.948) with irradiation of the region evaluated (p-value .034). CONCLUSION: Flap and associated soft tissue type had no significant effect on 5-year implant survival or peri-implant inflammatory parameters. However, the large heterogeneity of the patient population indicates that further prolonged studies are required for a more differentiated assessment of the long-term success.

Variation of resection margins in oral cancer in dependence of tumor stage and subsite - a retrospective cohort study.

OBJECTIVES: Surgical resection is a key component of the treatment of head and neck cancer and the achievement of free surgical margins are essential for the patients' outcome in terms of survival. While there is a general recommendation for a free resection range of 5 mm, up to date, there is a lack of investigations on the quality of tumor resection in dependence of affected subsite and tumor stage. In the presented study, predictors for the achieved resection margins in surgically treated oral squamous cell carcinomas were analyzed. MATERIALS AND METHODS: A cohort of 567 patients was included in a retrospective analysis and resection status with exact margin ranges were analysed. Tumor stage, affected subsite and the results of the intraoperative frozen section analysis were assessed. Primary endpoint was the achieved resection margin in mm, secondary endpoints were overall and progression-free survival. RESULTS: The observed mean values of minimal resection margins differed significantly between the investigated subsites (p = 0.042),pathological tumor stages (p < 0.001) and in tumors which demonstrated perineural infiltration (Pn1, p = 0.002). Furthermore, there was a significant impact of the results of the intraoperative frozen section analysis on progression-free and overall survival (p < 0.001). CONCLUSIONS: Our data clearly indicate that resection status differs between tumors of different subsites and tumor stages. CLINICAL RELEVANCE: Clinical procedures should be adapted in order to achieve similar certainty in all resections, and, thus to improve patients' outcome.

Second primary squamous cell carcinoma of the oral cavity - a retrospective cohort study of therapeutic procedures and oncological outcome.

OBJECTIVES: In the presented study, the occurrence rates of second primary oral carcinomas and their prognostic relevance were analyzed. MATERIALS AND METHODS: All patients with surgically treated oral squamous cell carcinomas within the years 2010 and 2022 in our department were included in this retrospective cohort study. Two groups were designed including patients with second primary carcinomas and patients with local tumor recurrences. Occurrence rates, tumor stages and applied therapies were assessed. Primary outcome was overall survival in dependence of the index tumor. Secondary outcomes were overall survival in dependence of local recurrences or second primary tumors. RESULTS: An overall number of 908 patients was included in the analysis. 98 patients (10.8%) developed a second primary oral squamous cell carcinoma. Patients with second primary tumors presented significantly (p < 0.001) better overall survival in dependence of the index tumor compared to patients suffering from local recurrences. There was no significant difference in overall survival (p = 0.4) in dependence of the date of second primary tumor or local recurrence. Patients with second primary tumors were more likely to receive surgery-based therapy compared to patients with local recurrences who more frequently received definitive radiotherapy. CONCLUSION: Our data indicates different clinical courses in terms of therapy and survival of patients suffering from second primary tumors compared to patients with local tumor recurrences. This may be due to a more aggressive biology of local recurrences and earlier detection of second primaries due to oncological follow-up of the index tumor. CLINICAL RELEVANCE: The differentiation of local tumor recurrences and second primary tumors is of clinical relevance, as applicable therapies and resulting prognosis may differ significantly.

Diagnostic accuracy comparing OPT and CBCT in the detection of non-vital bone changes before tooth extractions in patients with antiresorptive intake.

OBJECTIVES: To compare the diagnostic accuracy in detecting early non-vital bone changes between orthopantomography (OPT) and cone-beam computed tomography (CBCT) in correlation with histopathological findings before tooth extractions in patients with antiresorptive (AR) intake. SUBJECTS: Patients with an indication tooth extraction who had received OPT and CBCT preoperatively while or after undergoing AR treatment were prospectively enrolled over a 24-month period in the progesterone in spontaneous miscarriage (PRISM) trial. Imaging studies were randomly analyzed by three examiners for early non-vital bone changes using specific predefined characteristics and a 5-level scale (1 definite absence of criteria to 5 definite presence of criteria). Sensitivity and specificity values were calculated in correlation with the histopathologically evaluated bone samples at the time point of tooth extraction. RESULTS: One hundred thirty patients with 237 treated extraction sites met the inclusion criteria. For all images evaluated by all examiners, CBCT (430/492; 87.4%; receiver operating characteristic [ROC]: area under the curve [AUC] = 0.88; p < 0.001) was more likely to detect histopathologically confirmed non-vital bone than the OPT (132/492; 26.8%; ROC: AUC = 0.562; p = 0.115). CONCLUSIONS: In the detection of non-vital bone changes, CBCT is superior to OPT in both sensitivity and specificity. Specific imaging characteristics allow for the prediction of early non-vital bone changes already at the time before tooth extractions.

