A review on the oral health impacts of acculturation.

Abstract

The impact of acculturation on systemic health has been extensively investigated and is regarded as an important explanatory factor for health disparity. However, information is limited and fragmented on the oral health implications of acculturation. This study aimed to review the current evidence on the oral health impact of acculturation. Papers were retrieved from five electronic databases. Twenty-seven studies were included in this review. Their scientific quality was rated and key findings were summarized. Seventeen studies investigated the impacts of acculturation on the utilization of dental services; among them, 16 reported positive associations between at least one acculturation indicator and use of dental services. All 15 studies relating acculturation to oral diseases (dental caries and periodontal disease) suggested better oral health among acculturated individuals. Evidence is lacking to support that better oral health of acculturated immigrants is attributable to their improved dental attendance. Further researches involving other oral health behaviors and diseases and incorporating refined acculturation scales are needed. Prospective studies will facilitate the understanding on the trajectory of immigrants' oral health along the acculturation continuum.

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ORIGINAL PAPER
A Review on the Oral Health Impacts of Acculturation
Xiaol-Li Gao•Colman McGrath
Published online: 17 November 2010
? The Author(s) 2010. This article is published with open access at Springerlink.com
Abstract
has been extensively investigated and is regarded as an
important explanatory factor for health disparity. However,
information is limited and fragmented on the oral health
implicationsofacculturation.Thisstudyaimedtoreviewthe
current evidence on the oral health impact of acculturation.
Papers were retrieved from five electronic databases.
Twenty-seven studies were included in this review. Their
scientific quality was rated and key findings were summa-
rized. Seventeen studies investigated the impacts of accul-
turationontheutilizationofdentalservices;amongthem,16
reported positive associations between at least one accul-
turation indicator and use of dental services. All 15 studies
relating acculturation to oral diseases (dental caries and
periodontal disease) suggested better oral health among
acculturated individuals. Evidence is lacking to support that
better oral health of acculturated immigrants is attributable
to their improved dental attendance. Further researches
involving other oral health behaviors and diseases and
incorporating refined acculturation scales are needed. Pro-
spective studies will facilitate the understanding on the tra-
jectory of immigrants’ oral health along the acculturation
continuum.
The impact of acculturation on systemic health
Keywords
Oral health ? Dental care
Acculturation ? Immigrants ? Ethnicity ?
Introduction
The last century has witnessed marked acceleration of
international immigration, mostly from less developed
countries to more developed countries. From year 1970 to
2002, the number of people living outside their countries of
birth grew from 80 to 185 million worldwide, leading to an
increasing ethnic and racial diversification of populations in
many countries [1]. Upon arriving in a new society, immi-
grants are exposed to a new culture and are subject to a
process of acculturation. Acculturation, as a term in
anthropology, comprehends those phenomena when groups
of individuals having different cultures come into continu-
ous first hand contact, with subsequent changes in the ori-
ginal culture patterns of either or both groups [2]. Pertaining
to ethnic minorities, there are four distinct possible out-
comes of their acculturation, namely assimilation (move-
ment toward the dominant culture), rejection (reaffirmation
of the traditional culture), integration (synthesis of the two
cultures), or marginalization (alienation from both cultures)
[3]. The speed and extent of acculturation vary among
individuals and have practical implications on one’s health.
The impacts of acculturation on health began gaining
prominence since 1960s, pioneered by the research work
linking acculturation and cardiovascular diseases [4]. The
interestinacculturationasanexplanatoryvariableforhealth
hasproliferatedandsteadilyincreasedoverthepast40 years
with almost 2,000 articles published [5]. Acculturation,
examined with regard to a wide variety of health behaviors,
appeared to be beneficial to some health behaviors, and
detrimental to others [6]. Evidence collected in the United
Stateshasshownthatacculturationexertsapositiveeffecton
use of health services [7, 8], negative effects on alcohol use
[9, 10] and diet [11, 12], and both positive effect [11] and
negative effect [13] on physical exercise in different
X.-L. Gao (&) ? C. McGrath
Dental Public Health, Faculty of Dentistry, The University of
Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road,
Sai Ying Pun, Hong Kong
e-mail: gaoxl@hkucc.hku.hk
123
J Immigrant Minority Health (2011) 13:202–213
DOI 10.1007/s10903-010-9414-9

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populations. The impact of acculturation on smoking was
often modified by gender, with a lower likelihood of smok-
ing in acculturated men and higher likelihood of smoking in
acculturated women [14, 15]. Overall, acculturation to
unhealthy lifestyles is an important explanation of the ele-
vated risk of many chronic diseases, such as obesity,
hypertension, coronary heart disease, diabetes, and cancer,
among ethnic minorities in the United States [16].
