[Distal surface caries in the mandibular second molar in the presence of a partially erupted/impacted third molar]. / Distale cariës van de tweede ondermolaar bij een gedeeltelijk geërupteerde of geïmpacteerde derde molaar.

Distal surface caries in the mandibular second molar is a common outcome of impaction of the adjacent third molar. To determine the prevalence of this type of caries in the Netherlands, 250 radiographs were evaluated. The prevalence among the research population was 26%. Risk factors for developing distal surface caries in the mandibular second molar were partially erupted/impacted third molars with a mesioangular or horizontal angulation, an LD loss of ≥ 2mm and an increased modified DMFT score. The relation between the point of contact of the third molar and the adjacent mandibular second molar, on the one hand, and, on the other, the cemento-enamel junction of the mandibular second molar and the prevalence of distal surface caries almost reached statistical significance (p = 0.052). The relatively low prevalence of distal surface caries in the Netherlands is probably related to the current clinical guidelines recommending early extraction of partially erupted/impacted third molars, particularly in cases of third molars with a mesioangular or horizontal angulation.

[A PhD completed. Oral manifestations in inflammatory bowel diseases]. / Serie: Hora est. Orale manifestaties van inflammatoire darmziekten.

Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the gastrointestinal tract. In addition to bowel symptoms, patients may also have oral manifestations. This thesis investigated potential associations between disease activity in the gut, oral health, salivary gland function, and saliva composition. Patients with Crohn's disease had a significantly higher DMFT index, but showed no difference in periodontal diseases compared to a healthy control group. The saliva composition in patients with active bowel disease differed from that in patients with inactive bowel disease, suggesting that saliva analysis could potentially be used in the future to determine the degree and severity of bowel disease. The knowledge of gastroenterologists and dentists regarding oral manifestations of bowel diseases was found to be limited. Gastroenterologists and dentists valued interdisciplinary patient consultation as very useful, but the frequency of consultation was considered insufficient.

[A PhD completed. More insight into the origin and composition of salivary stones]. / Serie: Hora est. Meer inzicht in het ontstaan en de samenstelling van speekselstenen.

Salivary stones are hardened, stony calcifications that primarily develop in the drainage duct of a salivary gland. They can lead to obstruction of the saliva flow, resulting in swelling and pain. Since the aetiology of salivary stones remains largely unclear, this was further investigated in this PhD study. A case-control review of patient records showed that systemic diseases and lifestyle factors most likely do not play a role in their occurrence. The biochemical composition of salivary stones removed by oral-maxillofacial surgeons was examined, revealing that large salivary stones have a different inorganic composition than small salivary stones. Several salivary proteins were detected in submandibular salivary stones, including lysozyme, s-IgA, and -amylase. Clumping together of these proteins may play a role in the initial formation of salivary stones.

[Portrayal of dentists in films]. / Uitbeelding van tandartsen in speelfilms.

To analyze the portrayal of dentists in films, 259 films from the period 1907 - 2018 featuring one or more dentists, were systematically analyzed. A total of 333 dentists were identified, mostly of Caucasian origin (85%) and male (86%). 228 dentists depicted dental procedures, sometimes using gloves (41%), (splash) glasses (35%), and mouth masks (24%). The depicted dental procedures mainly consist of the use of pocket probes and mirrors (46%), drilling/filling (31%), and extractions (25%). Furthermore, dentists in films are relatively often involved in negative activities such as physical violence (29%) and sexual offences (18%). In 16 films (6%), dentists murdered people. Although there is no single stereotypical portrayal of dentists in films, the overall picture seems to need improvement as it is not contributing to the reputation of the dental profession.

[A PhD completed. Long-term effects of childhood cancer therapy on oral health]. / Serie: Hora est. Langetermijneffecten van de behandeling van kinderkanker op de mondgezondheid.

In recent years, the five-year survival rate for childhood cancer has increased to about 80%. However, childhood cancer therapy can have serious long-term adverse effects on general health later in life. Of survivors, 75% experience 1 or more late effects. This PhD research aimed to gain more insight into the long-term effects on oral health of childhood cancer therapy, 15 years or more after diagnosis. This study, which is part of the Dutch Childhood Cancer Survivor Study Late Effects 2 (DCCSS LATER 2 Study), showed that oral complications such as dental developmental disorders and hyposalivation occur frequently. Most important risk factors were head and neck radiotherapy of the salivary glands, (alkylating) cytostatic agents, and age at the time of the cancer diagnosis. Dentists should be aware of childhood cancer in the medical history of their patient and of the type of therapy received. Regular dental visits are an essential part of long-term follow-up care of childhood cancer survivors.

