Quantifying dysmorphologies of the neurocranium using artificial neural networks.

BACKGROUND: Craniosynostosis, a congenital condition characterized by the premature fusion of cranial sutures, necessitates objective methods for evaluating cranial morphology to enhance patient treatment. Current subjective assessments often lead to inconsistent outcomes. This study introduces a novel, quantitative approach to classify craniosynostosis and measure its severity. METHODS: An artificial neural network was trained to classify normocephalic, trigonocephalic, and scaphocephalic head shapes based on a publicly available dataset of synthetic 3D head models. Each 3D model was converted into a low-dimensional shape representation based on the distribution of normal vectors, which served as the input for the neural network, ensuring complete patient anonymity and invariance to geometric size and orientation. Explainable AI methods were utilized to highlight significant features when making predictions. Additionally, the Feature Prominence (FP) score was introduced, a novel metric that captures the prominence of distinct shape characteristics associated with a given class. Its relationship with clinical severity scores was examined using the Spearman Rank Correlation Coefficient. RESULTS: The final model achieved excellent test accuracy in classifying the different cranial shapes from their low-dimensional representation. Attention maps indicated that the network's attention was predominantly directed toward the parietal and temporal regions, as well as toward the region signifying vertex depression in scaphocephaly. In trigonocephaly, features around the temples were most pronounced. The FP score showed a strong positive monotonic relationship with clinical severity scores in both scaphocephalic (ρ = 0.83, p < 0.001) and trigonocephalic (ρ = 0.64, p < 0.001) models. Visual assessments further confirmed that as FP values rose, phenotypic severity became increasingly evident. CONCLUSION: This study presents an innovative and accessible AI-based method for quantifying cranial shape that mitigates the need for adjustments due to age-specific size variations or differences in the spatial orientation of the 3D images, while ensuring complete patient privacy. The proposed FP score strongly correlates with clinical severity scores and has the potential to aid in clinical decision-making and facilitate multi-center collaborations. Future work will focus on validating the model with larger patient datasets and exploring the potential of the FP score for broader applications. The publicly available source code facilitates easy implementation, aiming to advance craniofacial care and research.

The state of oral health in patients with haemophilia in the Netherlands.

INTRODUCTION: Previous studies show contradictory outcomes regarding dental, gingival and periodontal status in persons with haemophilia (PWH) compared to healthy controls. PWH may experience disease-specific barriers to access dental care due to their bleeding tendency, which may lead to delays in oral care and severe dental problems. AIM: To determine the current subjective and objective oral health status in adult PWH. METHODS: Randomly selected PWH of the Erasmus MC Haemophilia Treatment Center (HTC), Rotterdam, the Netherlands, were invited to participate. Data was collected using the Oral Health Impact Profile (OHIP-14NL) and personal interviews. A dentist used the DMFT index, the Dutch Periodontal Screening index (DPSI), plaque and bleeding index to score the dental status. RESULTS: Forty-eight adult PWH were included in this study, 20 mild, 15 moderate-severe and 13 severe haemophilia with a mean age of 44.7. PWH scored low on the OHIP-14 questionnaire (median total score 1.0; IQR .0-3.0), indicating a high self-rating oral health status. The number of bleeding events, bleeding- and plaque index score was not statistically significant between patients with mild, moderate or severe haemophilia. The mean number of decayed, missing, and filled teeth (DMFT-score) was significantly lower in the group of patients with severe haemophilia (median 2.0) compared to mild haemophilia (median 16.0) (p = .04). Twenty-five patients (52.1%) reported to have encountered bleeding problems during or after dental interventions during their lifetime. CONCLUSION: Dutch adult PWH A/B have good dental status and oral health status.

Adherence to dietary guidelines and dental caries among children: a longitudinal cohort study.