Researches on the impact of acculturation on systemic
health have contributed significantly to our understanding
of many health issues, especially the deterioration in
immigrants’ health after settlement and with each succes-
sive generation [17, 18]. Such a health decline has led to
the shift of the ‘‘healthy immigrant’’ phenomenon (i.e. new
immigrants are healthier than natives in the host country) to
the health disadvantage of immigrants [18]. For maintain-
ing health of the immigrant populations and reducing
health disparity, considering the impacts of acculturation is
essential, as stressed by numerous professional bodies [16].
In contrast to the long history of acculturation research
in the medical arena, the impacts of acculturation on oral
health receive attention only in recent years. From 1982 to
1984, the United State conducted the Hispanic Health and
Nutrition Examination Survey (HHANES), providing a
platform for understanding the relationship between
acculturation and various health behaviors and diseases [7,
19, 20]. Utilizing the dental data of this survey, Ismail &
Szpunar analyzed how Mexican Americans with low and
high acculturation differed in their use of dental care
(dental insurance and dental visit) and oral health (caries
and periodontal status) [21]. This became the first study
explicitly articulating the term ‘acculturation’ in the dental
context. In the past two decades, although more reports
have emerged, the information appeared to be incomplete
and fragmented on the relationship between acculturation
and oral health. No literature review was published on this
issue. As the Surgeon General calls for a better under-
standing of the cultural factors influencing the oral health
of immigrants and ethnic minorities [22], a review on the
oral health impact of acculturation would inform future
research and policy making. Such information would be
useful for effective delivery of interventions and optimal
allocation of resources for reducing oral health disparity. In
view of the need of synthesizing the research evidence on
the oral health impacts of acculturation, we conducted this
systematic review, aiming to evaluate the quality of pub-
lished literatures and summarize the existing findings.
Methods
This systematic review was performed by both authors who
developed the protocol together and conducted the literature
search and review following the PRISMA (formerly
QUOROM) guideline. When the reviewers disagreed, dis-
cussions took place until a consensus was reached.
Acculturation is a multidimensional construct [23]. Tra-
ditionally, various proxy measures were used for assessing
acculturation [24, 25]. The indicators, used individually, in
combination, or integrated as psychometric scales, include
language competency or preference, generational status,
nativity, age at immigration, length of residence in the host
country, ethnic identification, and social affiliation [15, 26].
Publications on the oral health impact of acculturation
were searched in January–February 2010 through five
electronic databases (PubMed, Medline, Web of Science,
Cochrane library, and PsycINFO). Combinations of medi-
cal subject headings (MeSH) and key words were used as
follows: (acculturation OR transculturation OR cultural
adaption/assimilation/acclimation/integration
identification OR social affiliation OR nativity OR country
of birth OR language preference/use/competency/profi-
ciency OR time/years after/since immigration/immigrating
OR time/years/length of residency/residence OR age at
immigration OR age of/on arrival) AND (oral health OR
oral disease OR dental OR dentistry) AND (immigrant/
immigrants OR ethnic minority/ethnic groups). Papers
were selected if the combination of words appeared any-
where in the paper, were published over the period of
1980–2009, and were written in English.
Altogether, 426 papers were retrieved in the primary
searchoffivedatabases(Fig. 1).Thesepaperswerescreened
by title and abstracts. Three hundred and seventy-seven
papers were notrelated to the impact of acculturation on oral
health. Forty-nine reports were identified as potentially rel-
evant to the topic and the full-text papers were obtained.
