Breastfeeding , bottle feeding and risk of malocclusion in mixed and permanent dentitions : a systematic review

The aim of the present study was to search for scientific evidence concerning the association between breastfeeding and bottle feeding and risk of malocclusion in mixed and permanent dentitions. An electronic search was performed in eight databases up to February 2015. Additionally, a gray literature search and hand searches of the reference lists of the selected studies were also carried out. There were no restrictions on language or on year of publication. The methodology of the included articles was evaluated using the Newcastle Ottawa scale. Out of the 817 identified citations, six studies fulfilled the eligibility criteria and were included in the systematic review. One study showed that children with mixed and permanent dentitions breastfed for more than 6 months presented greater mean protrusion of mandibular incisors and inclination of maxillary incisors compared with those breastfed for less than 6 months or those who were bottle-fed (p < 0.05). One study revealed that breastfeeding and bruxism were associated with Class II [OR = 3.14 (1.28 7.66)] and Class III [OR = 2.78 (1.21 6.36)] malocclusion in children with permanent dentition, while another study showed that an increase in breastfeeding duration was associated with a lower risk of malocclusion in children with both mixed and permanent dentitions (p < 0.001). Three studies did not report any significant association. Risk of bias was high in most selected articles. These findings do not support an association between breastfeeding and bottle feeding and the occurrence of malocclusion in mixed and permanent dentitions.


Introduction
Exclusive breastfeeding for at least six months has been highly recommended for preventing gastrointestinal infections and growth deficits in the first months of life. 1,2However, the findings of some studies have confirmed the association between feeding habits and the occurrence of malocclusion in the primary dentition. 3,4Indeed, both breastfeeding and bottle feeding have been associated with a greater chance of cross-bite development when preschool children are evaluated. 5,6Moreover, a recent systematic review has shown that the scientific evidence that breastfeeding Declaration of Interests: The authors certify that they have no commercial or associative interest that represents a conflict of interest in connection with the manuscript.

Eligibility criteria
The inclusion criteria for this systematic review were epidemiological studies (cross-sectional, case-control, cohort studies and clinical trials) addressing breastfeeding, bottle feeding and mixed feeding (bottle and breastfeeding) and risk of malocclusion in mixed or/and permanent dentitions.Studies on primary dentition conducted with children younger than 7 years; epidemiological studies evaluating outcomes other than malocclusion (dental caries, trauma, temporomandibular disorders); and studies reporting risk factors unrelated to feeding or infancy and the treatment, diagnosis or prevention of malocclusion were excluded.So were literature reviews; letters to the editor; case reports; case series; laboratory studies; studies on food intake; and studies addressing parents' /dentists' knowledge about oral health.

Information sources
A systematic computerized search was performed up to February 2015 in eight electronic databases: Pubmed (http://www.pubmed.gov),Medline via Ovid (http://gateway.ovid.com),Web of Science (http://www.isiknowledge.com), the Cochrane Library (http://www.cochrane.org/index.htm),Clinical Trials (http://controlled-trial.com), UK National Institute for Health and Care Excellence (http://www.nice.org.uk),US National Institutes of Health (http://www.clinicaltrials.gov)and Lilacs and the Brazilian Library of Dentistry (BBO) through the Virtual Health Library (Bireme, Latin America) (www.bireme.br).There were no restrictions on language or on year of publication.The reference lists of the selected articles were also hand-searched for applicable studies that might have been missed in the computerized searches.Additionally, a partial gray literature search was conducted with OpenGrey and Google Scholar limiting the search to the first 100 most relevant hits.The Reference Manager Software ® (Reference Manager, Thomson Reuters, version 12.0.3)was used to organize the list of studies.Duplicate results were removed upon identification.

