| Sign In to gain access to subscriptions and/or personal tools. |
The Seven-year Outcome of an Early Orthodontic Treatment Strategy
1 Institute of Clinical Dentistry, Faculty of Medicine, University of Tromsø, N-9037 Tromsø, Norway; Correspondence: * corresponding author, heidi.kerosuo{at}fagmed.uit.no
The benefits of early orthodontic treatment are continuously discussed, but studies are few. We examined whether definite need for orthodontic treatment could be eliminated in public health care by systematically focusing on early intervention. One age cohort living in a rural Finnish municipality (N = 85) was regularly followed from ages 8 to 15 years, and persons with malocclusions were treated according to a pre-planned protocol. Treatment need was assessed according to the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need, and treatment outcome by the Peer Assessment Rating Index (PAR). Fifty-two percent of the cohort received treatment, and definite treatment need decreased from 33% to 9%. In the treated group, the mean PAR score reduction was 63%, and 51% showed more than 70% improvement. The results suggest that an early treatment strategy may considerably reduce the need for orthodontic treatment in public health care with limited specialist resources.
Key Words: early treatment • PAR • orthodontic treatment need • IOTN • DHC
Ensuring orthodontic treatment for those in need of such treatment is a challenge in public health care with limited specialist resources. Functionally good and esthetically acceptable occlusion has been considered the main goal of treatment in public dental health care in Finland (Svedström-Oristo et al., 2001), but considerable regional variation in access to and organization of public orthodontic treatment has been reported in both Finland and Sweden (Bergström and Halling, 1996; Pietilä et al., 2004). Due to the uneven regional distribution of specialists, general dentists have been involved in the implementation of orthodontic treatments. Focusing on early intervention with simple appliances has made it possible for treatment to be offered to a larger number of children and adolescents with malocclusion. Hence, the average age of initiation of orthodontic treatments in Finnish health centers has been low, from an international viewpoint: 9.5 yrs (Pietilä et al., 1997). The optimal age for the initiation of orthodontic treatment is still debatable. The present evidence supports early treatment of persons with functional anterior or posterior crossbites, marked overjet (including trauma risk), and Class III malocclusion (Pirttiniemi et al., 1990; Hesse et al., 1997; Nguyen et al., 1999; Westwood et al., 2003; Årtun et al., 2005). The eventual benefits of early Class II treatment have not been evidence-based (Tulloch et al., 2004). Long treatment times following an early start have frequently been considered a disadvantage (Hsieh et al., 2005; Pirttiniemi et al., 2005), although early treatment has been found to reduce the difficulty of and priority for phase 2 treatment in Class II malocclusion (King et al., 1999). Early headgear treatment has recently been shown to have a long-term positive effect on crowding by producing wider and longer dental arches (Pirttiniemi et al., 2005). However, the optimal timing of orthodontic treatment should always be defined individually (Tulloch et al., 1998; King et al., 1999). Studies on the applicability of systematically implemented early treatment strategies are few. Early treatment has been reported to reduce further treatment need in compliant individuals (Chung and Kerr, 1987; Al Nimri and Richardson, 2000). Also, the cost and productivity ratio of orthodontic care can be improved by starting treatments early (Pietilä et al., 1998), although contradictory results also exist (Järvinen and Widström, 2002). Early treatment has often been considered as only an interceptive treatment preliminary to subsequent obligatory fixed appliances in the permanent dentition (Gianelly, 1995; Tulloch et al., 2004). However, early treatment can be a much broader concept, involving all orthodontic treatment started in the early mixed dentition and performed with simple appliances (Väkiparta et al., 2005). Information is needed on the potential long-term outcome of early treatment as the primary modality not necessarily followed by fixed appliances. We intended to find out whether it is possible to eliminate definite need for orthodontic treatment in systematically organized public orthodontic care by focusing on early orthodontic intervention. The changes in treatment need and treatment outcome during occlusal development in children from 8 to 15 yrs old were also examined.
This was a prospective intervention study where the participants were regularly followed from 8 to 15 yrs of age, and those with malocclusions were identified and treated according to pre-planned criteria and protocol.