Infants With Trigonocephaly Treated With Fronto-Orbital Remodelling and Endocortical Positioning of Resorbable Plates-A Retrospective Cohort Study Including 101 Patients.

PURPOSE: Fronto-orbital remodeling is the gold standard for surgical treatment of metopic synostosis in many craniofacial centers. For fixation, resorbable materials are widely used. Because of swelling during resorption, the positioning of the plates can be relevant. Therefore, the goal of this study was to investigate whether there are limitations to endocortical positioning of resorbable plates. METHODS: In this retrospective study, all patients with metopic craniosynostosis resulting in trigonocephaly, who were treated with a standardized fronto-orbital remodeling and endocortical positioning of resorbable plates, between February 2012 and December 2019 were included. The endpoint of this study was the postoperative complications that can be attributed to the material used. RESULTS: A total of 101 patients, who were treated at our unit, could be included with a male predominance, 81 (80.2%) boys versus 20 (19.8%) girls. Surgery was performed at a median age of 9 months (±2.56). No complications were seen related to resorbable plates. All patients of our study population were categorized as Whitaker classification I and II. CONCLUSION: This study shows that the risk level in using endocortical resorbable plates positioned on the inner surface of the bone is low. From an aesthetic point of view, we could not detect any disadvantage.

Comparing the Influence of Surgical and Conservative Therapy on Quality of Life in Patients with Early-Stage Medication-Related Osteonecrosis of the Jaw-A Prospective Longitudinal Study.

Background and Objectives: The purpose of this study was to evaluate the impact of surgical and conservative, non-surgical treatment on general health-related (QoL) and oral health-related quality of life (OHRQoL) in patients suffering from AAOMS stage I MRONJ. Materials and Methods: In the course of this prospective clinical study, QoL and OHRQoL using QLQ-C30 and QHIP G14 questionnaire were longitudinally assessed in N = 174 prospectively enrolled patients with indication of treatment of MRONJ stage I over a period of 12 months. Patients received conservative or surgical treatment. The measurement time points were preoperatively (T0), 12 weeks (T1), 6 months (T2) and 1 year after operation (T3). Results: For OHRQoL, no significant (p > 0.05) differences were found between both treatment groups for all timepoints (T0-T3). In the surgical treatment group, OHIP scores of T1, T2 and T3 were significantly lower than baseline measures (T0) (T0-T1 (2.99, p = 0.024), T0-T2 (5.20, p < 0.001), T0-T3 (7.44, p < 0.001)). For conservative treatment group OHIP, scores of T2 and T3 were significantly lower than baseline measures (T0) (T0-T2 (9.09, p = 0.013), T0-T3 (12.79, p < 0.001)). There was no statistically significant effect of time on QLQ-C30 scores in both groups (surgical treatment: F(3, 174) = 1.542, p < 0.205, partial η2 = 0.026; conservative treatment: F(3, 30) = 0.528, p = 0.667, partial η2 = 0.050). QLQ-C30 scores turned out to be significantly lower in the non-surgical group at T1 (p = 0.036) and T3 (p = 0.047) compared to the surgical treatment group. Conclusions: Surgical and conservative treatment of MRONJ stage I significantly improves patients' OHRQoL. Surgical treatment is superior to conservative treatment of MRONJ stage I regarding general QoL. Therefore, surgical treatment of MRONJ stage I should not be omitted for QoL reasons.

Neuralgia-inducing cavitational osteonecrosis - A systematic review.

OBJECTIVE: To assess the aetiologic factors, proposed diagnostic means and treatment strategies for neuralgia-inducing cavitational osteonecrosis. METHODS: A search of the literature published up to June 2020 was conducted using Medline, the Cochrane Library, PsycINFO, CINAHL and Web of Science. The scientific quality of the evidence was rated according to NIH Quality Assessment Tools. RESULTS: 4,051 articles were found, 59 were reviewed in full text, and 29 studies were included. With the exception of hereditary coagulopathies, which were identified as potential risk factors in five studies, suggestions concerning the aetiology varied widely. No gold standard diagnostic mean could be identified. Treatment was most often performed by surgical curettage of the affected bone. Surgical treatment outcomes were equally varied: significant facial pain remission was reported in 66%-100% for periods varying between 2 months to 18 years, whereas no or little relief and recurrences were reported in up to ⅓ of cases. All studies were observational in their design. All investigations were rated as poor quality because of high risk of bias and non-transparent reporting. CONCLUSIONS: Evidence concerning the aetiology, diagnosis and treatment of NICO is poor. Prospective diagnostic and therapeutic studies are needed before the usefulness of invasive therapeutic procedures can be evaluated.

