Effect of molar intrusion with temporary anchorage devices in patients with anterior open bite: a systematic review

Alsafadi et al. Progress in Orthodontics (2016) 17:9 DOI 10.1186/s40510-016-0122-4 REVIEW Open Access Effect of molar intrusion with temporary anchorage devices in patients with anterior open bite: a systematic review Ahmad Saleem Alsafadi1*, Mohannad M. Alabdullah1, Humam Saltaji2 , Anas Abdo3 and Mohamed Youssef1 Abstract Objective: The objective of the study is to assess the effect of molar intrusion with temporary anchorage devices on the vertical facial morphology and mandibular rotation during open bite treatment in the permanent dentition. Methods: We performed a systematic review of the published data in seven electronic databases up to September 2015. We considered studies for inclusion if they were examining the effects of posterior teeth intrusion on the vertical facial morphology with open bite malocclusion in the permanent dentition. Study selection, risk of bias assessment, and data-extraction were performed in duplicate. Meta-analysis was not possible due to dissimilarity and heterogeneity among the included studies. Results: Out of the 42 articles that met the initial eligibility criteria, 12 studies were finally selected. Low level of scientific evidence was identified after risk of bias assessment of the included studies with no relevant randomized controlled trial performed. Out of the 12 selected studies, five studies used miniplates and seven studies used miniscrews. Mandibular counterclockwise rotation was found to be between 2.3° and 3.9° in six studies (as sassed by mandibular plane angle, between MeGo or GoGn and SN or FH plane) while it was less than 2° in the remaining studies. Conclusions: Current weak evidence suggests that molar intrusion with temporary anchorage devices may cause mandibular counterclockwise autorotation. Future well-conducted and clearly reported multicenter randomized controlled trials that include a non-treatment control group are needed to make robust recommendations regarding the amount of mandibular rotation during open bite treatments. Keywords: Systematic review, Skeletal open bite, Molar intrusion Review Introduction Open bite malocclusion is considered one of the most difficult orthodontic problems to correct because it appears as a result of the interaction of numerous etiological factors (genetic, dental, skeletal, functional, soft tissue, and habit) that contribute to its development [1]. An open bite can occur unilaterally or bilaterally in the buccal segments; it is particularly seen in the anterior teeth. Generally, different features have been found * Correspondence: 1 Department of Orthodontics, Faculty of Dentistry, Damascus University, Damascus, Syria Full list of author information is available at the end of the article to be associated with the skeletal anterior open bite distinguishing it from other types of malocclusion including increased lower face height, short posterior face height, [2] increased gonial and mandibular plane angles, [3] and increased maxillary molar dentoalveolar height [4]. Several reports have found correlations between orofacial muscle activity and vertical facial morphology [5–8]. These studies showed positive relationships between anterior open bite and weak musculature. Various therapeutic approaches have been proposed for the treatment of an anterior open bite. These approaches vary depending on the causative factors and involve myotherapy, preventive treatment, functional therapy, orthognathic surgery, and orthodontic treatment using © 2016 Alsafadi et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. Alsafadi et al. Progress in Orthodontics (2016) 17:9 anterior teeth extrusion or posterior teeth intrusion [9]. Among the non-surgical orthodontic treatment methods are the temporary anchorage devices (TADs) including miniplates [10] and miniscrew or micro-screw implants [9, 11]. Extrusion of anterior teeth is another alternative approach for open bite management, but it must take into consideration the smile esthetic [12]. Extrusion, however, is a less stable treatment than intrusion. The intrusion of posterior teeth with temporary anchorage devices was suggested to lead to decreased lower facial height by a counterclockwise rotation of the mandible; this may resemble the orthognathic surgery outcomes for any open bite patients [10]. Molar intrusion is recommended in open bite patients who usually have increased molar height [13]. While many reports indicated that increased molar height is one of the common findings in individuals with skeletal open bite [14], others do not support those findings [15, 16]. In order to evaluate the results of molar intrusion in the treatment of open bite malocclusion, it is necessary to recognize the effect of the posterior teeth intrusion on the mandibular rotation and facial morphology. Many reports evaluated the effect of open bite treatment during mixed dentition stage [17] and [18]. A recent systematic review examined open bite treatment modalities in children found no consistent findings regarding the most effective treatment modality in growing patients with open bite malocclusion [19]. However, no comprehensive review was conducted to examine the effects of posterior teeth intrusion on vertical facial morphology in non-growing patients. Therefore, the goal of the current report is to systematically review the effect of molar intrusion with temporary anchorage devices on the vertical facial morphology and mandibular rotation during open bite treatment in the permanent dentition stage. Material and methods This systematic review was reported according to the principles of the PRISMA statement for reporting systematic reviews of the health sciences [20]. Search strategy Comprehensive electronic searches up to September 30, 2015, were conducted in the following databases: PubMed, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Ovid, Scopus, and Web of science. The literature searches used the following Medical Subject Headings (MeSH) terms: “molar intrusion,” “posterior teeth intrusion,” and “anterior open bite” which were crossed with the following terms “mandibular autorotation” and “facial morphology.” In addition, the following journals were searched individually to find out any missing Page 2 of 13 articles: The Angle Orthodontists, American Journal of Orthodontics and Dentofacial Orthopedics, European Journal of Orthodontics, Korean journal of orthodontics, and Journal of Orofacial Orthopedics. No restrictions were applied regarding date of publication, language, or status during database searches. The search strate (...truncated)