Malocclusions – from infancy to adulthood. What is the influence of infant behaviours on their occurrence and what are the long-term outcomes of orthodontic treatment?

Abstract

Malocclusions, defined as deviations in the intra- and/or inter-maxillary relationships of teeth from normal, can hamper the attainment of oral health if they adversely impact on physiological functions such as speech and mastication, or psychologically linked capabilities like smiling. Malocclusions have multifactorial aetiology; one’s phenotype is a result of their genotype’s interaction with the environment. While genetic factors presently cannot be altered, environmental factors such as nutritive or non-nutritive habits, are modifiable. Where malocclusions can be prevented from developing, this should be promoted as orthodontic treatment presents economic consequences, amongst others, for the individual, their carer/families, health service providers and the broader population. If a decision is made between the dental healthcare practitioner and the patient (or carers/parents) to treat malocclusions, this may be relatively short in duration and limited to intercepting a few features during the mixed dentition, or longer and comprehensive, dealing with multiple features simultaneously in the secondary dentition. Although patients may have certain expectations, these need to be carefully moderated, particularly if they seem unreasonable or unattainable, by relying on the bestavailable evidence during the process of informed consent. Orthodontic treatment, like any medical or surgical intervention, carries benefits, risks and limitations. The overarching aims of this research were twofold: 1. To examine the association of environmental factors during infancy and childhood on the development of malocclusions, and, 2. To discern the long-term outcomes, in adulthood, of orthodontic treatment. These aims were achieved through the following objectives: 1. To assess the quality of information available on the Internet to the lay public concerning breastfeeding and malocclusions, 2. To produce estimates of the risk of malocclusion development associated with non-nutritive sucking behaviours and sub-optimal breastfeeding, 3. To determine whether any long-term differences exist in the level of dental caries experience, psychosocial outcomes, dental knowledge and dental behaviour between adults based upon receipt of fixed orthodontic treatment. One research protocol and six original research articles addressed these objectives. A dynamic cross-sectional analysis of Internet content gauged the quality of information targeting the lay public about breastfeeding and malocclusions. The Joanna Briggs Institute methodology for conducting systematic reviews of association (etiology) was used to synthesise evidence and generate estimates of effect for the association of nonnutritive sucking behaviours and breastfeeding on the development of different malocclusion features in the primary and mixed dentitions. Statistical analyses including modelling were applied to data from the Oral Health of Adults Entering their Fourth Decade study, a population-based prospective, observational investigation that followed children (aged 13 years) in South Australia in 1988-89 to early adulthood (aged 30 years) in 2005-06. Internet information on breastfeeding and malocclusions was of moderate quality, with supportive references ranging between moderate and very low-level evidence. Although children who breastfed sub-optimally had increased risk of developing malocclusions, the risk from non-nutritive sucking behaviours was greater. Orthodontically treated participants had slightly better dental knowledge, though no difference existed in dental behaviours, dental health or psychosocial outcomes, regardless of initial malocclusion, based upon previous receipt of orthodontic treatment.