Search strategy
The following strategy was used in Medline, Pubmed, Web of Science and Cochrane databases: ((malocclusion* OR malocclusion[Mesh] OR dental occlusion[Mesh] OR Maxillofacial Development [Mesh]) AND (bottlefeed* OR bottle feed* OR bottle-feed* OR bottlefed OR bottle fed OR bottle-fed OR "bottle feeding"[Mesh] OR "breast feeding"[Mesh] OR breastfeed* OR breast feed* OR breast-feed* OR breastfed OR breast fed OR breast-fed OR weaning OR "Sucking behavior"[Mesh] OR "Feeding Behavior"[Mesh] OR "risk factors"[Mesh])) NOT ("animals"[Mesh] NOT "humans" [Mesh]).Medline and Pubmed were limited by "humans."Bireme, Clinical Trials, UK National Institute for Health and Care Excellence and US National Institutes of

Study selection
The review process was carried out in two phases.In phase 1, two researchers (CCM and LGA) independently reviewed the list of titles and abstracts for inclusion.Once potentially adequate abstracts were selected, full articles were retrieved for a second selection process.If the abstract was judged to contain insufficient information for a decision of inclusion or exclusion, the full text was obtained and reviewed before a final decision was made.In phase 2, the eligibility criteria were applied to the full articles by the same two researchers (CCM and LGA).In both phases, any discrepancies in the inclusion of the articles between researchers were addressed through discussion until consensus was reached.

Data collection process
Two researchers (CCM and LGA) independently extracted data from the articles that met the inclusion criteria and compared their findings for accuracy.They discussed and re-examined any discrepancies until an agreement was reached.When additional or missing information was required, the authors of the articles were contacted.

Data items
Data on the following items were collected: country, study design, initial and final sample, data collection setting, child's age at the time of the dental examination, how data on feeding habits were collected, how malocclusion was evaluated, statistical analyses, adjustment for confounders, overall result and direction of the effect (statistically significant or not).
The main outcome was malocclusion, which was considered the endpoint of disease (present/absent).Feeding habits were extracted as categorical or numerical variables based on the duration of breastfeeding and bottle feeding, as reported by the authors.Confounders and interactions were extracted and described when evaluated in the multivariate analyses.

Risk of bias in individual studies
The methodological quality was assessed by two researchers (CCM and LGA) using the Newcastle-Ottawa scale for case-control studies and the modified Newcastle-Ottawa scale for cross-sectional ones. 13For the case-control studies, a quality score was calculated based on three major categories: group selection (four items), comparability between groups (one item), and outcome and exposure assessment (three items).A maximum of one point was allocated to each item in the group selection and outcome and exposure assessment categories and a maximum of two points was awarded for comparability.Therefore, the maximum score was nine points and represented the highest methodological quality.For the cross-sectional studies, the score was calculated based on the same three categories.However, those categories had a different number of items: group selection (two items), comparability (one item), and outcome and exposure assessment (two items).Thus, the maximum score was six points and also indicated the highest methodological quality.Any disagreement between researchers was resolved by means of discussion.

Summary measures
Any outcome measure that evaluated the association between breastfeeding and bottle feeding and malocclusion in mixed and permanent dentitions was considered and included odds ratio (OR) and confidence intervals (CI).For the studies in which CI were not provided, p-values were presented.

Synthesis of the results and risk of bias across studies
The heterogeneity among the included studies was evaluated through the examination of various characteristics of the finally selected reports, such as dissimilarity between study participants and outcomes. 14If the data were homogeneous and appropriate for pooling, then a meta-analysis would be considered.If the data were heterogeneous and inappropriate for a meta-analysis, a qualitative synthesis would be performed instead.

Additional analysis
P ubl ic at ion bi a s wa s con side r e d a s a n additional analysis.

Study selection
The computerized search yielded 958 references across the eight electronic databases.After removal of duplicate references, 817 titles and abstracts were read and analyzed in phase 1, of which 615 were excluded.Therefore, a total of 202 studies were selected for the analysis of the full texts in phase 2. After reading of the full texts, only six articles 15,16,17,18,19,20 met the eligibility criteria and were included in the present systematic review.A list of the articles excluded in phase 2 along with the reasons for their exclusion is displayed in Appendix 1 and is available upon request.One report was identified through the hand-search of the reference lists.No article was identified through the gray literature search.A flowchart depicting the selection process of the articles at each stage of the systematic review is provided in Figure.

