Effect of rapid maxillary expansion on glenoid fossa and condyle-fossa relationship in growing patients (MEGP): Study protocol for a controlled clinical trial

Abstract

Aims and Objectives:Rapid maxillary expansion (RME) is an orthodontic nonsurgical procedure aiming at increasing the width of the maxilla by opening mainly the intermaxillary suture in patients presenting a transverse maxillary skeletal deficiency. The objectives of the current prospective controlled clinical and radiographic study are to evaluate the hypothesis that RME in growing patients will result in radiographic changes at the level of interglenoid fossa distance, condyle-fossa relationship, and nasal cavity widths compared to the group who received no treatment initially and served as untreated control.Materials and Methods:In this prospective controlled clinical and radiographic study, forty healthy growing patients selected from a school-based population following a large screening campaign, ranging in age between 8 and 13 years, presenting a maxillary constriction with bilateral crossbite, and candidates for RME are being recruited. The first group will include participants willing to undergo treatment (n = 25) and the other group will include those inclined to postpone (n = 15).Results:The primary outcome is to compare radiologically the interglenoid fossa distance and the condyle-fossa relationship; nasal cavity width will be a secondary outcome. A multivariable analysis of Covariance model will be used, with the assessment of the time by group interaction, using age as covariate. The project protocol was reviewed and approved by the Ethics Committee of the Lebanese University, National Institute in Lebanon (CUEMB process number 31/04/2015). The study is funded by the Lebanese University and Centre National de Recherche Scientifique, Lebanon (Number: 652 on 14/04/2016).Conclusion:This prospective controlled clinical trial will give information about the effect of RME on the glenoid fossa and condyle-fossa relationship and its impact on the nasal cavity width.Trial Registration:Retrospectively registered in BioMed Central (DOI10.1186/ISRCTN77788053).

Effects of rapid maxillary expansion on temporomandibular joints:

“…Thus, the remaining 15 records were selected for full-text reading. Of these, one study was eliminated because it was a protocol proposal to be followed in future studies, 15 one for evaluating pre-and post-intervention changes through gypsum models and bite registration, 16 one for assessing condylar change by means of zonograms, 17 and five studies were excluded since they examined patients who underwent slow maxillary expansion. 10,[18][19][20][21] Therefore, seven articles from the systematic search were included for qualitative analysis; [22][23][24][25][26][27][28] as well as one record found by hand search (n ¼ 1); 29 totaling eight articles included in this review ( Table 1).…”

Systematic review of major considerations of rapid maxillary expansion

“…3 Thus, the surgical expansion of the maxilla with the use of the Hyrax expander has become a poorly indicated procedure, since the great majority of patients with maxillary atresia also have other vertical and/or sagittal bony bases of the face. 4 In this context, however, the rapid expansion of the surgically assisted maxilla presents as a safe and easy procedure to be performed in the office, and is also a low-cost and acceptable procedure for patients. 1 Furthermore, the arches that were segmented are also easier to be orthodontically terminated after surgical treatment, to the extent that some experienced orthodontists systematically prefer upper arch segmentation not only to treat it transversally, but also to finalize better and faster clinical cases.…”

“…1 Thus, as a literary corollary, the NSARME technique is adequate for patients with incomplete maxillary bone maturation and transverse maxillary deficiency that cannot be corrected by fixed apparatus. 4,5 Another indirect benefit of maxillary expansion techniques is the improvement of upper airflow reducing respiratory distress, promoting the increase of air cavity. 5 Thus, the most accepted age for performing NSARME varies widely according to the literature, being proposed for patients with a maximum age of 14 years in women and 16 years in men, according to.…”

“…1 It has as main objective the maxillary disjunction through palatal expanders and, therefore, improves the transversal dimension of patients affected by maxillary deficiencies. 4 In this context, NSARME is contraindicated in patients with complete bone maturation and, for these cases, surgical rapid maxillary expansion (SARME) is indicated, which is preferable with Hyrax or Haas expander. 1 The study of maxillary discrepancies is currently an area of great scientific interest in dentistry.…”

“…SARME can be performed by maxillary osteotomy and rafepalatine associated with a palatal expander, or LeFort I osteotomy associated with maxillary segmentation. 4,5 From the Haas dental orthodontic expander, many others were developed, including the modified Haas and the Hyrax apparatus. 6 The latter is a supported dento expander that leads to greater posterior dentoalveolar inclinations, if compared as Haas expander.…”