Participants
Occlusal Indices PAR score 0 indicated ideal occlusal alignments, and the higher the score, the greater was the deviation from the ideal. All PAR scores were weighted with the British weighing factors. PAR reduction (pre-treatment PAR - post-treatment PAR) greater than 70% = "greatly improved", from 70% to 30% = "improved", and reduction less than 30% = "not improved or worse".
Study Protocol A consultant specialist (MV) examined all participants clinically at ages 8 and 15 yrs. Bite was registered in the centric relation, and the specialist assessed the participants’ treatment needs based on the casts. After the first examination at age 8 yrs, orthodontic treatment was begun for the children with definite treatment need (DHC 4–5) who were considered to benefit from early treatment. Malocclusions in this category included crossbite (anterior or lateral), increased overjet (> 6 mm), deep overbite with palatal contact, and severe crowding. Two participants who had had quad-helix treatment before the first examination were scored according to their pre-treatment casts. The consultant specialist made all treatment plans based on clinical records, casts, and radiographs. Two experienced general practitioners carried out the orthodontic treatments according to the consultant’s plan. Quad-helix was preferred for the correction of posterior crossbite, and headgear was usually the appliance of choice for the correction of distal sagittal relationships. Multi-bonded fixed appliances were not used before the 12-year examination, after which participants needing fixed appliances were referred to the specialist for treatment. Lingual/palatal arches were used for space maintenance and retention. At the 10- and 12-year examinations, DHC 4–5 was an indication for starting treatment. Occlusal indices were not assessed for participants undergoing active treatment. At the 15-year examination, three participants were still undergoing treatment.
Data Analysis
Method Error
The intra-class correlation coefficient between the examiner’s duplicate PAR assessments was 0.96 (95% CI 0.92–0.98), and that between the examiner and the calibrating specialist was 0.97 (0.94–0.99).
Definite need for orthodontic treatment (DHC 4–5) among all participants decreased from 33% to 9.5% during the seven-year observation period, after which 3% were still receiving treatment (Fig. 1
By 15 yrs of age, 44 participants (51.8%) had received either comprehensive or limited orthodontic treatment. Six treatments (14% of those treated) were discontinued by mutual agreement because the children were non-compliant. Two children with definite treatment need due to hypodontia and spacing refused orthodontic treatment. At baseline, 62% of the participants in the treatment group had definite treatment need (DHC 4–5), and the DHC scores were significantly differently distributed between the treated and non-treated groups (Table 1  ). By age 15, definite treatment need in the treated participants had diminished considerably, and the DHC scores did not differ significantly between the participants with and those without treatment (Table 1).
The mean PAR score of the treatment group at age 8 was 18.6, which was twice as high as that of the non-treatment group (Table 2 ). By age 15, the mean PAR score of the treated children had decreased highly significantly (p < 0.001), and no difference existed between the mean PAR scores of the treated and non-treated participants (Table 2). The mean percentage PAR score reduction in the treatment group was 63%, and the mean PAR change was 12.5 points. Half of the treated cases (51%) fell into the "greatly improved" category (> 70% improvement). The four (10%) showing less than 30% improvement either had no improvement or had become worse (Table 2).
Of the finished treatments, 88% were performed exclusively with simple orthodontic appliances, typically starting after the first examination at age 8. Fixed appliances, comprehensive or limited to one jaw only, were used in five of the finished treatments (12%). Of the three participants in treatment, two had fixed appliances and one had an activator. Thirty-two percent of the treatments were started after the 12-year examination. The choice of appliance did not have a significant effect on PAR improvement (p = 0.94).
