Main findings
In this survey, the majority of both preterm and controls rated their experience of dental care as very good or good, which is a sustaining result for the dental care system and may reflect a low overall rate of dental fear and anxiety (DFA). It appears that the transition from pediatric dentistry to adult dental care for all adolescents are well prepared. Results concerning DFA, oral health behaviour, and intake of sweets and sugary containing drinks of 17–19-year-old adolescents born preterm was comparable to that of the full-term control group. Thus, the proposed hypothesis that preterm adolescents would have higher levels of CFSS-DS scores than full-term control group is rejected. The expectation was that it would be higher in the preterm group because of the correlation to the reported increased risk for anxiety/depression during adolescence and young [6]. According to a meta-analysis, those born preterm or low birth weight were three times more likely to receive a diagnosis of a psychiatric condition, including anxiety and depression, in late childhood, adolescence and young adulthood [6]. Furthermore, different aspects of anxiety and depressive symptoms have been reported to be risk factors during early adulthood for dental fear and anxiety [20].
DFA refers to the patient’s experiences in dental care and is related to characteristics like temperamental factors and psychiatric problems as reported in preterm children [21, 22], and therefore, relevant to study. The prevalence of DFA is approximately 9% in a child population [23] and around 20% in an adult population [24]. In relation to this survey, the results showed 5.5% in the preterm group and 2.1% of the controls. In several population studies, CFSS-DS is the most frequently used measure of DFA, and the mean scores are lower than previously reported rates in adolescents [23] but fall in line with data from a study of 13–19-year-old Swedish adolescents, comparable as a reference group [25]. Also, the finding that girls had higher levels of CFSS-DS scores in both preterm and control groups is in line with previous population studies [23].
The hypotheses that adolescents born preterm are not to be considered as special needs patients in future dental care is partly rejected. Almost 50% of the adolescents reported consuming sweets and sugary drinks between meals several days per week, although in comparisons with full-term controls. The frequent consumption of soft drinks may increase the risk of caries and dental erosion [26], and it is linked to an unhealthy lifestyle in general. That more boys than girls reported a frequent intake of sweets and soft drinks several times per week is in line with a recent Swedish study of 16 year olds which named the consumption of sweets and soft drinks as a risk factor for being overweight and obese later in life, and therefore, a public health concern also from this perspective [27]. In comparison with early adolescence, the reported consumption of sweets and sugary drinks between meals several days per week in this survey had increased by about 100% in both groups. For the preterm group, with their increasingly compromized health status during adolescence, this reflects that preterm-born adolescents may be potentially at risk for oral health problems in adult life. Further, according to Sharafi et al. 2016 [12], less healthy dietary behaviours contribute to risk factors for cardiovascular disease in young adults born preterm.
The adolescent’s health status in this study increased twice from early adolescence (12–14 years) to late adolescence (17–19 years) in both the preterm and control group. These health problems included, for example, neuropsychiatric disorders, asthma, chronic lung disease, diabetes, and hearing impairments, with a prevalence of 34.4% in extremely preterm 17–19 year olds. These figures are in comparison with another Swedish study with extremely preterm 18-year-old adolescents reporting 37.6% chronic illness [28].
Dental procedures can be associated with pain, unpleasant feelings, and worry, and may result in stress and anxiety [29]. How the pain is perceived and rated relates to, for example, age, gender, and previous dental experiences [30]. Highly anxious children reported more pain than less anxious children [31]. Further, research suggests that preterm children’s experience of pain during neonatal intensive care might influence later pain sensitivity [32] and might contribute to adverse long-term physiologic and behavioural sequelae [33]. A radiographic examination is a common part of clinical dental examination and might be associated with more or less pain for everyone, even adults. The results from this survey showed that girls in both preterm and the control group rated significantly more pain than boys during radiographic exposure. This corresponds well with previous results reported by Krekmanova et al. 2009 [30]. To our knowledge, few studies have been carried out on pain sensitivity in the dental situation in preterm children. The finding that 41% of extremely adolescents and 32% of very preterm adolescents claimed pain associated with this examination suggests further exploration. The combination of common reported illness of differing severity and lower cognitive function, as frequently reported in preterm children, increases the importance of identifying pain management strategies [33], this may also include dental procedures.
Study limitations
A limitation of the study is the small number of extremely preterm participants, making comparisons within the preterm group difficult; however, this falls in line with official statistics in Sweden. Further, the longitudinal study design made it impossible to include a larger number of extremely preterm individuals.
Study strengths
This study was population-based and is a follow-up of a group surveyed from 3 to 14-years of age [9]. Consequently, the response rate of 76% in preterm and 73% in the control group is considered a satisfactory return. Another strength was the use of the same measurements and method of compiling data as in the previous study at 12–14 years. Further, the same examiner (SBR) carried out the studies on both occasions.