Additional articles wereidentifiedfromthebibliographiesof
these 49 papers and reference linked. This further search
yielded another 8 more papers. The full articles of these 57
reports were carefully assessed for eligibility. Thirty papers
wereexcluded,while27paperswereincludedforthisreview.
During the screening and selection of papers, the fol-
lowing inclusion criteria were followed: (a) One or more
immigrant or ethnic minority group(s) were included in the
study; (b) The research analyzed the association between
acculturation and at least one oral health behavior or oral
disease/condition; (c) Acculturation was measured by at
least one clearly defined indicator; (d) Oral health out-
come(s) were specified and the method of their measure-
ment was described. A study was excluded if it merely
observed oral health of immigrants or ethnic minorities,
without analyzing the relationship between their oral health
and levels of acculturation. Both cross-sectional and lon-
gitudinal studies and both qualitative and quantitative
studies were eligible to be included. Commentaries, case
reports, and editorials were excluded.
ORethnic
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The methodological quality of the selected studies was
rated according to a scoring tool developed on the basis of a
previous work [27]. There are 18 elements in the original
scoringtool.Sinceallstudiesonacculturationandoralhealth
are observational studies, 5 scoring elements pertaining to
interventional studies were excluded. A total of 13 study
elements were critically appraised to determine a study
quality score (Appendix). Elements reviewed included
sample selection, description of the independent variable
(acculturation), description of the outcome measure (oral
health behavior or disease), reliability and validity of the
measurements, blinding, data analyses, and reporting. The
possibletotalscoresrangedfrom13to36.Asrecommended,
anystudywithaqualityscorebelow67%(i.e.24)ofthetotal
possible score was to be eliminated from the review [27].
Results
Quality and Type of Studies
The methodologic quality scores of the 27 selected studies
ranged from 26 to 34, all above 67% (i.e. 24) of the total
possible score (Table 1). Therefore, none of these 27
papers were eliminated from the review.
Ten studies were conducted among Hispanics in the
United States (Table 2),with 6studies inotherimmigrant or
ethnic minority groups in the United States (Table 3). The
rest 11 studies were conducted in other countries (Table 4).
The age of subjects ranged widely, from 2–5 to over
70 years. All 27 reports were quantitative cross-sectional
studies. Random sampling was adopted in 12 studies,
whereas convenience samples were used in other 15 studies.
A variety of acculturation measures used in the medical
field were adopted in the dental studies, including single
indicators (language, country of birth, age at immigration,
and length of residence) used in 14 studies, combination of
these indicators in 9 studies and acculturation scales used
in 4 studies. The majority (22 out of 27) of studies
employed multivariate analysis, in which the impact of
acculturation on oral health was evaluated after controlling
for demographic and socioeconomic factors. In one study,
a data mining tool (KnowledgeSEEKER) was adopted for
the analysis.
Acculturation and Utilization of Dental Services
Theimpactsofacculturationonutilizationofdentalservices
havebeeninvestigatedin17studies.Amongthem,16studies
supported a positive association between at least one accul-
turation indicator and utilization of dental services.
Among Hispanics in the United States (Table 2), data of
the HHANES revealed better dental insurance coverage and
more dental visits reported by adolescents and adults with
higher acculturation, as measured by multidimensional
scales [7, 21]. Such a trend was found in all three Hispanic
groups (Mexican–American, Cuban-American and Puerto
Ricans) [28]. English-speaking Hispanic adults in Florida
weremorelikelytohaveadentalhome,ascomparedwiththe
non-English-speaking group [29]. In a sample of Hispanic
adults who were suffering from orofacial pain, those who
were Spanish-speaking or more close to Hispanic culture
were less likely to seek treatment and/or have a regular
dentist [30]. However, in another study, while the bivariate
analysis suggested a link between language preference and
dental visit, such association was not significant after con-
trolling for potential confounders in multivariate analysis
[31]. In Hispanic farmworker families, dental cares were
more received by children born in the United States [32].
