Literature Review

Study Review

On this page, you will find an overview of the most important studies published about thumb sucking over the past few years. Of course, there are many more, though. If you think a particularly important study is missing from our page, please send us a message.

Effects of nonnutritive sucking habits on occlusal characteristics in the mixed dentition (2005)

John J Warren, Rebecca L Slayton, Samir E Bishara, Steven M Levy, Takuro Yonezu, Michael J Kanellis


Purpose: Little is known about the extent to which nonnutritive sucking habits contribute to malocclusion in the mixed dentition. The purpose of this study was to report on the relationship between certain occlusal traits in the mixed dentition and longitudinal sucking behaviors.

Methods: Dental examinations were conducted on 630 children in the mixed dentition who participated in a large, ongoing longitudinal study. Five hundred eighty consented to impressions, and 524 adequate study models were obtained. Of these, 444 also had adequate longitudinal nonnutritive sucking data obtained via mailed questionnaires to parents at 3- to 6-month intervals from birth to 8 years. Sucking behaviors were grouped by predominant type and duration. Study models were hand articulated using wax bites to evaluate the occlusion for the presence of open bite, crossbite, molar relationship, and excessive overjet. Bivariate statistical analyses related presence of these malocclusions to sucking duration and type.

Results: Fifty-five percent of the children had malocclusions (anterior open bite, posterior crossbite, bilateral Class II molar relationship, or overjet >4 mm). Class II molar relationship was most common (30%). Overall, anterior open bite and posterior crossbite was associated with habits of 36 months or more. Sustained pacifier habits, including those of 24 to 47 months, were associated with anterior open bite and Class II molar relationships, while digit habits were associated with anterior open bite when sustained for 60 months or longer.

Conclusions: Malocclusions are quite prevalent in the mixed dentition, and anterior open bite and posterior crossbite may be preventable by modifying nonnutritive sucking behaviors.

Suffer the little children: fixed intraoral habit appliances for treating childhood thumbsucking habits: a critical review of the literature (2008)

Nicholas L Moore


A critical review of the literature is presented covering the treatment of childhood thumbsucking habits using fixed intraoral habit appliances (hayrake, palatal crib). The habit appliances are classified into type and function. Data is tabulated for key references revealing the fragmented and distorted nature of the literature and its lack of consistency. A chronological approach is presented to confirm the confused and idiosyncratic character of the literature. Information is provided on the early work of Massler and Graber and the paradox of Mack, Korner and Reider. Haryett’s seminal studies at the University of Alberta regarding aspects of the treatment used are critically reviewed. Reflections are presented on why Larsson’s study, casting doubt on the wisdom of using habit appliances, continues to be ignored. The emergence of the Bluegrass Appliance is discussed in terms of its being a more humane appliance and the seeming reluctance of practitioners to apply it as a kinder form of appliance therapy. Information is reported on the pain and serious injuries inflicted on children by habit appliances. A comparison of the use of appliances in the USA is made with the UK, where fixed habit appliances are not popular. Concludes that fixed intraoral habit appliances are cruel and inflict pain and suffering on children out of all proportion to their necessity. Questions why these appliances continue to be used, implying that it could be a combination of financial inducement, professional insularity and the absence of concerted opposition from behavioural therapists.

Relationship between breast- and bottle-feeding and non-nutritive sucking habits

Ana Larissa Fernandes de Holanda, Shirley Alexandre dos Santos, Marina Fernandes de Sena, Maria Angela Fernandes Ferreira


Purpose: The objective of the present study was to assess the persistence of non-nutritive sucking habits and its relationship with breastfeeding, as well as to establish the influence of sociodemographic factors on these habits among children aged 3 to 5 years.

Materials and methods: A case-control study was conducted with 1107 children from public and private daycare centres in Natal, Brazil: 450 in the case group (312 pacifier suckers and 138 thumb suckers) and 657 in the control group (habit-free). Data regarding sociodemographic conditions and duration of breastfeeding were obtained using a structured questionnaire.

