Year : 2007 | Volume
: 25 | Issue : 4 | Page : 174--176
Incidence of cleft lip and palate in Tehran
A Jamilian1, F Nayeri2, A Babayan1,
1 Orthodontic Department, Islamic Azad University, Tehran, Iran
2 Imam Khomeini Hospital, Tehran, Iran
No 1479, Corner of Ravanpoor Alley - Next to Jam-e-Jam, Valiasr Street, Tehran 19668
The purpose of this study was to assess the epidemiology and some of the possible risk factors causing oral cleft in Tehran. The study was a 7-year retrospective study from March 1998 to March 2005. Twenty-five live births with cleft lip and/or palate (CL ± P) were born between 20 March 1998 and 20 March 2005 from the total of 11,651 live births in a maternity hospital in Tehran. After recognizing the child as a cleft patient, previous and following children born were recognized as a noncleft sample. Cleft and noncleft samples were compared for variables such as gender, mother«SQ»s age, parity, consanguineous marriage and infant«SQ»s weight, and then analyzed with Chi-square. The overall incidence was 2.14 per 1000 live births. CL+ P is more prevalent, which was 52% and the least incidence was for «DQ»only cleft lip«SQ»«SQ» patients, which was 12%. This study reveals that the incidence of oral clefts in Tehran is higher than many other countries. Consanguineous marriage and low birth weight in cleft group were significant statistically from those of noncleft group.
|How to cite this article:|
Jamilian A, Nayeri F, Babayan A. Incidence of cleft lip and palate in Tehran.J Indian Soc Pedod Prev Dent 2007;25:174-176
|How to cite this URL:|
Jamilian A, Nayeri F, Babayan A. Incidence of cleft lip and palate in Tehran. J Indian Soc Pedod Prev Dent [serial online] 2007 [cited 2020 Jan 22 ];25:174-176
Available from: http://www.jisppd.com/text.asp?2007/25/4/174/37013
Cleft lip and/or palate (CL ± P) is the most common congenital malformation of the head and neck;  it accounts for 65% of all head and neck anomalies.  Blacks have the lowest incidence rate of clefts.  The highest incidence rate was found in Native Americans as 3.74 per 1000, followed by Japanese subjects as 3.36 per 1000 live births.  In USA, these conditions affect about one in every 700 children, with a slightly lower incidence rate of 1.3 per 1000.  Most of the epidemiological studies have been carried out in USA, Europe or other countries. Asians are at higher risk than whites or blacks. , The contradictory results of two different previous researches done in Tehran made another research necessary to shed light on the matter. The previous results reported an incidence of 1.03 to 3.73 per 1000 live births in Tehran. ,
The cause of CL ± P is known to be multifactorial in nature and includes both environmental and genetic factors.  Medications, intake of anticonvulsants, radiation, smoking, and alcohol consumption during pregnancy have all been proposed as factors, which may contribute to its etiology. In contrast, folic acid has been reported to have a protective effect. ,,
The aim of the present study was to establish the incidence and some possible risk factors for CL ± P in Iran, which were not given due attention, from 20 March 1998 to 20 March 2005. Having this information will help to establish integral treatment programs through appropriate CL ± P clinics and offer rehabilitation, education and genetic counseling.
Materials and Methods
The present study was a retrospective, observational study. The data for this epidemiological study was retrieved from the documented files at the largest maternity hospital in the center of Tehran during 20 March 1998 until 20 March 2005. Firstly, all patients with a CL ± P were recognized and various types of CL ± P were categorized. Those infants who were born with a cleft on their lips were called as CL patients. Those infants who were born with a cleft only on their palate were called as CP patients and those who were born with a cleft on their lips extending to their palates were called as CL + P patients. After recognizing the children with cleft, previous and following born children were recognized as noncleft sample. The hospital, in which this study was carried out, had several particular characteristics. Besides being located in the center of Tehran, it is one of the largest hospitals in the city. The natality rate is much higher than other hospitals in the city. This hospital is a tertiary care center; therefore, it receives patients from all over Tehran and from different strata of society. The characteristics of this hospital have made it a perfect center in Tehran for carrying out studies since it signifies the whole population of Tehran. In the first year, there were approximately 177 deliveries done every month and the rate was 150 per month in the last year. The cleft and noncleft samples were compared for variables such as gender, mother's age, parity, consanguineous marriage and the infant's weight. Then, the above-mentioned risk factors were analyzed with Chi-square test.
