Cross-sectional analysis comparing prefabricated titanium to individualized hybrid zirconia abutments for cemented zirconia based fixed dental prostheses: a critical concept assessment.

PURPOSE: Despite the differences in material properties and shapes among the different types of prefabricated titanium (pTiA) and individualized hybrid zirconia abutments (ihZiA), the biological and clinical relevance of materials and construction features remains vague. Yet, individualized ihZiA are increasingly implemented into daily routine aiming to satisfy rising expectations. The objective was to compare these two types of abutments in fixed dental prostheses (FDP). METHODS: This cross-sectional study examined 462 implants in 102 patients comparing pTiA (52 patients) to ihZiA (50 patients) for FDP. These different treatment regimens were evaluated in terms of peri-implant health, radiographic bone loss, and oral-health related quality of life (OH-QoL) with special consideration of abutment type and superstructure design. RESULTS: ihZiA showed significantly different design features than prefabricated pTiA, but the annual bone loss in both groups did not. Visible titanium in the esthetic zone negatively impacted OHIP 14 scores. The combination of an emergence angle (EA) of < 30° and a concave emergence profile (EP) as well as gingiva thickness (p = 0.002) at the time of the prosthetic restoration significantly improved the annual peri-implant bone loss, independently of the abutment type. CONCLUSION: ihZiA showed comparable results to pTiA. To optimize the long-term outcome, not just material alone but generating adequate soft tissue thickness, minimizing the EA, and applying a concave EP seem to be the most relevant factors. To improve OH-QoL, particular attention must be paid to the esthetic zone.

A modified pull-through approach with a pedicled bone flap for oral and oropharyngeal cancer resection: a feasibility study.

PURPOSE: Compromised swallowing, speaking, and local complications are the major disadvantages of established approaches to the posterior tongue and oropharynx. The mandibular split involves an esthetically unpleasant bipartition of the lower lip and is prone to bony non-union or sequestration. The conventional pull-through technique on the other hand lacks the secure reattachment of the lingually released soft tissues. METHODS: The feasibility of a new modified pull-through approach was tested on three anatomical specimens. CAD/CAM cutting guides were used to design a retentive bone flap to properly refixate the genioglossus and geniohyoid muscles after the procedure. The radiographic assessment and treatment planning was performed on 12 cadavers. The entire procedure was tested surgically via dissection in three of those cases. This procedure was then applied in a clinical case. RESULTS: Precise repositioning and dynamic compression of bony segments was possible reproducibly and without injury to adjacent structures. In all dissected cases, a median lingual foramen was found and in two cases vessels entering it could be dissected Radiologic anatomical landmarks were sufficient in all 12 cases to perform the clinical planning procedure. Clinically, the osteotomized segment demonstrated good blood supply and plateless repositioning was verified postoperatively via cone beam scan. CONCLUSION: The method presented is safe and easy to perform. Individual cutting guides improve the safety and accuracy of the procedure, potentially eliminating the need for osteosynthesis. We provide the anatomical and radiologic basis for clinical evaluation of this pedicled bone flap procedure and present the clinical application of this modified pull-through approach.

Clinical Success of Periorbital Craniofacial Implants: Introduction of a Staging System and Treatment Algorithm for Peri-implant Infections.

Purpose: To compare different assessment methods for peri-implant inflammation to evaluate potential risk factors and to generate a comprehensive algorithm for clinical staging, treatment, and evaluation of success in periorbital implants. Materials and Methods: In this hospital-based cross-sectional study, 111 periorbital implants in 40 patients with orbital defects after exenteration were clinically analyzed. Skin reaction according to Holgers (SRH), probing depth (PD) , and sulcus fluid flow rate (SFFR), as well as patient-specific data, such as age, sex, smoking and irradiation status, cleaning agent and frequency, defect etiology, implant system, implant location, time span since implantation, and type of retention, were assessed and statistically analyzed via mixed-model calculations. Success was defined as the absence of necessary invasive or antibiotic treatment. Results: A total of 62 implants (55.9%) had been placed in male patients and 49 implants (44.1%) in female patients. There were 18 patients (52 implants, 46.8%) who had received radiotherapy. Mean inflammation levels were low. PD and SFFR were highly correlated, whereby PD increased significantly with time after implantation. SRH ≥ 2 was correlated significantly with higher PD and SFFR values. While 80% of the implants did not require invasive or antibiotic treatment, 45% of the patients presented at least one affected implant. The data gathered allowed for the definition of a staging and treatment algorithm for peri-implantitis in periorbital implants. No patient-specific factors showed a significant impact on peri-implant inflammation. Conclusion: Periorbital implant restorations with magnetic abutments are a safe treatment option for orbital defects. PD and SRH were proven to be valuable quick assessment tools and should be complemented by SFFR, if inconclusive. The established parameters for the staging of peri-implant tissue health and clinical success can serve as a viable tool for reliable and comparable assessment in clinical and scientific settings. Further studies are necessary to assess the suggested treatment algorithm.

