A retrospective analysis of autotransplanted teeth including an evaluation of a novel surgical technique.

OBJECTIVES: To assess survival rates and frequency of complications for immature and mature autotransplanted teeth after at least 1 year in function. MATERIALS AND METHODS: All consecutive patients who had undergone tooth autotransplantation between 2000 and 2018 were invited to a clinical and radiographic follow-up examination. First, survival rates were calculated on the basis of a phone inquiry. A clinical follow-up examination allowed for the calculation of the success rate, i.e., absence of any potentially adverse clinical and radiographic findings of the autotransplanted teeth. Moreover, the effect of demographic, dental, and surgical variables on survival/success was analyzed statistically. RESULTS: Thirty-eight teeth in 35 patients were transplanted during the study period. Three teeth in 3 patients were excluded due to missing records. All other patients were successfully contacted and interviewed by phone. Out of these 35 transplants, 32 were still in function, and 3 had been extracted, yielding a 91.4% survival probability after a median follow-up of 3.4 years. Of the 32 teeth qualifying for the success analysis, 20 (62.5%) showed absence of potentially adverse findings, while 3 (9.4%) required root canal treatment (RCT). Out of the 9 mature, root-end resected transplants, 4 exhibited ongoing pulp canal obliteration, all with a single root canal. Postoperative and potentially adverse findings or failures were found more frequently in the group of mature transplants (55.6%) than immature transplants (30.4%) and for molars (72.7%) than premolars (17.6%) or canines (25%). None of the potential predictors had a statistically significant effect on survival or success. CONCLUSION: Autotransplanted teeth yielded a satisfying midterm survival rate regardless of their stage of development. An additional, extraoral root-end resection of mature transplants may lead to rates of revascularization and postoperative pulp canal obliteration higher than the data reported on unmodified mature transplants. CLINICAL RELEVANCE: Extraoral root-end resection of mature teeth shows promising outcomes for transplants especially with a single root canal and uncomplicated root morphology.

The effect of tooth loss on gait stability of community-dwelling older adults.

OBJECTIVE: To investigate the effects of tooth loss on gait stability in a healthy elderly population. METHODS: A case-control study was conducted among healthy and prosthetically well-restored seniors over the age of 65 years. The test group comprised 24 edentulous participants who were restored with complete dentures in the upper jaw and an overdenture fixed on two implants in the lower jaw. The control group comprised 25 dentate participants who either still had their natural teeth or were restored with conventional fixed partial dentures. Gait stability was evaluated by measuring the parameters 'gait velocity' and 'cycle-time variability' during self-selected normal walking speed and under dual-task performance conditions. Measurements were conducted using the GAITRite(®) electronic walkway system. RESULTS: Dentated and fixed restored participants (the control group) had a significantly higher gait velocity compared with denture wearers (the test group) under both normal walking (p = 0.03) and dual-task performance conditions (p = 0.01). In each test condition, among edentulous participants, gait velocity did not significantly differ according to whether the participant wore their dentures. CONCLUSION: The present results suggest that tooth loss in healthy seniors is associated with lower gait velocity and therefore may have a negative impact on gait stability.

Dacryocystography using cone beam CT in patients with lacrimal drainage system obstruction.

PURPOSE: To assess the usefulness of cone beam CT (CBCT) for dacryocystography (DCG) using either direct syringing or passive application of contrast medium. METHODS: Ten consecutive patients with epiphora who had CBCT-DCG in a sitting position were retrospectively analyzed. CBCT-DCGs were performed using 2 techniques: direct syringing with contrast medium or using the passive technique, where patients received 3 drops of contrast medium into the conjunctival sac before CBCT-DCG. Clinical and radiologic diagnoses were compared for both groups. RESULTS: The 10 patients (men = 3) had a mean age of 63.2 years. Both techniques proved to be simple procedures with good delineation of the bone, soft tissue, and the contrast medium in the lacrimal system. No side effects were noted. CONCLUSIONS: CBCT-DCG is a useful alternative to determine the localization of stenosis in patients with chronic epiphora.

Assessment of smoking behaviour in a dental setting: a 1-year follow-up study using self-reported questionnaire data and exhaled carbon monoxide levels.

