Luc Martens - Academia.edu (original) (raw)

Papers by Luc Martens

American Journal of Medical Genetics Part A, 2004

Ehlers–Danlos syndrome (EDS) dermatosparaxis type (type VIIC) and the related disease of cattle d... more Ehlers–Danlos syndrome (EDS) dermatosparaxis type (type VIIC) and the related disease of cattle dermatosparaxis, are recessively inherited connective tissue disorders, caused by a deficient activity of procollagen I N‐proteinase, the enzyme that excises the N‐terminal propeptide in procollagen type I, type II, and type III. Although well documented in cattle, to date only seven human cases have been recorded, most of them aged under 2 years. We document the natural history of three patients with EDS dermatosparaxis type, two of whom have been reported before the age of 2 years, and one new patient. The phenotype of the patients, and especially the facial resemblance, is striking, making this a clinically recognizable condition. The most consistent anomalies during the first years of life are premature rupture of the membranes, extreme skin fragility and easy bruising, large fontanels, blue sclerae, puffy eyelids, micrognathia, umbilical hernia, and short fingers. Joint hypermobility...

Scientific Reports, 2021

Calcium (Ca2+) signalling plays an indispensable role in dental pulp and dentin regeneration, but... more Calcium (Ca2+) signalling plays an indispensable role in dental pulp and dentin regeneration, but the Ca2+ responses of human dental pulp stem cells (hDPSCs) stimulated with tricalcium silicate-based (TCS-based) dental biomaterials remains largely unexplored. The objective of the present study was to identify and correlate extracellular Ca2+ concentration, intracellular Ca2+ dynamics, pH, cytotoxicity, gene expression and mineralization ability of human dental pulp stem cells (hDPSCs) stimulated with two different TCS-based biomaterials: Biodentine and ProRoot white MTA. The hDPSCs were exposed to the biomaterials, brought in contact with the overlaying medium, with subsequent measurements of extracellular Ca2+ and pH, and intracellular Ca2+ changes. Messenger RNA expression (BGLAP, TGF-β, MMP1 and BMP2), cytotoxicity (MTT and TUNEL) and mineralization potential (Alizarin red and Von Kossa staining) were then evaluated. Biodentine released significantly more Ca2+ in the α-MEM medium...

Journal of Dentistry, 2020

This is a repository copy of Quantifying increased rates of erosive tooth wear progression in the... more This is a repository copy of Quantifying increased rates of erosive tooth wear progression in the early permanent dentition.

International Journal of Environmental Research and Public Health, 2019

Recent data on erosive tooth wear (ETW) in Belgium have associated a vocational/technical type of... more Recent data on erosive tooth wear (ETW) in Belgium have associated a vocational/technical type of education with ETW risk. Since the role of schools is essential to the promotion of healthy diets, this study aimed to investigate school food policies (SFP) related to soft drink and fruit juice consumption and to detect differences among schools in Flanders, Belgium (BE-F). An online questionnaire related to the control of acidic beverages and promotion of healthy drinking habits was sent to all Flemish secondary schools. For analysis, schools (n = 275) were grouped by type of education (vocational secondary education (VSE) and general secondary education (GSE)), and by socioeconomic status. Multiple factor analyses (MFA) were performed to identify schools with a similar SFP profile. Additionally, descriptive analyses were performed to determine other associations. Overall, 44% of schools in BE-F claimed to have written SFP related to the consumption of soft drinks. SFP expressly proh...

Dentomaxillofacial Radiology, 2019

Objectives: The main objective of this study was to perform a retrospective reject analysis (or a... more Objectives: The main objective of this study was to perform a retrospective reject analysis (or audit) of 79 cone-beam CTs (CBCTs) taken in under-aged patients at the Ghent University hospital over a 2-year timespan. Methods: Observer agreement between two oral radiologists and two senior year Master students in Paediatric Dentistry was performed for quality, diagnostic and therapeutic value. The senior year Master Students followed appropriate modules of an online course. Descriptive and comparative statistics were performed. Results: For the oral radiologists, all intra rater reliabilities were moderate to good (Gwet's AC1 = 0.41-0.75). For the senior students in Paediatric dentistry, these varied highly from fair to very good (Gwet's AC1 = 0.28-0.95). There was a high level of disagreement between oral radiologists and students (Gwet's AC1 = 0.16-0.45) and in-between students concerning observed quality (Gwet's AC1 = 0.29). A total of 16 CBCTs (20%) was rejected, 24 images (30%) were acceptable and 39 images (50%) had an excellent quality. 50 CBCTs were perceived to have a diagnostic advantage. 13 of the images would have no influence on the therapy, according to the oral radiologists. A significant correlation was found between unacceptable quality, absence of perceived diagnostic advantage (p = 0.004, RR = 2.4) and influence on therapy (p < 0.0005, RR = 1.8). A small field of view (FOV) was positively correlated to an excellent quality of the image (p = 0.011, RR = 2.8). conclusions: Image quality did not reach the proposed boundary of 10% according to the European Guidelines on Radiation Protection in Dental Radiology. This is the first published audit on an overall database of under-age children for CBCT.