BACKGROUND: Even though dietary sugars are the most important nutrient for caries development, the disease process is dependent on other dietary practices. The intake of individual nutrient components cannot be evaluated separately from the overall diet which includes other nutrients, foods and habits. Therefore, the aim of this study was to investigate the association between adherence to dietary guidelines and dental caries. METHODS: This study was embedded in the Generation R Study, conducted in Rotterdam, the Netherlands. In total, 2911 children were included in the present analyses. Dietary intake at the age of 8 years was assessed using food-frequency questionnaires. Diet quality scores were estimated, reflecting adherence to Dutch dietary guidelines. Dental caries was assessed at the age of 13 years using intra-oral photographs. Associations were estimated using multinomial logistic regression analyses, adjusted for sociodemographic characteristics and oral hygiene practices. RESULTS: The prevalence of dental caries at the age of 13 years was 33% (n = 969). Better diet quality was associated with a lower occurrence of severe dental caries after adjustments for sociodemographic factors [e.g. highest vs. lowest quartile of diet quality: odds ratio (OR) 0.62, 95% confidence interval (CI) 0.39-0.98]. After additional adjustments for oral hygiene practices, this association was not statistically significant (OR 0.65, 95% CI 0.41-1.03). CONCLUSION: Adherence to dietary guidelines has the potential to reduce dental caries in children; however, with proper oral hygiene practices, this relationship might be attenuated. To understand the role of dietary patterns and dental caries, the contributing role of daily eating occasions needs to be studied further.

Oral and craniofacial research in the Generation R study: an executive summary.

OBJECTIVES: Oral conditions are of high prevalence and chronic character within the general population. Identifying the risk factors and determinants of oral disease is important, not only to reduce the burden of oral diseases, but also to improve (equal access to) oral health care systems, and to develop effective oral health promotion programs. Longitudinal population-based (birth-)cohort studies are very suitable to study risk factors on common oral diseases and have the potential to emphasize the importance of a healthy start for oral health. In this paper, we provide an overview of the comprehensive oral and craniofacial dataset that has been collected in the Generation R study: a population-based prospective birth cohort in the Netherlands that was designed to identify causes of health from fetal life until adulthood. METHODS: Within the multidisciplinary context of the Generation R study, oral and craniofacial data has been collected from the age of 3 years onwards, and continued at the age of six, nine, and thirteen. Data collection is continuing in 17-year-old participants. RESEARCH OUTCOMES: In total, the cohort population comprised 9749 children at birth, and 7405 eligible participants at the age of seventeen. Based on questionnaires, the dataset contains information on oral hygiene, dental visits, oral habits, oral health-related quality of life, orthodontic treatment, and obstructive sleep apnea. Based on direct measurements, the dataset contains information on dental caries, developmental defects of enamel, objective orthodontic treatment need, dental development, craniofacial characteristics, mandibular cortical thickness, and 3D facial measurements. CONCLUSIONS: Several research lines have been set up using the oral and craniofacial data linked with the extensive data collection that exists within the Generation R study. CLINICAL RELEVANCE: Being embedded in a multidisciplinary and longitudinal birth cohort study allows researchers to study several determinants of oral and craniofacial health, and to provide answers and insight into unknown etiologies and oral health problems in the general population.

Non-Surgical Respiratory Management in Relation to Feeding and Growth in Patients with Robin Sequence; a Prospective Longitudinal Study.

OBJECTIVE: To reflect upon our non-surgical respiratory management by evaluating clinical outcomes regarding airway, feeding, and growth during the first year of life in patients with Robin Sequence. DESIGN: Prospective study. SETTING: Sophia Children's Hospital, Rotterdam, the Netherlands. PATIENTS/ PARTICIPANTS: 36 patients with Robin Sequence who were treated between 2011 and 2021. INTERVENTIONS: Positional therapy and respiratory support. MAIN OUTCOME MEASURE(S): Data on respiratory outcomes included polysomnography characteristics and capillary blood gas values. Feeding outcomes were based on the requirement of additional tube feeding. Outcomes on growth were expressed as standard-deviation-scores (SDS) for weight-for-age (WFA) and height-for-age (HFA). RESULTS: Twenty patients were treated with positional therapy (PT), whilst the other 16 patients required respiratory support. Twenty-two patients presented with non-isolated Robin Sequence (RS). During the first year of life, obstructive apnea hypopnea index decreased, oxygen levels enhanced, and capillary blood gas values improved. Eighty-six percent (31/36) experienced feeding difficulties, which completely resolved in 71% (22/31) during their first year of life. From start treatment, to stop treatment, to the age of 1 year, the SDS WFA worsened from -0.40 to -0.33 to -1.03, respectively. CONCLUSIONS: Non-surgical respiratory treatment resulted in an improvement of respiratory outcomes to near normal during the first year of life in patients with RS. These patients often experience feeding difficulties and endure impaired weight gain up to 1 year of age, despite near normalization of breathing. The high prevalence of feeding difficulties and impaired weight for age indicate the urgency for early recognition and adequate treatment to support optimal growth.