Results: Breastfeeding for a duration of > 6 months (adjusted odds ratio = 0.311; 95% confidence interval = 0.226 to 0.428) was an independent protective factor against persistent pacifier sucking. The use of pacifiers was more frequent among 3-year-old children and among those from a higher income family and a higher level of schooling of parents. The relation between duration of breastfeeding and thumb sucking was not statistically significant (P = 0.087). There was an association between the thumb sucking habit with sex (female), low level of schooling of father and the child being born as the last male child in the birth order. No relation was found between breastfeeding and habit frequency (day/night and night) (P = 0.301). An association with habit frequency was found with the age of 3 years, female, the family income group that ranged between US $176 and US $875, and those attending private institutions.

Conclusions: Breastfeeding for a duration of > 6 months was a protective factor against the persistence of pacifier sucking, but the subjectivity of the mother-child relationship must be investigated further.

Sucking habits in childhood and the effects on the primary dentition: findings of the Avon Longitudinal Study of Pregnancy and Childhood

Karen Duncan, Clare McNamara, Anthony J Ireland, Jonathan R Sandy


Introduction: Most previous research on non-nutritive sucking habits has been cross-sectional in nature. This study determined the prevalence of non-nutritive sucking habits and the effects on the developing dentition within a longitudinal observational cohort.

Methods: The Children in Focus group of the Avon Longitudinal Study of Pregnancy and Childhood study was studied. Questionnaire data on non-nutritive sucking habits were collected on the children at 15 months, 24 months, and 36 months of age. Dental examinations were performed on the same children at 31 months, 43 months, and 61 months of age.

Results: At 15 months, 63.2% of children had a sucking habit, 37.6% used just a dummy, and 22.8% used a digit. By 36 months, sucking had reduced to 40%, with similar prevalence of dummy and digit sucking. Both habits had effects on the developing dentition, most notably in upper labial segment alignment and the development of anterior open bites and posterior crossbites.

Conclusions: The majority of children had non-nutritive sucking habits up until 24 months of age. Both digit and dummy sucking were associated with observed anomalies in the developing dentition, but dummy-sucking habits had the most profound influence on the anterior and posterior occlusions of the children.

Digit sucking in children resident in Kettering (UK)

Anjli Patel, David Moles, Julian O'Neil, Joseph Noar


Coming soon

Do sucking habits in preschool children influence the position of the primary incisors?

Gisele Moraes Abrahão, Daniel Jogaib Fernandes, José Augusto Miguel, Catia Quintão, Branca Heloísa de Oliveira


The aim of this study was to verify whether sucking habits influence the position of the primary incisors. The sample comprised 34 preschool children (mean age 44 months ± 9 months). They were divided into three groups: group B (n=9) with a baby bottle habit; group BP (n=13) with baby bottle and pacifier habits; and a control group C (n=12) with no sucking habit. Data were derived from face-to-face interviews with the parents/guardians, oral examinations, study casts, facial photographs (frontal/lateral views), and cephalograms. The cephalograms were scanned and subsequently analyzed by one trained and calibrated operator. The cephalometric parameters recorded were: interincisal angle (U1/L1), U1/NA (angle/distance), and L1/NB (angle/distance). The data were analyzed using Stata 7.0. The Kruskall-Wallis test was used to compare the cephalometric measurements in the children with and without sucking habits. The level of significance was set at P≤.05. This study found a significant relationship between existing sucking habits and a protrusion of the maxillary and mandibular primary incisors.

