According to a Brazilian study, children with a congenital syndrome caused by the mosquito-borne Zika virus may be missing several teeth.
This is thought to be the first recorded case of oligodontia. Oligodontia refers to the absence of six or more teeth in children who have been exposed to the Zika virus (ZIKV) in the womb.
“The results of this study confirm the importance of oral examination and highlight this new association with ZIKV, pointing to a possible role for the virus in odontogenesis,” write the authors, led by Dr Carla Cristina Gonçalves da Costa of the Primary Health Care Program at Montes State University. Claros in Minas Gerais, Brazil.
In 2013, the Zika virus made its way to North America, and in 2016 the World Health Organization declared it an international public health emergency. The virus is mainly spread by the yellow fever mosquito (Aedes aegypti). However, it can also be transmitted through sexual, intrauterine, and circulatory routes. The Zika virus causes birth defects, growth and developmental abnormalities, and some motor neurological diseases in adults.
There is currently no local transmission of the Zika virus in the continental US, with the last cases reported in Florida and Texas in 2017, according to the US Centers for Disease Control and Prevention. While there are currently no outbreaks of the Zika virus worldwide, India faced a significant outbreak in November 2021.
Congenital absence of teeth is important, especially since oligodontia is a marker of more than 120 syndromes, including hypohidrotic ectodermal dysplasia. Understanding the features of dental agenesis can serve as an additional diagnostic tool that dentists can use in their daily practice.
To characterize oral differences in patients with congenital Zika virus syndrome, the researchers collected data on 10 children with the disease from the Association of Mothers of Children with Microcephaly in Brazil. They interviewed the children's parents and collected intraoral specimens for analysis and X-rays from the children.
Two out of ten children have oligodontia. According to a study, a 3-year-old boy was missing 12 teeth congenitally – two primary maxillary lateral incisors, two primary mandibular lateral incisors, two primary maxillary canines, one primary mandibular canine, one primary maxillary first molar, two primary mandibular second molars jaw and two primary second molars of the upper jaw.
Another child, a 5-year-old boy, was missing 15 teeth – four primary central incisors, one primary right maxillary lateral incisor, two primary mandibular lateral incisors, two primary maxillary canines, one primary mandibular canine , one primary mandibular first molar, and four primary second molars.
These dental abnormalities may be due to Zika virus-infected crest cells, which are embryonic cells that help form craniofacial features, including teeth. Odontogenesis, which begins around the fifth week of gestation, may be a contributing factor, as Zika infection causes significant comorbidities in fetuses during this period.
The study had a limitation: neurological diseases of children, in particular their lack of cervical tone, affected x-rays. As a result – images with artifacts, incomplete images and lack of standardization.
Gonçalves da Costa and her colleagues believe that more reports with different patients with Zika are needed to better understand the occurrence of oligodontia.
The results of the present study reinforce the importance of oral examination and highlight this new association with ZIKV, pointing to a possible role for the virus in aberrant odontogenesis.