OBJECTIVES: This study analyses the changes in smoking habits over the course of 1 year in a group of patients referred to an oral medicine unit. MATERIALS AND METHODS: Smoking history and behaviour were analysed at baseline and after 1 year based on a self-reported questionnaire and on exhaled carbon monoxide levels [in parts per million (ppm)]. During the initial examination, all smokers underwent tobacco use prevention and cessation counselling. RESULTS: Of the initial group of 121 patients, 98 were examined at the follow-up visit. At the baseline examination, 33 patients (33.67 %) indicated that they were current smokers. One year later, 14 patients (42.24 % out of the 33 smokers of the initial examination) indicated that they had attempted to stop smoking at least once over the follow-up period and 15.15 % (5 patients) had quit smoking. The mean number of cigarettes smoked per day by current smokers decreased from 13.10 to 12.18 (p = 0.04). The exhaled CO level measurements showed very good correlation with a Spearman's coefficient 0.9880 for the initial visit, and 0.9909 for the follow-up examination. For current smokers, the consumption of one additional cigarette per day elevated the CO measurements by 0.77 ppm (p < 0.0001) at the baseline examination and by 0.84 ppm (p < 0.0001) at the 1-year follow-up. CONCLUSIONS: In oral health care, where smoking cessation is an important aspect of the treatment strategy, the measurement of exhaled carbon monoxide shows a very good correlation with a self-reported smoking habit. CLINICAL RELEVANCE: Measurement of exhaled carbon monoxide is a non-invasive, simple and objective measurement technique for documenting and monitoring smoking cessation and reduction.

Assessment of bone channels other than the nasopalatine canal in the anterior maxilla using limited cone beam computed tomography.

PURPOSE: The anterior maxilla, sometimes also called premaxilla, is an area frequently requiring surgical interventions. The objective of this observational study was to identify and assess accessory bone channels other than the nasopalatine canal in the anterior maxilla using limited cone beam computed tomography (CBCT). METHODS: A total of 176 cases fulfilled the inclusion criteria comprising region of interest, quality of CBCT image, and absence of pathologic lesions or retained teeth. Any bone canal with a minimum diameter of 1.00 mm other than the nasopalatine canal was analyzed regarding size, location, and course, as well as patient gender and age. RESULTS: A total of 67 accessory canals ≥1.00 mm were found in 49 patients (27.8%). A higher frequency of accessory canals was observed in males (33.0%) than in females (22.7%) (p = 0.130). Accessory canals occurred more frequently in older rather than younger patients (p = 0.115). The mean diameter of accessory canals was 1.31 ± 0.26 mm (range 1.01-2.13 mm). Gender and age did not significantly influence the diameter. Accessory canals were found palatal to all anterior teeth, but most frequently palatal to the central incisors. In 56.7%, the accessory canals curved superolaterally and communicated with the ipsilateral alveolar extension of the canalis sinuosus. CONCLUSIONS: The study confirms the presence of bone channels within the anterior maxilla other than the nasopalatine canal. More than half of these accessory bone canals communicated with the canalis sinuosus. From a clinical perspective, studies are needed to determine the content of these accessory canals.

Assessment of smoking behaviour in the dental setting. A study comparing self-reported questionnaire data and exhaled carbon monoxide levels.

The present study validated the accuracy of data from a self-reported questionnaire on smoking behaviour with the use of exhaled carbon monoxide (CO) level measurements in two groups of patients. Group 1 included patients referred to an oral medicine unit, whereas group 2 was recruited from the daily outpatient service. All patients filled in a standardized questionnaire regarding their current and former smoking habits. Additionally, exhaled CO levels were measured using a monitor. A total of 121 patients were included in group 1, and 116 patients were included in group 2. The mean value of exhaled CO was 7.6 ppm in the first group and 9.2 ppm in the second group. The mean CO values did not statistically significantly differ between the two groups. The two exhaled CO level measurements taken for each patient exhibited very good correlation (Spearman's coefficient of 0.9857). Smokers had a mean difference of exhaled CO values of 13.95 ppm (p < 0.001) compared to non-smokers adjusted for the first or second group. The consumption of one additional pack year resulted in an increase in CO values of 0.16 ppm (p = 0.003). The consumption of one additional cigarette per day elevated the CO measurements by 0.88 ppm (p < 0.001). Based on these results, the correlations between the self-reported smoking habits and exhaled CO values are robust and highly reproducible. CO monitors may offer a non-invasive method to objectively assess current smoking behaviour and to monitor tobacco use cessation attempts in the dental setting.

