Mandibular retrognathism with overjet of the incisors isn’t an uncommon sight as far as children are concerned and appears with high frequency in orthodontics. Many orthodontists recommend an early treatment when children are at primary school and the permanent dentition hasn’t developed yet. Their arguments are: Early intervention enhances the growth of the facial skeleton, it can achieve better and more stable results, the treatment duration would be shorter and extractions or orthognatic surgery would be rarely needed.
Until 1990 the knowledge base on predicting the right time for orthodontic treatment of mandibular retrognathism was inadequate that’s why the given statements have to be seen in a rhetorical light. In order to change this situation several randomized clinical trials (RCTs) have been started since 1995 in the USA. RCTs are high-quality studies for answering the question of therapeutic effectiveness in medicine. At the University of Chapel Hill (North Carolina) 175 young patients (mean age 9,4 years) with mandibular retrognathism were randomized: they were separated randomly into three groups. One of the groups was treated with a bionator, the second with a headgear and the third one was the untreated control group. After early treatment the children started a second treatment course with fixed appliances. Patients from the control group were then treated with fixed appliances as well.
It could be observed that minimal growth changes of short duration were found in about 75% of those receiving early treatment with either a headgear or a functional appliance. (We are talking about one millimeter.) But the effects of early orthodontics weren’t stable and moreover undetectable two years after active treatment. Early treated children must have had less jaw growth after the first course of orthodontic treatment so that the control group was able to catch up. Extractions and orthognatic surgery were the same in all of the groups so in this light early orthodontics proved to be inefficient. Moreover early treatment is more time-consuming, a bigger burden and increases costs in comparison to the 1-phase treatment with only one fixed appliance.
The authors mentioned that they had been impressed by the effects on mandibular retrognathism at first but they also emphasized that this was an example of making conclusions based on clinical observations too early. The authors conclude that early orthodontics regarding changes in mandibular retrognathism appears to be clinically inefficient. It can only be justified when its merits can be proved. This may be the case looking at a small amount of patients whose indications are well-defined. As a rule early orthodontic treatment shouldn’t be performed at all because it’s a burden to children, parents and health insurances rather than a merit.
A tip for parents: As a rule orthodontic treatment should be started when the early permanent dentition is fully developed. This is usually the case when children are 11 years old. An early start of orthodontic treatment leads to a longstanding treatment duration, a bigger burden to the children and parents and higher costs. It should only be performed in a few exceptional cases.
- Tulloch JF, Phillips C, Koch G, Proffit WR. The effect of early intervention on skeletal pattern in Class II malocclusion: a randomized clinical trial. Am J Orthod Dentofacial Orthop. 1997 Apr;111(4):391-400. PubMed PMID: 9109584
- Tulloch JF, Proffit WR, Phillips C. Outcomes in a 2-phase randomized clinical trial of early Class II treatment. Am J Orthod Dentofacial Orthop. 2004 Jun;125(6):657-67. PubMed PMID: 15179390