[Hora est. The relationship between stress, salivary proteins and caries experience in children]. / Serie: Hora est. De relatie tussen stress, speekseleiwitten en cariëservaring bij kinderen.

Dental caries is a major public health problem and untreated caries has serious consequences for children. Psychosocial factors have multiple consequences, among others on the composition of saliva. Therefore, this study investigated whether stress and various salivary protein levels are associated with dental caries experience in children. The activity of the Matrix Metalloproteinases MMP-8 and MMP-9 and the total proteolytic activity in saliva turned out to be indicators for the caries experience. Salivary Alpha-Amylase seems to be a protector and was a strong indicator for caries experience. In cases where children were exposed to two different dental treatments, the level of salivary cortisol- and alpha-amylase increased, in which a distinction could be made between non-invasive and invasive treatment. The results of the study emphasise the need for further research into the way stress and salivary protein concentrations can affect the caries experience and how different dental treatments can influence the behaviour and stress levels in children.

[A challenging dental treatment of a patient with spinal muscular atrophy]. / Een uitdagende tandheelkundige behandeling van een patiënt met spinale musculaire atrofie.

After a fall from his wheelchair, a 23-year-old wheelchair-dependent patient with spinal muscular atrophy type 1 was initially seen by an emergency dentist, who repositioned and splinted the luxated teeth number 31 and 32. For stabilization, the patient was subsequently referred to a centre for special dental care. In the past, few treatments had been carried out on the patient. A jaw defect and very limited mouth opening compromised dental treatment. In addition, due to the muscle disease, the patient had respiratory and breathing problems, for which he used respiratory equipment. This case describes the importance of a multidisciplinary team in the treatment of patients with spinal muscular atrophy, and the options for performing minimally invasive dental treatment, where the priority is a painless dentition.

[The level of knowledge of master's dental students in the Netherlands and Flanders about matrix metalloproteinases]. / Kennisniveau van masterstudenten tandheelkunde in Nederland en Vlaanderen over matrixmetalloproteïnases.

Matrix metalloproteinases (MMPs) are enzymes involved in the remodelling and degradation of the extracellular matrix, which is essential for maintaining healthy oral tissues. It is therefore important for dental students to know the role of MMPs in biological processes and diseases. Using a questionnaire, a cross-sectional study was conducted among master's dental students from 3 universities in the Netherlands and Belgium. The general level of knowledge about MMPs of the 80 respondents was predominantly low (91.3%). Significant differences were observed among students from the various dental schools, with students from the University of Groningen and Ghent University scoring significantly higher than those from the Academic Centre for Dentistry in Amsterdam (ACTA). Gender was associated with a few questions on the relationship between MMPs and dentistry, with female students achieving higher scores. Improving dental curricula regarding MMPs and their role in dental processes seems warranted.

[A PhD completed. General conclusions of doctoral research into regional mouth dryness]. / Serie: Hora est. Algemene conclusies promotieonderzoek naar regionale monddroogte.

Dry mouth has a complex aetiology which makes proper diagnosis complicated. Until now, dry mouth diagnosis has mainly focused on the overall oral dryness, without taking into account regional differences within the mouth. This research showed, among other things, that there are unique patterns of oral dryness, each with its own cause. For example, patients suffering from Sjogren's syndrome mainly experienced dryness of the posterior of the palate. Patients with dry mouth due to the side effects of medication, in contrast, experienced the front part of the tongue as the driest. These findings suggest that mapping of intraoral dryness may be a useful diagnostic tool to differentiate between possible causes of dry mouth.

Use and efficacy of dry-mouth interventions in Sjögren's disease patients and possible association with perceived oral dryness and patients' discomfort.

