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The effect of facemask in patients with unilateral cleft lip and palate: a systematic review and meta-analysis.

BACKGROUND
Patients with cleft lip and palate usually present a Class III skeletal pattern. Facemask (FM) is one of the conventional orthodontic treatment modalities used to address the skeletal discrepancy in cleft patients.


OBJECTIVE
To investigate the potential effectiveness of FM in unilateral cleft lip and palate (UCLP) patients.


SEARCH METHODS
Search without restrictions except language in seven databases since inception and hand searching until January 2019 was conducted. Detailed search strategies were developed for each database which were based on the PubMed strategy and adapted accordingly.


SELECTION CRITERIA
Controlled studies assessing the effect of FM in UCLP patients were to be included.


DATA COLLECTION AND ANALYSIS
After retrieval and selection of the studies, data extraction was performed. Both angular and linear cephalometric measurements were collected. Weighted mean differences (WMDs) and 95% confidence intervals (CΙs) between treated and untreated UCLP patients concerning the pre- and post-treatment angular measurements of each group were calculated using a random-effects meta-analysis model. The risk of bias in individual studies was assessed using the ROBINS-I tool.


RESULTS
From nine eligible studies, five were included in the meta-analysis investigating the use of FM in patients and controls with UCLP (with and without maxillary expansion). Statistically significant differences were evident for SNA/S-N-ss, SNB/S-N-sm, ANB/ss-N-sm, and SN-MP. FM was found to induce an increase of SNA (WMD = 2.12 degrees, 95% CI: 1.58 to 2.66), ANB (WMD = 4.17 degrees, 95% CI: 3.60 to 4.74), and SN-MP angles (WMD = 2.60 degrees, 95% CI: 1.10 to 4.10) and a decrease of SNB angle (WMD = -1.94 degrees, 95% CI: -2.48 to -1.40) in UCLP patients. Low to moderate heterogeneity was observed.


LIMITATIONS
They emerge due to risk of bias, exclusion of non-English papers and methodological characteristics of the included papers.


CONCLUSIONS
According to the available data, FM seems to improve the sagittal skeletal relationships in UCLP patients, increasing the SNA and ANB angles and decreasing the SNB angle. Moreover, in the vertical dimension, FM increases the SN-MP angle. Regarding dental measurements, there are controversial results. More high-quality studies need to be conducted in order to further clarify the impact of FM on UCLP patients.


REGISTRATION NUMBER
PROSPERO: CRD42019131619.