The need for orthodontic treatment in the studied age cohort decreased significantly during the study period from 8 to 15 yrs of age. By age 15, half of the study cohort had received free orthodontic treatment. The original difference in DHC and the mean PAR scores between treated and non-treated participants leveled off, indicating equality and correct allocation of treatment. Definite treatment need was not, however, completely eliminated by the age of 15 yrs. Participants who had either discontinued or totally refused the offered treatment can be one explanation. Also, there are always children with malocclusions who typically benefit from late treatment, i.e., those requiring surgical-orthodontic treatment, those with hypodontia needing prosthetic treatment, and those needing obvious extraction treatment. They would still be in active treatment or might even have not yet started treatment. Most participants/parents did not seek treatment themselves, but the dentist suggested treatment if the child’s malocclusion fulfilled the treatment criteria, which is the normal practice in public dental care in Finland. Providing treatment before subjective demand may sometimes lead to motivation problems, manifesting as lack of compliance and resulting in compromised treatment results. The rate of discontinued treatments in our study was in line with previous reports (Trenouth, 2003; Mc Mullan, 2005). Yet, in hindsight, the decisions to interrupt treatment should have been more strict, since some "finished" treatments were apparently sustained, and were carried through with difficulties due to missed appointments and problems in compliance. Most of the treated children had either greatly improved or improved occlusion by age 15. The 63% mean PAR score reduction in our study was somewhat greater than the PAR reductions of 46–60% reported from the public health services using a similar mixture of appliances (Richmond et al., 1993; Turbill et al., 1996; Fox et al., 1997; Teh et al., 2000). However, it is less than the over 70% reductions usually reported after treatments with full sets of fixed appliances (O’Brien et al., 1993; Richmond and Andrews, 1993; Birkeland et al., 1997). Outcomes similar to ours have also been presented for full fixed-appliance treatments (Turbill et al., 1996; Teh et al., 2000). The relatively low pre-treatment PAR scores in our study are likely to reflect the fact that, owing to the early treatment protocol, most scorings were done in early mixed dentitions. Roughly 2 out of 3 treatments were started in early mixed dentitions, and all except 3 of them were finished before the child was age 12. Therefore, a considerable number of our PAR scores at age 15 represent the post-retention rather than the post-treatment occlusal situation, and the previously reported over-10% post-treatment relapse in PAR reduction in five-year follow-up is at least partially included in our mean PAR reduction at age 15 (Birkeland et al., 1997). The total outcome of our treatment protocol will not be seen until all treatments have been finished by the next examination at age 20. According to several studies, the most potent predictor of marked occlusal improvement assessed by the PAR index consists of high pre-treatment PAR scores (Al Yami et al., 1998; Firestone et al., 1999; Pangrazio-Kulbersh et al., 1999; Teh et al., 2000). A method like PAR, which counts on predominantly permanent teeth (Templeton et al., 2006), typically gives relatively low scores in early mixed dentition, regardless of the existing definite treatment need. This may be one reason for the often modest PAR reductions reported for early treatment outcome (Pangrazio-Kulbersh et al., 1999). Posterior crossbite is a typical example: Correction of functional posterior crossbite in the early mixed dentition, with no other anomalies, hardly ever results in "greatly improved" PAR reduction, due to the low initial score. Rather, crossbite correction can be masked by the appearance of slight crowding in the permanent dentition, which has a minor impact on treatment need, but affects PAR, thus causing the case to be graded as "improved" or even "not improved", although the original cause of treatment was successfully addressed. The early treatment strategy was adopted primarily due to the limited availability of specialists in relation to the population in need of treatment. Experienced general practitioners implemented most treatments, according to the consultant’s instructions, with simple appliances, usually starting in the early mixed dentition. The use of fixed appliances was minimized, because they are generally more complicated and therefore more difficult to master without post-graduate orthodontic education. Hence, fixed appliances, if needed, were limited to treatment after the 12-year examination. The treatment outcome in our study seems to be close to the standard carried out by general practitioners with two-year clinical assistant training in orthodontics, using both fixed and removable appliances (Power et al., 1996). In conclusion, our results suggest that an early treatment strategy may be a useful option for considerable reduction in the definite need for orthodontic treatment in a child population in a public health care system with limited specialist resources.
This investigation was supported by the Intermunicipal Health Center of Kokkola, Finland. Received for publication June 4, 2007. Revision received October 23, 2007. Accepted for publication February 11, 2008.
Journal of Dental Research, Vol. 87, No. 6,
584-588 (2008) This article has been cited by other articles:
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
|
 |
|
Sign In to gain access to subscriptions and/or personal tools.
TOP
ABSTRACT
INTRODUCTION
= 0.76) and has been reported earlier (