Journal of dentistry, 2018

To determine if the Basic erosive tooth wear index (BEWE index) is able to assess and monitor ETW... more To determine if the Basic erosive tooth wear index (BEWE index) is able to assess and monitor ETW changes in two consecutive cast models, and detect methodological differences when using the corresponding 3D image replicas. A total of 480 pre-treatment and 2-year post-treatment orthodontic models (n = 240 cast models and n = 240 3D image replicas) from 120 adolescents treated between 2002 and 2013 at the Gent Dental Clinic, Belgium, were scored using the BEWE index. For data analysis only posterior sextants were considered, and inter-method differences were evaluated using Wilcoxon Signed Rank test, Kappa values and Mc Nemar tests (p < 0.05). Correlations between methods were determined using Kendall tau correlation test. Significant changes of ETW were detected between two consecutive models when BEWE index was used to score cast models or their 3D image replicas (p < 0.001). A strong significant correlation (τb: 0.74; p < 0.001) was shown between both methods However, 3D ...

Materials (Basel, Switzerland), Jan 13, 2018

Tricalcium silicate cements (TSC) are used in dental traumatology and endodontics for their bioac... more Tricalcium silicate cements (TSC) are used in dental traumatology and endodontics for their bioactivity which is mostly attributed to formation of calcium hydroxide during TSC hydration and its subsequent release of calcium and hydroxide ions. The aim of this study was to determine the effect of volume (Vol), exposed surface area (ESA) and pH of surrounding medium on calcium ion release. Three commercially available hydraulic alkaline dental cements were mixed and condensed into cylindrical tubes of varying length and diameter (= 6/group). For the effect of ESA and Vol, tubes were immersed in 10 mL of deionized water. To analyze the effect of environmental pH, the tubes were randomly immersed in 10 mL of buffer solutions with varying pH (10.4, 7.4 or 4.4). The solutions were collected and renewed at various time intervals. pH and/or calcium ion release was measured using a pH glass electrode and atomic absorption spectrophotometer respectively. The change of pH, short-term calcium i...

IFMBE Proceedings, 2016

When correctly calibrated, gray value levels of medical images reflect physical properties. In de... more When correctly calibrated, gray value levels of medical images reflect physical properties. In dental X-ray imaging radioopacity of the scanned material is measured through the attenuation of the beam. The measurements are performed with an increasing resolution and bit depth. The human eye though has limited perception capabilities. Therefore, it is not possible for a human being to explore all information represented in the images. Transforming gray value levels as stipulated in the DICOM standard is designed to optimize the representation for human sight. The gray values are altered to transform gray value differences into Just Noticeable Differences (JND) when represented on high quality calibrated medical displays. In this study we explored the eye sight of dental practitioners. A variety of sight patterns detecting gray value differences was observed. Although extremely useful, a transformation such as DICOM cannot optimize the representation for all practitioners, it may even worsen the representation. Transformation of gray value levels should be made dependent on the eyesight of the practitioner.

European Archives of Paediatric Dentistry, 2007

European journal of paediatric dentistry : official journal of European Academy of Paediatric Dentistry, 2014

Dens Invaginatus (DI) is a rare malformation of the teeth, showing a broad spectrum of morphologi... more Dens Invaginatus (DI) is a rare malformation of the teeth, showing a broad spectrum of morphologic variations. The aim of this study was to perform in vitro radiographic analyses of three extracted dens invaginatus (DI) teeth with complex root anatomy using plain radiographs, CBCT, MRI and micro CT techniques. Study design: Three maxillary lateral incisors (A, B and C) from two patients were extracted due to poor prognosis and were radiographically analysed. Initially, conventional two dimensional digital radiographs were taken. Subsequently CBCT, micro CT and MRI analyses were performed. According to the Schulze and Brand system of classification, teeth A, B and C were classified as A2, B3 and B2 respectively. To detect the relationship between the invagination to the oral cavity and pulp chamber, conventional two dimensional radiographs were of no help. CBCT and MRI images were found to be complementary to each other but provided lesser structural detail than micro CT images. Repo...

