Association of Temporomandibular Joint Osseous Changes with Anxiety, Depression, and Limitation of Mandibular Function in Elderly Vietnamese.

OBJECTIVES: This study aimed (1) to determine the prevalence of anxiety, depression, and TMJ osseous changes in elderly Vietnamese according to sex and residence, and (2) to investigate the association of temporomandibular joint (TMJ) osseous changes with anxiety, depression, and limitation of mandibular function. METHODS: Elderly people living in Danang, Vietnam were recruited. Participants were screened for anxiety and depression using the self-reported 7-item Generalized Anxiety Disorder Scale (GAD-7) and 9-item Patient Health Questionnaire (PHQ-9), respectively. Participants then self-rated the limitation of their mandibular function using the 20-item Jaw Functional Limitation Scale (JFLS-20) questionnaire. TMJ osseous changes (erosion, flattening, osteophytes, and sclerosis) were evaluated using digital orthopantomography. RESULTS: Of 179 participants aged 65 to 74 years, 17.9% and 35.8% had anxiety and depression symptoms, respectively. Compared with urban residents, rural residents had higher prevalence of anxiety (23.3% vs 12.4%, p = 0.009) and depression (46.62% vs 24.7%, p = 0.019). The prevalence of TMJ osseous changes was 58.1%. The most common TMJ osseous change was flattening (41.3%), followed by erosion (34.6%), sclerosis (16.2%), and osteophytes (7.8%). Participants with or without TMJ osseous changes were comparable in terms of GAD-7 score, PHQ-9 score, and JFLS-20 score and sub-scores. CONCLUSIONS: Anxiety and depression and TMJ osseous changes were prevalent in elderly Vietnamese. Rural residents had higher prevalence of anxiety and depression than urban residents. TMJ osseous changes were not associated with anxiety, depression, or limitation of mandibular function.

A missense mutation in DUSP6 is associated with Class III malocclusion.

Class III malocclusion is a common dentofacial phenotype with a variable prevalence according to ethnic background. The etiology of Class III malocclusion has been attributed mainly to interactions between susceptibility genes and environmental factors during the morphogenesis of the mandible and maxilla. Class III malocclusion shows familial recurrence, and family-based studies support a predominance of an autosomal-dominant mode of inheritance. We performed whole-exome sequencing on five siblings from an Estonian family affected by Class III malocclusion. We identified a rare heterozygous missense mutation, c.545C>T (p.Ser182Phe), in the DUSP6 gene, a likely causal variant. This variant co-segregated with the disease following an autosomal-dominant mode of inheritance with incomplete penetrance. Transcriptional activation of DUSP6 has been presumed to be regulated by FGF/FGFR and MAPK/ERK signaling during fundamental processes at early stages of skeletal development. Several candidate genes within a linkage region on chromosome 12q22-q23--harboring DUSP6--are implicated in the regulation of maxillary or mandibular growth. The current study reinforces that the 12q22-q23 region is biologically relevant to craniofacial development and may be genetically linked to the Class III malocclusion.

Non-syndromic tooth agenesis associated with a nonsense mutation in ectodysplasin-A (EDA).

Mutations in the ectodysplasin-A (EDA) gene have been generally associated with X-linked hypohidrotic ectodermal dysplasia (XLHED). Recently, missense mutations in EDA have been reported to cause familial non-syndromic tooth agenesis. In this study, we report a novel EDA mutation in an Estonian family segregating non-syndromic tooth agenesis with variable expressivity. Affected individuals had no associated defects in other ectodermal organs. Using whole-exome sequencing, we identified a heterozygous nonsense mutation c.874G>T (p.Glu292X) in the TNF homology domain of EDA in all affected female patients. This protein-altering variant arose de novo, and the potentially causative allele was transmitted to affected offspring from the affected mother. We suggest that the dental phenotype variability described in heterozygous female carriers of EDA mutation may occur because of the differential pattern of X-chromosome inactivation, which retains reduced levels of EDA-receptor signaling in tissues involved in tooth morphogenesis. This results in selective tooth agenesis rather than XLHED phenotype. The present study broadens the mutation spectrum for this locus and demonstrates that EDA mutations may result in non-syndromic tooth agenesis in heterozygous females.