Evaluation of dental maturity in Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis.

OBJECTIVES: To determine whether dental maturity (dental development) was delayed in patients with Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis, compared with a Dutch control group without syndromes. MATERIALS AND METHODS: This study included 60 patients (38 patients with Muenke syndrome, 17 patients with Saethre-Chotzen syndrome, and 5 with TCF12-related craniosynostosis), aged 5.8-16.8 years that were treated at the Department of Oral Maxillofacial Surgery, Special Dental Care, and Orthodontics, in Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, the Netherlands. Dental age was calculated according to Demirjian's index of dental maturity. The control group included 451 children without a syndrome. RESULTS: Compared with the control group, dental development was delayed by an average of one year in 5- to 8-year-old patients with Muenke syndrome (P = 0.007) and in 8- to 10-year-old patients with Saethre-Chotzen syndrome (P = 0.044), but not in patients with TCF12-related craniosynostosis. CONCLUSIONS: Our results indicated that dental development was delayed by one year, on average, in patients with Muenke syndrome and Saethre-Chotzen syndrome, compared with a Dutch control group without syndromes. IMPLICATIONS: Our findings have improved the understanding of dental development in patients with Muenke and Saethre-Chotzen syndrome. These results can provide guidance on whether the orthodontist needs to consider growth disturbances related to dental development.

Associations Between Prenatal, Perinatal, and Early Childhood Vitamin D Status and Risk of Dental Caries at 6 Years.

BACKGROUND: Previous studies have suggested that insufficient concentrations of vitamin D are associated with dental caries in primary teeth, but evidence remains inconclusive. OBJECTIVES: We assessed the longitudinal associations between prenatal, perinatal, and early childhood serum 25-hydroxyvitamin D concentrations [25(OH)D] and the risk of dental caries in 6-year-old children. METHODS: This research was conducted within the Generation R Study, a large, multi-ethnic, prospective cohort study located in Rotterdam, the Netherlands. Dental caries were assessed in children using the decayed-missing-filled-primary teeth index at a mean age of 6.1 years (90% range, 4.8-9.1). We measured serum total 25(OH)D concentrations at 3 time points: prenatally (at 18-24 weeks of gestation), perinatally (at birth), and during early childhood (at age 6 years). We performed logistic regression analyses to determine the longitudinal association of serum 25(OH)D concentrations with caries risks in 5257 children. Additionally, we constructed a Genetic Risk Score (GRS) for the genetic predispositions to serum total 25(OH)D concentrations based on 6 vitamin D-related single nucleotide polymorphisms in a subsample of 3385 children. RESULTS: Children with severe prenatal and early childhood serum 25(OH)D deficiencies (<25 nmol/L) were more likely to be diagnosed with caries [OR, 1.56 (95% CI, 1.18-2.06) and 1.58 (95% CI, 1.10-2.25), respectively] than children with optimal concentrations (≥75 nmol/L). After adjustment for residuals of serum 25(OH)D concentrations at other time points, only the early childhood serum 25(OH)D concentration was inversely associated with the caries risk at 6 years (OR, 0.97; 95% CI, 0.95-0.98). However, our GRS analysis showed that children who are genetically predisposed to have lower serum 25(OH)D concentrations do not have a higher risk of developing caries in primary teeth. CONCLUSIONS: Our study suggests a weak association between serum 25(OH)D concentrations and risks of caries in primary teeth. Based on our results, we do not recommend vitamin D supplementation for the prevention of dental caries in children.

Rasch Analysis of Patient- and Parent-Reported Outcome Measures in the International Consortium for Health Outcomes Measurement Standard Set for Cleft Lip and Palate.