Study characteristics
Among the six articles included in the present systematic review, one was a case-control 16 study and five were cross-sectional studies. 15,17,18,19,20able 1 provides a summary of their characteristics, including methodological data and relevant findings.
A l l a r t icle s were publ i shed i n Eng l i sh.One study was a population-based study with data collected from the US National Health Inter view Sur vey (NHIS), represent i ng the American population aged 9 to 17 years. 15One study provided sample size calculation and was representative of a Brazilian city. 20The other four papers involved convenience samples. 16,17,18,19One included participants from a private office, 16 one included individuals from a university setting, 19 one included adolescents from schools of an Italian city, 18 and one included individuals from three public schools of a Brazilian city. 17     A case referred to a child for whom the parent responded "yes" to one or both questions.If the answers to both questions were "no", the child was considered to be a control.Two studies revealed the existence of malocclusion through parents' reports, 15,16 in which parents were asked if a dentist had ever said that their children needed braces or if the parents had perceived that their children needed braces or orthodontic treatment.In three studies, the diagnosis of malocclusion was established in a clinical evaluation performed by calibrated dentists. 17,18,20In another study, malocclusion was evaluated based on cephalometric data. 19In four studies, 15,16,18,20 feeding habits were determined from a questionnaire administered to parents and two studies 17,19 failed to report how data on feeding habits were collected.
In general, the studies lacked details, in the Methods section, of approval by the institutional ethics committee. 15,16,17,18,19Nonetheless, all papers had sufficient information for data collection for the systematic review. 15,16,17,18,19,20

Risk of bias in individual studies
The methodological quality evaluation using the Newcastle-Ottawa scale is shown in Tables 2 and 3.The case-control study 16 scored three points (Table 2).The scores for the cross-sectional studies 15,17,18,19,20 ranged from one to four points (Table 3).

Results of individual studies
One study showed no significant association bet ween the duration of bottle feeding and the need for orthodontic treatment [OR = 1.73 (CI = 0.82 -2.10), p = 0.058)]. 16Another study reported that a longer breastfeeding period was associated with a decreased risk of malocclusion (p < 0.001) 15 Only one study adjusted the statistical analysis for confounders and found an interaction between the history of breastfeeding and bruxism, with a synergistic effect on significantly increasing the risk of Angle Class II [OR = 3.14 (CI = 1.28 -7.66), p < 0.05)] and Class III malocclusion [OR = 2.78 (CI = 1.21 -6.36), p < 0.05)]. 20Based on cephalometric data, children breastfed for more than 6 months had greater mean protrusion of mandibular incisors (p = 0.023) and inclination of maxillary incisors (p = 0.047) in comparison with children who were breastfed for 6 months or less.Children breastfed for more than 6 months also presented a greater mean protrusion of mandibular incisors and inclination of maxillary incisors when compared with bottle-fed children (p < 0.05). 19Two studies did not report any significant association (p > 0.05). 17,18nthesis of the results and risk of bias across studies A meta-analysis was not possible.The six studies included in this systematic review described different types of malocclusion and used different cut-off times to evaluate feeding practices.Therefore, the pooled data from those studies were deemed not suitable because of the differences in the study designs and in the collected information.

Additional analysis
Publication bias was not assessed as there were not enough studies to be entered into a funnel plot.