Patients' awareness of the potential benefit of smoking cessation. A study evaluating self-reported and clinical data from patients referred to an oral medicine unit.

The present study analyzed history of smoking and willingness to quit smoking in patients referred for diagnosis and treatment of different oral mucosal lesions. Prior to the initial clinical examination, patients filled in a standardized questionnaire regarding their current and former smoking habits and willingness to quit. Definitive diagnoses were classified into three groups (benign/reactive lesions, premalignant lesions and conditions, and malignant diseases) and correlated with the self-reported data in the questionnaires. Of the 980 patients included, 514 (52%) described themselves as never smokers, 202 (21%) as former smokers, and 264 (27%) as current smokers. In the group of current smokers, 23% thought their premalignant lesions/conditions were related to their smoking habit, but only 15% of the patients with malignant mucosal diseases saw that correlation. Only 14% of the smokers wanted to commence smoking cessation within the next 30 days. Patients with malignant diseases (31%) showed greater willingness to quit than patients diagnosed with benign/reactive lesions (11%). Future clinical studies should attempt (1) to enhance patients' awareness of the negative impact of smoking on the oral mucosa and (2) to increase willingness to quit in smokers referred to a dental/oral medicine setting.

Wear of ceramic and titanium ball attachments in subjects with an implant-retained overdenture: a controlled clinical trial.

STATEMENT OF PROBLEM: Loss of retention of implant-retained overdentures due to wear of the patrix or matrix of the attachment system is a common clinical problem. PURPOSE: The purpose of this controlled clinical trial was to compare the wear of ceramic and titanium ball attachments and their corresponding gold matrices after 1 year of clinical function in subjects with implant-retained mandibular overdentures. MATERIAL AND METHODS: Forty subjects who had been treated with a 2-implant-retained overdenture received either 2 ruby ball attachments (20 subjects) or 2 titanium ball attachments (20 subjects). The diameter of the ball attachments and the thickness of the matrix were measured optically before insertion and after 1 year of clinical function. Differences among groups were then compared with the Wilcoxon rank sum test (α=.05). To estimate any correlation between clinical parameters and wear, the Spearman rank test was used. RESULTS: There was no significant difference (P=.73) in the median wear of ball attachments for the titanium group (5.3 µm; median 1.3 µm) and for the ceramic group (1.3 µm; median 1.3 µm). In the ceramic group, a fracture rate of 30% was observed. The mean wear of the matrices in the titanium group was 3.1 µm (median 6.8 µm) and in the ceramic group 2.1 µm (median 3.4 µm), P=.01. No correlation was found between ball attachment wear and matrix insert wear (Spearman rank test). Wear of matrices was weakly correlated with an increase in divergence between implant axes in the sagittal plane (P=-.28 and P=.021). Ball attachment wear was associated with an increase in divergence between matrix axes in the sagittal plane (P=-.34 and P=.047). CONCLUSIONS: Matrices on ceramic ball attachments showed less wear than those placed on titanium ball attachments. However, the use of ruby ball attachments cannot be recommended because of a high fracture rate.

Immediate loading of two unsplinted mandibular implants in edentulous patients with an implant-retained overdenture: an observational study over two years.

OBJECTIVES: Immediate loading of two unsplinted mandibular implants by means of an overdenture may be a viable and cost-effective treatment option to improve the patient's oral health-related quality of life. We therefore conducted a prospective observational study to estimate implant survival and patient satisfaction after an immediate loading protocol in edentulous patients. MATERIALS AND METHODS: Twenty edentulous patients who received two interforaminal implants (Straumann Standard implant, length 12 mm) were included in our study. Immediately after implant placement, ball attachments with a diameter of 2.25 mm were placed on the implants and the respective matrices were directly incorporated in the existing complete denture. Clinical recalls were scheduled 1 week, 1, 3, 6 months, and 1 and 2 years after implant placement. The following clinical parameters were assessed: gingival bleeding index (GBI), visual plaque index (VPI), and soft tissue overgrowth. In addition, we also assessed radiological bone level change (RBLC) using panoramic radiographs, and patient satisfaction using a visual analogue scale at baseline, after 6 months and 2 years. RESULTS: No implant failures occurred during the 2-year observation period, resulting in a survival rate of 100%. The mean RBLC was 0.67 mm (95% Confidence Interval [95% CI]: 0.47-0.86 mm) two years after surgery. The GBI and VPI after two years were 24 (95% CI: 9-38)% and 36 (95% CI: 19-53)%, respectively. Soft tissue overgrowth was 1.6 mm (95% CI: 1.1-2.1) on average after two years. In a multivariate regression model, patients with a GBI ≥50% on average showed an increased RBLC (-0.6 mm, p = 0.007). High patient ratings were recorded for overall satisfaction. Overall patient satisfaction measured on a scale between one and ten was 5.2 (95% CI: 2.1-8.5) before implant placement and 9.5 (95% CI: 9.1-10) after 2 years. CONCLUSION: Immediate loading of two unsplinted interforaminal implants in overdenture patients using ball attachments is a clinically viable treatment option that leads to a high survival rate and oral health-related quality of life.

Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography.

OBJECTIVES: To analyze the dimensions and anatomic characteristics of the nasopalatine canal and the corresponding buccal bone plate of the alveolar process, using limited cone-beam computed tomography (CBCT) imaging. MATERIAL AND METHODS: Partially edentulous patients scheduled for CBCT imaging for further radiographic evaluation of a prospective implant recipient site in the anterior maxilla were consecutively enrolled in this study. For all CBCT images, a limited field of view (FOV) of 4 × 4 cm, 6 × 6 cm or 8 × 8 cm was selected. Reformatted sagittal and coronal slices were analyzed with regard to dimensions and anatomic characteristics of the nasopalatine canal as well as the dimensions of the buccal bone wall. Factors influencing these parameters were evaluated using univariate and multivariate linear regression models. RESULTS: The study population comprised 44 men and 56 women with a mean age of 43.09 years. Gender of the included patients had a statistically significant influence on the dimensions of the buccal bone plate, the mean values being generally higher for male subjects. In the multivariate linear regression model, the status of the central maxillary incisors (both present, one missing, and both missing) and the time elapsed since loss of the central incisors (<1 year vs. >1 year) were independently associated with buccal bone wall measurements, adjusted for age and sex. CONCLUSION: The present study demonstrates decreasing values for the coronal width of the buccal bone wall in patients with missing central incisors and a time span since tooth loss of over 1 year. The age of the patients had a significant influence only on the length of the nasopalatine canal, with the mean values generally decreasing with an increasing age. The limited CBCT scans with FOVs varying between 4 × 4 and 8 × 8 cm are a valid diagnostic alternative to cross-sectional imaging in the anterior maxilla for dental implant treatment planning.

Characteristics and dimensions of the Schneiderian membrane: a radiographic analysis using cone beam computed tomography in patients referred for dental implant surgery in the posterior maxilla.

OBJECTIVES: To determine the dimensions of the Schneiderian membrane using limited cone beam computed tomography (CBCT) in individuals referred for dental implant surgery, and to determine factors influencing the mucosal thickness. MATERIAL AND METHODS: The study included 143 consecutive patients referred for dental implant placement in the posterior maxilla. A total of 168 CBCT images were taken using a limited field of view of 4 × 4 cm, 6 × 6 cm, or 8 × 8 cm. Reformatted coronal CBCT slices were analyzed with regard to the thickness and characteristics of the Schneiderian membrane in nine standardized points of reference. Factors such as age, gender, or status of the remaining dentition that could influence the dimensions of the Schneiderian membrane were evaluated using univariate and multivariate linear regression models. RESULTS: The thickness of the Schneiderian membrane exhibited a wide range, with a minimum value of 0.16 mm and a maximum value of 34.61 mm. The highest mean values, ranging from 2.16 to 3.11 mm, were found for the mucosa located in the mid-sagittal regions of the maxillary sinus. The most frequent mucosal findings diagnosed were flat thickenings of the Schneiderian membrane (62 positive findings, 37%). For the multivariate linear regression model, only gender had a statistically significant influence on the mean overall and mid-sagittal thickness of the sinus mucosa. CONCLUSION: There is great interindividual variability in the thickness of the Schneiderian membrane. Gender seems to be the most important parameter influencing mucosal thickness in asymptomatic patients. Future studies are needed to assess the therapeutic and prognostic consequences of mucosal alterations in the maxillary sinus.

