The role of different factors in the development of cleft lip, palate, or both 
  
 

Vol 12 No 1 (2024)    DOI 10.5195/d3000.2024.647 

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The role of different factors in the development of cleft lip, 
palate, or both 
 
Natheer Ayed Jassem1, Ghufran A. Hasan 2, Mudher MB. Alsunbuli3 

1 Consultant in oral and maxillofacial surgery in Iraqi minister of health; Doctor teacher in Al-bayan university Oral and maxillofacial department, 

college of dentistry, Al-Bayan University, Baghdad /Ira 

2Department of Oral Diagnosis, College of Dentistry, Baghdad University/Baghdad/Iraq; Department of Oral and Maxillofacial Surgery, College of 

Dentistry, Al- Bayan University /Baghdad/Iraq; Teacher, B.D.S. (Bachelor of dental surgery), MSc in oral medicine 

3BDS, FIBMS, Oral and Maxillofacial Surgery Department, College of Dentistry. Al-Bayan University/Baghdad/ Iraq. 

 

 

Abstract 

Background: Cleft lip and cleft palate refer to congenital malformations characterized by fissures or 
divisions in the upper lip, the palatal region of the mouth, or both. Cleft lip and cleft palate occur due to 
incomplete closure of face tissues during fetal development. 

Objective: To identify the primary elements that could contribute to the occurrence of cleft lip and 
palate.  

Materials and Methods: The sample included 1080 patients distributed between cleft lip only, cleft 
palate only, and cleft lip and palate. Parents of participants answered questions related to their medical 
and exposure history. Subjects were seen over 13 years, from 1 January 2010 to 31 December 2022. 
Participants came to our hospital with ages from a few hours to 3 months.  

Results: The distribution of cleft types in the sample was as follows: 11.6% had cleft lip alone, 29.5% had 
cleft palate exclusively, and 57.3% had both cleft lip and palate. The most significant  number of patients, 
28%, were found to be first-born individuals. The majority of dads who exhibited patience were aged 30 
years or older, accounting for 65% of the sample. Among these individuals, 8.6% had a concurrent 
systemic ailment, while 40% were identified as smokers. Most moms were between the age range of 16 
to 30 years (65.4%). Incorporate additional factors into the analysis, including the presence of familial 
cleft history and psychiatric disorders.                                                                                                                                    
Conclusion: We found a high frequency of consanguinity between the parents maternal psychology 

factors such as fear, hearing bad news or 
hearing loud sounds like gunshots (prevalent 
during civilian war in Iraq between 2010-2014 
years) among parents of children born with 
cleft lip and palate.  

 

Keywords: Alternative medicine, Cytotoxicity, 
Plant extract, Aristolochia cymbifera, Oral 
medicine. 

Citation: Jassem, NA et al. (2024) The role of different 
factors in the development of cleft lip, palate, or both  
Dentistry 3000. 1:a001  doi: 10.5195/d3000.2024.647 
Received:  November 13, 2023 
Accepted: January 14, 2024 
Published: February 12, 2024 
Copyright: ©2024 Jassem, NA et al. This is an open 
access article licensed under a Creative Commons 
Attribution Work 4.0 United States License. 
Email: natheer.ayed@albayan.edu.iq

 

 

Introduction 

Cleft lip and cleft palate are 

among the most common birth 

disorders and are inheritable 

conditions that can be part of a 

syndrome (1-5). Multiple genes 

and genetic mechanisms (6-11) 

as well as some teratogens and 

maternal illnesses have been 

associated with clefts (13-23). 

Clefts can be associated with 

defects of the central nervous 

system, eyes, heart, muscle-

skeleton, genitalia, abdomen, 

ears, thorax, endocrine system 

and skin (24).   The aim of this 

work was to identify risk factor 

for clefts relevant to the 

studied population.  

Materials and Methods 

The sample of this study 

included 1080 patients (592 

males and 488 females) who 

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mailto:natheer.ayed@albayan.edu.iq


The role of different factors in the development of cleft lip, palate, or both 
  
 

Vol 12 No 1 (2024)    DOI 10.5195/d3000.2024.647 

 http://dentistry3000.pitt.edu 

came to Al-wasity hospital as 

they are referred from different 

areas. We studied all clefts 

born between 1 January 2010 

to 31 December 2022, and 

children were a few hours to 3 

months of age. Parents were 

asked to fill out a questionnaire 

and a clinical examination was 

done for recording the type of 

cleft.  

The comprehensive assessment 

of a patient often encompasses 

a clinical examination, 

consisting of both extraoral and 

intraoral examinations. 

Following this examination, 

relevant information is 

recorded, and a case sheet is 

completed, which involves 

addressing key inquiries of 

utmost significance. The 

categorization of abnormalities 

includes cleft lip, full cleft 

palate, soft palate cleft, and 

cleft lip and palate. The 

inquiries pertain to details such 

as name, age, residence, and 

the number of siblings they 

have. Additionally, there are 

queries on the health state of 

their father, including if he 

smokes, his educational 

background, the presence of 

chronic illnesses, and any 

medications he may be taking. 