Discussion
This systematic review attempted to evaluate the association bet ween feeding habits and malocclusion in mixed and permanent dentitions.Oral and craniofacial development may be a health issue on which feeding practices may have a measurable and relevant impact. 21Although the first study addressing this topic in schoolchildren and adolescents dates back to more than 25 years, the question remains unanswered and conclusions are yet to be fully confirmed.
One study showed an association between breastfeeding duration and an increased risk of malocclusion, 15 while another one did not reveal any statistical significance between feeding habits and malocclusion. 16However, those studies lacked a clinical evaluation of malocclusion, which was determined through parents' reports.The clinical data collected from parents' reports may be subjective and prone to information bias and, therefore, unreliable. 22ne study revealed an interaction between breastfeeding and bruxism, which increased the risk of Class II and Class III malocclusion.This study conducted a multinomial regression analysis, considering gender, age, household income, education level, bottle use, bruxism, digit sucking habit and mouth breathing pattern as confounding variables. 20   Representativeness and selection of individuals with feeding habits 2 Control for confounders 3 Diagnosis of malocclusion 4 Response rate 5   Labbok and Hendershot  Adjustment for confounders is very important in epidemiological studies, since an outcome, such as malocclusion, may be associated with multiple risk factors, including gender, genetics, income, feeding practice, non-nutritive sucking habit and other harmful oral habits. 23Failure to evaluate demographic and clinical factors as potential confounders can bias study results and lead to erroneous conclusions. 24Also, the methodology of this study was strengthened by the adoption of a representative sample of Brazilian adolescents, allowing the authors to perform a meaningful statistical analysis and to generalize the results for that population. 25hen malocclusion was determined based on cephalometric data, greater mean protrusion of the mandibular incisors and inclination of the maxillary incisors seem to occur among children breastfed for more than 6 months in comparison with those breastfed for less than 6 months and those who were bottle-fed. 19Notwithstanding, this study presented the lowest methodology quality and shortcomings with respect to response rate, sample representativeness, control for confounding variables, and selection of individuals with feeding habits.
Some limitations of the present systematic review should be acknowledged.The first one regards the lack of homogeneous data for a meta-analysis.The included studies had different methodologies and different measures for malocclusion, thus hindering the pooling of data. 14The second flaw noted during data compilation was the limited number of articles that met our eligibility criteria.Additionally, most evidence found was cross-sectional and no high quality study addressing the association between feeding habits and the occurrence of malocclusion in mixed and permanent dentitions was identified.
Finally, the authors of the included articles were unable to group, separately, children who had exclusive breastfeeding or bottle feeding and mixed feeding, making the comparison between those groups impossible.Therefore, breastfeeding and bottle feeding could not be confirmed as risk factors for malocclusion in children and adolescents.
Further research with stronger methodological strategies should be conducted to examine the association between feeding habits and malocclusion in mixed and permanent dentitions.Future studies should also consider the longitudinal design to assess such association more accurately.In cohort evaluations, participants are disease-free at the onset of the study and data regarding exposure to risk factors are collected at distinct points in time before the outcome.Thus, this design enables the assessment of causal hypothesis. 26

Conclusion
The findings presented herein do not support an association between breastfeeding and bottle feeding and the occurrence of malocclusion in mixed and permanent dentitions.
The association between feeding practices and this outcome of concern requires additional investigation through prospective cohort studies.Not selected -The study reports breathing.
2. Paunio P, Rautava P, Sillanpaa M. The Finnish Family Competence Study: the effects of living conditions on sucking habits in 3-year-old Finnish children and the association between these habits and dental occlusion.Acta Odontol Scand 1993; 51(1):23-29.
Not selected -Breast feeding and bottle feeding are not associated to malocclusion, are only associated to sucking habits.Selected-The study is from Iowa Fluoride Study.However did not enter meta-analysis.
Not selected -breast feeding is not reported.Bottle feeding is reported along years, and there is no frequency data or OR that could be extracted.Not selected -The study longitudinally follows up children to evaluate changes of malocclusion pattern during years.Bottle feeding of children with malocclusion is reported along the years, but there is no information of bottle feeding in children without malocclusion.OR is not reported and it was not possible to obtain this data from the paper.Not selected -The study does not associate malocclusion to breast feeding or bottle feeding.
Not selected -The study does not associate malocclusion to breast feeding or bottle feeding.Not selected -The study does not report breast feeding or bottle feeding; only non-nutritive sucking habits.Not selected -The study does not associate malocclusion to breast feeding or bottle feeding.
Not selected -the study is conducted with children under primary dentition 110.Adair SM, Milano M, Dushku JC.Evaluation of the effects of orthodontic pacifiers on the primary dentitions of 24-to 59-month-old children: preliminary study.Pediatr Dent 1992; 14(1):13-18.
Not selected -The study correlates malocclusion with the use of orthodontic pacifiers.No feeding habits are reported.
Not selected -The study does not correlate breast feeding or bottle feeding to malocclusion; it is related only to non-nutritive sucking habits.
Not selected -The study is comprised of a high selected group of patients with otitis media.Other variables are associated to otitis media, but not malocclusion and feeding habits directly.Not selected -The study does not report breast feeding or bottle feeding; only non-nutritive sucking habits.
Not selected -The study does not report breast feeding or bottle feeding; only non-nutritive sucking habits.Not selected -The study is a thesis and it was published in scientific periodicals.Papers published were not read and not selected.The study is about non-nutritive sucking habits.
Not selected -The study describes p-value of the statistics between malocclusion and feeding habits, but it was not possible to extract data.