The nasopalatine duct cyst: an analysis of the relation between clinical symptoms, cyst dimensions, and involvement of neighboring anatomical structures using cone beam computed tomography.

PURPOSE: This study evaluates the dimensions of nasopalatine duct cysts (NPDCs) and the involvement of neighboring anatomical structures using standardized limited cone beam computed tomography (CBCT) and a possible correlation to the patient's age, gender, preoperative symptoms, and postsurgical complications. MATERIALS AND METHODS: The study included 25 patients with a confirmed histopathologic diagnosis of NPDC. Standardized measurements of NPDC dimensions were performed on sagittal, coronal, and axial CBCT sections. Maximas, minimas, mean, standard error of mean, and confidence intervals (95%) of all measurements were performed. The Kruskal-Wallis test was used to analyze group differences and to assess any association between measurements and preoperative symptoms or postoperative complications. RESULTS: The patients' mean age was 49.5 years, and a male-to-female ratio of 2.1:1 was assessed. Mean cyst dimensions for men and for patients less than 50 years old tended to be higher, without statistical significance. The cyst dimensions had no statistically significant correlation to preoperative symptoms. Initial symptoms were present in all cases with a nasal defect, however. Most of the standardized cyst dimensions exhibited a statistically significant correlation to postoperative complications. CONCLUSIONS: The presence or the absence of symptoms does not correlate with the dimensions of an NPDC. With progressive size of the cyst, the risk for minor postsurgical complications increases.

Estimating long-term survival of densely sintered alumina crowns: a cohort study over 10 years.

STATEMENT OF PROBLEM: Alumina-core crowns have become a standard treatment option in contemporary dental practice. The short-term survival of alumina crowns has been well documented. However, there is still a paucity of long-term survival data. PURPOSE: The purpose of this prospective cohort study was to estimate long-term survival of alumina crowns in anterior and posterior areas over an observation period of up to 10 years. MATERIAL AND METHODS: Between 1997 and 2005, 155 alumina crowns were placed in 50 subjects. Clinical and technical parameters were assessed at baseline. In 2005 and 2008, the crowns were clinically assessed using modified U.S. Public Health Service (USPHS) guidelines. Treatment failure was defined as crown or tooth loss and separated into technical or biological failures. Survival probabilities were estimated using the Kaplan-Meier method. RESULTS: In 2008, 29 subjects with 112 alumina crowns, including 86 (77%) posterior and 26 (23%) anterior crowns, were available for clinical assessment. The average observation period for these subjects was 7.8 years, with a range from 3 to 10.7 years. In total, 3 technical and 8 biological failures were observed. The estimated survival probability considering technical failures only was 95% (95% Confidence Interval (CI), 89% to 100%). The estimated overall survival probability after 10 years was 84% (95% CI, 74% to 95%). There was no significant difference in treatment failures in posterior as compared to anterior crowns (all failures: P=.713; technical failures: P=.352). CONCLUSIONS: The results suggest that the expected 10-year survival rate of alumina crowns due to technical failures is 95% (95% CI, 89% to 100%).

Dealing with Bad Risk in Cost-Effectiveness Analysis: The Cost-Effectiveness Risk-Aversion Curve.

Cost-effectiveness analysis has been advocated and is widely used to inform policy and decision makers in setting priorities for resource allocation. Since the costs and effects of health care interventions are uncertain, much research interest has focused on handling uncertainty in cost-effectiveness analysis. The most widely used method to summarize uncertainty in cost-effectiveness analysis is the cost-effectiveness acceptability curve, which estimates the probability that an intervention is cost effective for a wide range of threshold ratios. However, by estimating the uncertainty associated with incremental costs and effects, information about the uncertainty associated with the costs and effects of the individual programs is lost, which may be important to inform risk-averse decision makers. In the present paper, we suggest to penalize the expected net monetary benefit (NMB) of a program for its downside risk (i.e. bad risk), which preserves the uncertainty of the individual programs and rank orders programs according to their risk-adjusted NMB. The cost-effectiveness risk-aversion curve (CERAC) is introduced, which estimates the net benefit-to-risk ratio for a wide range of threshold rations. The CERAC is a helpful additional tool to inform decision and policy makers who are risk averse, and can easily be constructed using the results of a cost-effectiveness analysis.