However, since this study only adopted bivariate analysis,
without controlling for socio-economic factors, the strength
of evidence is compromised. As to Hispanic preschoolers,
dental visits were more common among those who were
local born or English-speaking [33].
Studies among other ethnic minorities in the United
States (Table 3) also demonstrated positive impacts of
acculturation on utilization of dental care. The use of dental
services increased with length of residence in the United
States among Chinese elderly immigrants [34] and adults
of Hispanic or Asian origins [35], but not among the
Papers screened (n = 426)
Titles and abstracts reviewed
Papers identified through
search of bibliographies
(n = 8)
Full-text articles assessed for eligibility
(n = 57)
Papers identified (n = 426)
PubMed (n = 229)
Web of Science (n = 23)
Medline (n = 31)
Cochrane Library (n = 121)
PsycINFO (n = 22)
(Excluding duplicate papers found in another
database searched)
Databases searched
PubMed (1980-2009)
Web of Science (1980-2009)
Medline (1980-2009)
Cochrane Library (1980-2009)
PsycINFO (1980-2009)
(Limited to literature in English)
Full-text paper retrieved (n = 49)
PubMed (n = 38)
Web of Science (n = 8)
Medline (n = 3)
Cochrane Library (n = 0)
PsycINFO (n = 0)
Papers included for review (n=27)
Fig. 1 Flowchart of literature search and selection
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Table 1 Methodologic quality scores of the 27 papers
Element
[7]
Solis
et al.
(1990)
[21]
Ismail
and Szpunar
(1990)
[28]
Stewart
et al.
(2002)
[29]
Graham
et al.
(2005)
[30]
Riley
et al.
(2008)
[31]
Jaramillo
et al.
(2009)
[32]
Quandt
et al.
(2007)
[33]
Nurko
et al.
(1998)
[34]
Wu
et al.
(2005)
[35]
Akresh
(2009)
[36]
Yu
et al.
(2001)
[37]
Lai
and Hui
(2007)
[38]
Locker
et al.
(1998)
[39]
Mikami
et al.
(1999)
1
Purpose of the study (1–3)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2
Sample selection (1–3)
2
3
3
2
3
3
3
2
2
3
2
2
3
3
3
Description of the sample (1–3)
2
3
3
3
3
2
3
2
2
2
2
3
2
2
4
Independent variables (1–3)
3
3
2
2
2
3
3
2
3
2
3
3
2
3
5
Dependent variables (1–3)
2
3
3
3
3
3
3
2
2
3
3
2
3
2
6
Reliability of measurement tool(s) (1–3)
2
2
2
2
2
2
2
2
2
2
3
2
2
2
7
Validity of measurement tool(s) (1–3)
2
2
2
2
2
3
3
2
2
2
3
3
2
2
8
Blinding (1–2)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
9
Conclusion (1–3)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
10
Procedures (1–2)
1
2
2
2
2
2
2
2
2
2
2
2
2
2
11
Descriptive statistics (1–3)
2
3
3
3
2
3
3
2
2
2
3
3
2
2
12
Inferential statistics (1–3)
3
3
3
2
2
3
3
2
2
3
3
3
3
2
13
Clinical and statistical significance (1–2)
2
2
2
1
2
2
2
2
2
2
2
2
2
2
Total score
28
33
32
29
30
33
34
27
28
30
33
32
30
29
Element
[40]
Ugur and
Gaengle
(2002)
[41]
Selikowitzand
Holst
(1986)
[42]
Marino
et al.
(2001)
[43]
Spolsky
et al.
(2000)
[44]
Watson
et al.
(1999)
[45]
Cruz
et al.
(2009)
[46]
Cruz
et al.
(2004)
[47]
Werneck
et al.
(2008)
[48]
Bedi
(1989)
[49]
Jacobsson
et al.
(2005)
[50]
Bissar
et al.
(2007)
[51]
Selikowitz
(1987)
[52]
Swoboda
et al.
