One versus two anterior miniscrews for correcting upper incisor overbite and angulation: a retrospective comparative study

Background

Miniscrews are effective devices for performing upper incisor intrusion. Different mechanics can be applied depending on the treatment objectives. This study aimed to evaluate the efficacy of one or two anterior miniscrews for upper incisor correction in cases of overbite and angulation in adult patients.

Methods

Forty-four adults with deep overbite were divided into two groups: group 1 was treated with one miniscrew between upper central incisors and group 2 with two miniscrews between upper lateral incisors and canines. Incisor intrusion and length were measured from lateral cephalograms before treatment, after treatment and at least 12 months into retention (T0, T1 and T2). Forces were applied (90 g) from the miniscrews to the archwire using elastomeric chains. ANOVA analysis was used to determine whether differences between evaluation times were statistically significant.

Results

Mean root resorption was 2.15 ± 0.85 mm, which ceased after active treatment. Overbite mean correction was − 3.23 ± 1.73 mm with no statistically significant relapse. Overbite correction and incisor intrusion were significantly greater in group 2 (− 3.80 ± 1.43 versus − 2.75 ± 1.63 for OB and 8.19 ± 3.66 versus 5.69 ± 2.66 for intrusion). Resorption and overbite correction were positively related. No counterclockwise rotation of the mandibular plane was observed.

Conclusions

Overbite correction can be performed by means of upper incisor intrusion without rotation of the mandibular plane. Correction of upper incisor intrusion and overbite is greater in patients treated with two miniscrews. The increase in upper incisor buccal angulation is greater with one miniscrew. Root resorption is positively related to the extent of intrusion. Stability is satisfactory regardless of whether one or two miniscrews are used.

The use of occlusal indices in high-impact literature

Malocclusion is difficult to define because individuals and cultures vary widely in their perceptions of what constitutes an occlusal problem. A number of occlusal indices have been devised but, probably because of this perceptual problem, none has ever emerged as a standard.

OBJECTIVE

The main objective was to review the use of the principal occlusal indices.

BASIC RESEARCH DESIGN

The PUBMED database was searched for the main occlusal indices employed, journals with an impact in dentistry and specialist orthodontics journals.

RESULTS

The occlusal indices most frequently employed were IOTN (163 studies), PAR (132 studies), DAI (68 studies) and ICON (32 studies). The journals publishing the greatest number of studies using these occlusal indices are those specialising in orthodontics.

CONCLUSIONS

In the high-impact scientific literature, the indices in greatest use are IOTN, followed by PAR, DAI and ICON. DAI and IOTN are mainly used in epidemiological or prevalence studies, while PAR is generally used for longitudinal studies. IOTN is used more in Europe. DAI is used worldwide; though least in Europe.