J Bagh College Dentistry Vol. 32(4), December 2020 Gingival health condition
25
Gingival health condition among children of inbreeding parents
compared to children of outbreeding parents in Babylon
governorate / Iraq
Zahraa M Wais(1)
, Nadia Aftan Al Rawi(2)
https://doi.org/10.26477/jbcd.v32i4.2915
ABSTRACT
Background: Consanguineous marriage is a relationship between biologically related individuals. Genetic factors have a role in
gene environment interactions that takes the center stage. The evidence of oral disease (gingivitis and periodontitis) may depend
on genetic syndromes, inherited diseases, familial studies etc. The present study aims at assessing dental plaque and gingival health
condition in children of inbreeding parents compared with children of outbreeding parents among primary schools in Al-Qasem
city/ Babylon governorate in Iraq.
Materials and methods: this comparative study included three hundred ninety eight (398) students, 6-12 years old, from 4 primary
schools; 199 children had their parents of inbreeding marriage with first level of inbreeding, and the other 199 children had parents
of outbreeding marriage. Plaque status was assessed according to index of Silness and Loe (1964), gingival health status according
to index of Loe and Silness (1963).
Results: Children of inbreeding parents showed significantly higher plaque index and gingival index mean values than children of
outbreeding parents. Mild gingivitis was found as the most prevalent type among both groups. A highly significant positive
correlation was found between gingival and plaque indices.
Conclusion: Inbreeding rates have an effect on oral health, as the children of outbreeding parents had significantly better oral
hygiene and gingival health condition than children of inbreeding parents.
Key words: Consanguineous marriage, inbreeding, oral health. (Received: 10/8/2019; Accepted: 1/9/2019)
INTRODUCTION
Inbreeding is defined as a union between two
individuals who related as second cousins or other
relation. Inbreeding rates differ in communities
depending on religion, culture, and geography. (1)
As a consequence of inheriting the identical
chromosomal segment through both parents, who
inherited it from ancestor, the individuals born of
consanguineous marriage have a number of pieces
of their chromosomes which are homozygous. For
this reason, inbreeding increases the homozygosity
and, then, recessive alleles masked by
heterozygosity with predominant alleles will be
assert through inbreeding. Therefore, it is
conventional that recessive traits such as most
human genetic disorders which occur when
frequency increase in the progeny of inbreeding
couples. As in more, many recessive alleles found
in natural populations that have adverse effects on
organism, usually inbreeding make decrease in size,
reproductive fitness and vigor. However, it is
)1( M.Sc. Student, Department of Pedodontics and
Preventive Dentistry, College of Dentistry, University of
Baghdad ..
)2(Assistant Professor, Department of Pedodontics and
Preventive Dentistry , College of Dentistry, University of
Baghdad .
Corresponding author, missdentist1990@yahoo.com
necessary to consider that consanguineous marriage
can happen through two different biological
positions.
(2)
The degree of relationship between the individuals
in a population depends on the size of that
population which is more closely related one to
other in limited population than in broad one. So,
inbreeding is a phenomenon usually combines with
small populations. In different circumstances,
inbreeding can happen in a large population as a
form of nonrandom marriage when the frequency of
consanguineous marriage is more than that
anticipated by chance.
(1,2)
Consanguineous marriage is common in many
countries, first-cousin marriage and other types of
consanguineous marriage are common in a number
of general populations from different places of the
world.
(3,4)
Research on the relationship between consanguinity
and many parameters of oral and periodontal health
status is limited, both in quality and quantity.
(5,6)
Periodontal disease is genetically inherited and
appears to follow an autosomal recessive pattern,
even though parents were phenotypically healthy
but carried the recessive gene for the syndrome so
can appear in their children. An increased
prevalence of parental consanguinity around 20-
40% has been reported in Papillon-Lefevre
Syndrome patients.