Prevalence of a posterior crossbite and sucking habits in Brazilian children aged 18-59 months

Maria Carolina Bandeira Macena, Cíntia Regina Tornisiello Katz, Aronita Rosenblatt


This cross-sectional study aimed to assess the prevalence of posterior crossbites and non-nutritive sucking habits in 2750 Brazilian children aged from 18 to 59 months. The data were collected by 123 previously trained dental students and recorded on a response card according to the model developed by the Forsyth Institute, Boston, Maryland, USA, for optical reading. Information concerning sucking habits and family income was obtained during an interview with a parent or guardian. A clinical examination was also undertaken. Statistical analysis included chi-square and Fisher’s exact tests. A posterior crossbite was observed as early as 18 months of age. The prevalence of a posterior crossbite was 10.4 per cent and was associated with age (P = 0.00) and with sucking habits (P = 0.01). The prevalence of sucking habits was 43.5 per cent. A posterior crossbite was not associated with socio-economic status (P = 0.38). While sucking habits were common among the age group studied (43.5 per cent), only a small percentage exhibited a posterior crossbite. These results suggest that further investigations into other aetiological factors, in particular genetics and respiratory problems, are necessary to provide more evidence that could clarify this issue.

Concomitant trichotillomania cessation and thumb-sucking elimination: of course, they're related...aren't they?

Shari Green


This article presents an overview of the current research literature that reveals some controversy, discussion of the need for more research, and report of some definitive success. In addition, four case studies of hair pulling and thumb-sucking are highlighted.

Influence of the respiratory mode and nonnutritive sucking habits in the palate dimensions

Luana Cristina Berwig; Márlon Munhoz Montenegro; Rodrigo Agne Ritzel ;Ana Maria Toniolo da Silva; Eliane Castilhos Rodrigues Corrêa; Carolina Lisbôa Mezzomo


Aim: To verify the influence of the respiratory mode and nonnutritive sucking habits in the transverse and vertical dimensions of the palate. Methods: Seventy-seven children aged 7 to 12 years, were divided, according the diagnosis of the respiratory mode and the presence of prolonged nonnutritive sucking habits. Models of the upper dental arc were obtained of all children for evaluation of the measures of the palate in the region of the canines, first and second premolars and first molars. These measures were analyzed by the Student’s t-test and Analysis of Variance. Tukey’s test was used for the multiple comparisons. The significance level was set at p<0.05. Results: It was verified that the mouth-breathing children showed smaller width and higher depth at the more posterior region of the palate. The children with prolonged nonnutritive sucking habits presented narrower and deeper palate at the anterior region of the palate. The canine distance was smaller in children who present mouth breathing associated to nonnutritive sucking habits and the depth at the second premolar was higher in mouth-breathers associated or not to prolonged nonnutritive sucking habits. Conclusions: The results suggest that the respiratory mode and prolonged nonnutritive sucking habits influence in the transverse and vertical palate dimensions in the children evaluated in this study.

Link to the publication

A longitudinal study of the association between breast-feeding and harmful oral habits

Suzely Adas Saliba Moimaz, Orlando Saliba, Luiz Fernando Lolli, Cléa Adas Saliba Garbin, Artênio José Ísper Garbin, Nemre Adas Saliba


Purpose: The purpose of this paper was to study the pattern of breast-feeding and harmful sucking habits (pacifier- and thumb-sucking) from birth to 12-months-old.

Methods: A prospective cohort study with 80 newborn infants and their mothers was conducted. A semi-structured questionnaire on breast-feeding and pacifier- and thumb-sucking behavior was administered during monthly household visits. Data were analyzed using the chi-square test.

Results: Exclusive breast-feeding occurred in 50% of infants from birth while 69% of participants were completely weaned by 12-months-old. Pacifier-sucking was more prevalent than thumb-sucking and was maintained at a higher rate than thumb-sucking throughout the study. The incidence of thumb-sucking was highest between the third and sixth month of life. There was a significant association between a low rate of breast-feeding and pacifier-sucking at the 12-month visit (chi-square=5.29; P<.05). Thumb-sucking did not significantly correlate with breast-feeding behavior.

