Oral characteristics and medical considerations in the dental treatment of individuals with Williams syndrome

Oral manifestations of nine individuals with Williams syndrome. A case series

AIMS

Williams syndrome (WS) is a congenital developmental disorder characterized, mainly, by distinctive facial features, cardiovascular anomalies, growth delay and a typical neurobehavioral profile. The oral manifestations have not been sufficiently described and, therefore, the aim of the current study was to present the clinical, radiographic and microbiological findings of individuals with WS.

METHODS AND RESULTS

A series of nine WS individuals (seven females) with mean age 21 years-old were evaluated. A complete intraoral clinical examination, a radiographic analysis using panoramic and cephalometric x-ray and a supra- and sub-gingival microbiological profiling were performed. We observed abnormal tooth morphology, excessive interdental spacing, congenitally missing permanent teeth and malocclusion. High levels of DMFT were observed and gingivitis was present in all subjects. Bacteria related to periodontal disease were detected in dental plaque. Three patients were classified with a gingival phenotype type I according to the Maynard and Wilson classification. The sella turcica bridging was a novel finding for this group of patients.

CONCLUSION

Due to the elevated prevalence of gingivitis, caries and malocclusion, a multidisciplinary approach including dental follow-ups should be the standard of care in WS patients.

Rare Disorders: Diagnosis and Therapeutic Planning for Patients Seeking Orthodontic Treatment

The available literature on the orthodontic treatment of patients with rare disorders is extremely scarce. The aim of this study was to analyze the diagnosis and orthodontic treatment of a group of 94 individuals with rare diseases, referred for orthodontic evaluation to a university special care dentistry center (University of Santiago de Compostela, Spain). We created a control group of 94 systemically healthy individuals, paired by sex and age range. For all participants, we recorded their dental and skeletal abnormalities, oromotor dysfunctions and the characteristics of their orthodontic treatment. Some of the morphological and functional abnormalities were more prevalent in the rare disorders group than in the control group, including dental agenesis, microdontia, enamel defects, maxillary hypoplasia, overbite, cleft lip/palate, mouth breathing, atypical swallowing, lingual/labial interposition, labial incompetence, modified consistency diet, bruxism, and muscle tone abnormalities. Compared with the control group, the 56 patients with rare disorders who underwent orthodontic treatment required more desensitization sessions, used mixed appliances (fixed and removable) more often and for longer periods and had more frequent complications, such as gingivitis, caries, mucosal ulcers and recurrent debonding of the device. In conclusion, for selected patients with rare disorders, it is feasible to perform orthodontic treatment, whose planning will be determined by the dental-skeletal abnormalities and oromotor dysfunctions. Although complications are more frequent, they can typically be solved without having to stop treatment.

Determination of craniofacial and dental characteristics of individuals with Williams-Beuren syndrome by using 3D facial scans and radiographs

BACKGROUND

Williams-Beuren syndrome (WBS) is caused by a microdeletion on chromosome 7q11-23 and clusters a variety of systemic affectations.

AIM

To investigate whether 3D facial scans can detect WBS by objectively addressing their craniofacial, skeletal and dental characteristics, compared with those of a non-affected control group.

MATERIALS AND METHODS

3D facial surface scans of 17 WBS individuals and 33 normal developing patients were analysed. Additionally, cephalometric and panoramic radiographs of subjects with WBS were compared with those of non-affected individuals.

RESULTS

The 3D surface scans showed significant facial differences around the nose and mouth area. The cephalometric aspects of individuals with WBS differed mainly at the lower incisor region. Additionally, hypoplastic tooth morphology seems to be more often present in WBS.

CONCLUSION

3D images are a non-invasive, efficient method to observe facial anomalies and facilitate an early diagnosis of WBS. Additionally, the analysis of the cephalometric and panoramic images revealed significant differences in dental characteristics. Together with early diagnosis through 3D images, these can help in the establishment of adequate medical, dental and orthodontic treatment planning.

Access to oral health care services for individuals with rare genetic diseases affecting skeletal development

OBJECTIVE

To identify factors associated with oral health care services for individuals with and without rare genetic diseases.

MATERIALS AND METHOD

A cross-sectional study was undertaken, with 140 individuals paired by sex and age (70 with rare genetic diseases and 70 without), aged between 3 and 27 years, and their parents. The sample was selected from two reference hospitals for patients with rare genetic diseases in southeastern Brazil. The parents completed a questionnaire on individual aspects and their child's medical/dental history. Participants who did and did not suffer from rare genetic diseases were examined for dental caries, malocclusion, dental anomalies, and oral hygiene. The theoretical model Directed Acyclic Graphs (DAG) was used to identify possible confounding variables in the association between rare diseases and access to dental care. Descriptive analyses and non-matched and matched logistic regression models (p < 0.05) were carried out.