(2006)
1
Purpose of the study (1–3)
3
3
3
3
3
3
3
3
2
3
3
3
3
2
Sample selection (1–3)
2
2
2
3
2
3
2
2
2
3
3
2
2
3
Description of the sample (1–3)
2
2
2
3
3
3
3
2
2
3
2
2
2
4
Independent variables (1–3)
2
2
3
3
2
3
3
3
3
3
3
2
3
5
Dependent variables (1–3)
2
3
3
2
3
3
3
3
2
3
3
2
3
6
Reliability of measurement tool(s) (1–3)
2
2
2
2
2
2
2
2
2
2
2
2
2
7
Validity of measurement tool(s) (1–3)
2
3
3
3
3
3
2
2
3
3
3
2
3
8
Blinding (1–2)
1
1
2
2
2
1
2
1
1
1
1
1
1
9
Conclusion (1–3)
3
3
3
3
3
2
3
3
2
3
3
3
3
10
Procedures (1–2)
2
2
2
2
2
2
2
2
1
2
2
2
2
11
Descriptive statistics (1–3)
2
2
3
3
3
3
3
3
2
3
2
3
3
12
Inferential statistics (1–3)
2
2
3
3
3
2
3
3
2
3
2
2
3
13
Clinical and statistical significance (1–2)
2
2
2
2
2
2
2
2
2
2
2
2
2
Total score
27
29
33
34
33
32
33
31
26
34
31
28
32
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Table 2 Studies among Hispanics in the United States
ImmigrantsAge (years)
N
Type of
sample
Acculturation
measures
Association with oral health outcomea
Reference
Host
country
Ethnicity Use of dental care Oral diseasesOthers
United
States
Hispanics 17–74 5,411Random Mexican–American:
Language
Ethnic identification
Cuban-Americans
and Puerto Ricans:
Language
Use of English language
(?) Recency of dental visit
Ethnic identification
(0) Recency of dental visit
[7]
12–74 2,289Random Acculturation scale:
Language
Ethnic identification
Nativity
Acculturation
(?) Dental insurance
(?) Dental visits
Acculturation
(0) decayed, missing
teeth
(-) gingivitis and
periodontal pockets
[21]
18–74 6,324Random Acculturation scale:
Mexican–
American:
Language
Ethnic
identification
Nativity
Cuban-Americans/
Puerto Ricans:
Language
Acculturation
(?) dental care in the past
5 years in all Hispanic
groups (Mexican–
American, Cuban-
American and Puerto
Ricans)
(?) dental care in the past
2 years in Cuban-American
and Puerto Ricans
[28]
318 810Random Language use Use of English language:
(?) Having a dental home
[29]
318911 Random Language
Nativity
Cultural
identification
Use of English language:
(?) healthcare visit for
orofacial pain
(?) having a regular dentist
Hispanic culture
identification:
(-) having a regular dentist
Use of English language:
(-) orofacial pain,
difficulty eating,
sleeping, depression
Nativity
(-) orofacial pain, sleep
difficulty
[30]
31821,958 RandomLanguage preference Use of English language:
(0) Use of dental services
[31]
318240 ConvenienceLanguage
proficiency
Language proficiency
(?) Oral Health Status
Index
[43]
213 years
(children);
Mean: 27.7
years
(mothers)
79 children;
108 mothers;
102 fathers
Convenience Place of birth,
language,
length of residence
Bivariate analysis:
Local-born children
(?) dental visit in the last
year
Mothers’ language
preference & length
of residence
(0) use of dental services
of any family member
Bivariate analysis:
Local-born children
(?) oral health rated
by mother
Mothers’ language
preference & length
of residence
(0) self-rated oral health
of any family member
[32]
3–6130ConvenienceCountry of birth,
language use
Born in United States
(?) dental visit
Use of English Language
(?) dental visit
Born in United States
(-) dental caries
Use of English language
(-) dental caries
[33]
2–5142Convenience Mother’s language
use
Mother’s length
of residency
Mother’s use of English
language
(0) Caries in children
Mother’s Length of
residence
(-) Caries in children
[44]
Unless indicated as ‘‘bivariate analysis’’, all results were obtained through multivariate analysis controlling for socioeconomic factors
a(?) positive correlation; (-) negative correlation; (0) no correlation
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