Prevalence of dental anomalies in cleft affected subjects and their family members

Introduction: It has been proven that people born with a developmental defect in their lip or in the bone of their upper jaw, called a cleft, have more anomalies in their teeth than the general public. The cause of these dental anomalies is unknown but some researchers believe genetics, the cleft itself and or early surgeries to correct the cleft may be causal factors. If the cause of these anomalies is genetic then we can suspect that seemingly unaffected relatives of individuals with clefts may also have more anomalies than the general public because they are genetically similar. Conversely if these anomalies are mostly due to the cleft itself or to sequelae associated with surgical repairs then one would not expect to find an increased risk for such anomalies in family members. A previous study published in 2015 found no evidence suggesting increased risk for unaffected relatives in a large cohort of individuals of mostly European and Asian descent. The purpose of this study is to evaluate the presence of such dental anomalies in a different international cohort including individuals of African and Hispanic ancestries and contribute additional knowledge to the etiology of these anomalies.

Methods: To answer these questions we examined photographs of over 1,000 people’s teeth including individuals with clefts, those without clefts and the family members of both to evaluate dental anomalies. Several types of anomalies were considered including missing teeth, extra teeth, position of teeth, tooth size, presence of decay and enamel quality.

Results: Cleft-affected subjects were found to have more missing teeth and misaligned teeth than the control group. Differences in dental anomalies between siblings and parents compared to controls were not significant except for incisal fissures, although several non-significant trends were observed. Subjects with cleft lip and palate presented with agenesis more often when compared to other types of clefts or controls.

Discussion: Generally our findings are consistent with previous work that found an elevated rate of dental anomalies in the cleft-affected population. However, based on this current data it cannot be reasoned that unaffected family members are at higher risk for dental anomalies.

Conclusion: These findings suggest that families with a history of clefting do not carry a genetic risk for dental anomalies greater than the general population. Higher rates of dental anomalies in the case probands may be a due to the physical cleft and surgical interventions to correct it.