Prevalence of dental caries in children with congenital heart disease.

BACKGROUND: Congenital heart defects (CHD) affect about 8 out of 1000 births worldwide. Most of the patients reach adulthood and are exposed to an increased risk of endocarditis. Since bacteria already enter the bloodstream during everyday activities, oral hygiene is given special importance in the prevention of endocarditis. METHODS: In this study 81 boys (55.1%) and 66 (44.9%) girls with CHD received a dental exam and additionally an assessment using the DIAGNOdent® pen. This study group consisting of patients with CHD was matched with a healthy epidemiological control group in Germany. RESULTS: Eighty-one boys (55.1%) and 66 (44.9%) girls were examined. The mean age was 11 ± 4 years. 38.8% showed at least one untreated carious lesions. 37.4% had a dmft/DMFT ≥2 and thus represented a group with an increased caries risk. The dmft value was 2.12 ± 1.25 in the age group 3-6 year olds. In the group of the 7-12 year old patients the DMFT/dmft was 2.06 ± 2.27, whereas DMFT in 13-17 year olds was at 2.12 ± 1.58. However, children and adolescents with CHD had a higher DMF index than healthy children in the same age group. CONCLUSIONS: The present study reveals that more than one third of those examined have a dental condition in need of rehabilitation. In future, close interdisciplinary cooperation between pediatric cardiologists and dentists should ensure regular dental check-ups.

Sonication versus the conventional method for evaluation of the dental microbiome: a prospective pilot study.

OBJECTIVES: To investigate sonication as a new tool in microbiological probing of dental infections. METHODS: Comparison of a standard probing method: intraoperative swab, with sonication, and vortex of the removed tooth, was performed on 20 carious destructed teeth. Illumina high throughput sequencing of the 16S-rRNA-gene was used for assessing the microbial composition. Antibiotic susceptibility has been assigned based on known resistances of each detected species. Probing procedures were compared using Bland-Altmann-Test, and antibiotic susceptibility using the Friedmann-Test and alpha-adjusted post-hoc-analysis. RESULTS: In total, 60 samples were analysed: 20 intraoperative swabs, 20 vortex fluids, and 20 sonication fluids. Sonication fluid yielded the highest number of bacterial sequencing reads in all three procedures. Comparing the operational taxonomic units (OTUs) of the identified bacteria, significantly more OTUs were found in sonication fluid samples. Phylum and order abundances varied between the three procedures. Significantly more Actinomycetales have been found in sonication fluid samples compared to swab samples. The assigned resistance rates for the identified bacteria (1.79-31.23%) showed no differences between the tested probing procedures. The lowest resistance rates were found for amoxicillin + clavulanate (3.95%) and levofloxacin (3.40%), with the highest in amoxicillin (30.21%) and clindamycin (21.88%). CONCLUSIONS: By using sonication on extracted teeth, it is possible to get a more comprehensive image of the residing microbial flora compared to the standard procedure. If sonication is not available, vortexing is a potential alternative. In immunocompromised patients, especially when actinomycosis is suspected, sonication should be considered for a more detailed microbiological evaluation of the potential disease-causing microbiome. Due to the high rates of antibiotic resistance, a more targeted antibiotic therapy is favourable. Levofloxacin should be considered as a first-line alternative to amoxicillin + clavulanate in patients with an allergy to penicillin.

Pilot investigation on the dose-dependent impact of irradiation on primary human alveolar osteoblasts in vitro.