Risk factors associated with onset of medication-related osteonecrosis of the jaw in patients treated with denosumab.

OBJECTIVES: While risk factors of bisphosphonate (BP) associated osteonecrosis of the jaw have been properly analyzed, studies focusing on risk factors associated with denosumab (DNO) are sparse. The purpose of this study was to identify risk factors influencing the onset of medication-related osteonecrosis of the jaw (MRONJ) in patients receiving antiresorptive treatment (ART) with DNO by comparing patients suffering from MRONJ and patients without MRONJ. Multiple variables were evaluated including the impact of a previous BP intake. MATERIALS AND METHODS: A retrospective single-center cohort study with patients receiving DNO was conducted. One-hundred twenty-eight patients were included and divided into three groups: I (control, n = 40) receiving DNO with absence of MRONJ; group II (Test 1, n = 46), receiving DNO with presence of MRONJ; and group III (Test 2, n = 42) sequentially receiving BP and DNO with presence of MRONJ. Patients' medical history, focusing on the identification of MRONJ risk factors, was collected and evaluated. Parameters were sex, age, smoking habit, alcohol consumption, underlying disease (cancer type, osteoporosis), internal diseases, additional chemo/hormonal therapy, oral inflammation, and trauma. RESULTS: The following risk factors were identified to increase MRONJ onset significantly in patients treated with DNO: chemo/hormonal therapy (p = 0.02), DNO dosage (p < 0.01), breast cancer (p = 0.03), intake of corticosteroids (p = 0.04), hypertension (p = 0.02), diabetes mellitus (p = 0.04), periodontal disease (p = 0.03), apical ostitis (p = 0.02), and denture use (p = 0.02). A medication switch did not affect MRONJ development (p = 0.86). CONCLUSIONS: Malignant diseases, additional chemotherapy, DNO dosage, and oral inflammations as well as diabetes mellitus and hypertension influence MRONJ onset in patients treated with DNO significantly. CLINICAL RELEVANCE: Patients receiving ART with DNO featuring aforementioned risk factors have a higher risk of MRONJ onset. These patients need a sound and regular prophylaxis in order to prevent the onset of MRONJ under DNO treatment.

Clinical outcome and prognostic factors in recurrent oral squamous cell carcinoma after primary surgical treatment: a retrospective study.

OBJECTIVES: Survival for patients with recurrent oral squamous cell carcinoma is usually poor, and the most effective treatment has not yet been clearly defined. The present study evaluates the outcome in radiotherapy-naïve patients after recurrence of oral squamous cell carcinoma with respect to different treatment modalities including surgery, radiation, chemoradiation, and palliative treatment. PATIENTS AND METHODS: In this retrospective study, we included all patients with primary oral squamous cell carcinoma who received exclusively surgical therapy between 2010 and 2020 and who suffered from locoregional recurrence in their follow-up. Patients with previous adjuvant therapy were excluded from this protocol. Clinical and pathological parameters were collected and statistically evaluated. Survival analysis was performed according to Kaplan-Meier. The primary endpoints were overall and progression-free survival in dependance of treatment strategy for recurrent tumors. RESULTS: Out of a total of 538 patients with surgically treated primary oral squamous cell carcinoma, 76 patients met the inclusion criteria. The mean follow-up was 38 ± 32 months. Patients who received surgically based therapy had a significantly better outcome in terms of disease-free survival (DFS) and overall survival (OS) (DFS p < 0.001; OS p < 0.001). The presence of regional metastases and a short disease-free interval (DFI) between primary and recurrent cancer were significant predictors for adverse outcomes (DFI p < 0.001). CONCLUSION: We recommend primary surgical therapy for radiotherapy-naïve patients with recurrent oral squamous cell carcinoma, supplemented by risk-adapted adjuvant therapy. CLINICAL RELEVANCE: Surgical therapy continues to play a central role in the treatment of radiotherapy-naïve patients with recurrent oral squamous cell carcinoma.