European journal of paediatric dentistry : official journal of European Academy of Paediatric Dentistry, 2003

This paper reviews the proceedings and conclusions of a meeting of experts concerned with the pro... more This paper reviews the proceedings and conclusions of a meeting of experts concerned with the problem of hypomineralised incisors and molars (MIH). The aims of this meeting were to establish criteria for the judgement of MIH, to select representative cases and to discuss how the name of the condition was best described as hypomineralised, or hypomaturated, first permanent molars. There was not complete agreement as to the correct diagnosis and aetiology of the condition. A suggested list of definitions of the judgement criteria to be used in diagnosing Molar Incisor Hypomineralisation (MIH) for prevalence studies was agreed upon.

European Journal of Dental Education, 2010

Dental education in Europe faces enormous challenges. One deals with the admission to dental scho... more Dental education in Europe faces enormous challenges. One deals with the admission to dental school. Although admission procedures vary considerably across Europe, a characteristic of some systems is that the same procedure is used across students who will ultimately pursue different majors (medical or dental). This is based on the assumptions that there is no significant difference in these students’ scores and that the requirements for medicine and dentistry are equal. This study examines these assumptions in the admission exam ‘Medical and Dental Studies’ in Flanders. Students who pass may choose whether they start medical or dental education. Over an 8‐year period (2000–2007), admission exam scores of students starting medicine (n = 4492) were compared to those of students starting dentistry (n = 547). Second, the validity of this exam is examined for both medical and dental education. It was found that students starting dentistry had a significantly lower total score on the adm...

European Archives of Paediatric Dentistry, 2011

European Archives of Paediatric Dentistry, 2010

BACKGROUND: Behaviour management is widely agreed to be a key factor in providing dental care for... more BACKGROUND: Behaviour management is widely agreed to be a key factor in providing dental care for children. Indeed, if a child's behaviour in the dental surgery/office cannot be managed then it is difficult if not impossible to carry out any dental care that is needed. It is imperative that any approach to behavioural management for the dental child patient must be rooted in empathy and a concern for the well being of each child. REVIEW: Based on various presentations given at Congresses of the European Academy of Paediatric Dentistry (EAPD), documents reviewing behaviour management prepared by the Clinical Affairs Committee of the EAPD, and written submissions to the Executive Board of the EAPD, a review of the various approaches to the behaviour management of the child dental patient was completed. All aspects of non-pharmacological behavioural management techniques described in the literature over the past 80 years were reviewed. FINDINGS: There is a very wide diversity of techniques used but not all are universally accepted by specialist paediatric and general dentists. Wide cultural and philosophical differences are apparent among European paediatric dentists that seem difficult to bridge when forming agreed guidelines. Accordingly, this review highlights those behaviour techniques that are universally accepted such as tell, show, do (TSD) or positive reinforcement, but nevertheless describes the most commonly mentioned techniques for which there are descriptions in the literature. CONCLUSION: A wide variety of behavioural management techniques are available to paediatric dentists which must be used as appropriate for the benefit of each child patient, and which, importantly, must take into account all cultural, philosophical and legal requirements in the country of dental practice of every dentist concerned with dental care of children.

Clinical Oral Investigations, 2012

Introduction Dentin hypersensitivity (DHS) is a problematic clinical entity that may become an in... more Introduction Dentin hypersensitivity (DHS) is a problematic clinical entity that may become an increasing clinical problem for dentists to treat as a consequence of patients retaining their teeth throughout life and improved oral hygiene practices. Objectives The aim of this review was to develop a decision tree for the management of exposed cervical dentin (ECD) and DHS. Material and methods A brief PUBMED literature search was performed on dentin hypersensitivity using "MeSH" terms, "review", and "management". In addition, some websites and local guidelines were screened. Results From this review, it became clear that all dentate patients should routinely be screened for ECD and DHS. In this respect, underdiagnosis of the condition will be avoided and the preventive management can be initiated early. Conclusion A decision tree process and a flowchart for daily practice were designed which should be started up as soon as a patient present with ECD or suffers from DHS. This approach takes into account the possible improved quality of life of the patient and is further based on a hierarchy of treatment options. In this respect, active management of DHS will usually involve a combination of athome and in-office therapies. Starting with the use of desensitizing toothpastes is strongly recommended.

Calcified Tissue International, 1987

The ESR spectrum near g = 2 of powdered human tooth enamel from upper central incisors and lower ... more The ESR spectrum near g = 2 of powdered human tooth enamel from upper central incisors and lower canines was studied as a function of microwave power, irradiation, and storage time. The results clearly demonstrate that the ESR spectrum is composite with at least five paramagnetic species contributing to the signal. The main stable component is assigned to CO2-. Two other components arise from CO3 3-radicals, one of which is demonstrated to be the same center as is present on a phosphate site in sodium-and carbonate-containing calciumapatite.

