PDF: Cri-du-Chat syndrome: conservative dental treatment in an 8-year old child

Cri-du-Chat syndrome (CdCS) (MIM ID # 123450) is a genetic disease resulting from the total or partial deletion of the short arm of chromosome number 5. 

The condition was first described by Lejeune et al. in 1963.

Cri du Chat in French means "cat-like cry" and refers to the characteristic cry of affected children at birth. Diagnosis can be made immediately after birth, based on the peculiar cry, probably caused by abnormal development of the larynx or a variety of neurological disorders. 

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Studies have reported incidence rates ranging from 1:15,000 to 1:94,000 live births but the prevalence found by Niebuhr4 in 6,000 individuals with mental retardation was approximately 1:350. Furthermore, data reported by Higurashi's et al. 5 suggested a significantly higher prevalence of the disorder among females. Mainardi et al. 6 analyzed 80 patients and 148 parents from the Italian CdCS Register and found a paternal origin of the deleted chromosome 5 in 90.2% of the cases. Clinical evaluation of those patients revealed higher degree severity for microcephaly, dysmorphism, and psychomotor retardation related to the size of deletion of chromosome 5, the more severe cases were those with larger deletions.

The main characteristics of CdCS are a high-pitched cat-like cry, distinct facial dysmorphism, microcephaly, severe psychomotor and mental retardation, as well as abnormal facial features , e.g., a round face, hypertelorism, micrognathia, epicanthal folds, and low-set ears. Cardiac malformations, neurological and renal abnormalities, preauricular tags, syndactyly, hypospadias, and cryptorchidism can also be found.

Reported orofacial manifestations include mandibular microretrognathia, high palate, variable malocclusion, enamel hypoplasia, poor oral hygiene, generalized chronic periodontitis, and delayed tooth eruption. Yáñez-Vico et al.  evaluated the craniofacial morphology of 10 CdCS patients using standard cephalometric methods. The main characteristics found were skeletal class II malocclusion caused by mandibular retrognathism, dental biprotrusion, and a small upper airway. Additionally, 70% of the patients had a steep palatal plane angle and a flattened skull base angle.