The purpose of this cross-sectional study was to determine the psychosocial impact of hypodontia (multiple dental agenesis) in children and the influence of factors such as severity of hypodontia, number of retained deciduous teeth, age, and sex. The implications of hypodontia for affected patients have been poorly investigated; this, in part, relates to the lack of appropriate measurements to assess the impact of oral conditions on quality of life, particularly among children and adolescents.
A total of 123 children (49.6% boys, 50.4% girls; mean age, 13.6 years; SD, 1.6 years) were recruited on the basis of predetermined inclusion criteria to either a hypodontia group or a routine orthodontic group of similar treatment need (index of orthodontic treatment need, dental health component 4 or 5) but without hypodontia. Each patient completed the child perceptions questionnaire and 2 visual analog scales to determine the global effects of hypodontia on esthetics and function.
The mean number of missing teeth in the hypodontia group was 4.52 (SD, 3.33). There were no statistically significant differences in child perceptions questionnaire scores (overall or at domain level) or visual analog scores between the hypodontia and the routine orthodontic groups ( P >0.05). Univariable linear regression analyses provided some evidence that difficulty with chewing was associated with the severity of hypodontia ( P = 0.030).
In this sample, hypodontia did not appear to affect the psychosocial status of patients any more than other features of a malocclusion measured with the index of orthodontic treatment need, dental health component 4 or 5. Patients with hypodontia did, however, have more difficulty in chewing when the deciduous teeth associated with the missing permanent teeth had been exfoliated. This highlights the possible importance of retaining deciduous teeth in patients with severe hypodontia.
Hypodontia is the term used to describe the developmental absence of at least 1 deciduous or permanent tooth, excluding the third molars. It is the most common dental developmental anomaly and has occurred in humans since at least Paleolithic times. The lack of 1 or 2 permanent teeth, with no associated systemic disorders, is the mildest and the most common phenotype. Hypodontia is more common among persons who are genetically related than in those who are not.
There is a wealth of research into the prevalence, probable etiology, and dentoskeletal effects of hypodontia, but the social, behavioral, educational, medical, and financial implications for an affected person and his or her immediate family have been poorly investigated. The psychosocial impact of hypodontia has received little attention in the literature. Hobkirk et al, in a retrospective study of 451 patients with hypodontia, found that the most common complaints were spacing between the teeth and poor esthetics, and some patients were aware that they had missing teeth. Functional problems because of the reduced surface area of the occlusal table comprised only 8.7% of patients’ complaints.
Facial esthetics and esthetic dentistry have become prominent forces in today’s popular culture. Dentofacial appearance can affect interpersonal relationships and perceived qualities such as friendliness, social class, intelligence, and popularity from infancy to adulthood. Attractive children are seen by others as more intelligent and having more positive social behavior, and they receive more positive treatment than their less attractive counterparts. Therefore, deviation from ideal dentofacial esthetics, particularly in children, might adversely affect self-esteem and self-confidence, and attract mockery from peers. It is reasonable to speculate that deviations from “ideal” or “normal” dentofacial esthetics could be detrimental to a person’s psychosocial well-being. The general assumption follows that less attractive children might experience some psychosocial distress as a result of their condition.
Orthodontic treatment need and effectiveness of treatment are often assessed by morphologic changes in anatomic parameters such as occlusal indexes and cephalometric measurements. However, these types of normative assessments are not always relevant to patients from a psychological, social, or functional aspect because “the demarcation between acceptable and unacceptable occlusion is influenced by idiosyncratic judgement.” More recently, there has been an emphasis on oral health-related quality of life (OHRQOL) research, which has evaluated the impact of oral conditions on patients’ lives and might enable a level of care that is appropriate for each patient. These approaches provide insight into the potential consequences of the condition, beyond clinical parameters, on the day-to-day lives of affected patients. This facilitates the understanding of the condition’s importance in the provision of oral health care and can ensure that the best practice guidelines are established.