For mother same question in 

addition to  

1- Psychological problem 

during first 12 weeks 

like stress, fairness, and 

any violence 

2- If she affected by 

disease during first 12 

weeks 

3- If she takes medication 

and type of these drugs  

4- Any history of 

apportion.  

Finally, we record family history 

of clefts. 

 

 

 

 
Results 
 
Table 1 shows the frequency of each cleft type by sex:  

 
 
 
 

  

 

 

 

 

  

Female male Type of cleft lip and palate 
9 4 Bilateral cleft lip 

53 75 Unilateral cleft lip 
38 42 Left unilateral cleft lip  
15 33 Right unilateral cleft lip 
150 169 Complete cleft palate 

9 20 Cleft soft palate 
295 324 Cleft lip and palate 

90 120 Bilateral cleft lip and palate 
95 131 Left unilateral cleft lip and palate 

110 73 Right unilateral cleft lip and palate 

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The father: Among fathers of 

children born with clefts, 

approximately 65% (702 

individuals) of fathers aged 

above 30 years age, 8.61% of 

these fathers (93 individuals) 

had been diagnosed with 

systemic diseases. The majority 

of these fathers (81%, 875 

individuals) were employed in 

the free enterprise sector, 

while the remaining individuals 

worked in civilian and non-

civilian occupations. The 

systemic diseases observed in 

these fathers include 

hypertension, diabetes, 

anemia, hormonal disorders, 

and others. Additionally, 40.6% 

of these fathers are smokers, 

and 2% consume alcohol. 

 Mother : The study revealed 

that a significant proportion of 

mothers, namely 65.4% (n = 

706), fell between the age 

range of 20 to 30 years. 

Furthermore, a substantial 

majority of mothers, 

accounting for 90% (n = 972), 

were identified as housewives. 

Among these housewives, 70% 

(n = 756) were discovered to 

possess a poor level of 

education. In the study, it was 

found that 80.6% (n=870) of 

women had normal births, 

whilst 19.4% (n=210) 

underwent 

cesarean operations. 

Furthermore, it was found that 

19.8% (n=216) of the surveyed 

mothers had a documented 

history of undergoing abortion 

procedures. Among this group, 

20% (n=216) had experienced 

repeated instances of abortion.   

Consanguinity: The study 

revealed that the degree of 

consanguinity among the 

parents was determined to be 

71% (N=767). The researchers 

acquired information about the 

occurrence of clefts within the 

nuclear family unit, which 

includes the father, mother, 

and siblings. The prevalence of 

clefts within this family was 

found to be 10%. There were 

two sets of male and female 

twins, all of them had cleft lip 

and palate at an identical 

location. All individuals with a 

familial predisposition to cleft 

lip and palate had full clefts, 

which were seen to be either 

unilateral or bilateral. During 

the first trimester of pregnancy, 

a significant proportion of 

mothers, namely 39.2%, 

experienced the presence of 

illnesses. The most frequent 

conditions were shown to be 

urinary tract infections, anemia, 

respiratory illnesses, and 

hypertension... During the first 

trimester of pregnancy, a 

significant proportion of 

mothers, namely 40% or 432 

individuals, reported the use of 

various medicines including 

antibiotics, vitamins, insulin, 

anti-inflammatory drugs, 

steroids, and contraceptive 

pills, among others.  

Psychological role in cleft 

development: 46.6% of 

mothers reported fear, hearing 

bad news or hearing loud 

sounds like gunshots. 6% of 

mothers had a history of 

physical trauma . Most events 

were concentrated between 

the years 2010 to 2014 where 

there was military action in 

most of Iraq.  

When taking the order of birth 

of the affected child, 32.12%, or 

347 were first born. 

  

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Table 2 shows the frequency of associations with other congenital anomalies: 

percentage System affected 

3.8           41 Craniofacial 

1.57         17          Central Nervous System 

0.64          7 Ocular  

2.6           28 Cardiac 

1.2           13         Urogenital 

3.61         39 Musculoskeletal system 

1.48         16 Ear 

Discussion 

In this research, the prevalence 

of cleft lip was seen to be lower 

(11.6%) compared to other 

types, which is consistent with 

the findings of previous studies 

such as Kinaan (15%), Al-

Zubaidee and Hammash 

(16.67%), and Dawood (15%) 

(21-23). However, a significant 

difference was seen among the 

other investigations conducted 

by Natsume and Kawai (2013) 

(41.3%), Manhal (2012) (10%), 

and Al-Zubaidee et al. (1998) 

(50%) in their respective 

findings. A previous study by 

Manhal (24), Al-Zubaidee, and 

Hammash (22) indicated that 

the frequency of unilateral 

clefts was greater than that of 

bilateral clefts.. The findings of 

this research also revealed a 

prevalence of left-sided clefts, 

which accounted for a greater 

proportion than right-sided 

clefts across all kinds of cleft lip 

instances. This phenomenon 

might perhaps be attributed to 

the rotation of the head 

towards the right during the 

embryonic development of the 

heart, resulting in the inferior 

positioning of the left side of 

the face. In the instance of cleft 

palate, the prevalence rate of 

29.5% was observed, which was 

somewhat lower compared to 

the findings reported by Sesgin 

and Stark (33%), Conway and 

Wagner (32%), Padilla and 

Gonzalez (1986) (33.1%), 

Dawood (1997) (33%), and Al-

Zubaidee et al. (2000) (38%). 

