Johanna Norderyd

Isolated oligodontia associated with mutations in EDARADD, AXIN2, MSX1, and PAX9 genes

Oligodontia is defined as the congenital lack of six or more permanent teeth, excluding third molars. Oligodontia as well as hypodontia (lack of one or more permanent teeth) are highly heritable conditions associated with mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes. Here we define the prevalence of mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes, and the novel candidate gene EDARADD in a cohort of 93 Swedish probands with non‐syndromic, isolated oligodontia. Mutation screening was performed using denaturing gradient gel electrophoresis and DNA sequence analysis. Analyses of the coding sequences of the six genes showed sequence alterations predicted to be damaging or potentially damaging in ten of 93 probands (10.8%). Mutations were identified in the EDARADD (n = 1), AXIN2 (n = 3), MSX1 (n = 2), and PAX9 (n = 4) genes, respectively. None of the 10 probands with mutations had other self‐reported symptoms from ectodermal tissues. The oral parameters were similar when comparing individuals with and without mutations but a family history of oligodontia was three times more frequent for probands with mutations. EDARADD mutations have previously been reported in a few families segregating hypohidrotic ectodermal dysplasia and this is, to our knowledge, the first report of an EDARADD mutation associated with isolated oligodontia.

WNT10A mutations account for ¼ of population‐based isolated oligodontia and show phenotypic correlations

A large proportion (>50%) of patients with isolated oligodontia were recently reported with WNT10A mutations. We have analyzed a population‐based cohort of 102 individuals diagnosed with non‐syndromic oligodontia and a mean of 8.2 missing teeth. The cohort included 94 families and screening of WNT10A identified that 26 probands (27.7%) had at least one WNT10A variant. When we included the MSX1, PAX9, AXIN2, EDA, EDAR, and EDARADD genes, 38.3% of probands were positive for a mutation. Biallelic WNT10A mutations were strongly associated with a larger number of missing teeth (11.09) when compared to both monoallelic WNT10 mutations (6.82) and the group without mutations in WNT10A, MSX1, PAX9, AXIN2, EDA, EDAR, or EDARADD (7.77). Genotype–phenotype analysis of individuals with WNT10A mutations showed that premolars were the most common missing teeth. Furthermore, biallelic WNT10A mutations were associated with absence of maxillary and mandibular molars as well as mandibular central incisors. Maxillary central incisors were always present. Thus, our study indicates that WNT10A mutations are associated with both the type and numbers of missing teeth. Furthermore, we show that this population‐based cohort of isolated oligodontia had a considerably lower frequency of mutated WNT10A alleles and a lower mean number of missing teeth when compared to patients recruited from dental specialist centers.

Chronic recurrent multifocal osteomyelitis involving both jaws : report of a case including magnetic resonance correlation

A case of chronic recurrent multifocal osteomyelitis in a 14-year-old girl is presented. The disease had an initial aggressive osteolytic appearance involving both the maxilla and the mandible. Conservative treatment with minimal surgical intervention has been successful in this case during a 2-year follow-up period. The value of magnetic resonance imaging and bone scintigraphy in this case and the cause of chronic recurrent multifocal osteomyelitis is discussed.

Using the International Classification of Functioning, Disability and Health (ICF) to Describe Children Referred to Special Care or Paediatric Dental Services

Children in dentistry are traditionally described in terms of medical diagnosis and prevalence of oral disease. This approach gives little information regarding a child’s capacity to maintain oral health or regarding the social determinants of oral health. The biopsychosocial approach, embodied in the International Classification of Functioning, Disability and Health - Child and Youth version (ICF-CY) (WHO), provides a wider picture of a child’s real-life experience, but practical tools for the application of this model are lacking. This article describes the preliminary empirical study necessary for development of such a tool - an ICF-CY Core Set for Oral Health. An ICF-CY questionnaire was used to identify the medical, functional, social and environmental context of 218 children and adolescents referred to special care or paediatric dental services in France, Sweden, Argentina and Ireland (mean age 8 years ±3.6yrs). International Classification of Disease (ICD-10) diagnoses included disorders of the nervous system (26.1%), Down syndrome (22.0%), mental retardation (17.0%), autistic disorders (16.1%), and dental anxiety alone (11.0%). The most frequently impaired items in the ICF Body functions domain were ‘Intellectual functions’, ‘High-level cognitive functions’, and ‘Attention functions’. In the Activities and Participation domain, participation restriction was frequently reported for 25 items including ‘Handling stress’, ‘Caring for body parts’, ‘Looking after one’s health’ and ‘Speaking’. In the Environment domain, facilitating items included ‘Support of friends’, ‘Attitude of friends’ and ‘Support of immediate family’. One item was reported as an environmental barrier – ‘Societal attitudes’. The ICF-CY can be used to highlight common profiles of functioning, activities, participation and environment shared by children in relation to oral health, despite widely differing medical, social and geographical contexts. The results of this empirical study might be used to develop an ICF-CY Core Set for Oral Health - a holistic but practical tool for clinical and epidemiological use.

