Cleft lip and alveolus (ORPHA:141291)
Cleft lip and alveolus is a fissure type embryopathy that involves the upper lip, nasal base and alveolar ridge in variable degrees.
Epidemiology
The annual incidence varies from 1/4,000 to 1/10,000 births with major variation among geographic regions and ethnic groups. Cleft lip/alveolus is twice as common in boys as girls and is seen more frequently on the left side.
Clinical description
The cleft is paramedian and is located at the philtrum level for the lip and nasal base and at the level of the upper lateral incisor for the alveolar ridge. It involves a cutaneous, muscular and mucosal interruption in the lip, in addition to nostril and nasal septum deformations and an interruption in the alveolar bone and dental arch. The maxillary lateral incisor, at the site of the alveolar cleft, can present with anomalies in shape, number (duplication or agenesis) and position. There is no correlation seen between temporary (primary) and permanent dentition.
Etiology
Cleft lip/alveolus is an embropathy that appears in the 5th to 7th week of pregnancy, following an error in fusion of the frontal processes (fronto-nasal process, medial and lateral nasal processes, maxillary process). Cleft lip and alveolus are isolated, non-syndromic anomalies in 70% of cases. The remaining 30% of cases are seen in about 300 syndromes where cleft lip/alveolus is just one of the featured anomalies. Non-syndromic clefts are believed to be caused by a combination of genetic and environmental factors. Factors such as the exposure to teratogenic substances during pregnancy (alcohol, tobacco or drugs) can influence genetic susceptibility.
Diagnostic methods
Diagnosis is clinical.
Differential diagnosis
The presence of associated malformations allows for differentiation between isolated and syndromic forms.
Antenatal diagnosis
Antenatal diagnosis is often made during prenatal ultrasound. The case is submitted to a multidisciplinary center for prenatal diagnosis in order to establish if it is an isolated anomaly.
Management and treatment
Management requires multidisciplinary medical and surgical intervention from birth until the end of development. It involves primary surgery followed by secondary maxilla-facial surgery along with plastic surgery. An initial treatment timeline is established during the neonatal period. Management is adapted to the child and based on morphological and functional problems that may arise during growth and development. Orthodontic management aims to correct the dental alignment problems, sometimes during the early primary teeth stage and then in the mixed and permanent stage. Treatment of the alveolar cleft requires a maxillary bone graft and a dental implant can correct permanent lateral incisor agenesis, if present after growth has stopped. The capacity to chew properly depends on the bucco-facial clinical history of the patient and any dental alignment problems. Breathing difficulties can occur due to the nostril anomaly as well as deviation of the vomer and nasal septum and turbinate hypertrophy. Secondary surgery of the nose can be performed to improve nasal appearance and function if necessary.
Prognosis
The prognosis depends on the quality of initial management and the regular follow-up by an experienced interdisciplinary team until the child is fully grown. Cleft lip/alveolus can have functional (morphological, respiratory), esthetic and psychological consequences that require management in a specialized health center.

                            Last update: 
                            December 2011


                            - Expert reviewer(s): 
                            Dr Eva GALLIANI  - Pr Marie-Paule VAZQUEZ