Figure .
Figure.Flowchart showing the results of the search process.

1 a
) yes, with independent validation ◊, b) yes, e.g., record linkage or based on self reports, c) no description.2 a) consecutive or obviously representative series of cases ◊, b) potential for selection biases or not stated.

3 a
) community controls ◊, b) hospital controls, c) no description.4 a) no history of disease ◊, b) no description of source.5 a) study control for one confounding variable ◊, b) study control for 2 or more confounding variables ◊◊.6 a) secure record (e.g., surgical records) ◊, b) structured interview blinded to case/control status ◊, c) interview not blinded to case/control status, d) written self-report or medical record only, e) no description.7 a) yes ◊, b) no. 8 a) same rate for both groups ◊, b) non-respondents described, c) different rate and no designation.* a maximum of 1 point for each item; ** a maximum of 2 points for each item; *** a maximum of 1 point for each item.**** a maximum of 9 points.◊1 point.

1 a
) clinical examination with independent validation ◊, b) without clinical examination or based on self reports, c) no description.2a) individuals with malocclusion in a defined catchment area or community, random sample, sample calculation ◊, b) not satisfying requirements in part (a) fully, c) not stated.3a) adjustment for one confounder ◊, b) adjustment for two confounders ◊◊, c) no description related to the adjustment analysis for confounding variables.

4 a
) clinical examination reporting the use of malocclusion index or report of observer agreement (kappa) ◊, b) based on self reports or not satisfying requirements in part (a) fully, c) no description.5 a) rate of sample loss ≤ 20% ◊, b) rate of sample loss > 20%, c) not stated.* a maximum of 1 point for each item; ** a maximum of 2 points for each item; *** a maximum of 1 point for each item.**** a maximum of 6 points.◊1point.

Appendix 1 :
Articles excluded after full text evaluation and reasons for exclusion Reference Classification 1. Backlund E. Facial growth, and the significance of oral habits, mouthbreathing and soft tissues for malocclusion.A study on children around the age of 10.Acta Odontol Scand 1963; 21:9-139.

Table
. Characteristics of studies included in the systematic review.

Table 2 .
Quality assessment of the case-control study based on the Newcastle-Ottawa scale.