OBJECTIVES: The aim of this study was to evaluate the psychometric performance of the patient- and parent-reported measures in the International Consortium for Health Outcomes Measurement (ICHOM) Standard Set for Cleft Care, and to identify ways of improving concept coverage. METHODS: Data from 714 patients with cleft lip and/or palate, aged 8 to 9, 10 to 12.5, and 22 years were collected between November 2015 and April 2019 at Erasmus University Medical Center, Boston Children's Hospital, Duke Children's Hospital, and from participating sites in the CLEFT-Q Phase 3 study. The Standard Set includes 9 CLEFT-Q scales, the Nasal Obstruction Symptom Evaluation (NOSE) questionnaire, the Child Oral Health Impact Profile-Oral Symptoms Scale (COHIP-OSS), and the Intelligibility in Context Scale (ICS). Targeting, item-fit statistics, thresholds for item responses, and measurement precision (PSI) were analyzed using Rasch measurement theory. RESULTS: The proportion of the sample to score within each instruments range of measurement varied from 69% (ICS) to 92% (CLEFT-Q teeth and COHIP-OSS). Specific problems with individual items within the NOSE and COHIP-OSS questionnaires were noted, such as poor item fit to the Rasch model and disordered thresholds (6 of 10). Reliability measured with PSI was above 0.82 for the ICS and all but one CLEFT-Q scale (speech distress). PSIs were lowest for the COHIP-OSS (0.43) and NOSE questionnaire (0.35). CONCLUSION: The patient- and parent-reported components within the facial appearance, psychosocial function, and speech domains are valid measures; however, the facial function and oral health domains are not sufficiently covered by the CLEFT-Q eating and drinking, NOSE, and COHIP-OSS, and these questionnaires may not be accurate enough to stratify cleft-related outcomes.

Early implant placement with or without alveolar ridge preservation in single tooth gaps renders similar esthetic, clinical and patient-reported outcome measures: One-year results of a randomized clinical trial.

OBJECTIVES: To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient-reported outcome measures (PROMs) compared with early implant placement without ARP. MATERIAL AND METHODS: Seventy-five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM-C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post-loading. RESULTS: A total of 70 patients were available for re-examination at one year post-loading. The median mid-facial mucosal margin change amounted to -0.02 mm (IQR -0.27-0.46) in the CM group, -0.13 mm (IQR -0.44-0.25) in the PG group and -0.14 mm (IQR -0.29-0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups. CONCLUSION: Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

Soft tissue contour and radiographic evaluation of ridge preservation in early implant placement: A randomized controlled clinical trial.

OBJECTIVES: To compare two ridge preservation techniques and spontaneous healing in terms of hard and soft tissue changes 2 months after tooth extraction. MATERIAL AND METHODS: The study was designed as a randomized controlled trial and included 75 patients. After single tooth extraction in the maxillary incisor/premolar area, patients were randomly allocated to one of the following groups: (a) ridge preservation with a xenogeneic bone substitute covered with a collagen matrix (CM-group), (b) ridge preservation with a xenogeneic bone substitute covered with a free palatal graft (PG-group) or (c) spontaneous healing (control). Eight weeks after tooth extraction, implants were placed and clinical, profilometric and radiographic evaluations were performed. In addition, the need for further guided bone regeneration (GBR) at implant placement was assessed. The differences between the treatment groups were compared with the One-way ANOVA or Kruskal-Wallis test with the corresponding post hoc analysis. The proportions of the categorical parameters were compared with the Fisher´s exact test. RESULTS: Seventy-five patients underwent early implant placement 8 weeks after tooth extraction and were evaluated. CM-group (-0.9 SD 0.6 mm) and PG-group (-1.0 SD 0.8 mm) showed less horizontal bone resorption compared to the control group (-3.2 SD 2.1 mm) (p < .001). Moreover, the necessity of GBR at implant placement was significantly less in CM-group (32%) and PG-group (24%) when compared to control group (72%) (p = .001). Patients in CM-group experienced less pain than PG-group, one week after tooth extraction (p = .042). No significant differences were found regarding graft evaluation, post-operative complications, and soft tissue contour. CONCLUSIONS: Ridge preservation using a xenogeneic bone substitute covered with a collagen matrix or a palatal graft, results in less bone resorption and fewer GBR procedures at early implant placement compared to spontaneous healing.