Further evidence for specific IFIH1 mutation as a cause of Singleton–Merten syndrome with phenotypic heterogeneity

Singleton–Merten syndrome (MIM 182250) is an autosomal dominant inherited disorder characterized by early onset periodontitis, root resorption, osteopenia, osteoporosis, and aortic valve or thoracic aorta calcification. The disorder can have significant intrafamilial phenotypic variability. Here, we present a mother and daughter with Singleton–Merten syndrome harboring a previously described pathogenic missense mutation, c.2465G>A p.(Arg822Gln), in IFIH1 (interferon induced with helicase C domain 1), encoding MDA5 (Melanoma Differentiation‐Associated protein 5). These data confirm the pathogenicity of IFIH1 c.2465G>A p.(Arg822Gln) for Singleton–Merten syndrome and affirm the striking phenotypic heterogeneity of this disorder. In addition, we expand the Singleton–Merten phenotype by adding severe systemic lupus erythematosus (SLE) to the clinical picture. Investigations of known SLE genes as well as a single nucleotide polymorphism suggested to be involved in development of SLE were normal.

Hypoplastic root cementum and premature loss of primary teeth in Coffin–Lowry syndrome: a case report

BACKGROUND Coffin-Lowry syndrome (CLS) is a rare genetic disorder. The syndrome presents with psychomotor retardation, short stature, skeletal deformations, digit abnormalities, and distinctive facial features. Oral and dental findings in CLS are common and they include thick prominent lips, high palate, midline lingual furrow, hypodontia, microdontia, delayed eruption, and early tooth loss. Only one earlier case suggesting hypoplastic root cementum as cause for primary loss of teeth in CLS has been published. CASE REPORT This case describes a 3-year-old boy with premature loss of primary incisors without preceding root resorption. In addition to the dental findings, the boy had several general signs and symptoms and the dental findings together with the other characteristics led to the clinical diagnosis of CLS, which later was genetically verified. Histological analysis of an extracted primary incisor showed hypoplastic root cementum. CONCLUSION Hypoplastic root cementum may explain early tooth loss in CLS. As early loss of primary teeth is rare, especially when there is no previous root resorption, the individual is likely to seek dental care. Thus, the dentist may play an important role in assisting in the diagnosing of CLS.

Sublingual administration of atropine eyedrops in children with excessive drooling – a pilot study

Background Drooling can be a severe disability and have high impact on daily life. Reversible treatment is preferable. Aim To analyse whether sublingual administration of atropine eyedrops is a useful reversible treatment option for severe drooling in children with disabilities. Design The study had a prospective, single‐system research design. The participants served as their own controls. The study period was 3 weeks without treatment, 4 weeks with atropine eyedrop solution 10 mg/mL one drop a day followed by 4 weeks of one drop twice a day. Parents’ rating of their childs drooling was assessed on a 100‐mm VAS, and unstimulated salivary secretion rate measurement was performed together with notations about side effects and practicality. Results Parents’ VAS assessment of drooling decreased from a median (range) of 74 (40–98) at baseline to 48 (18–88) (P = 0.05) and 32 (12–85) (P = 0.004) after 4 weeks of atropine once a day and another 4 weeks of atropine twice a day, respectively (n = 11). Unstimulated salivary secretion rates decreased from baseline to end of study (P = 0.032). Several parents complained about difficult administration. No irreversible side effects were noted. Conclusions Sublingual atropine eyedrops may be an alternative for treatment of severe drooling in children with disabilities.