Wound closure and alveoplasty after preventive tooth extractions in patients with antiresorptive intake-A randomized pilot trial.

OBJECTIVES: To compare success rates between the sub-periosteal prepared (SPP) muco-periosteal flap and the epi-periosteal prepared (EPP) mucosa flap and the feasibility of alveoplasty after surgical tooth extractions in patients undergoing/after antiresorptive treatment. SUBJECTS: Patients with an indication for preventive tooth extraction undergoing/after antiresorptive treatment were enrolled over a 24-month period in a parallel-group randomized clinical pilot trial and randomly assigned for primary wound closure to either the SPP or the EPP group. The primary outcome was treatment failure 8 weeks after surgery. To assess the feasibility of alveoplasty, necrotic bone changes at the time point of tooth extraction were evaluated. RESULTS: One hundred and sixty patients were randomized to the SSP (n = 82) or the EPP (n = 78) group. One hundred and fifty-seven patients met the primary endpoint 8 weeks after surgery with five treatment failures for the SPP group (6.3%) and 18 (23.4%) for the EPP group (p = .004). A significant relationship (p < .0001) was observed between symptomatic teeth and non-vital bone found in 54.8% of all biopsies. CONCLUSIONS: The strong superiority of the muco-periosteal flap as primary wound closure revealed the feasibility and effectiveness of the study. The large number of necrotic biopsies emphasizes the importance of alveoplasty as a preventive measure.

The Type of Antiresorptive Treatment Influences the Time to Onset and the Surgical Outcome of Medication-Related Osteonecrosis of the Jaw.

PURPOSE: Few data exist focusing on differences in the time to disease onset and the success rates in patients suffering from medication-related osteonecrosis of the jaw (MRONJ) dependent on their different antiresorptive treatment. The purpose of this study was to analyze and compare these variables for patients treated with bisphosphonate (BP) or denosumab (DNO) and for patients who switched the antiresorptive drug (BP/DNO). PATIENTS AND METHODSS: A retrospective single-center cohort study with patients suffering from MRONJ was conducted. The predictor variable was the antiresorptive treatment, the outcome variables were 1) time to onset of MRONJ (time of antiresorptive treatment to MRONJ diagnosis) and 2) treatment success (mucosal integrity 12 months postoperatively). The other variables include data on demographic, underlying disease, MRONJ stage, and trigger events. Cox and logistic regression, Phi-coefficient, Cramer's V, and Kruskal-Wallis tests were applied. RESULTS: One hundred thirty-two patients were included and divided into 3 groups: group I (BP) n = 45 patients, n = 59 lesions; group II (BP/DNO) n = 42 patients, n = 71 lesions; and group III (DNO) n = 45 patients, n = 62 MRONJ lesions. Treatment success and time to onset differed significantly between the groups: success rates in group I BP (84.7%) were significantly lower (P = .04) than in group II BP/DNO (91.5%, P = .12) and group III DNO (90.3%, P = .35). The onset was significantly earlier in group III DNO (median 2.0 years, Q0.25: 1.49, Q0.75: 2.98; confidence interval 95%: 1.93 to 2.83) than in group II BP/DNO (median 4.07 years, Q0.25: 1.64, Q0.75: 6.70; confidence interval 95%: 3.55 to 5.68) and group I BP (median 3.86 years, Q0.25: 1.69, Q0.75: 6.46; confidence interval 95%: 3.43 to 5.87). CONCLUSIONS: The different antiresorptive drugs show distinctive characteristics of time to onset and treatment success with the lowest success rates in the BP group and the earliest onset in the DNO group. The switch of the antiresorptive therapy (BP to DNO) did not influence the outcome variables negatively.

Development of osteomyelitis following dental abscesses-influence of therapy and comorbidities.

OBJECTIVES: Bacterial osteomyelitis of the jaw is a severe disease potentially requiring extensive surgical treatment. We have evaluated the incidence rates of bacterial osteomyelitis following dental abscessation associated with primary or secondary tooth extraction. MATERIALS AND METHODS: A retrospective cohort study was designed and included patients with dental abscesses and surgical treatment including the extraction of focus teeth. Patients were either treated with primary removal during acute infection or secondary delayed extraction within an infection-free interval. The primary outcome variable was the occurrence of bacterial osteomyelitis following the abscess. Secondary outcomes were the influence of general disease, antibiotic therapy, and surgical technique. RESULTS: One hundred nine patients were enrolled in the study; 4 patients (3.7%) developed osteomyelitis. Primary tooth extraction was performed on all these patients (p = 0.017). Significant associations of diabetes (p = 0.001), the use of clindamycin (p = 0.025), and transcutaneous incision (p = 0.017) with the incidence of osteomyelitis were detected. CONCLUSIONS: More severe infections may be associated with a higher risk for the development of osteomyelitis following dental abscesses. A history of diabetes and clindamycin therapy might form further predisposing risk factors. Because of the low incidence and the small case number, our data need to be interpreted carefully. CLINICAL RELEVANCE: Osteomyelitis of the jaw is a rare but severe disease that may require extensive therapy and that impairs the quality of life of affected patients. The evaluation of risk factors to enable further reduction of incidence is therefore urgently required.