Neighbourhood characteristics and children's oral health: a multilevel population-based cohort study.

BACKGROUND: To understand determinants of oral health inequalities, multilevel modelling is a useful manner to study contextual factors in relation to individual oral health. Several studies outside Europe have been performed so far, however, contextual variables used are diverse and results conflicting. Therefore, this study investigated whether neighbourhood level differences in oral health exist, and whether any of the neighbourhood characteristics used were associated with oral health. METHODS: This study is embedded in The Generation R Study, a prospective cohort study conducted in The Netherlands. In total, 5 960 6-year-old children, representing 158 neighbourhoods in the area of Rotterdam, were included. Data on individual and neighbourhood characteristics were derived from questionnaires, and via open data resources. Caries was assessed via intraoral photographs, and defined as decayed, missing and filled teeth (dmft). RESULTS: Differences between neighbourhoods explained 13.3% of the risk of getting severe caries, and 2% of the chance of visiting the dentist yearly. After adjustments for neighbourhood and individual characteristics, neighbourhood deprivation was significantly associated with severe dental caries (OR: 1.48, 95% CI: 1.02-2.15), and suggestive of a low odds of visiting the dentist yearly (OR: 0.81, 95% CI: 0.56-1.18). CONCLUSIONS: Childhood caries and use of dental services differs between neighbourhoods and living in a deprived neighbourhood is associated with increased dental caries and decreased yearly use of dental services. This highlights the importance of neighbourhoods for understanding differences in children's oral health, and for targeted policies and interventions to improve the oral health of children living in deprived neighbourhoods.

Breastfeeding and Childhood Dental Caries: Results from a Socially Diverse Birth Cohort Study.

Previous studies showed that prolonged breastfeeding increases the risk of caries. However, the observed associations were mainly based on non-European populations, and important confounding and mediating factors like socioeconomic position (SEP) and diet were often neglected. The aim of this study was to investigate the role of breastfeeding and bottle-feeding practices on dental caries during childhood while accounting for SEP, ethnic background, and sugar intake. This study was part of the Generation R Study, a prospective multiethnic cohort study conducted in Rotterdam, The Netherlands. In total, 4,146 children were included in the analyses. Information about feeding practices was derived from delivery reports and questionnaires during infancy. Caries was measured via intraoral photographs at the age of 6 years and defined as decayed, missing, and filled teeth (dmft). Negative binomial hurdle regression analyses were used to study the associations between several infant feeding practices and childhood caries. The prevalence of dental caries at the age of 6 years was 27.9% (n = 1,158). Prolonged breastfeeding (for >12 months) was associated with dental caries (OR 1.35, 95% CI 1.04-1.74) and the number of teeth affected by dental caries (RR 1.27, 95% CI 1.03-1.56). Furthermore, nocturnal bottle-feeding was associated with dental caries (OR 1.52, 95% CI 1.20-1.93). All associations were independent of family SEP, ethnic background, and sugar intake. Results from this Dutch cohort study confirmed the previously observed associations between prolonged breastfeeding and nocturnal bottle-feeding and the increased risk of childhood dental caries, even after proper adjustments for indicators of SEP, ethnic background, and sugar intake. Future studies are encouraged to elaborate further on possible explanations for the observed relationships. Healthcare professionals should be aware and advise caregivers about the potential risk of prolonged breastfeeding on caries development by applying the current recommendations on breastfeeding, oral hygiene, and feeding frequency.

Modelling growth curves of the normal infant's mandible: 3D measurements using computed tomography.

OBJECTIVES: Data on normal mandibular development in the infant is lacking though essential to understand normal growth patterns and to discriminate abnormal growth. The aim of this study was to provide normal linear measurements of the mandible using computed tomography performed in infants from 0 to 2 years of age. MATERIAL AND METHODS: 3D voxel software was used to calculate mandibular body length, mandibular ramus length, bicondylar width, bigonial width and the gonial angle. Intra- and inter-rater reliability was assessed for these measurements. They were found to be sufficient for all distances; intra-class correlation coefficients were all above 0.9. Regression analysis for growth modelling was performed. RESULTS: In this multi-centre retrospective study, 109 CT scans were found eligible that were performed for various reasons (e.g. trauma, craniosynostosis, craniofacial abscesses). Craniosynostosis patients had larger mandibular measurements compared to non-craniosynostosis patients and were therefore excluded. Fifty-one CT scans were analysed. CONCLUSIONS: Analysis showed that the mandible increases more in size vertically (the mandibular ramus) than horizontally (the mandibular body). Most of the mandibular growth occurs in the first 6 months. CLINICAL RELEVANCE: These growth models provide insight into normal mandibular development in the first 2 years of life. This reference data facilitates discrimination between normal and abnormal mandibular growth.