Specialised dental care for children with complex disabilities focusing on child’s functioning and need for general anaesthesia

Abstract Purpose: To describe and analyse dental care and treatment modalities for children with complex disabilities from a biopsychosocial perspective, with special focus on dental treatment under general anaesthesia (GA) and its relationship to child’s functioning. Method: An ICF-CY Checklist for Oral Health was completed using structured interview, direct observations, and dental records for patients attending a specialist paediatric dentistry clinic. Descriptive and comparative data analysis was performed. Performance qualifiers from the ICF-CY component Activities and participation were used to calculate functional factors. Results: Median referral age was 1.5 years and the majority were referred by their paediatrician. Almost all visited a dental hygienist regularly. Dental treatment under GA was common and was combined in 78% of sessions with medical treatment. Children with limitations in their interpersonal interactions and relationships were most likely to have dental GA. Conclusion: Children without caries experience had been referred for specialist dental care at an earlier age than children with caries experience. GA was a common treatment modality and dental and medical treatments were coordinated under the same GA for a majority of children. By using the ICF-CY, it was possible to identify functional limitations characterising children with disabilities that require dental treatment under GA. Implications for Rehabilitation Early referral to a specialist in paediatric dentistry is valuable for oral disease prevention in children with disabilities. Availability of dental treatment under general anaesthesia (GA) is also important. Combining dental and medical interventions during the same GA session optimises resources both for the individual and for the health organisation. Children with limitations in interpersonal interactions and relationships are more likely to need dental treatment under GA than other children.

Abnormal primary and permanent dentitions with ectodermal symptoms predict WNT10A deficiency

BackgroundThe WNT10A protein is critical for the development of ectodermal appendages. Variants in the WNT10A gene may be associated with a spectrum of ectodermal abnormalities including extensive tooth agenesis.MethodsIn seven patients with severe tooth agenesis we identified anomalies in primary dentition and additional ectodermal symptoms, and assessed WNT10A mutations by genetic analysis.ResultsInvestigation of primary dentition revealed peg-shaped crowns of primary mandibular incisors and three individuals had agenesis of at least two primary teeth. The permanent dentition was severely affected in all individuals with a mean of 21 missing teeth. Primary teeth were most often present in positions were succedaneous teeth were missing. Furthermore, most existing molars had taurodontism. Light, brittle or coarse hair was reported in all seven individuals, hyperhidrosis of palms and soles in six individuals and nail anomalies in two individuals. The anomalies in primary dentition preceded most of the additional ectodermal symptoms. Genetic analysis revealed that all seven individuals were homozygous or compound heterozygous for WNT10A mutations resulting in C107X, E222X and F228I.ConclusionsWe conclude that tooth agenesis and/or peg-shaped crowns of primary mandibular incisors, severe oligodontia of permanent dentition as well as ectodermal symptoms of varying severity may be predictors of bi-allelic WNT10A mutations of importance for diagnosis, counselling and follow-up.

Oral health, medical diagnoses, and functioning profiles in children with disabilities receiving paediatric specialist dental care – a study using the ICF-CY

Abstract Purpose: To describe 0–16-year-old children with disabilities receiving paediatric specialist dental care from a biopsychosocial perspective, with focus on relationship between oral health, medical diagnosis, and functioning. Method: A questionnaire with an International Classification of Functioning, Disability and Health – Children and Youth version (ICF-CY) Checklist for Oral Health was completed using structured interview, direct observation, and information from dental records. Descriptive data analysis was performed together with principle component analysis to calculate factors of functioning used in cluster analysis in order to present functioning profiles. Results: Ninety-nine children with at least one major medical diagnosis were included. Twenty had previous caries experience. Two factors of functioning were calculated, labelled “Physical ability” and “Intellectual ability, communication, and behaviour”. Based on functioning profiles three clusters were determined. There were no statistically significant differences in caries experience between medical diagnoses or clusters. Conclusion: It was possible to identify profiles of functioning in children with disabilities receiving specialist dental care. Despite complex disabilities, the children had good oral health. Neither medical diagnosis nor functioning was found to have a clear relationship with oral health. To understand the environmental context leading to high-quality oral health, further studies of dental management in relation to medical and oral diagnoses and child functioning are needed. Implications for Rehabilitation Child Oral Health The use of ICF-CY makes it possible for paediatric dentists to assess children’s functioning, disability, and health from a biopsychosocial perspective, showing that the medical diagnosis alone is not enough to assess functions relevant for oral health in the individual. In order to adequately organize, plan, and improve dental care for this heterogenic group of young patients with disabilities a biopsychosocial approach is valuable, aiding a holistic perspective on oral health. Despite complex medical and functional disabilities that may challenge oral health and dental care, this study finds oral health to be good in a group of children with disabilities attending a specialist dental clinic.