Table 3 .
Quality assessment of the cross-sectional studies based on the Newcastle-Ottawa scale.
Antonini A, Marinelli A, Baroni G, Franchi L, Defraia E. Class II malocclusion with maxillary protrusion from the deciduous through the mixed dentition: a longitudinal study.Angle Orthod 2005; 75(6):980-986.Not selected -The study associates malocclusion to skeletal characteristics based on cephalograms.No breast feeding or bottle feeding is reported.18.Gois EG, Ribeiro-Junior HC, Vale MP, Paiva SM, Serra-Negra JM, Ramos-Jorge ML et al.Influence of nonnutritive sucking habits, breathing pattern and adenoid size on the development of malocclusion.Angle Orthod 2008; 78(4):647-654.Not selected -The study does not report breast feeding or bottle feeding.It associates malocclusion to other risk factors.
16. Larsson E. Sucking, chewing, and feeding habits and the development of crossbite: a longitudinal study of girls from birth to 3 years of age.Angle Orthod 2001; 71(2):116-119.Not selected -The study does not associates breast feeding or bottle feeding to malocclusion.Breast feeding is only associated to sucking habits.17.Not selected -the study is conducted with children under primary dentition 25.Courson F. [Dental facial orthopedics in young children].Arch Pediatr 2006; 13(6):679-682.Not selected -Review 26.Ferro A, Cefariello S. [Prevention of malocclusion].Arch Stomatol (Napoli) 1979; 20(3):387-410.Not selected -The study does not associates malocclusion to bottle or breast feeding.27.Legovic M, Ostric L. The effects of feeding methods on the growth of the jaws in infants.ASDC J Dent Child 1991; 58(3):253-255.Not selected -the study is conducted with children under primary dentition 28.Turgeon-O'Brien H, Lachapelle D, Gagnon PF, Larocque I, Maheu-Robert LF.Nutritive and nonnutritive sucking habits: a review.ASDC J Dent Child 1996; 63(5):321-327.36.Bertrand FR.The relationship of prolonged breast feeding to facial features.Cent Afr J Med 1968; 14(10):226-227.Not selected -The study does not report epidemiological and quantitative data on breast feeding.37.Kisling E, Krebs G. Patterns of occlusion in 3-year-old Danish children.Community Dent Oral Epidemiol 1976; 4(4):152-159.Not selected -The study is a survey of patterns of occlusion in 3 year-old children.Oral habits are seldom reported as non-nutritive sucking habits associated to malocclusion.
. GEDICKE K. [On the predevelopment of the mandible in breast-and bottle-fed children from the standpoint of its function and the prevention of later distalization.].Monatsschr Kinderheilkd 1961; 109:361-369.
Not selected -Data could not be extracted for meta-analysis.66.Peres KG, Oliveira Latorre MR, Sheiham A, Peres MA, Victora CG, Barros FC.Social and biological early life influences on the prevalence of open bite in Brazilian 6-year-olds.Int J Paediatr Dent 2007; 17(1):41-49.Not selected -the study is conducted with children under primary dentition 67.Duncan K, McNamara C, Ireland AJ, Sandy JR.Sucking habits in childhood and the effects on the primary dentition: findings of the Avon Longitudinal Study of Pregnancy and Childhood.Int J Paediatr Dent 2008; 18(3):178-188.Not selected -The study does not report breast feeding or bottle feeding; only non-nutritive sucking habits.85.Robke FJ.Effects of nursing bottle misuse on oral health.Prevalence of caries, tooth malalignments and malocclusions in North-German preschool children.J Orofac Orthop 2008; 69(1):5-19.Not selected -The stud correlates nursing bottle to its consequences such as nursing bottle caries and malocclusion.Types of malocclusion reported are crowding and premature loss of teeth and space in consequence to nursing bottle caries; not malocclusion caused by bottle feeding.94.Piras V, Tuveri F, Dessi C, Pittau R, Origa R, Basile R et al. [Relation between hypogonadism and malocclusion in betathalassemia major patients: analysis of 122 subjects].Minerva Stomatol 2003; 52(5):241-246.Not selected -The study is comprised of a selected group of patients with beta-thalassemia and its association with malocclusion.95 Bertoldi PM, Felficio CM, Matsumoto MA. [Effect of the early intervention of oral habits on the development of dental occlusion].Pro Fono 2005; 17(1):37-44.Not selected -The study reports the effect of counseling on interruption of oral habits.117.Maciel CT, Leite IC. [Etiological aspects of anterior open bite and its implications to the oral functions].Pro Fono 2005; 17(3):293-302.Kobayashi HM, Scavone Junior H, Ferreira RI, Garib DG. [Relanshionshipbetween non-nutritive sucking habits and posterior crossbite in the deciduous dentition].Ortodontia 41[4], 367-372.2008.Not selected -The study reports sucking habits and malocclusion.169.Aravena A. P, Alvarez J. F, Roizen G. S. [Effect of bad sucking habit in the dentition of children].Pediatr día 14[5], 269-272.1998.Not selected -The study is a review.170.Sousa JM, Fracasso MLC.