# Effects of Surgically Assisted Rapid Palatal Expansion on Facial Soft Tissues: A Systematic Review
###### Abstract  
Surgically assisted rapid palatal expansion (SARPE) is a successful method for treating transverse discrepancies in adult patients. The relocation of maxillary segments may induce changes at the surrounding soft tissues as well. The aim of this systematic review was to examine the possible effects that SARPE may have in the soft tissues of the face. Our search strategy included electronic databases (Pubmed, Scopus, ProQuest, Google Scholar, Cochrane Library) and a hand search of the reference list of found reviews. A priori definition of inclusion and exclusion criteria was made. Finally, 15 articles were included in qualitative synthesis. Risk of bias was generally high among the included studies. Study outcomes included nasal, labial, nasolabial and other facial soft tissue measurements. The evaluation of the changes was two-dimensional in six studies, and three-dimensional in nine studies. Meta-analysis was unfeasible due to lack of standardization, important methodological limitations, and shortcomings of the studies. A post-surgical increase in the dimensions of the alar width and the alar base width was commonly reported among the included studies. However, the above should be considered with caution due to the high risk of bias and the inability for quantitative synthesis.  
expansion; distraction osteogenesis; soft-tissue; SARPE +
Footnote †: journal: Medical  
performed in order to decrease the resistance resulting from the consolidation of facial and skull joints [3; 4; 5].  
Generally, surgical expansion is indicated in skeletal mature patients with a severe constricted maxillary arch, and can be performed with two different techniques: SARPE or segmental osteotomy of the maxilla with a wider repositioning of the two halves. [PERSON] et al. recommended that the latter technique can be chosen when the patient's skeletal problems are to be addressed with a single maxilla-mandibular surgical procedure to correct discrepancies in the sagittal and the vertical dimensions as well. On the other hand, SARPE is preferred when the patient's skeletal discrepancy is isolated on the transverse dimension [6].  
The first to propose SARPE to address TMD was [PERSON] (1938) [7]. SARPE is based on the principles of distraction osteogenesis described by [PERSON] (1987) [8]. The distraction force is transferred and applied to the bone via tooth-borne or bone-borne devices. It is a reliable method of treating TMD with clinically efficient long-term dental and skeletal changes [9; 10; 11]. These changes are reflected in the facial soft tissue as well. An increased projection of the cheek area in the lateral direction and widening of the nose were most commonly reported [12]. Treatment varies in terms of the surgical technique, the appliance used to achieve the expansion, and the expansion protocol. Recently published systematic reviews seem to reach different conclusions concerning the necessity of pterygoid plate separation [10; 13]. Furthermore, the effect of SARPE on nasal airway volume was recently reviewed as well [14]. The authors of this study reported a significant increase in nasal cavity volume and no increase in oropharyngeal volume. Accordingly, SARPE cannot be suggested as part of the treatment of respiratory dysfunctions [14].  
Although several papers investigate the dental and skeletal effects of SARPE, its potential outcome on facial soft tissues has not been reviewed yet. The aim of this article is to systematically search the literature and review the effects that it may have on the soft tissues of the face.