Conclusion: The rate of exclusive breast-feeding was lower than that recommended by the World Health Organization. More than half the infants had a pacifier- and / or thumb-sucking habit during the study, and the incidence of breast-feeding was lower in those who used a pacifier.

Abnormal oral habits: A review

N. Shahraki, S. Yassaei and M. Goldani Moghadam


Oral habits, if persist beyond certain developmental age, can pose great harm to the developing teeth, occlusion, and surrounding oral tissues. In the formative years, almost all children engage in some non-nutritive sucking habits. Clinicians, by proper differential diagnosis and thorough understanding of natural growth and developmental processes, should take a decision for intervening. This article describes case series reports of thumb sucking, finger sucking, and tongue thrusting habits, which have been successfully treated by both removable and fixed orthodontic appliances. The cases shown are ranging from the age group of 9-19 years presenting combination of both mixed and permanent dentition development. All cases show satisfactory correction of habits and stable results.

Link to the publication.

Childhood thumb sucking habit: the burden of a preventable problem! (2012)

Gupta B Indushekar, Bhavna Gupta and Indushekar KR


Suckling is a physiological act that provides nourishment and comfort. A baby’s sucking can be either nutritive or nonnutritive. Nonnutritive sucking can turn into a continuous behavior practiced unconsciously, leading to a deleterious oral habit (eg, thumb sucking).The extent of damage caused by this habit is dependent on the duration, frequency and intensity. Till the age 3, this habit is termed to be normal but later certain intervention has to be taken. This habit can have a negative impact on speech, psychology and dental development (maxillary prognathism, increased overjet, mandibular retrognathism, posterior crossbite, midline diastema and open bite) of the child. A combined multidisciplinary team comprising of the Family physician, Speech therapist, psychologist, Pediatric dentist, Orthodontist, pediatrician and Orofacial mycologist is needed for the management and treatment planning of this delirious habit. Thumb sucking is a non meaningful habit commonly found in children. This habit can have a negative impact on speech, psychology and dental development (maxillary prognathism, increased overjet, mandibular retrognathism, posterior crossbite, midline diastema and open bite) of the child. This paper stresses upon the need of combined effort by the multidisciplinary team for the effective treatment planning.

Link to the publication. 

Digit Sucking – What to do (2013)

Matthew Clover, Ross Hobson


Dentists are often questioned by anxious parents about the effects of digit sucking and the possible ways of stopping their child’s habit. This article discusses the aetiology, prevalence and effects of digit sucking, various means of stopping the habit and the problems that may occur if digit sucking persists into the permanent dentition.

Link to publication. 

Nutritive And Non-Nutritive Sucking Habits Effect On The Developing Oro-Facial Complex; A Review (2014)

Sapna Jyoti Pavanlakshmi GP


Children have unique dental needs. During developmental period, the children go through various phases i.e., from no teeth, to primary teeth, to loosing teeth, to permanent teeth, which occur in about the first 12-14 years. If this routine goes without any disturbance, the child enters the adulthood with a strong and healthy dentition and oral structures. If there is any disturbance, either physical or psychological or both, it will result in mal development and malocclusion. The development and maturation of normal oropharyngeal function plays an important role in craniofacial growth and occlusal physiology. Any muscular imbalance caused by intrinsic or extrinsic pressure will show their effect on the growing bone which will result in malocclusion. One of the important factors resulting in malocclusion is oral habit practiced by a child. Having an oral habit is not a tragic situation, but needs to be stopped at the appropriate time with an appropriate method to get a good long-term result.

Influence of nail biting and finger sucking habits on the oral carriage of Enterobacteriaceae (2015)

Firoz G Kamal, Reginald Ajay Bernard


Background: Oral habits like thumb sucking and nail biting are pernicious habits that act as an adaptive function in obtaining pleasure and subduing anxiety. These habits may also act as carriers of numerous microorganisms into the oral cavity, of which, Enterobacteriaceae members are transient pathogens, which might result in debilitating systemic conditions.