Three-Dimensional Stereophotogrammetry in the Evaluation of Craniosynostosis: Current and Potential Use Cases.

ABSTRACT: Three-dimensional (3D) stereophotogrammetry is a novel imaging technique that has gained popularity in the medical field as a reliable, non-invasive, and radiation-free imaging modality. It uses optical sensors to acquire multiple 2D images from different angles which are reconstructed into a 3D digital model of the subject's surface. The technique proved to be especially useful in craniofacial applications, where it serves as a tool to overcome the limitations imposed by conventional imaging modalities and subjective evaluation methods. The capability to acquire high-dimensional data in a quick and safe manner and archive them for retrospective longitudinal analyses, provides the field with a methodology to increase the understanding of the morphological development of the cranium, its growth patterns and the effect of different treatments over time.This review describes the role of 3D stereophotogrammetry in the evaluation of craniosynostosis, including reliability studies, current and potential clinical use cases, and practical challenges. Finally, developments within the research field are analyzed by means of bibliometric networks, depicting prominent research topics, authors, and institutions, to stimulate new ideas and collaborations in the field of craniofacial 3D stereophotogrammetry.We anticipate that utilization of this modality's full potential requires a global effort in terms of collaborations, data sharing, standardization, and harmonization. Such developments can facilitate larger studies and novel deep learning methods that can aid in reaching an objective consensus regarding the most effective treatments for patients with craniosynostosis and other craniofacial anomalies, and to increase our understanding of these complex dysmorphologies and associated phenotypes.

Consortium-based genome-wide meta-analysis for childhood dental caries traits.

Prior studies suggest dental caries traits in children and adolescents are partially heritable, but there has been no large-scale consortium genome-wide association study (GWAS) to date. We therefore performed GWAS for caries in participants aged 2.5-18.0 years from nine contributing centres. Phenotype definitions were created for the presence or absence of treated or untreated caries, stratified by primary and permanent dentition. All studies tested for association between caries and genotype dosage and the results were combined using fixed-effects meta-analysis. Analysis included up to 19 003 individuals (7530 affected) for primary teeth and 13 353 individuals (5875 affected) for permanent teeth. Evidence for association with caries status was observed at rs1594318-C for primary teeth [intronic within ALLC, odds ratio (OR) 0.85, effect allele frequency (EAF) 0.60, P 4.13e-8] and rs7738851-A (intronic within NEDD9, OR 1.28, EAF 0.85, P 1.63e-8) for permanent teeth. Consortium-wide estimated heritability of caries was low [h2 of 1% (95% CI: 0%: 7%) and 6% (95% CI 0%: 13%) for primary and permanent dentitions, respectively] compared with corresponding within-study estimates [h2 of 28% (95% CI: 9%: 48%) and 17% (95% CI: 2%: 31%)] or previously published estimates. This study was designed to identify common genetic variants with modest effects which are consistent across different populations. We found few single variants associated with caries status under these assumptions. Phenotypic heterogeneity between cohorts and limited statistical power will have contributed; these findings could also reflect complexity not captured by our study design, such as genetic effects which are conditional on environmental exposure.

Impact of orthodontic treatment need and deviant occlusal traits on oral health-related quality of life in children: A cross-sectional study in the Generation R cohort.