(7) Dental plaque can be defined
as “the soft non mineralized bacterial deposit which
form and adhere firmly to the tooth, clinically can
J Bagh College Dentistry Vol. 32(4), December 2020 Gingival health condition
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be realized when it reaches certain thickness as a
whitish or a yellowish layer along gingival margin”.
(8) Plaque accumulation is greatest in the sheltered
interdental region hence gingival inflammation tend
to start in the interdental papilla and spreads from
there around the neck of the tooth lead to gingivitis.
(9)
In a study by Cal???r(10) about relation of inbreeding
and oral health between consanguineous and the
non-consanguineous groups, the gingival index was
higher in the siblings of the consanguineous
marriage than non-consanguineous group. In
addition, he found displayed the siblings of the
consanguineous marriage about eight times more
prevalence of aggressive periodontitis than the
siblings of the non-consanguineous marriage.
Moreover, the mode of transmission of disease was
recorded to fit greater to the autosomal recessive
inheritance design.
Kindler syndrome, represented as uncommon
subtype of inherited epidermolysis bullosa, is
characterized by oral symptoms like periodontitis,
gingivitis, and loss of teeth. However, a common
feature in populations with high rates of inbreeding
marriage was Kindler syndrome.
(11) Chronic
granulomatous disease (CGD) is inherited disease
of the innate immune system that is characterized
by impaired phagocyte microbicidal activity. It is
caused by genetic defects, inherited as an autosomal
recessive pattern, and characterized by severe
neutropenia. Patients suffer from recurrent
gingivitis and even severe periodontitis. To have a
family history of consanguineous parenthood may
be a predisposing factor for genetic agranulocytosis.
(12)
In 1995, dental examination of 120 pupils aged (6-
19) years old with high prevalence of inbreeding
69% were studied and compared to Tunisian
pediatric dentistry society (TPDS) that outbreeding
marriage. The results showed similar caries
experience, and that carious process is infectious
and not inherited.
(13)
This study was conducted in order to assess the
impact of inbreeding on oral hygiene and gingival
health condition in comparison to children of
outbreeding parents.
MATERIALS AND METHODS
Three hundred ninety eight (398) students, 6-12
years old, were collected from 4 primary schools,
they were divided into 199 children that their
parents of first level of inbreeding marriage (study
group), and other 199 children their parents
outbreeding marriage (control group), in Al-Qasem
city/ Babylon governorate, in Iraq. This
comparative study sample was calculated by the
formula: n=ZP2(1-P)/d2.
(14)
This study was done during the period from
December 2018 to February 2019. A pre-study
ethical approval was assigned, also the children s
parent consent form was taken before starting the
study. Family history of type of marriage was taken.
Information on the type of marriage of the parents
was obtained; whether the inbreeding marriage or
outbreeding marriages by answering the papers
presented to them as seen in descriptive statistics of
consanguineous marriage for both the Pakistan and
the Bangladesh.
(15)
Inclusion criteria; students with:
•No history of medication, (antimicrobial treatment
or anti- inflammatory) within last three months .
•No history of orthodontic treatment. Diagnostic
criteria included the gender, age and history of
family if inbreeding parents or not .
Oral examination was performed on chairs,
under good illumination by using dental mirror,
probe and dental tweezers following the main
approach of the oral health survey recommended by
(WHO, 1997). Oral cleanliness was assessed
according to the criteria of plaque index by Silness
and Loe (1964) (16) by examining the thickness of
plaque at the cervical margin of the tooth. Four
areas were examined, distal, facial or buccal,
mesial, and lingual. The 6 index teeth were
examined to represent entire dentition.
Gingival condition was assessed using Loe and
Silness (1963) (17), the GI assesses the severity of
gingivitis based on consistency, color and bleeding
on probing. It describes the severity of gingival
inflammation and its location. Mesial, lingual,
distal, and facial (or buccal) surface of teeth were
examined .
Data description, analysis and presentation were
performed using the statistical package for social
sciences (SPSS, version 21). Statistical analysis
included:
1-Descriptive analysis: mean and SE.