[Maternal behavior versus child temper: influence on the oral health pattern].Comportamento materno versus temperamento da criança: influência no padrão de saúde bucal.Pesquisa brasileira em odontopediatria e Clínica Integrada 10[1].2010.:47-54 Not selected -The study does not associates breast feeding or bottle feeding to malloclusion; only prevalence data is reported.171.Moraes ESd, Lira CC, Ely MR, Thomaz EBAF, Valença AMG.[Prevalence of openbite and crossbite in deciduous dentition ].Rev Bras Ciênc Saúde 5[1], 23-30.2001.Not selected -The study does not report breast feeding or bottle feeding; only associated non-nutritive sucking habits.172.Silva LPMd, Souza Júnior MA, Bastos EPdS.[Posterior crossbite in deciduous dentintion.Relationship with oral habits].Rev Bras Odontologia 62[1/2], 49-51.2005.Not selected -the study is conducted with children under primary dentition 173.Oliveira ABd, Souza FPd, Chiappetta ALdML.[The relationship between non-nutritive sucking habits, infant feeding methods and malocclusion in children with primary dentition].Rev CEFAC 8[3], 352-359.2006.Not selected -the study is conducted with children under primary dentition 174.Fote FD, Bosco VL. [Prevalence of habits of non nutritive suction in Florianópolis-SC's children].Rev Fac Odontol Univ Fed Bahia 20, 25-28.2000.Not selected -The study does not report outcomes of malocclusion, breast feeding or bottle feeding.175.Tomita LM, Carrascoza KC, Possobon RdF, Ambrosano GMB, Moraes ABAd.[The relathionship between breastfeeding duration, oral habits introduction and malocclusion ocurrence].Rev Fac Odontologia da Univ Passo Fundo 9(2), 101-104.2004.Not selected -The study does not associate feeding habits and malocclusion.176.Martins RJ, Forte FDS, Garbin CAS, Saliba NA. [Ralationship between non-nutritive sucking habits and anterior open bite].Rev Inst Ciên Saúde 21[4], 401-404.2003.Not selected -The study does not report breast feeding or bottle feeding; only associated non-nutritive sucking habits.177.Thomaz EBAF, Valença AMG.[Prevalence of malocclusions and factors related to its occurence in preschool children in São Luís -MA -Brazil].Rev Pós-Graduação 12[2], 212-221.2005.Not selected -The study does not report breast feeding or bottle feeding as risk factors.178.Furtado ANdM, Vedovello Filho M. [The outcomes of the breast-feeding period in the settlement of nonnutritive sucking habits and in the occurrence of malocclusion in primary dentition].RGO 55[4], 337-341.2007.Not selected -the study is conducted with children under primary dentition 179.Dimberg L, Bondemark L, Soderfeldt B, Lennartsson B. Prevalence of malocclusion traits and sucking habits among 3-yearold children.Swed.Dent.J 34[1], 35-42.2010.Not selected -The study does not report breast feeding or bottle feeding; the study evaluated non-nutritive sucking habits, breathing pattern and snoring.180.Souza Júnior MA. [Contribution to the study of the posterior cross-bite effect in complete primary dentition].Contribuiçäo ao estudo da mordida cruzada posterior em dentiçäo decídua completa.THESIS/ RIO DE JANEIRO .1998.Not selected -The published study was identified and selected.The thesis was excluded in order to avoid duplicate data.181.Soviero VLM.[Study of the influence of feeding methods and durantion in the no nutrition sucking habits development and dental oclusion in the primary dentition].Estudo da influência do tipo e duraçäo do aleitamento no desenvolvimento de hábitos de sucçäo näo nutritivos e no relacionamento entre as arcadas decíduas.THESIS/ RIO DE JANEIRO.1999.Verrastro AP. [Association between nutritive and non nutritive sucking habits and occlusal and oral myofunctional characteristics in children with primary dentition].Associação entre os hábitos de sucção nutritiva e não nutritiva e as características oclusais e miofuncionais orais em crianças com dentição decídua.THESIS/MONOGRAPH, 150p.2008.Castro LAd.[Cross-section study of the evolution of primary dentition].Estudo transversal da evoluçäo da dentiçäo decídua.THESIS/RIO DE JANEIRO.2001.Not selected -The study evaluates the primary dentition and its development.184.Ribeiro-Jr, H. [Influence of nutritive and non-nutritive sucking habits on primary occlusion of brazilian children: a case-control study].Influence of nutritive and non-nutritive sucking habits on primary occlusion of brazilian children: a case-control study.THESIS.Katz CRT.[Relationship among nonnutritive sucking habits, anterior open bite, posterior crossbite and facial morphology in children preschool in the city of Recife/PE, Brazil: a longitudinal study].Relação entre hábitos de sucção, mordida aberta anterior, mordida cruzada posterior e morfologia facial em pré-escolares do Recife/PE: um estudo longitudinal.THESIS.2003.