Infection as an Important Factor in Medication-Related Osteonecrosis of the Jaw (MRONJ).

Medication-related osteonecrosis of the jaw (MRONJ) has become a well-known side effect of antiresorptive, and antiangiogenic drugs commonly used in cancer management. Despite a considerable amount of literature addressing MRONJ, it is still widely accepted that the underlying pathomechanism of MRONJ is unclear. However, several clinical and preclinical studies indicate that infection seems to have a major role in the pathogenesis of MRONJ. Although there is no conclusive evidence for the infection hypothesis yet, available data have shown a robust association between local infection and MRONJ development. This observation is very critical in order to implement policies to reduce the risk of MRONJ in patients under antiresorptive drugs. This critical review was conducted to collect the most reliable evidence regarding the link between local infection and MRONJ pathogenesis.

Differences between auto-fluorescence and tetracycline-fluorescence in medication-related osteonecrosis of the jaw-a preclinical proof of concept study in the mini-pig.

OBJECTIVES: Fluorescence-guided bone surgery is a well-established technique in the treatment of medication-related osteonecrosis of the jaw. No histopathological evidence for bone auto-fluorescence is currently available, and thus, any differences from tetracycline-fluorescence remain unclear. Therefore, the goals of this study were to find out if macroscopic and histological differences occur between the auto- and tetracycline-fluorescence in the delineation of viable and necrotic jawbone in the mini-pig. MATERIALS AND METHODS: According to the proof of concept, osteonecrosis was provoked in eight Göttingen minipigs. Pigs were divided into two groups (AF group: no fluorochrome label; TF group: tetracycline label). Delineation of necrosis and viable bone was evaluated in vivo and in vitro macro-/microscopically, correlated to fluorescence properties and compared between the two study groups. RESULTS: No macroscopic and microscopic clinical differences were seen in fluorescence between the AF and TF groups. Macroscopic and microscopic viable bone fluoresced green, whereas necrotic bone showed no or only pale fluorescence in both groups. The auto-fluorescence was attributable to the arrangements and structure of collagen and the cell-filled bone lacunae. CONCLUSION: Neither in vivo nor in vitro macroscopically differences are apparent between the auto-fluorescence and the tetracycline-fluorescence of bone. The auto-fluorescence is attributable to the arrangements and structure of collagen and the cell-filled bone lacunae. Tetracycline-fluorescence is a mixture of tetracycline (at the bone edges with increased bone formation) and large components of auto-fluorescence. CLINICAL RELEVANCE: Because auto-fluorescence is easy to apply, reproducible, and does not rely on the subjective impression of the surgeon, it promises to be an important standardized alternative to tetracycline-labeled MRONJ therapy.

Traumatologie des Gesichtsschädels im Kindesalter.

Associated injuries are a common feature in pediatric facial fractures, which reinforce the importance of a complete initial assessment of a child with facial trauma.Particular kinds of fracture tend to occur at specific anatomic sites in children, with the severity and extent of the fracture varying according to the patient's age and the stage of skeletal development. The frequency of severe fractures increases with age, as does the frequency of surgically treated fractures. Maxillofacial surgical intervention is indicated only for the repair of severely displaced fractures that are likely to cause functional impairment, esthetic deformity, or both. The effect of treatment on long-term growth and development must be the cornerstone when choosing the optimal therapeutic option. While internal fixation is routinely used for adult facial trauma patients, the application of these surgical techniques in children is controversial as subperiosteal dissection might disturb the growth of the bone.

Impact of Le-Fort I osteotomy on anatomical and functional aspects of the nasal airway and on quality of life.