OBJECTIVES: Sjögren's disease (SjD) patients use various interventions to relief their oral dryness. However, the use and efficacy of these interventions have only partially been evaluated. The present study aims to investigate whether there is an association between the perceived oral dryness and discomfort of SjD patients and their use of specific interventions. MATERIALS AND METHODS: A cross-sectional study was performed among SjD patients, who completed several questionnaires to assess the severity of their oral dryness and an inventory of dry-mouth interventions. The perceived efficacy of each intervention was reported on a 5-point Likert-scale. RESULTS: The questionnaires were returned by 92 SjD patients. For relief of oral dryness, they mostly used "eating fruit", "drinking tea", "moistening the lips", "drinking water, and "drinking small volumes" (> 50%). Three interventions had a frequency of use ranging from 2-6 times/day, whereas, "drinking water" and "drinking small volumes" showed higher frequencies (> 14). The highest overall efficacy (≥ 3.5) was reported for "chewing gum" and "using a mouth gel". Furthermore, various dry-mouth interventions showed significant associations with oral dryness scores and/or patients' discomfort. For example, "drinking small volumes" and "using XyliMelts" were associated with the Bother Index score. CONCLUSION: Great variation was found in the use of dry-mouth interventions by the participants and the severity of the oral dryness and/or patients' discomfort seemed to affect their choice of intervention. Notably, the mostly used interventions did not show the highest reported efficacy. CLINICAL RELEVANCE: These findings might help SjD patients and clinicians in their choice of effective dry-mouth interventions.

[Knowledge and attitude of oral care providers in the Netherlands on skin lesions]. / Kennis en attitude van mondzorgverleners over huidafwijkingen.

To gain insight into the current knowledge of oral care providers in the Netherlands on facial skin lesions, a survey was distributed to 7,670 oral care providers. Their knowledge was tested by means of 4 multiple-choice questions and on the basis of 5 cases. The survey was completed in full by 90 respondents. The median age was 50.3 years and 62.2% were female. During dental check-ups, 55.6% always examined the face and 41.1% sometimes did so. Compared to the group 41 years old and older, the group 21-40 years of age alerted their patients more often to skin lesions (p = 0.017), was more afraid a specialist would find the referral useless (p < 0.001) and was more in need of a guideline (p = 0.049). The respondents scored 1.90 out of 4 correct answers to the knowledge questions. On the case studies, they scored 1.46 out of 5 for the correct diagnosis, 3.48 out of 5 for the correct choice of policy and 1.01 out of 5 for the combination correct diagnosis and correct policy. The total score was 2.91 out of 9. The results indicate that knowledge on aspects of skin lesions is limited and additional training and the availability of a guideline are necessary.

[Oral health of recreational ecstasy-users]. / Mondgezondheid bij recreatief ecstasygebruik.

In a cross-sectional study, dental records of 149 individuals visiting an Academic Dental Clinic in Amsterdam who reported recreational ecstasy use, defined as no more than twice a week, were systematically analyzed and compared to a group of age- and sex-matched non-drug-users. The parameters retrieved from the dental records were decayed, missing, and filled permanent teeth-index (DMFT-index), number of endodontically treated teeth, presence of active caries lesions, periodontitis, tooth wear, xerostomia, and self-reported use of oral hygiene devices. Periodontitis, active caries lesions, and xerostomia were statistically significantly more present in ecstasy-users. Ecstasy-users brush their teeth significantly less frequent per day than non-recreational-drug-users. There were no significant differences in DMFT-index and in the devices used for brushing and interdental cleaning, and frequency of use of these interdental devices between both groups. We conclude that periodontitis, active caries lesions, and xerostomia, are more frequently present in recreational ecstasy-users compared to age- and sex-matched non-users.

Knowledge of diagnosis and management of selected oral mucosal lesions among dentists in The Netherlands.

BACKGROUND: Knowledge of oral mucosal lesions (OMLs) among dentists is relevant in diagnosing potentially malignant diseases and oral cancer at an early stage. The aim of this survey was to explore dentists' knowledge about OMLs. MATERIAL AND METHODS: Respondents to a web-based questionnaire, containing 11 clinical vignettes representing patients with various OMLs, provided a (differential) diagnosis and management for each. Information about demographics and clinical experience of the participants was acquired as well. Descriptive statistics were performed and T-tests were used to test for significant (p<0.05) differences in mean scores for correct diagnosis and management between subgroups based on demographic variables. RESULTS: Forty-four of 500 invited dentists completed the questionnaire. For (potentially) malignant OMLs, the number of correct diagnoses ranged from 14 to 93%, whilst the number of correct management decisions ranged from 43 to 86%. For benign OMLs, the number of correct diagnoses and management decisions ranged from 32 to 100% and 9 to 48%, respectively. For 11 clinical vignettes, mean scores for correct diagnosis, correct management and correct diagnosis and management were respectively 7.2 (±1.8), 5.7 (±1.5), and 3.8 (±1.7). CONCLUSIONS: The results show that dentists in the Netherlands do not have sufficient knowledge to accurately diagnose some OMLs and to select a correct management. This may result in over-referral of benign OMLs and under-referral for (potentially) malignant OMLs. Clinical guidelines, that include standardized criteria for referral, and continuing education, may improve dentists' ability to correctly diagnose and accurately manage OMLs.