The occurrence of cleft of the 

soft palate was comparatively 

less frequent as compared to 

that of the hard palate. 

Borcbakan (1969) documented 

a greater prevalence of clefts 

occurring in the soft palate 

compared to those occurring in 

the hard palate. Cleft lip and 

palate, also known as orofacial 

clefts, are congenital conditions 

characterized by a separation 

or gap in the upper lip and/or 

the roof of the mouth. The 

aforementioned group 

constituted the majority of 

various forms Previous 

investigations have shown the 

occurrence of cleft, with 

Manhal (21-25) reporting a 

prevalence rate of 67%, 

Dawood (23) reporting a rate of 

52.14%, and Al-Zubaidee (22) 

reporting a rate of 45%. The 

research conducted in this 

study revealed a more 

significant occurrence of 

unilateral cleft lip and palate 

compared to bilateral cleft lip 

and palate, which aligns with 

the findings provided by 

Dawood (23). However, these 

results differ from those 

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obtained by Manhal (24). The 

individual in question, referred 

to as Kinaan (21), is the subject 

of discussion. The examination 

revealed a lack of occurrences 

of median cleft lip and palate, a 

facial abnormality that is 

seldom seen and has been 

hardly documented in previous 

studies, including the research 

conducted by Manhal (24). 

Dawood (2019) discovered a 

specific form of median cleft in 

a subset of individuals, 

constituting around 1.07% of 

the population. When 

considering the impact of sex, it 

is seen that males are impacted 

to a greater extent than 

females, with a ratio of 1.2:1. 

Specifically, a study conducted 

by Manhal (24) found a slightly 

higher ratio of 1.27:1. The 

sexual dimorphism in the 

prevalence of clefts remains 

uncertain; nonetheless, it has 

been postulated that divergent 

morphogenic processes in facial 

development between males 

and females may underlie this 

disparity.. Upon examination of 

the fathers' age, it was noted 

that there was a greater 

incidence of cleft in the older 

age cohort. Nevertheless, 

Jensen et al. (1988) 

documented a somewhat 

elevated incidence of cleft 

births in cases when the fathers 

were below the age of 24, 

which contrasts with the 

relationship between maternal 

age and cleft occurrence. 

Specifically, it was found that 

approximately 65.4% of cleft 

patients were born to younger 

mothers aged between 14 and 

30 years old. This finding aligns 

with the research conducted by 

Manhal (24). According to 

Slavkin (1992), research 

conducted by Fraser and Calnan 

(1961) discovered a positive 

correlation between the 

incidence of mouth clefts and 

advanced maternal age. This 

research reveals that a 

significant proportion of 

parents, namely 71%, exhibit a 

familial relationship. This 

finding aligns with the findings 

of Dawood (23). The prevalence 

of family history, as reported by 

Pietrzyk et al. (1985), was found 

to be consistent with the 

findings of the current study in 

10% of cases. AL-Zubaidee et al. 

(2000)(22), on the other hand, 

found a lower rate of 

6.8%. According to Dawood 

(23), a study found that 39.2% 

of women experienced illnesses 

during the first trimester of 

their pregnancy. Additionally, 

the study reported that 36.3% 

of moms had a condition during 

this period. Several studies 

have identified certain diseases, 

like epilepsy (Niebly, 12), 

diabetes (Nada, 1975), and 

Rubella (Seaver and Hoye, 

1992), as potential causes of 

cleft lip and palate.. A study 

conducted by Manhal (24) 

found that around 46.6% of 

moms experienced 

psychological distress. It is 

worth noting that this 

percentage falls within the 

range of 65% given by Manhal. 

Around 50.8% of children who 

get a diagnosis of either 

unilateral or bilateral cleft lip 

and palate need the use of a 

feeding plate, a medical 

intervention normally delivered 

by an orthodontist. In instances 

when there is a co-occurrence 

of defects in other organs, it 

has been shown that around 

14.9% of patients exhibit 

conditions such as cranial 

abnormalities, intellectual 

disability, visual impairments, 

cardiac malformations, and 

urogenital abnormalities. The 

prevalence of related 

abnormalities in the 

musculoskeletal system and ear 

was found to be greater in the 

current research compared to a 

previous study conducted in 

Iran. The previous study had a 

sample size of 1669 patients 

with cleft lip and palate and 

reported a prevalence rate of 

around 7.73% for associated 

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anomalies. However, in 

research conducted in France 

(25), it was shown that the 

proportion was lower than 

36.7%. 

Conclusions 

1 The use of drugs during 

the first trimester of 

pregnancy has a crucial 

role in the occurrence of 

this particular kind of 

deformity.  

2 In the sample, a positive 

consanguinity between 

the parents was 

observed in 71% of 

cases. 

3 The research 

demonstrates the 

potential of 

psychological variables 

in influencing outcomes. 

Disclosure of interest 

The authors declare that they 

have no competing interests. 

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