Trisomy 18: Case Report With Genetic, Systemic, and Oral Findings

CED/NOF-IADR Oral Health Research Congress 2026, Lisbon, Portekiz, 3 - 05 Eylül 2026, ss.296, (Tam Metin Bildiri)

Objectives: Trisomy 18 (Edwards syndrome) is a rare autosomal aneuploidy characterized by severe

congenital anomalies, high neonatal mortality, and complex clinical outcomes. The estimated prevalence is

approximately 1 in 6000 live births, with a higher incidence in females than males. Due to limited survival

beyond infancy, oral and dental findings in individuals with trisomy 18 remain insufficiently documented. This

case report aims to describe the systemic, genetic, and oral findings of a child with trisomy 18 and to highlight

the importance of preventive dental management.

Methods: A 3-year-old female patient with a confirmed karyotype of 47,XX,+18 was presented to the Istanbul

Kent University Faculty of Dentistry for dental evaluation. Medical history, systemic findings, and clinical and

radiographic oral examination were recorded. Preventive dental procedures and oral hygiene instructions were

provided.

Results: The patient was born at 33 weeks of gestation with a low birth weight and had a history of

prematurity, intrauterine growth restriction, respiratory distress, and a ventricular septal defect. Systemic

examination revealed features typical of trisomy 18, including rocker-bottom feet, low-set ears, generalized

hypertrichosis, micrognathia, and severe developmental delay. Intraoral examination revealed delayed tooth

eruption, a double tooth in the mandibular left anterior region, gingival recession affecting the mandibular right

central incisor, a high and narrow palate, and a persistent hand-to-mouth habit. Dental plaque was

mechanically removed, fluoride varnish was applied, and oral hygiene instructions were provided to the

caregiver.

Conclusions: Children with trisomy 18 may present with multiple oral and craniofacial abnormalities requiring

dental assessment and preventive management. Because these patients often have significant systemic

conditions, including congenital heart defects, complex dental treatment can be challenging. Therefore, early

identification of oral findings, preventive strategies before dental disease develops, and comprehensive

caregiver education are essential to maintain oral health and reduce the need for invasive dental treatment in

these medically compromised children.