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1.  Lingual orthodontic treatment duration: performance of two different completely customized multi-bracket appliances (Incognito and WIN) in groups with different treatment complexities 
Head & Face Medicine  2014;10(1):46.
The occurrence of side-effects of fixed orthodontic therapy, such as white-spot lesions and root resorption, are known to be significantly more frequent with increasing duration of treatment. Multi-bracket treatment should be as short as possible, in order to minimize the risks of collateral damage to teeth. The aim of this non-randomized clinical trial was to compare treatment duration with each of two types of customized lingual orthodontic appliances (Incognito, 3 M-Unitek; WIN, DW LingualSystems), taking into account treatment complexity. The null-hypothesis was that there would be no significant difference in active orthodontic treatment duration between them.
Of 402 potentially eligible participants, a population sample of n = 376 subjects (nIncognito = 220; nWIN = 156; m/f 172/204; mean age ± SD 17.3 ± 7.7Y) treated in one orthodontic center (Bad Essen, Germany) with completely customized lingual appliances in upper and lower permanent dental arches was recruited with the inclusion criterion of initiated and completed lingual multi-bracket treatment within the assessment period of April 1st 2010 – Nov 30, 2013, and the exclusion criterion of less than 24 bracketed teeth. We used four-factorial ANOVA to assess the impact of the following factors: initial degree of severity of malocclusion (mild to moderate, S1; severe, S2), appliance type (Incognito; WIN), sex, and age group (<=16; >16 Y) on the duration of lingual multi-bracket treatment.
Overall, mean treatment duration was 21.7 (SD 7.2) months, which was significantly shorter for WIN for both sub-groups of treatment complexity (S1: 17.96 mo; S2: 20.49 mo) compared to Incognito (S1: 22.7 mo; S2: 29.79 mo). ANOVA revealed a significant influence of the main effects ‘appliance type’, and ‘severity’, independent of each other. Therefore, the null-hypothesis was rejected.
In terms of treatment duration, the WIN appliance performed significantly better than the Incognito appliance. Consequently, subjects treated with the WIN appliance are expected to be exposed to lower risks of the typical side-effects associated with longer multi-bracket treatment durations, such as root resorption and enamel decalcification.
PMCID: PMC4228173  PMID: 25361639
Orthodontic treatment duration; Lingual multibracket appliance; Incognito appliance; WIN appliance; In vivo
2.  Spline-based procedures for dose-finding studies with active control 
Statistics in Medicine  2014;34(2):232-248.
In a dose-finding study with an active control, several doses of a new drug are compared with an established drug (the so-called active control). One goal of such studies is to characterize the dose–response relationship and to find the smallest target dose concentration d*, which leads to the same efficacy as the active control. For this purpose, the intersection point of the mean dose–response function with the expected efficacy of the active control has to be estimated. The focus of this paper is a cubic spline-based method for deriving an estimator of the target dose without assuming a specific dose–response function. Furthermore, the construction of a spline-based bootstrap CI is described. Estimator and CI are compared with other flexible and parametric methods such as linear spline interpolation as well as maximum likelihood regression in simulation studies motivated by a real clinical trial. Also, design considerations for the cubic spline approach with focus on bias minimization are presented. Although the spline-based point estimator can be biased, designs can be chosen to minimize and reasonably limit the maximum absolute bias. Furthermore, the coverage probability of the cubic spline approach is satisfactory, especially for bias minimal designs. © 2014 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.
PMCID: PMC4288315  PMID: 25319931
dose-finding study; active control; spline interpolation; design considerations
3.  Oral health status of patients with acute coronary syndrome – a case control study 
BMC Oral Health  2012;12:17.
The aim of this investigation was to assess the state of oral health of patients with acute coronary syndrome (ACS) and to compare this with that of a provably healthy control group (H).
33 patients who were receiving treatment as inpatients following acute myocardial infarction or unstable angina pectoris took part in the study (ACS-group). A healthy control group (H-group) made up of blood donors, was formed following matching for age, gender, and smoking habit with the study patient group.
The dental investigation consisted of the dental status (DMF-T), a plaque-Index (PI), an assessment of gingival inflammation (GI) and periodontal situation (Periodontal Screening Index: PSR®/PSI), and attachment loss (AL). Statistical evaluation: t-test, Mann–Whitney-test and chi- squared test (level of significance p < 0.05).
