Table 3. Synthesis of articles selected for systematic review about other sleep-related problems in Down syndrome (other than obstructive sleep apnea); (age>18 years).

Author/year	Study	N° of patients	Mean of age (years/months)	Time of follow up	Outcome	Conclusion
Gomes et al., 2020 25	Case series-maximum mouth opening-MMO; maximum bite force-MBF; maximum voluntary clench-MVC	35 (C) 35 (DS)	19–40 years	-	Electrical activities of the masseter and temporal muscles (at rest and in maximum voluntary clench-MVC), maximum bite force-MBF, and maximum mouth opening-MMO were investigated.	Masseter and temporal muscle hypotonia were found in all atypical subjects with DS. This muscle dysfunction strongly was related to overweight/obesity, risks for development of cardiovascular/metabolic diseases, OSA severity, successive snoring episodes, and salivary flow reduction in DS.

OSA: obstructive sleep apnea; DS: Down syndrome.