OBJECTIVES: Orthognathic surgery is a well-established procedure for skeletal deformities. Beneficial influences to the posterior airway space (PAS) have been described, but little is known about the subjective aesthetical and functional nasal aspects after orthognathic surgery. The aim of this study was to evaluate nasal airflow by anterior rhinomanometry and volumetric changes in the nasal airway space after mono- or bimaxillary surgery using cone-beam computed tomography (CBCT) and a new segmentation software. Furthermore, changes of patient's quality of life (QoL) should be assessed. METHODS: Ten patients (9 skeletal class malformation III, 1 skeletal class malformation I) were included. CBCT images, rhinological inspections and anterior rhinomanometries were performed before (T0) and after surgery (T1). All patients completed the FROI-17, the ROE and the SF-36 questionnaires. RESULTS: A significant postoperative gain for nasal airway volume compared with the baseline was shown (p < 0.014). No statistically significant differences between pre- and postoperative flow rates were found (p = 0.114). Pre- and postoperative cohorts did not differ in responses of disease-specific (ROE and FROI-17) and generic QoL questionnaires (SF-36). CONCLUSION: Maxillary relocation surgery leads to a significant increase in nasal airway space. Subjectively, orthognathic patients did not experience any functional but psychosocial aspects after bimaxillary surgery.

Mechanical performance of cement- and screw-retained all-ceramic single crowns on dental implants.

OBJECTIVES: This in-vitro study was performed to compare the contact wear, fracture strength and failure mode of implant-supported all-ceramic single crowns manufactured with various fabrication and fixation concepts. MATERIALS AND METHODS: Fifty dental implants (Conelog Ø 4,3mm/L11mm, Camlog Biotechnologies AG) were embedded and treated with all-ceramic molar single-crowns. Three groups received hand-layered zirconia crowns (IPS e.max Ceram/ IPS e.max ZirCAD, Ivoclar Vivadent AG): CZL (cement-retained zirconia-based layered) group crowns were cemented conventionally, SZL (screw-retained zirconia-based layered) group crowns were screw-retained, MZL (modified zirconia-based layered) group crowns showed a different coping design with screw retention. The specimens of SST (screw-retained sintering-technique) and SFL (screw-retained full-contour lithium-disilicate) group were CAD/CAM (Computer-aided design/computer-aided manufacturing) fabricated in the sintering technique (IPS e.max ZirCAD/IPS e.max CAD, Ivoclar Vivadent AG) and full-contour of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent AG) respectively and screw-retained. All specimens underwent artificial aging, load until failure and a scanning electron microscopy (SEM) analysis. The received data were statistically compared (one-way ANOVA; Student-Newman-Keuls test; Mann-Whitney U-test) at a significance level of 5%. RESULTS: Mouth-motion fatigue testing caused two abutment fractures (SST group and SZL group) and two chipping events (CZL group). Specimens of MZL group showed statistically significant less contact wear compared to the other groups (p<0.001). There was no statistical difference between the groups in terms of the maximum fracture load. SEM-analysis showed a more homogenous structure and surface of CAD/CAM fabricated specimens towards manually veneered components. CONCLUSIONS: The mode of retention did not influence the fracture resistance but the failure patterns of the specimens. CAD/CAM milled lithium-disilicate crowns seemed to be a preserving factor for dental implants. CLINICAL RELEVANCE: The mode of retention and veneering influences the mechanical performance of implant-supported single crowns.

Free Vastus Intermedius Muscle Flap: A Successful Alternative for Complex Reconstruction of the Neurocranium in Preoperated Patients.

The reconstruction of large cranial and scalp defects is a surgical and esthetic challenge. Single autologous tissue transfer can be insufficient due to the defect size and the anatomic complexity of the recipient site. Alloplastic patient-specific preformed implants can be used to recover hard tissue defects of the neurocranium. Nevertheless, for long-term success adequate soft tissue support is required. In this brief clinical study, the authors describe calvarian reconstruction in a 33-year-old patient with wound healing disorder after an initial resection of ependymoma. The patient suffered from osteonecrosis and wound breakdown in the fronto-parietal region. An alloplastic polymethylmethacrylate implant for hard tissue support was manufactured based on 3-dimensional visualization of a computed tomography scan. After the resection of remaining pathologic bone from earlier surgical procedures, the alloplastic implant was inserted to achieve functional coverage of the brain. Due to anatomic variation of donor site vessels during anterolateral thigh flap preparation, the authors performed a vastus intermedius free flap as a new muscular flap for craniofacial reconstruction. The authors achieved excellent functional and esthetic results. The muscular vastus intermedius free flap in combination with a split skin graft proves to be a new alternative to the anterolateral thigh flap for soft tissue reconstruction of the neurocranium.