From a total of 11,651 cases, 25 children with CL ± P were born between 20 March 1998 and 20 March 2005. The overall incidence was 2.14 per 1000 live births. According to this incidence, the confidence interval by the probability 95% was 1.9-2.34 per 1000 live births. Distribution of CL ± P is shown in [Table 1] according to type of cleft. It shows that both cleft lip and palate are more prevalent, which was 52% and the least was for only cleft lip patients (12%). 52% of all cleft patients were girls and 48% were boys [Table 2].
The role of related factors in CL ± P is given in [Table 3]. It shows that gender, age of mother and parity in cleft group were not significantly different from those of noncleft samples. However, consanguineous marriage and low birth weight in cleft group were significantly different from noncleft group.
31.8% of CL ± P infants were the result of consanguineous marriages. However, 8% of noncleft samples were born as a result of consanguineous marriages ( P P  It was also reported that high dose of vitamin A has teratogenic effect during pregnancy. 
In Asia, incidence of 1.94:1000 was found in the Philippines.  The incidence of CL ± P was 1.81 per 1000 live births in Korea.  In Pakistan, the incidence for CL ± P was 1.91 per 1000 live births.  It is supposed that among Native Americans, there is a greater incidence of palatal clefts, with figures of up to 1:300 live births.  In the African American population, it is approximately one per 2500 births. This latter figure suggests that the incidence of CL ± P among African Americans is even lower than African natives.  In European countries, Owens et al.  found the incidence rate of 1.4:1000 births in England. In Italy, Calzolari et al .  found 1.3:1000 and 0.6-0.7:1000 live births in Sweden.  In Ireland, the incidence was 1.28:1000.  In the former German Democratic Republic, the incidence rate was 1.88:1000  and in Slovenia, the incidence rate was 1.64:1000. 
In the present study, there was no genderwise difference in CL ± P and 52% of all patients were girls and 48% were boys. Similarly, in Nigeria, both types of clefts were equally distributed between males and females.  In Sudan, girls made up a higher proportion than boys with a male-to-female ratio of 3:10,  in contrast to the reports coming from Europe and the USA ,, where females were less often affected.
The present study showed that gender, mother's age and parity were not found statistically significant in relation to cleft lip and palate. The mother's age was not an important factor for this malformation. Blanco-Davila  also reported the same result, but Habib  stated the incidence of CL ± P probably increases with mother's age.
This study showed that there is a relation between low birth weight and CL ± P. Rintalla and Gylling  reported a lower average birth weight among newborns with clefts, but Henriksson  reported a mean birth weight of 3405.6 g for Swedish children with clefts without associated defects. As clefting occurs in the first trimester, birth weight is only finalized in the later trimesters; therefore, low birth weight, logically, cannot be a cause of clefts. Nevertheless, this study showed that there is a relation between low birth weight and cleft that cannot be disregarded. According to what is said in regards of trimesters of cleft and birth weight, there might be some likelihood of CL ± P leading to low birth weight in the last trimester of pregnancy. The possibility of cleft's effects on birth weight needs more studies.
This study showed that parity does not have any effect on causing CL ± P. In addition, Rajabian and Sherkat  reported the same result.
In this study, the risk of CL ± P was increased in consanguineous marriage. Similarly, Harville  found that the risk of cleft lip alone, but not of cleft lip and palate, was increased for twins and infants whose parents were first cousins. This interesting result needs more studies.
Based on the results obtained in this study, we conclude that:
The overall incidence of cleft lip and / or palate in Tehran was 2.14 per 1000 live births.Consanguineous marriage and low birth weight in cleft group were significantly different from those of noncleft group.Gender, mother's age and parity in cleft group were not significantly different from those of noncleft group.
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