Radiotherapy of head and neck squamous cell carcinoma can lead to long-term complications like osteoradionecrosis, resulting in severe impairment of the jawbone. Current standard procedures require a 6-month wait after irradiation before dental reconstruction can begin. A comprehensive characterization of the irradiation-induced molecular and functional changes in bone cells could allow the development of novel strategies for an earlier successful dental reconstruction in patients treated by radiotherapy. The impact of ionizing radiation on the bone-forming alveolar osteoblasts remains however elusive, as previous studies have relied on animal-based models and fetal or animal-derived cell lines. This study presents the first in vitro data obtained from primary human alveolar osteoblasts. Primary human alveolar osteoblasts were isolated from healthy donors and expanded. After X-ray irradiation with 2, 6 and 10 Gy, cells were cultivated under osteogenic conditions and analyzed regarding their proliferation, mineralization, and expression of marker genes and proteins. Proliferation of osteoblasts decreased in a dose-dependent manner. While cells recovered from irradiation with 2 Gy, application of 6 and 10 Gy doses not only led to a permanent impairment of proliferation, but also resulted in altered cell morphology and a disturbed structure of the extracellular matrix as demonstrated by immunostaining of collagen I and fibronectin. Following irradiation with any of the examined doses, a decrease of marker gene expression levels was observed for most of the investigated genes, revealing interindividual differences. Primary human alveolar osteoblasts presented a considerably changed phenotype after irradiation, depending on the dose administered. Mechanisms for these findings need to be further investigated. This could facilitate improved patient care by re-evaluating current standard procedures and investigating faster and safer reconstruction concepts, thus improving quality of life and social integrity.

Influence of implant-specific radiation doses on peri-implant hard and soft tissue: An observational pilot study.

OBJECTIVES: The aim of this study was to investigate the influence of real implant-bed-specific radiation doses on peri-implant tissue health in head and neck cancer (HNC) patients after radiotherapy. MATERIAL AND METHODS: Specific radiation doses in the area of 81 implants, in 15 irradiated HNC patients, were analyzed by matching data from the radiotherapy planning system with those of three-dimensional follow-up scans after implantation. Peri-implant bone resorption was measured radiographically after 1 and 3 years, and peri-implant tissue health was evaluated clinically. Individual parameters, such as age, gender, and localization, regarding the implant-specific radiation dose distribution were analyzed statistically. RESULTS: The mean implant-bed-specific radiation dose was high, with 45.95 Gy to the mandible and 29.02 Gy to the maxilla, but significantly lower than the mean total dose to the tumor bed. Peri-implant bone resorption correlated with local inflammation and plaque. After 1 year, women temporarily showed significantly more bone loss than men and implant-specific radiation dose had a significant impact on peri-implant bone loss after 3 years. CONCLUSIONS: The presented method is a feasible option to define precise implant-bed-specific radiation doses for research or treatment planning purposes. Implant-based dental restoration after radiotherapy is a relatively safe procedure, but a negative radiation dose-dependent long-term effect on peri-implant bone resorption calls for interdisciplinary cooperation between surgeons and radio-oncologists to define high-risk areas.

Rediscussing the Role of Traditional Risk Factors in Young Adults With Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: The current literature conjectures that oral squamous cell carcinoma (OSCC) in younger patients is an entirely separate entity with a different risk profile. We aimed to uncover the potential risk factors of OSCC and evaluated the long-term outcome in such patients. PATIENTS AND METHODS: This hospital-based case-control study included 40 patients with OSCC and 40 controls under the age of 46 years. Survival was analyzed via Kaplan-Meier estimates, including a follow-up of up to 24.3 years. RESULTS: The patients with OSCC were prone to smoking and drinking heavily and even suffered secondary organ damage to the lungs and the liver at this young age. Early diagnosed as well as surgically treated patients had superior 5-year recurrence-free and overall survival. CONCLUSION: Young patients with OSCC were found to have a traditional risk profile. Secondary organ damage to the liver and the lungs might be considered as a risk indicator. The meticulous screening of every age group with this risk profile is key to early diagnosis and acceptable treatment results.

The diagnostic performance of perfusion CT in the detection of local tumor recurrence in head and neck cancer.