Salivary film thickness and MUC5B levels at various intra-oral surfaces.

OBJECTIVES: In this study, we investigated the salivary film thickness and the MUC5B levels at various intra-oral locations in healthy volunteers, with a focus on the palate. Besides, measurements of the palatal surface area were included to explore the possible relationships between the palatal surface area and the palatal salivary film and MUC5B levels. MATERIALS AND METHODS: The salivary film thickness was determined using filter strips, which were pressed to the mucosal surfaces of five different intra-oral locations; conductance was then analysed using a Periotron. After elution of the strips, the MUC5B levels at various intra-oral locations were determined using ELISA. The palatal surface area was measured using an intra-oral scanner. The surface area was subsequently calculated using the software. RESULTS: The anterior tongue had the thickest salivary film and also the highest levels of MUC5B, while the anterior palate had the thinnest salivary film and lowest MUC5B levels. There was no association between the palatal surface area and the salivary film thickness of the palate. CONCLUSION: The salivary film and MUC5B levels are unequally distributed over the intra-oral regions of the soft tissues. The lack of association between the palatal surface area and the salivary film thickness indicates that a larger surface area is not associated with a relative thinner palatal salivary film. CLINICAL RELEVANCE: The results of the current study increase our understanding of saliva distribution in the oral cavity and could be used as reference values for future studies.

Correlations of palatal surface area with anthropometric dimensions of the head and face.

PURPOSE: Saliva distribution over the palatal surface plays an important role in the perception of dry mouth. It is envisaged that non-invasive estimation of the palatal surface area by anthropometric measurements of the head and face can be useful in the assessment of oral dryness. For this purpose, the relationship between the palatal surface area and anthropometric measurements of the head and face was investigated. METHODS: The palatal surface was measured in 51 healthy volunteers using an intra-oral scanner. The distances between anthropometric landmarks of the head and face were determined using an anatomical sliding caliper. Correlations between the palatal surface area and the anthropometric landmarks were investigated. RESULTS: The median palatal surface area for the total study population was found to be 2120.6 mm2. Virtually, all anthropometric measurements showed significant differences between females and males. Various head and face measurements had a significant correlation with the palatal surface area. However, these correlations disappeared when the participants were stratified based on their sex, with the exception of mandibular length and palatal width in females. CONCLUSION: The surface area of the palate correlates with nearly all anthropometric measurements of the head and face included in this study. Yet, the clinical applicability seems limited to females.

[Human papillomavirus vaccination available for boys also; information for oral healthcare providers]. / Humaan papillomavirus-vaccinatie nu ook beschikbaar voor jongens: informatie voor mondzorgverleners.

Recently, the Dutch National Immunization Programme has started to offer the human papillomavirus (HPV) vaccination to boys as well as girls from the age of 10. The vaccine protects against long-term HPV infection, which can lead to cervical, anogenital and oropharyngeal cancer. Besides malignant disorders, a HPV infection can also lead to certain disorders of the skin and oral cavity. Since the national HPV vaccination campaign has probably resulted in more awareness among patients about the relation between HPV and oropharyngeal cancer, patients may consult oral healthcare professionals with questions about HPV infection. Oral healthcare professionals are thus able to play a role in preventing HPV related disorders by counseling their patients on HPV. They can also contribute to early diagnosis of HPV related oral and oropharyngeal disorder, although the possibility of detecting oropharyngeal cancer during routine dental examination  is limited.

[Can dental equipment interfere with correct functioning of an ICD?] / Beïnvloedt tandheelkundige apparatuur de werking van een ICD?

An implantable cardioverter defibrillator (ICD) is often placed in patients at high risk of ventricular tachycardia and ventricular fibrillation. An ICD is potentially sensitive to electromagnetic interference (EMI) from dental equipment. Between 2000 to 2020, this was investigated in 7 in vitro studies and 4 in vivo studies. Most dental equipment appears to be safe for routine use in patients with an ICD. However, caution seems appropriate with regard to the use of piezoelectic and magnetostrictive scalers as some can cause EMI up to a distance of 20 to 45 centimeter. Use of an electrotome appears to be contraindicated in ICD wearers.