Investigation of children’s OHRQOL has been addressed only relatively recently in the literature, probably because of the greater complexity of assessing OHRQOL in children than adults. The psychosocial impact of hypodontia in children has received little attention in the literature to date, and it was our purpose to investigate this area. The null hypotheses for the study were (1) there is no difference in psychosocial status between subjects with hypodontia and those with no hypodontia but with a malocclusion of a similar treatment need as classified by index of orthodontic treatment need (IOTN), dental health component (DHC) 4 or 5; and (2) age, sex, and extent of hypodontia have no effect on psychosocial status.
Material and methods
The research proposal was approved by the Joint University College London/University College London Hospitals Committee on the Ethics of Human Research Committee. The subjects were recruited from new-patient orthodontic clinics in a teaching hospital by 1 researcher (E.L) from July 2006 to January 2007, and consecutive patients who satisfied the inclusion criteria were invited to participate. Two groups of participants were recruited: a hypodontia group and an orthodontic group not affected by hypodontia (the routine orthodontic group). The criteria for inclusion in the study were patients between 11 and 16 years of age; IOTN, DHC 4 or 5; and radiographically confirmed hypodontia (for the hypodontia group) or no hypodontia (for the routine orthodontic group). Exclusion criteria were previous orthodontic treatment, associated medical conditions, not accompanied by a parent or guardian, or non-English speaker.
Each patient and the parent or legal guardian were given written information outlining the details of the study, and its purpose was explained verbally. If the patient and parent or legal guardian agreed to participate, they were taken to a quiet nonclinical area, where written informed consent was obtained. The following demographic details were recorded: age and sex.
A sample size calculation was performed using nQuery Advisor software (version 5.0, Statistical Solutions, Saugus, Mass) with data from the first 33 hypodontia patients and the first 10 routine orthodontic patients to be recruited. It was found that, for a chi-square test (with a 0.05 level of significance) to have 80% power to detect a 25% difference in questionnaire scores, 61 subjects were required in each group.
Each child filled out a validated self-completed questionnaire, the child perceptions questionnaire (11-14 years) (CPQ) compiled by Jokovic et al at the Faculty of Dentistry, University of Toronto in Canada. The authors’ consent to use the questionnaire was obtained before the study. The CPQ was developed with orthodontic and pediatric dentistry patients and performed well as a discriminative measure between study group patients and was therefore appropriate for our research question. It was shown to be a valid measure with excellent internal consistency and test-retest reliability. Marshman et al further investigated these parameters and confirmed that the validity and reliability were acceptable for use in an orthodontic population in the United Kingdom. These aspects were therefore not investigated in this study.
The CPQ consists of 37 questions divided into 4 health domains: oral symptoms, functional limitations, emotional well-being, and social well-being. The questions cover the child’s views and perceived views of peers about his or her dental appearance, and behavioral difficulties at home and at school. The response options and scores for the 37 CPQ questions were as follows: 0, never; 1, once or twice; 2, sometimes; 3, often; and 4, every day or almost every day.
After completion of the CPQ, the participants were asked to complete 2 visual analog scales (VAS) related to the appearance and function of their teeth. These comprised 2 horizontal lines, 100 mm long, anchored by word descriptors at each end. The function VAS was anchored with “I find it easy to eat” and “I find it hard to eat”; the appearance VAS had “I like the way my teeth look” and “I hate the way my teeth look” at either end. Each patient’s score was obtained by using a ruler to measure the distance from the left anchor to where he or she had marked the response. Possible scores ranged from 0 to 100, corresponding to the distance in millimeters to where the cross was placed. An example was provided to clarify the exercise. Since all questions in both tasks were closed, a box for comments was provided at the end of the questionnaire.
Participants were allowed as much time as they needed to complete the CPQ and the VAS, and it was made clear that these were for them to complete on their own, without the assistance of a parent or guardian. On average, the tasks took each child 10 minutes to complete. If the patient and the parent or guardian did not have enough time that day, they were given a stamped, addressed envelope and asked to return the completed CPQ and VAS. It was made clear that the child should complete the exercise at home.