BACKGROUND: Detecting local tumor recurrence from post-treatment changes in head and neck cancer (HNC) remains a challenge. Based on the hypothesis that post-therapeutically altered tissue is bradytroph, lower perfusion values are expected in perfusion CT (PCT) while higher perfusion values are expected in recurrent malignant tissue. OBJECTIVES: This prospective study investigates PCT for post-treatment recurrent HNC detection with a maximum slope algorithm. METHODS: A total of 80 patients who received PCT of the head and neck for post-therapy follow-up, of which 63 had no tumor recurrence and 17 presented a histopathologically confirmed recurrence were examined. Regions of interest were placed in the location of the initial tumor, in reference ipsilateral nuchal muscle tissue and the corresponding internal carotid artery. Perfusion was calculated using a single-input maximum slope algorithm. RESULTS: With PCT, recurrent HNC can be differentiated from post-treatment tissue (p < 0.05). It further allows delineating recurrent tumor tissue from benign nuchal tissue of reference (p < 0.05). PCT data of patients with and without recurrent HNC are comparable as perfusion values of reference tissues in patients with and without HNC do not differ (p > 0.05). CONCLUSIONS: PCT in combination with a commercially available maximum slope algorithm offers radiologists a reliable imaging tool to detect recurrent head and neck cancer within post-therapeutically altered tissue.

Replacing one evil with another: Is the fibula really a dispensable spare part available for transfer in patients with medication-related osteonecrosis of the jaws?

Because of the long-term and consecutive use of different causative agents, clinicians are increasingly encountering patients needing restoration of the stomatognathic system after surgical resection of highly advanced necroses of the jaw. For plastic restoration in these cases, microvascular reconstruction seems to represent the most viable option. According to the limited data available, the risks of this operation are considered comparable with those faced by other patient cohorts. We report here the case of a patient who suffered 2 successive pathologic fractures of the tibia after microsurgical reconstruction of the mandible with a free fibula flap. This exemplifies a general problem, especially because the patient also suffered from a treatment-refractory infection of the transplanted bone. Although the present literature indicates otherwise, fibula transplants might not be the gold standard in these cases. Therefore, alternatives to transplants from the weight-bearing parts of the body need to be considered until more data are available.

Primary oral manifestation of Langerhans cell histiocytosis refractory to conventional therapy but susceptible to BRAF-specific treatment: a case report and review of the literature.

Langerhans cell histiocytosis (LCH) is a diagnostic and therapeutic challenge. We report on a rare case of its primary oral manifestation that was treated successfully with the BRAF-specific agent, vemurafenib, after insufficient standard LCH treatment. This case underlines the importance of proper diagnosis and the evaluation of targeted therapy as a valuable tool in LCH treatment. Furthermore, the close collaboration of surgeons, oncologists, and dentists is mandatory to ensure adequate treatment, restore the stomatognathic system in debilitating post-treatment situations, improve quality of life, and ensure effective disease control in infants and young patients.

Erlotinib and gefitinib responsiveness in head and neck cancer cell lines--a comparing analysis with cetuximab.

OBJECTIVE: The objective of this study is to examine the efficacy of erlotinib and gefitinib with respect to epidermal growth factor (EGF) and cetuximab response in head and neck cancer cell lines. MATERIALS AND METHODS: Five human head and neck carcinoma cell lines were treated with EGF, cetuximab, erlotinib, and gefitinib, and the effects were measured with a crystal violet assay. The efficacies of cetuximab, erlotinib, and gefitinib in clinically relevant concentrations were statistically analyzed. The expression of the epidermal growth factor receptor (EGFR) and phosphorylation patterns were detected with fluorescence-activated cell sorting (FACS) analysis and western blot analysis. The endogenous production of EGF by the cells was detected with an enzyme-linked immunosorbent assay. Finally, EGFR, KRAS, BRAF, and PI3K mutation analyses were performed. RESULTS: All of the cell lines had a poor or no response to EGF but exhibited distinct EGFR phosphorylation and EGFR expression. Compared to cetuximab, erlotinib and gefitinib demonstrated a greater impact on the majority of the cell lines. The only cell line that showed a concentration-dependent behavior toward EGF and strong EGFR phosphorylation was entirely resistant to cetuximab, erlotinib, and gefitinib. The production of EGF in all cell lines was very low. Mutational analysis of all cell lines revealed wild-type EGFR, KRAS, BRAF, and PI3K. CONCLUSIONS: The prediction of anti-EGFR treatment cannot be based on responsiveness to EGF or EGFR activation. CLINICAL RELEVANCE: Erlotinib and gefitinib show good response in EGF-independent cell lines and might be useful drugs in tumors that are less responsive to cetuximab.