BMJ open, Jan 20, 2017

Oral health inequality in children is a widespread and well-documented problem in oral healthcare... more Oral health inequality in children is a widespread and well-documented problem in oral healthcare. However, objective and reliable methods to determine these inequalities in all oral health aspects, including both dental attendance and oral health, are rather scarce. To explore oral health inequalities and to assess the impact of socioeconomic factors on oral health, oral health behaviour and dental compliance of primary school children. Data collection was executed in 2014 within a sample of 2216 children in 105 primary schools in Flanders, by means of an oral examination and a validated questionnaire. Intermutual Agency database was consulted to objectively determine individuals' social state and frequency of utilisation of oral healthcare services. Underprivileged children were compared with more fortunate children for their mean DMFt, DMFs, plaque index, care index (C, restorative index (RI), treatment index (TI), knowledge and attitude. Differences in proportions for dichot...

European journal of paediatric dentistry : official journal of European Academy of Paediatric Dentistry, 2004

This study was designed to examine the oral health status of asthmatic children and to compare th... more This study was designed to examine the oral health status of asthmatic children and to compare the oral health condition and habits of different groups of asthmatic children. 140 asthmatic children were involved in the present study. Of those, 30 were younger than 7 years of age, 73 were between 7 and 12, 37 were older than 12. Dental caries was scored according to the guidelines of the BASCD. No radiographs were taken. The gingival health and the amount of plaque were assessed using the bleeding index described by Mühleman and Son [1971] and the plaque index of Silness and Löe [1964] respectively. To differentiate between the asthmatic children three explanatory variables were used: the time the asthmatic symptoms had lasted, the exposure time to the medication and the severity of the asthmatic condition. Finally the parents and children were asked to fill in a questionnaire referring to oral health habits. The mean dmft was 1.99 (SD+/-2.74) and the mean DMFT was 1.10 (SD+/-1.98). ...

Family & Community Health, 2005

This study examined the relationship between early childhood caries (ECC) and measures of socioec... more This study examined the relationship between early childhood caries (ECC) and measures of socioeconomic status as environmental determinants of oral health inequalities. Dental caries and quality of oral hygiene were reported on 384 young inner-city children (24-35 months) by clinical examination. Early childhood caries was diagnosed in 18.5% of children. Ethnicity (P < 0.001) and neighborhood (P < 0.001) were the social variables significantly predictive of ECC in a logistic regression model. Living in a deprived neighborhood and the mother being of East European descent were the social variables with strongest association with ECC. These variables can be considered adequate criteria to identify groups at risk within the overall population.

BMC Oral Health, 2019

Background: Special Olympics (SO) events represent an opportunity to obtain considerable informat... more Background: Special Olympics (SO) events represent an opportunity to obtain considerable information regarding intellectual disable (ID) patients. Studies done with SO data have shown an overview of the oral health status of these athletes; however, no information exists regarding the erosive tooth wear (ETW). Therefore, the aim of this study is to determine the presence and severity of ETW in athletes with ID who participated in the SO Belgium 2016. Methods: The study population consisted in 232 athletes with ID who participated in the SO special smiles program, Belgium 2016. For analysis, the sample was divided in three groups: a) athletes with ID under the age of 25 not diagnosed with Down Syndrome (DS) (n = 174), b) athletes with DS under the age of 25 (n = 39) and c) athletes with DS from 25 and older ages (n = 58). Two calibrated dentists performed dental examinations using the Basic Erosive Wear Examination Index (BEWE). The BEWE sum > 0 was used to determine prevalence of ETW. Severity was determined by two-indicators: 1) By risk levels (low, medium and high risk) proposed by the BEWE index, and 2) by the highest score reached per subject in at least one tooth (BEWE1, 2 or 3). Chi-square test and Mann-Whitney U test were used to detect significant differences among different groups (p < 0.05). Results: The prevalence of ETW for young athletes with ID was 51.14%. Within these athletes, the DS group presented a significant higher mean BEWE sum (4.67, SD 5.64) and prevalence of ETW (69.2%BEWE> 0) when compared to athletes without DS (mean BEWE sum: 1.96, SD 3.47 and 46.3% BEWE> 0; p < 0.05). Furthermore, a significantly higher percentage of athletes with DS were considered at high risk of ETW (p < 0.05). Conclusions: As a conclusion, half of the young athletes with ID presented at least one affected surface with ETW. The recorded prevalence and severity of ETW for the younger group of athletes with DS was distinctly higher than the athletes with ID not having DS. This shows the need to generate knowledge in order to provide correct management and prevention of erosive tooth wear in populations with ID.