2-Inferential analysis: T test, Spearman correlation
(r), (p-value<0.05 considered significant).
RESULTS
Table 1 demonstrates the distribution of total
sample by age. A high percentage of students was
found at age group 6-10 years old among both
groups. The distribution of total sample according
to gender is seen in table 2. This table shows a
J Bagh College Dentistry Vol. 32(4), December 2020 Gingival health condition
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higher percentage of females was recorded among
both groups .
Table (1): Distribution of the total sample by age among
inbreeding and outbreeding.
Groups
Age (years)
6-10 +10-12
Inbreeding N 130 69
% 65.3 34.6
outbreeding N 140 59
% 70.3 29.6
Table (2): Distribution of total sample by gender among
inbreeding and outbreeding.
Groups
Gender
Male Female
Inbreeding N 98 101
% 49.25 50.75
outbreeding
N 96 103
% 48.24 51.76
Table 3 demonstrates the mean value and SE of
plaque index according to age, gender and breeding
rate among children. Regarding age group, the
result showed a higher mean value of plaque index
at age 6–10 years old than children at age 10.1–12
years among in breeding group, while for
outbreeding group, the result was opposite showed
the children at age 10.1–12 years had higher plaque
index mean than children at age 6–10 years. For the
total sample this table shows that the mean value of
dental plaque index was 2.05±0.05 in inbreeding
group and 1.16±0.06 among outbreeding group,
statically highly significant differences were existed
between two groups with P=0.00 .
Table (3): Mean and standard error of plaque among
inbreeding and outbreeding by age and gender .
Age
(Y)
Groups T
Inbreeding outbreeding
N
Mea
n
N Mean
<=
10
63 2.06 61 1.02 7.07
67 2.16 79 1.20 7.23
130 2.12 140 1.12 10.0
10
+
35 1.86 35 1.31 2.76
34 1.97 24 1.19 3.45
69 1.91 59 1.26 4.42
Total 199 2.05 199 1.16 10.6
p value 0.00 *significant p< 0.05
Mean value of gingival index tended to be higher in
inbreeding group than in outbreeding group,
differences were statistically highly significant
existed between both groups (p =0.00). In addition,
gingival index tended to be higher in age group (6–
10) compared with age group (10.1–12) among both
inbreeding and outbreeding groups (table 4).
Table (4): Mean and standard error of gingival index
among inbreeding and outbreeding by age and gender.
Age
(Y) G
Groups
T
p
value
Inbreeding outbreeding
N Mean N Mean
<=10
M 63 2.06 61 1.02 7.07* .00
F 67 2.16 79 1.20 7.23* .00
T 130 2.12 140 1.12 10.0* .00
10+
M 35 1.86 35 1.31 2.76* .00
F 34 1.97 24 1.19 3.45* .00
T 69 1.91 59 1.26 4.42* .00
Total 199 2.05 199 1.16
10.6*
.00
*significant p< 0.05
A highly significant strong positive correlation
coefficient was recorded between plaque and
gingival index among inbreeding group, while
highly significant weak positive was found in
outbreeding group (table 5).
Results showed mild gingivitis was the most
common type of gingival severity among children,
followed by a moderate and severe type (table 6) .
Table (5): Correlation coefficient between plaque index
and gingival index among inbreeding and outbreeding .
Groups Gingival
index
Inbreeding Plaque
index
r .542*
p .000
outbreeding Plaque
index
r .451*
p .000
J Bagh College Dentistry Vol. 32(4), December 2020 Gingival health condition
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Table (6): Distribution of children according to gingival
health condition among inbreeding and outbreeding .
DISCUSSION
To our knowledge, there was no previous Iraqi
study to compare the findings of this study with.
Therefore, the data of current study can be
compared with other studies in other countries in the
world regarding impact of inbreeding on oral health
of their children.