The analysis of the data was carried out by using Statistical Package for the Social Sciences software (version 14, SPSS, Chicago, Ill). The data analysis comprised 2 sections: analysis of both groups, by using descriptive statistics and 2-sample t tests to test for differences in CPQ scores (overall and at domain level) and Mann-Whitney U tests to test for differences in VAS scores. In the second section, analysis was restricted to the hypodontia group to investigate the specific effects of the extent and location of hypodontia on the CPQ and VAS scores. To investigate the effects of retention of deciduous teeth, hypodontia was defined in this study as “absolute” and “relative.” Absolute hypodontia was the number of missing permanent teeth, and relative hypodontia was the number of missing permanent teeth minus the number of retained deciduous teeth. These 2 scoring methods enabled the effects of retention of the associated deciduous tooth to be considered. Univariable linear regression analyses were used to identify variables contributing to differences in the total and domain CPQ and the VAS scores. In all regression analyses, the model assumptions were found to be satisfactory.
All 123 patients in the hypodontia and routine orthodontic groups who were approached agreed to participate; there were no withdrawals. Eleven participants took their questionnaires home to complete them, and they were all returned by mail. The sample comprised 62 hypodontia patients (35 boys, 27 girls) and 61 nonhypodontia patients (26 boys, 35 girls) ( Table I ). The chi-square test for independent samples showed no statistically significant difference in sex distribution between the groups ( P = 0.176). The mean age of both groups was 13, with an age range of 11 to 16 years ( Table I ).
|Group||Hypodontia (n = 62)||Nonhypodontia (n = 61)|
An overall CPQ score was calculated for each child by adding all questionnaire item scores, with a maximum possible score of 148. Scores ranged from 2 to 80, and, for both groups, the scores were approximately normally distributed ( Table II ). The higher the CPQ score, the more often a child would be affected, and it was inferred that the higher the score, the greater the psychosocial impact. A 2-sample t test showed no statistically significant difference in total questionnaire scores between the hypodontia and the routine orthodontic groups ( P = 0.566) ( Table II ). With respect to each of the 4 CPQ domains, 2-sample t tests showed no evidence of any statistically significant differences in mean scores between the 2 groups ( Table II ).
|Domain||Maximum possible score||Hypodontia mean||Nonhypodontia mean||Mean difference in CPQ scores||95% CI of difference||P value|
|Oral symptoms||24||5.03||5.74||0.705||–0.443, 1.855||0.227|
|Functional limitations||36||6.06||6.16||0.994||–1.526, 1.725||0.904|
|Emotional well-being||36||6.56||7.49||0.927||–1.647, 3.501||0.477|
|Social well-being||52||5.77||5.75||–0.020||–1.900, 1.860||0.983|
|Total CPQ score||148||26.82||28.52||1.70||–4.149, 7.553||0.566|
Mann-Whitney U tests for 2 independent samples were performed to investigate any potential differences in median VAS scores for eating and appearance between the groups. However, there was no evidence of any intergroup differences in VAS scores for function or appearance ( P = 0.766 and P = 0.869, respectively) ( Table III ).
|Question||Group||Median score||P value|
In the statistical analysis of the hypodontia group, the mean number of missing teeth per subject was 4.52 (SD, 3.33). The numbers of developmentally missing teeth per sextant and retained deciduous teeth per sextant were recorded. From these data, it was possible to calculate a relative hypodontia score. Thus, the mean absolute hypodontia was 4.52, and the mean relative hypodontia was 2.03 missing teeth per subject (SD, 1.76). There was an approximately even distribution of both mean absolute and relative hypodontia by sextant, but the mandibular middle sextant most commonly had missing teeth ( Table IV ). The maxillary labial segment had the fewest retained deciduous teeth and was the sextant with the greatest relative hypodontia ( Table IV ).
|Absolute hypodontia ∗||Relative hypodontia †|
|Sextant||Mean||95% CI||Mean||95% CI|
|Maxillary right||0.76||0.53, 0.99||0.26||0.11, 0.40|
|Maxillary middle||1.02||0.75, 1.29||0.76||0.55, 0.97|
|Maxillary left||0.65||0.42, 0.87||0.21||0.08, 0.34|
|Mandibular right||0.74||0.55, 0.94||0.19||0.08, 0.30|
|Mandibular middle||0.66||0.38, 0.94||0.40||0.21, 0.60|
|Mandibular left||0.69||0.50, 0.89||0.21||0.10, 0.32|
|Total||4.52||3.67, 5.36||2.03||1.58, 2.48|