Postretention assessment of deep overbite correction in Class II Division 2 malocclusion

Multiloop edgewise archwire technique and denture frame analysis: a systematic review

Background

The Multiloop Edgewise Archwire (MEAW) appliance is an orthodontic treatment method suitable for the therapy of severe types of malocclusions such as open bites or anterior crossbites. The cephalometric Denture Frame Analysis (DFA) provides a supportive diagnostic tool for patient-specific treatment planning concerning the rearrangement of occlusion within the “denture frame”. The objective of this study is to give a comprehensive overview of the national and international scientific literature about MEAW and DFA regarding the general therapeutic effects, advantages and limitations.

Methods and materials

A computerized literature search was performed using four principal medical databases (PubMed/Medline, Google Scholar, Web of Science and Cochrane Central Register of Controlled Trials) and supplemented by manual searching of the references listed in the retrieved articles. The results were screened and assessed following the PRISMA guidelines.

Results

Six hundred seventy-seven full articles were assessed for eligibility. A number of 134 articles went through qualitative analysis and 3 studies were finally involved in comparative synopsis. The findings reveal advantageous characteristics of the MEAW technique such as a high degree of three-dimensional individual tooth control and a comparatively low load deflection rate, causing mostly dentoalveolar changes without significantly influencing the skeletal structures.

Conclusion

Based on current literature, the MEAW technique appears to have several therapeutic benefits and serves as a sufficient alternative treatment method for dentoalveolar compensation, when measures of orthognathic surgery are rejected. Concerning the deficient data basis of available literature and the low level of scientific evidence, further studies are required in order to expand on the knowledge in this subject area. Several aspects like the effectiveness or the long-term stability have to be evaluated more extensively. Moreover, the transferability of the DFA to ethnic groups other than the Asian ethnicity should be examined further.

Correction of Deep Overbite by Using a Modified Nance Appliance in an Adult Class II Division 2 Patient with Dehiscence Defect

A modified Nance Appliance (MNA) is introduced as a treatment option for an adult class II division 2 malocclusion (CII/2) patient with deep overbite and dehiscence on the facial root surface of retroclined upper incisors through the cone-beam computed tomography (CBCT). Indications for this modified MNA as well as a brief description of fabrication procedure and biomechanical analysis of the treatment effects are shown in detail. Root control and absolute intrusion without enlarging the bony defect were achieved. The treatment results were satisfying and favorable.

Stability of Class II fixed functional appliance therapy--a systematic review and meta-analysis

OBJECTIVES

To systematically search for scientific evidence concerning the stability of treatment (Tx) results achieved by means of Class II fixed functional appliance therapy and to assess possible differences between appliances.

SEARCH METHODS

An electronic search of databases and orthodontic journals was carried out (until December 2013), with supplemental hand searching. In addition to the names of all identified appliances, the term fixed functional was used in combination with each of the following search terms: long-term, post-Tx, relapse, retention, stability.

SELECTION CRITERIA

To be included in the review, the articles had to contain clear data on: Class II Tx with a fixed functional appliance (>5 patients), post-Tx period ≥ 1 year, assessment of ANB angle, Wits appraisal, molar relationship, soft-tissue profile convexity excluding the nose, overjet and/or overbite.

DATA COLLECTION AND ANALYSIS

The literature search revealed 20 scientific investigations which corresponded to only two of the 76 identified appliances (Herbst and Twin Force Bite Corrector). As only one publication was found for the Twin Force Bite Corrector, a meta-analysis could only be performed for Herbst Tx. The data were extracted, pooled and weighted according to the number of patients in each study.

RESULTS

The mean values for post-Tx relapse (percentages relative to the Tx changes) were: ANB angle 0.2 degrees (12.4 per cent), Wits appraisal 0.5mm (19.5 per cent), sagittal molar relationship 1.2mm/0.1 cusp widths (21.8 per cent /6.5 per cent); soft-tissue profile convexity excluding nose less than 0.1 degrees (1.0 per cent), overjet 1.8mm (26.2 per cent), overbite Class II:1 1.4mm (44.7 per cent), overbite Class II:2 1.0mm (22.2 per cent).

CONCLUSIONS

The scientific evidence concerning the stability of Tx results is inexistent for most fixed functional appliances for Class II correction except for Herbst appliance Tx. Even if the evidence level of most included studies is rather low, good dentoskeletal stability without clinically relevant changes was found for most variables.

Stability of deep-bite correction: A systematic review

OBJECTIVES

Deep bite occurs in about 15% to 20% of the US population. Currently, it is unknown which types of correction are most efficient or stable. The purpose of this systematic review was to investigate factors related to stability of deep-bite correction.

MATERIALS AND METHODS

An electronic search of 4 databases was performed from January 1, 1966 to June 27, 2012. Studies were considered for inclusion if they reported on deep bite samples that underwent orthodontic treatment in the permanent dentition. Records were required at the initial, posttreatment, and 1-year posttreatment times. Hand searching of reference lists of the included studies was performed. Data were abstracted using custom forms, and risk of bias was assessed using a modified Newcastle-Ottawa Scale.

RESULTS

Twenty-six studies met the inclusion criteria. Most were case series, with considerable potential for bias. The significant heterogeneity of the studies precluded meta-analyses, and only descriptive statistics and stratified comparisons were reported. On average, patients underwent significant overbite improvement during treatment, and most of the correction was maintained long-term. Across all studies, the mean initial overbite, posttreatment overbite, and long-term overbite were 5.3, 2.6, and 3.4 mm, respectively. Initial severity appeared to be related to long-term stability. However, this relationship was difficult to isolate from other factors. The length of follow-up did not appear to be related to the amount of relapse.

CONCLUSIONS

Although the quality of the current evidence is not high, patients with deep-bite malocclusion appear to undergo relatively successful treatment, and most of the correction appears to be stable.