Aim: To study the oral carriage of Enterobacteriaceae in children having habit of nail biting and thumb sucking. And to study the association of the organism with the individual’s respective plaque indices.

Subjects and methods: Totally, 40 chronic nail biters, 40 chronic thumb suckers, and 20 controls (no habit) (8-15 years old) were enrolled in the study. Appropriate history and their plaque indices recorded. Sterile containers were used to collect the salivary samples and later cultured on Agar plates. Biochemical tests categorized the organisms into subspecies.

Statistical analysis used: ANNOVA, Student’s t-test.

Results: Presence of a nail biting habit indicated a higher plaque index, which in turn showed a higher carriage of Enterobacteria spps, predominantly Escherichia coli.

Conclusions: Oral surgical intervention in individuals with pernicious oral habits need to be counseled and educated on the possible complications, which might otherwise provide an environment that disseminates these microorganisms resulting in a broad range of local and systemic infections.

Keywords: Bacteremia; Enterobacteriaceae; cellulitis; extraction complications; nail biting; thumb sucking.

Non-nutritive sucking habits after three years of age: a case-control study (2015)

Izabella Barbosa Fernandes, Túlio Silva Pereira, Monize Ferreira Figueiredo de Carvalho, Joana Ramos-Jorge, Leandro Silva Marques, Maria Letícia Ramos-Jorge


Background: Non-nutritive sucking habits can result in negative consequences on the development of orofacial structures and occlusion.

Aim: Assess factors associated with non-nutritive sucking habits in children after 3 years old.

Materials and methods: A case-control study was carried out in two stages. In the first stage, a cross-sectional study was conducted with 638 children aged 3-6 years. In the second stage, a case-control study (1:2) was conducted. The case group included all children who presented some non-nutritive sucking habits in the first stage of the study (n = 110). The control group (n = 220) was made up of children who had never presented non-nutritive sucking habits, matched to the case group for gender and age. The data were collected during the national poliomyelitis vaccination campaign, through a questionnaire applied to parents/guardians with questions related to the presence of sucking habits, sociodemographic aspects, birth aspects, and early life of the child. Statistical analysis involved descriptive analysis, chi-square test, Mann-Whitney test, and conditional logistic regression.

Results: Reduction in maternal education was a protective factor for the development of non-nutritive sucking habits (education ≤8 years OR = 0.38, CI 95%: 0.16, 0.89, P = 0.025). Prematurity (OR = 3.30, CI 95%: 1.13, 9.69, P = 0.030) and a longer period using a baby bottle (OR = 1.03, CI 95%: 1.01, 1.05, P = 0.006) remained associated with a greater possibility of the occurrence of sucking habits, regardless of monthly family income.

Conclusion: Non-nutritive sucking habits were associated with maternal education, premature birth, and greater time of bottle feeding in children after 3 years old.

Oral Habits in School Going Children of Pune: A Prevalence Study (2015)

Mohammed Nadeem Bijle


Background: Oral habit beyond preschool age is an important etiological factor in developing malocclusion. The aim was to study the prevalence of the oral habits in the school going children of Pune region of Maharashtra. Materials and Methods: A total of 3663 children were selected randomly from the private and municipal schools between the age range of 5 and 13 years. The questionnaire was given to the parents and consent was obtained. The children were examined in the schools and the presence or absence of the thumb sucking; tongue thrusting and mouth breathing habit were recorded. Statistical analysis was done using Chi-square test and Fisher’s exact test. Results: Out of total study population, 16.8% showed the presence of at least one of the oral habits. The habits were significantly higher in municipal schools. Boys showed a higher prevalence of oral habits. Depending upon the age, Group I showed the highest prevalence. Conclusion: From the study, it can be concluded that there is a need to intensify oral health education targeting both parents and school children to enable them to get benefit from interceptive orthodontic care.

Link to the publication.