The mean DMF-T of the ACS-group (18.7 ± 6.8) and the H-group (19.4 ± 5.1) showed no difference (p = 0.7). Although, in the ACS-group the average loss of teeth (M-T: 8.4 ± 5.2) was higher than in the H-group (M-T: 5.8 ± 6.6) the difference was not significant (p = 0.2). Whereas with the PI no difference between the two groups was found (p = 0.9), the ACS-group showed significantly more signs of inflammation (GI) than the H-group (p = 0.045). In the case of PSR®/PSI, there was no difference between the two groups (p = 0.7). With regard to AL, no difference was revealed between ACS- and H-group (p = 0.2).
Although, the state of oral health of the ACS-group differed only insignificantly from that of control, patients with ACS showed more signs of gingival inflammation and a higher loss of teeth.
PMCID: PMC3444382  PMID: 22727119
Oral health; Oral hygiene; Gingival inflammation; Periodontitis; Acute coronary syndrome; Acute myocardial infarction; Unstable angina pectoris
4.  Adhesion Maturation of Neutrophils on Nanoscopically Presented Platelet Glycoprotein Ibα 
ACS Nano  2013;7(11):9984-9996.
Neutrophilic granulocytes play a fundamental role in cardiovascular disease. They interact with platelet aggregates via the integrin Mac-1 and the platelet receptor glycoprotein Ibα (GPIbα). In vivo, GPIbα presentation is highly variable under different physiological and pathophysiological conditions. Here, we quantitatively determined the conditions for neutrophil adhesion in a biomimetic in vitro system, which allowed precise adjustment of the spacings between human GPIbα presented on the nanoscale from 60 to 200 nm. Unlike most conventional nanopatterning approaches, this method provided control over the local receptor density (spacing) rather than just the global receptor density. Under physiological flow conditions, neutrophils required a minimum spacing of GPIbα molecules to successfully adhere. In contrast, under low-flow conditions, neutrophils adhered on all tested spacings with subtle but nonlinear differences in cell response, including spreading area, spreading kinetics, adhesion maturation, and mobility. Surprisingly, Mac-1-dependent neutrophil adhesion was very robust to GPIbα density variations up to 1 order of magnitude. This complex response map indicates that neutrophil adhesion under flow and adhesion maturation are differentially regulated by GPIbα density. Our study reveals how Mac-1/GPIbα interactions govern cell adhesion and how neutrophils process the number of available surface receptors on the nanoscale. In the future, such in vitro studies can be useful to determine optimum therapeutic ranges for targeting this interaction.
PMCID: PMC4122703  PMID: 24093566
biomimetic surfaces; nanopatterning; biofunctionalization; cell adhesion; neutrophils; platelets
5.  Individualized Surgery: Gamma-Probe-Guided Lymphadenectomy in Patients with Clinically Enlarged Lymph Node Metastases from Melanomas 
Annals of Surgical Oncology  2013;20(5):1714-1721.
The value of a preoperative lymphoscintigraphy in melanoma patients with clinically evident regional lymph node metastases has not been studied. Therapeutic lymph node dissection (TLND) is regarded as the clinical standard, but the appropriate extent of TLND is controversial in all lymphatic basins.
Patients and Methods
Of the 115 consecutive patients with surgery on palpable lymph node metastases, 34 received a pre-operative lymphoscintigraphy. Lymphatic drainage to a second nodal basin outside the clinically involved basin was found in 15 cases. In 13 patients, the ectopic tumor-draining lymph nodes were excised as in a sentinel node biopsy. The lymph nodes from the TLND specimens were postoperatively separated and classified as either radioactive or non-radioactive.
A total of 493 lymph nodes were examined pathologically. The largest macrometastasis maintained the ability to take up radiotracer in 77% of cases. Radioactively labeled lymph nodes carried a higher risk of being involved with metastasis. The proportions of tumor involvement for radioactive and non-radioactive lymph nodes were 44.5 and 16.9%, respectively (P=0.00002). Of the 13 ectopic nodal basins surgically explored, six harbored clinically occult metastases.
In patients undergoing TLND for palpable metastases, tumor-draining lymph nodes in a second, ectopic nodal basin should be excised, because they could be affected by occult metastasis. With respect to radioactive lymph nodes situated within the nodal basin of the macrometastasis but beyond the borders of a less-radical lymphadenectomy, further studies are needed.
PMCID: PMC3618405  PMID: 23314605

Results 1-6 (6)