RESULTS

The chance of individuals without rare genetic disease having access to oral health care service was 5.32 times higher (95% CI 2.35-12.01) than those with such conditions. Individuals who had not suffered upper respiratory tract infections had a 3.16 times greater chance of being in the group with access to oral health care service (95% CI 1.45-6.90).

CONCLUSION

Individuals with no rare genetic diseases and no history of upper respiratory tract infections had a greater chance of belonging to the group of individuals with access to a dental service. Individuals with rare genetic diseases have less access to oral health care.

Williams syndrome

Williams syndrome (WS) is a relatively rare microdeletion disorder that occurs in as many as 1:7,500 individuals. WS arises due to the mispairing of low-copy DNA repetitive elements at meiosis. The deletion size is similar across most individuals with WS and leads to the loss of one copy of 25-27 genes on chromosome 7q11.23. The resulting unique disorder affects multiple systems, with cardinal features including but not limited to cardiovascular disease (characteristically stenosis of the great arteries and most notably supravalvar aortic stenosis), a distinctive craniofacial appearance, and a specific cognitive and behavioural profile that includes intellectual disability and hypersociability. Genotype-phenotype evidence is strongest for ELN, the gene encoding elastin, which is responsible for the vascular and connective tissue features of WS, and for the transcription factor genes GTF2I and GTF2IRD1, which are known to affect intellectual ability, social functioning and anxiety. Mounting evidence also ascribes phenotypic consequences to the deletion of BAZ1B, LIMK1, STX1A and MLXIPL, but more work is needed to understand the mechanism by which these deletions contribute to clinical outcomes. The age of diagnosis has fallen in regions of the world where technological advances, such as chromosomal microarray, enable clinicians to make the diagnosis of WS without formally suspecting it, allowing earlier intervention by medical and developmental specialists. Phenotypic variability is considerable for all cardinal features of WS but the specific sources of this variability remain unknown. Further investigation to identify the factors responsible for these differences may lead to mechanism-based rather than symptom-based therapies and should therefore be a high research priority.

Williams–Beuren syndrome: a complete guide for oral healthcare

Introduction: Williams–Beuren syndrome is a rare, congenital, multisystem disorder, resulting from genetic alterations on chromosome 7q11.23. Characteristic features of WBS are the developmental, physical and mental abnormalities associated with it. Typical facial features and a spectrum of tooth disorders are associated with this condition. Cardiac and renal involvement may be so severe that sudden death during oral healthcare procedures is a possibility. Photophobia and hyperacusis further make dental treatment a challenge in these patients. Corpus: Routine dental treatment in the dental office pose a significant risk, depending upon the mental and physical compromise of the patient, thereby making hospital admission a safer approach. A multispeciality approach is necessary to provide effective and safe oral healthcare to such patients. This article provides undergraduates, residents, general dental practitioners, and specialists involved in oral healthcare with a comprehensive overview of the condition with emphasis on its genetic basis, pathology, clinical features, diagnosis, and management of general and oral health. Conclusion: Adequate knowledge regarding the various aspects of Williams–Beuren syndrome allows the oral health care student or specialist to plan and manage oral procedures safely and effectively. Specialist referral and multidisciplinary care may be considered when appropriate.

Oral Manifestations of Wolf-Hirschhorn Syndrome: Genotype-Phenotype Correlation Analysis

Background: Wolf-Hirschhorn syndrome (WHS) is a rare disease caused by deletion in the distal moiety of the short arm of chromosome 4. The objectives of this study were to report the most representative oral findings of WHS, relate them with other clinical characteristics of the disease, and establish possible phenotype-genotype correlation. Methods: The study was conducted at 6 reference centers distributed throughout Spain during 2018–2019. The study group consisted of 31 patients with WHS who underwent a standardized oral examination. Due to behavioral reasons, imaging studies were performed on only 11 of the children 6 years of age or older. All participants had previously undergone a specific medical examination for WHS, during which anatomical, functional, epilepsy-related, and genetic variables were recorded. Results: The most prevalent oral manifestations were delayed tooth eruption (74.1%), bruxism (64.5%), dental agenesis (63.6%), micrognathia (60.0%), oligodontia (45.5%), and downturned corners of the mouth (32.3%). We detected strong correlation between psychomotor delay and oligodontia (p = 0.008; Cramér’s V coefficient, 0.75). The size of the deletion was correlated in a statistically significant manner with the presence of oligodontia (p = 0.009; point-biserial correlation coefficient, 0.75). Conclusion: Certain oral manifestations prevalent in WHS can form part of the syndrome’s phenotypic variability. A number of the characteristics of WHS, such as psychomotor delay and epilepsy, are correlated with oral findings such as oligodontia and bruxism. Although most genotype-phenotype correlations are currently unknown, most of them seem to be associated with larger deletions, suggesting that some oral-facial candidate genes might be outside the critical WHS region, indicating that WHS is a contiguous gene syndrome.