INTRODUCTION: Many studies have investigated the impact of orthodontic treatment need (OTN) on children's oral health-related quality of life (OHRQOL). However, few studies have explored the impact of deviant occlusal traits on OHRQOL regarding the severity of OTN. This cross-sectional study aims to address this gap in the literature. METHODS: This study was conducted within the Generation R Study, a population-based prospective cohort study. We assessed OTN with the Index of Orthodontic Treatment Need and OHRQOL with a parental short-form of the Child Oral Health Impact Profile in 3048 children at a median age of 9.74 years (9.5-10.0). We also further assessed individual malocclusion traits in a subsample of 2714 children. We investigated the association between OTN, malocclusion traits, and OHRQOL using multiple regression analysis with weighted least squares. RESULTS: Children with definite (adjusted effect estimate = -0.81; 95% confidence interval -1.12 to -0.50) or borderline (adjusted effect estimate = -0.34; 95% confidence interval -0.61 to -0.08) OTN experienced significant decreases in their OHRQOL than those with no need. An impacted tooth, increased overjet, or crowding had significant negative impacts on children's OHRQOL. Children with an overjet experienced negative impacts on OHRQOL even when orthodontic treatment was not necessary. CONCLUSIONS: Progressively greater OTN has increasingly negative impacts on parent's perception of children's OHRQOL. In particular, children presenting with large overjets and impacted teeth have lower OHRQOL. These perspectives add to better patient-clinician communication and understanding of patient expectations around OTN, which may potentially lead to improvements in quality of care from the patient perspective.

Dental development and craniofacial morphology in school-age children.

INTRODUCTION: The growth of the craniofacial complex is important for establishing a balanced relationship among the teeth, jaws, and other facial structures. However, there is still a lack of information about craniofacial parameters that are affected by the rate of dental development. The aim of this study was to investigate the association between dental development and craniofacial morphology in school-age children. METHODS: This study was embedded in the Generation R Study, Rotterdam, The Netherlands. In 3,896 children aged 8 to 11 years, dental development was assessed from panoramic radiographs and craniofacial morphology was assessed by combining cephalometric parameters into 9 uncorrelated principal components, each representing a distinct skeletal or dental craniofacial pattern. The statistical analysis was performed using linear and nonlinear regression model. RESULTS: Dental development was positively associated with the bimaxillary growth (ß = 0.04; 95% CI 0.01 to 0.08). Children with above-average dental development had a tendency toward Class II jaw relationship (ß = -0.08; 95% CI -0.13 to -0.04). Regarding dental parameters, the proclination increased for incisors and lips with advanced dental development (ß = 0.15 [95% CI 0.10 to 0.19] and ß = 0.13 [95% CI 0.09 to 0.17], respectively), but the incisor proclination remained more pronounced in children that had above-average dental development. CONCLUSIONS: The findings of this large population-based study show that dental development is associated with specific dental and skeletal cephalometric characteristics in school-age children. Further longitudinal studies are necessary to confirm the observed effects over time.

The role of accelerated dental development on the occurrence of aberrant dental traits that indicate malocclusion.

BACKGROUND: Timing of dental development might help orthodontists to optimize initiation of treatment and to prevent and intercept dental misalignment. This study examines the association between timing of dental development and aberrant dental traits such as crowding, impaction, and hypodontia. METHODS: This study was performed using 4446 ten-year-old children from a multiethnic birth cohort, the Generation R Study. Dental development was defined using the Demirjian method. Crowding, impaction, and hypodontia were ascertained from 2D and 3D pictures and radiographs. We built three series of logistic regression models to test the associations of dental age with crowding, impaction, and hypodontia. Similar models were built to investigate the associations of the developmental stages of each left mandibular tooth with crowding, impaction, and hypodontia. RESULTS: Inverse associations were found between every 1-year increase in dental age and the presence of crowding [odds ratio (OR) = 0.84, 95% confidence interval (CI): 0.79, 0.89], impaction of teeth (OR = 0.66, 95% CI: 0.52, 0.84), and hypodontia (OR = 0.52, 95% CI: 0.47, 0.56). Lower developmental stages of the second premolar were associated with the presence of crowding (OR = 0.90, 95% CI: 0.83, 0.98). Lower developmental stages of the second premolar (OR = 0.88, 95% CI: 0.79, 0.98), first molar (OR = 0.76, 95% CI: 0.65, 0.90), and the second molar (OR = 0.83, 95% CI: 0.73, 0.94) were associated with the presence of tooth impaction. Lower developmental stages of all mandibular teeth except the central incisor were associated with hypodontia (P < 0.05). CONCLUSION: Accelerated dental development is associated with lower occurrence of crowding, impaction, and hypodontia.

