The incidence of cleft lip and/or palate among newborns in Lithuania, 1993-1997

Arunas Vasiliauskas1, Algirdas Utkus2, Auðra Matulevieiene2, Laura Linkevieiene2,3, Vaidutis Kueinskas2 1 Clinic of Orthodontics, Kaunas University of Medicine, J. Luksos-Daumanto 6, Kaunas, Lithuania 2 Department of Human and Medical Genetics, Vilnius University, Santariðkio 2, Vilnius, Lithuania 3 Institute of Odontology, Vilnius University, Vilnius, Lithuania Introduction. The clefts of lip, alveolar ridge and palate are the most common congenital anomalies in head and neck region. The incidence of cleft lip and/or palate nowadays is not falling and sometimes shows a tendency to an increase. There has not been any epidemiological survey on the incidence and distribution of cleft lip and/or palate over the last years in Lithuania. According to previous data, the cleft rate was 1 : 720– 740 newborns. The aim of the survey was to establish the incidence rate of cleft lip and/or palate in Lithuania and in its separate regions during 1993–1997; to create a structural model registry and to perform a retrospective comparative analysis of lip and/or palate clefts. Patients and methods. Material of the study was medical records of newborns with congenital cleft lip and/or palate, 1993 through 1997 and obtained from the Lithuanian Registry of Congenital Anomalies (LIRECA), Kaunas University of Medicine Clinic of Orthodontics and Clinic of Maxillo-facial and Oral Surgery, Institute of Odontology of Vilnius University, and Klaipeda City Center of Maxillo-facial Surgery. The aim of the study was to form a structural model registry of cleft lip and/or palate, to assess the incidence of cleft lip and/or palate in different regions of Lithuania and to perform a retrospective comparative analysis of cleft lip and/or palate incidence rates. Medical records of the total of 382 newborn with congenital cleft lip and/or palate, 1993–1997, were studied retrospectively. The type of cleft was classified according to Kernahan’s, ICPRS and ICD-10 classifications. Additionally, syndromic clefts and lethality due to multiple congenital anomalies were assessed. Statistical analysis of the data was performed using the SYSTAT software package (license No. 41000 63920 82182 15191 00930 59324 71373 651). Results. According to the data of the structural model registry of congenital cleft lip and/or palate for 1993 through 1997, the incidence of cleft lip and palate was 18.4 per 10 000, i.e. 1 : 544 live births. Due to improved diagnosis and registration of these anomalies the relative increase of syndromic cleft lip and/or palate cases in 1993 through 1997 made up 18.0% (a = 0.05; b = 0.05) as compared to the data of 1954 through 1964. According to the data on non-syndromic cleft lip and/or palate structural model registry in Lithuania, complete unilateral cleft lip and palate were found in 26.6% of all male newborns with cleft lip and/or palate, which exceeds that of female newborns with cleft lip and/or palate by 11.7% (a = 0.05; b = 0.05). Different regions of Lithuania were divided into four clusters, but due to a relatively small number of the observed cases incidence of cleft lip and/or palate cases per 1000 newborns in 1993 through 1997 did not differ statistically (p > 0.05) in the administrative regions of Lithuania. Conclusions. The incidence rate of cleft lip and/or palate for 1000 livebirths in Lithuania during 1993–1997 was 1.84 (1 : 544 live births), and in separate regions of Lithuania the rate of clefts for 1000 live births was from 0.01 (Kelme region) to 3.34 (Paneveþys region). Isolated lip and/or palate clefts formed 74.1% of all clefts. Syndromic clefts formed 25.9% of all clefts and comparing to the period 1953–1964 showed a statistically reliable increase owning to improved diagnostics and registration. Unilateral clefts of lip and/or palate are more frequent than bilateral, and the left unilateral cleft is more common than the right. The annual variation of cleft rate during the period 1993–1997 is statistically insignificant. The most common diagnoses were isolated palatal clefts forming 40.4% of all clefts and statistically reliably diagnosed more for female patients. Unilateral total upper lip, maxillary alveolus and palate cleft was diagnosed for 21.8% of all clefts and was statistically reliably more common for male newborns.