Priyanshi Ritwik BDS, MS
There are more than 12 methods to correct anterior crossbites, but only weak evidence to support rapid correction (within weeks) of such crossbites in the primary or mixed dentition using bite planes or reversed temporary crowns.
In children with primary or mixed dentition, who have an anterior crossbite involving the incisors without an underlying skeletal class III malocclusion, how do different treatment modalities compare to each other?
The authors searched five databases, and hand searched five journals to identify pertinent studies published up to November 2010. They included studies that reported on the correction on anterior dental crossbite in the primary and/or mixed dentition, without an underlying skeletal class III malocclusion. They limited their search to literature published in English.
The authors identified 499 articles, from which 46 met the inclusion criteria. Of the included studies, 40 were case reports, three were case series and three were retrospective cohort studies. The literature reported multiple treatment modalities for the early correction of anterior crossbite including removable appliances with finger springs, functional appliances, cemented bite planes, reversed crowns, bonded composite or compomer ramps, fixed expansion appliances, conventional orthodontics using 2x4 appliance, cross elastics, removal of occlusal interferences and surgical repositioning. The authors found that similar treatment modalities spanned over similar treatment durations. Correction with a bite plane or reversed crown took the least time, spanning over a few weeks. Mainstream approaches were removable appliances with finger springs, bite planes (composite, compomer or reversed crowns) , fixed 2x4 orthodontic appliances and cemented appliances (quad helix or w-arch). Only one case reported surgical repositioning. Treatment time with removable appliances ranged from 6 weeks to 3 months, from 3-4 weeks with cemented appliances and from 2-7 months with 2x4 orthodontic treatment. The authors rated the evidence quality of each of the included studies as low or very low.
Although multiple treatment modalities (more than 12) have been identified in the literature for the management of anterior crossbite in the primary and mixed dentition, there is a lack of high quality evidence to support any particular treatment modality. Comparative studies for the management of this clinical problem are missing. There is weak evidence to show that use of bite plane or reverse crown require the shortest treatment time.
Source of Funding:
Importance and Context:
Anterior crossbite is an abnormal labiolingual relationship between the maxillary and mandibular incisors, with the maxillary incisor(s) lingually positioned. If left untreated, it can lead to damage of the dental hard tissue, gingival recession, loss of alveolar bone support, temporomandibular dysfunction, lower incisor mobility, poor esthetics and, in growing children, abnormal skeletal growth. Clinical correction with interceptive orthodontics is usually simple, noninvasive and rapid. The biomechanics of correction is usually at the treating dentist's discretion. Multiple treatment modalities exist, but the treatment type and duration have not been systematically analyzed before.
Strengths and Weaknesses of the Systematic Review:
The authors used accepted methods to identify published studies on the topic. They searched five databases and hand searched five journals. They only included articles published in English. They did not search grey literature. They used the PICO (P: population; I: intervention; C: Comparison; O: outcome) methodology to develop a focused search and clearly stated the search string. The kappa statistic was established to be 0.84; disagreements were resolved by discussion. The authors clearly stated inclusion and exclusion criteria, excluding studies if the patients had an underlying class III malocclusion and if the treatment duration was not stated. The review did not include study selection or data extraction in duplicate. The authors assessed the evidence quality using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. The authors did not state any conflicts of interest. They reflected on publication bias in their discussion but could not account for it in their data analysis.
Strengths and Weaknesses of the Evidence:
Case reports made up the majority of included studies (40 out of 46). There were three retrospective cohorts and three case series. Thus, the level of evidence of the included studies was low. Since there were several different treatment modalities reported in the literature, the authors did not perform quantitative or statistical analysis. Instead, they performed a qualitative comparison of the multiple treatment modalities. The authors did not distinguish between primary and permanent teeth. There were 18 case reports in which the crossbite was corrected in the primary dentition. In these cases, bite plane or reversed crowns were most commonly used. Although these are the treatment modalities that take the shortest time to correct the problem (a few weeks), the data comes from their use mainly in primary dentition. All three cohort studies utilized the 2x4 appliance for permanent incisors; where as the case series reported on the use of composite ramps for permanent incisors. All the included studies reported on the success of corrections of the crossbite. However, a publication bias exists; clinicians are likely to publish case reports documenting successful treatment rather than failure of treatment.
Implications for Dental Practice:
There are multiple treatment approaches to correcting anterior crossbite in the primary and early mixed dentition. However, there is a lack of high quality evidence to support any particular technique.