Prevalence of Missing Values and Protest Zeros in Contingent Valuation in Dental Medicine.

BACKGROUND: The number of contingent valuation (CV) studies in dental medicine using willingness-to-pay (WTP) methodology has substantially increased in recent years. Missing values due to absent information (i.e., missingness) or false information (i.e., protest zeros) are a common problem in WTP studies. The objective of this study is to evaluate the prevalence of missing values in CV studies in dental medicine, to assess how these have been dealt with, and to suggest recommendations for future research. METHODS: We systematically searched electronic databases (MEDLINE, Web of Science, Cochrane Library, PROSPERO) on 8 June 2021, and hand-searched references of selected reviews. CV studies in clinical dentistry using WTP for valuing a good or service were included. RESULTS: We included 49 WTP studies in our review. Out of these, 19 (38.8%) reported missing values due to absent information, and 28 (57.1%) reported zero values (i.e., WTP valued at zero). Zero values were further classified into true zeros (i.e., representing the underlying preference of the respondent) or protest zeros (i.e., false information as a protest behavior) in only 9 studies. Most studies used a complete case analysis to address missingness while only one study used multiple imputation. CONCLUSIONS: There is uncertainty in the dental literature on how to address missing values and zero values in CV studies. Zero values need to be classified as true zeros versus protest zeros with follow-up questions after the WTP elicitation procedure, and then need to be handled differently. Advanced statistical methods are available to address both missing values due to missingness and due to protest zeros but these are currently underused in dental medicine. Failing to appropriately address missing values in CV studies may lead to biased WTP estimates of dental interventions.

Handling Uncertainty in Cost-Effectiveness Analysis: Budget Impact and Risk Aversion.

Methods to handle uncertainty in economic evaluation have gained much attention in the literature, and the cost-effectiveness acceptability curve (CEAC) is the most widely used method to summarise and present uncertainty associated with program costs and effects in cost-effectiveness analysis. Some researchers have emphasised the limitations of the CEAC for informing decision and policy makers, as the CEAC is insensitive to radial shifts of the joint distribution of incremental costs and effects in the North-East and South-West quadrants of the cost-effective plane (CEP). Furthermore, it has been pointed out that the CEAC does not incorporate risk-aversion in valuing uncertain costs and effects. In the present article, we show that the cost-effectiveness affordability curve (CEAFC) captures both dimensions of the joint distribution of incremental costs and effects on the CEP and is, therefore, sensitive to radial shifts of the joint distribution on the CEP. Furthermore, the CEAFC also informs about the budget impact of a new intervention, as it can be used to estimate the joint probability that an intervention is both affordable and cost-effective. Moreover, we show that the cost-effectiveness risk-aversion curve (CERAC) allows the analyst to incorporate different levels of risk-aversion into the analysis and can, therefore, be used to inform decision-makers who are risk-averse. We use data from a published cost-effectiveness model of palbociclib in addition to letrozole versus letrozole alone for the treatment of oestrogen-receptor positive, HER-2 negative, advanced breast cancer to demonstrate the differences between CEAC, CEAFC and CERAC, and show how these can jointly be used to inform decision and policy makers.

Incorporating Portfolio Uncertainty in Decision Rules for Healthcare Resource Allocation.

Cost-effectiveness analysis is widely adopted as a means to inform policy and decision makers in setting priorities for healthcare resource allocation. In resource-constrained settings, decision makers are confronted with healthcare resource reallocation decisions, e.g., moving funds from one or more existing healthcare programs to fund new healthcare programs. The decision-making plane (DMP) has been developed as a means to graphically present the results of reallocating available healthcare resources when healthcare program costs and effects are uncertain. Mapping a value function over the DMP allows the analyst to value all possible combinations of net costs and net effects that may result from reallocating available healthcare resources under conditions of uncertainty. In this paper, we extend this approach to include a change in portfolio risk, stemming from a change in the portfolios of funded healthcare programs, as an additional source of uncertainty, and demonstrate how this can be incorporated into the value function over net costs and net effects for a risk-averse decision maker. The methodology presented in this paper is of particular interest to decision makers who are risk averse, as it will help to better incorporate their preferences in the process of deciding how to best allocate scarce healthcare resources.

CO2 and diode laser for excisional biopsies of oral mucosal lesions. A pilot study evaluating clinical and histopathological parameters.