Dental plaque thickness and gingival health status
were assessed in the present study among children
of inbreeding parents and children of outbreeding
parents using plaque index of Silness and Loe(16)
and gingival index of Loe and Silness.
(17) These
indices are widely used in the controlled and
epidemiological studies because of their flexibility
which provides the possibility of measuring the
severity of the disease and to get more precise result
to overcome any inaccuracy due to missing teeth.
Another advantage is the ease of application.
(18)
In this study, the plaque index showed highly
significant differences between children of
inbreeding marriage and children of outbreeding
marriage. This may be related to genetic factors,
(19)
lifestyle and work, and environment.
(20) In addition,
the evidence of periodontitis is dependent on the
genetic syndromes, inherited diseases, familial
studies etc.
(21) Susceptibility of periodontal diseases
is inherited as an X-linked dominant trait. Evidence
of plaque index has been confirmed by studies of
fraternal twins and identical twins which reared
together and identical twins reared apart.
(22)
Results of current study revealed that gingival index
showed highly significant differences between
children of inbreeding marriage and children of
outbreeding marriage, which could be due to that
periodontal disease is genetically inherited and
appears to follow an autosomal recessive pattern,
even though parents were phenotypically healthy
but carried the recessive gene for the syndrome, so
can appear in their children.
(7)
As mean of plaque index, mean of gingival index
increase, this due to positive highly significant
correlation between plaque and gingival indices in
this study, and this in agreement with study done by
Layth and Al-Rawi who reported positive highly
significant relation between gingival index and
plaque index.
(23) This may be attributed to that when
dental plaque increases, bacteria increase in number
and increase in bacterial toxins which lead to
increase in gingival disease (24)
CONCLUSION
The gingival disease was significantly higher in
inbreeding group than in outbreeding group, with a
worst oral hygiene .
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الخالصة
الخلفية: زواج األقارب هو عالقة بين األفراد ذوي الصلة بيولوجيا. العوامل الوراثية لها دور في التفاعالت البيئة الجينية تأخذ مركز الصدارة.
يعتمد الدليل على أمراض الفم )التهاب اللثة والتهاب اللثة والعظم( على دراسة األمراض الوراثية والمتالزمات الوراثية والدراسات العائلية
وما إلى ذلك
اهداف الدراسة: أجريت هذه الدراسة لتقييم حدوث وانتشار نظافة الفم )الحالة الصحية للثة اللويحة السنية( عند األطفال من أولياءمتزوجين
أقارب ، مقارنة بأطفال من اآلباء المتزوجين خارج اقارب في المدارس االبتدائية في مدينة القاسم / محافظه بابل ، في العراق
طفًال المواد وطرق العمل: ثالثمائة وثمان وتسعون )398 )طالًبا ، تتراوح أعمارهم بين 6 -12 عا ًما ، من 4 مدارس ابتدائية ، شارك 199
والداهم في زواج األقارب ، و 199 طفًال آخر من آبائهم لم يتزوجوا زوا ًج اقارب (المجموعة الضابطة(
ا ل قياس)1964 )Loe and Silness . تم تقييم صحه اللثة وفقا لقياس 1963(Silness and Loe )
تم تقييم حالة الصفيحه الجرثومية وفقً
النتائج: قيمة متوسطة عالية لمؤشر الصفيحة الجرثومية ومؤشر اللثة لدى أطفال الوالدين زواج األقارب مقارنه ب األطفال من اآلباء غير
زواج األقارب مع اختالف كبير إحصائيا. تم العثور على التهاب اللثة الخفيف أكثر األنواع انتشا ًرا بين المجموعتين ، يليه نوع معتدل وشديد.
يوجد ارتباط إيجابي كبير للغاية بين مؤشرات اللثة والبالك
االستنتاج: تم تسجيل ارتفاع في معدل انتشار الصفيحة الجرثومية ومؤشر اللثة ، عند أطفال الوالدين زواج األقارب مقارنه ب األطفال من
اآلباء زواج خارج األقارب .