Ancestry and dental development: A geographic and genetic perspective.

OBJECTIVE: In this study, we investigated the influence of ancestry on dental development in the Generation R Study. METHODS: Information on geographic ancestry was available in 3,600 children (1,810 boys and 1,790 girls, mean age 9.81 ± 0.35 years) and information about genetic ancestry was available in 2,786 children (1,387 boys and 1,399 girls, mean age 9.82 ± 0.34 years). Dental development was assessed in all children using the Demirjian method. The associations of geographic ancestry (Cape Verdean, Moroccan, Turkish, Dutch Antillean, Surinamese Creole and Surinamese Hindustani vs Dutch as the reference group) and genetic content of ancestry (European, African or Asian) with dental development was analyzed using linear regression models. RESULTS: In a geographic perspective of ancestry, Moroccan (ß = 0.18; 95% CI: 0.07, 0.28), Turkish (ß = 0.22; 95% CI: 0.12, 0.32), Dutch Antillean (ß = 0.27; 95% CI: 0.12, 0.41), and Surinamese Creole (ß = 0.16; 95% CI: 0.03, 0.30) preceded Dutch children in dental development. Moreover, in a genetic perspective of ancestry, a higher proportion of European ancestry was associated with decelerated dental development (ß = -0.32; 95% CI: -.44, -.20). In contrast, a higher proportion of African ancestry (ß = 0.29; 95% CI: 0.16, 0.43) and a higher proportion of Asian ancestry (ß = 0.28; 95% CI: 0.09, 0.48) were associated with accelerated dental development. When investigating only European children, these effect estimates increased to twice as large in absolute value. CONCLUSION: Based on a geographic and genetic perspective, differences in dental development exist in a population of heterogeneous ancestry and should be considered when describing the physiological growth in children.

The effect of resorbable membranes on one-stage ridge augmentation in anterior single-tooth replacement: A randomized, controlled clinical trial.

AIM: To evaluate the effect of resorbable membranes on one-stage ridge augmentation procedures in small (2-4 mm) buccal bony dehiscences in anterior maxillary single-tooth replacement. MATERIALS AND METHODS: Patients with a buccal bony dehiscence after implant placement in the esthetic zone were randomly allocated to one-stage ridge augmentation with (M+) or without a membrane (M-). Second-phase surgery was performed after 8 weeks, and follow-up was performed 1, 6, and ≥12 months after loading. Outcomes included implant survival and success, complications, clinical and radiographic parameters, esthetic results and patient satisfaction. RESULTS: Fifty-two patients were randomized to one-stage ridge augmentation with (n = 25) or without use of a membrane (n = 27). No significant differences in implant survival and success have been observed. The risk of having a small mucosal dehiscence was more than six times higher in the M+ group than in the M- group (RR 6.24, 95% CI 0.81 to 48.21). At the last follow-up, the bleeding index (BI) was marginally higher in the M+ group (14/9/2/0) compared to the M- group (24/2/0/0) (U = 205, Z = -2.97, p = .003, r = .42). The median change in marginal bone level was statistically lower in the M+ group (0.06 mm) than the M- group (0.60 mm) at last follow-up (U = 120, Z = -2.73 a p = .006 r = .42). Total pink esthetic index (PES) and white esthetic score (WES) and combined PES/WES were not significantly different between treatment groups at more than 12 months after loading. Only the subcategory root convexity/soft tissue color scored significantly lower in the M+ group (1.5) compared to the M- group (2.0) at the last follow-up (U = 172, Z = -2.34, p = .019 r = .34). No differences were found in patient satisfaction. CONCLUSION: The use of a resorbable membrane in small buccal bony dehiscences in anterior maxillary single-tooth replacement resulted in less marginal bone loss, but showed more mucosal dehiscences, higher bleeding scores and lower scores on root convexity and soft tissue color after at least one year of loading. No effect was seen on implant survival and success, overall esthetic results, and patient satisfaction. The research protocol was registered at the Dutch Trial Register (NTR) with ID NTR6137.