PURPOSE: The present pilot study evaluates the histopathological characteristics and suitability of CO2 and diode lasers for performing excisional biopsies in the buccal mucosa with special emphasis on the extent of the thermal damage zone created. PATIENTS AND METHODS: 15 patients agreed to undergo surgical removal of their fibrous hyperplasias with a laser. These patients were randomly assigned to one diode or two CO2 laser groups. The CO2 laser was used in a continuous wave mode (cw) with a power of 5 W (Watts), and in a pulsed char-free mode (cf). Power settings for the diode laser were 5.12 W in a pulsed mode. The thermal damage zone of the three lasers and intraoperative and postoperative complications were assessed and compared. RESULTS: The collateral thermal damage zone on the borders of the excisional biopsies was significantly smaller with the CO, laser for both settings tested compared to the diode laser regarding values in pm or histopathological index scores. The only intraoperative complication encountered was bleeding, which had to be controlled with electrocauterization. No postoperative complications occurred in any of the three groups. CONCLUSIONS: The CO2 laser seems to be appropriate for excisional biopsies of benign oral mucosal lesions. The CO2 laser offers clear advantages in terms of smaller thermal damage zones over the diode laser. More study participants are needed to demonstrate potential differences between the two different CO2 laser settings tested.

A Systematic Review of WTA-WTP Disparity for Dental Interventions and Implications for Cost-Effectiveness Analysis.

Cost-effectiveness analysis is widely adopted as an analytical framework to evaluate whether health care interventions represent value for money, and its use in dentistry is increasing. Traditionally, in cost-effectiveness analysis, one assumes that the decision maker's maximum willingness to pay (WTP) for health gain is equivalent to his minimum willingness to accept (WTA) monetary compensation for health loss. It has been documented in the literature that losses are weighted higher than equivalent gains, i.e., that WTA exceeds WTP for the same health condition, resulting in a WTA/WTP ratio greater than 1. There is a knowledge gap of published WTA/WTP ratios for dental interventions in the literature. We therefore conducted a (i) systematic review of published WTA-WTP estimates in dentistry (MEDLINE, Web of Science, Cochrane Library, London, UK) and (ii) a patient-level analysis of WTA/WTP ratios of included studies, and (iii) we demonstrate the impact of a WTA-WTP disparity on cost-effectiveness analysis. Out of 55 eligible studies, two studies were included in our review. The WTA/WTP ratio ranged from 2.58 for discontinuing water fluoridation to 5.12 for mandibular implant overdentures, indicating a higher disparity for implant rehabilitations than for dental public health interventions. A WTA-WTP disparity inflates the cost-effectiveness of dental interventions when there is a substantial risk of both lower costs and health outcomes. We therefore recommend that in these cases the results of cost-effectiveness analyses are reported using different WTA/WTP ratios in a sensitivity analysis.

Breaking the silence: exploring the potential effects of explicit instructions on incorporating income and leisure in TTO exercises.

OBJECTIVES: An underexplored question in the debate on incorporating productivity costs as costs or effects in a cost-effectiveness (CE) analysis is whether people include effects of ill health on income in health state valuations (HSV). The same holds for the actual inclusion in HSV of the effects of ill health on leisure. This study aims to test whether respondents to HSV using time trade-off (TTO) questions include income and leisure effects without instructions. Moreover, it tests the consequences of explicit instructions to include or exclude income effects. METHODS: Three questionnaires were administered among the general public. Respondents were asked to value three distinct EuroQol descriptive system health states using TTO. In version 1, respondents were asked afterwards whether they included income effects. In versions 2 and 3, respondents were instructed upfront to include or exclude income effects. They were furthermore asked whether they included leisure effects. RESULTS: A total of 222 respondents completed the questionnaire. In version 1, 64% of the respondents spontaneously included income effects, not resulting in differences in mean valuations. In versions 2 and 3, 88% included leisure time, resulting in a significantly lower TTO value in one health state. With explicit instructions, respondents instructed to include income gave lower HSV for the worst health state presented. CONCLUSIONS: Respondents in our sample did not consistently include income effects and leisure effects. Including income effects only had (some) effect on TTO valuations after an explicit instruction. If these results are confirmed in future research, this implies that income effects may be best captured on the cost-side of the CE ratio. Spontaneous inclusion or exclusion of leisure time appeared to be more influential.