Sjogreen 2010.

Methods	1 group, single‐treatment, counterbalanced design
Participants	8 children and adolescents aged 7 to 19 years with myotonic dystrophy type 1 with onset congenitally or in childhood. Participants randomly assigned to 2 groups (A, B). A: treatment group ‐ n = 4; 7 to 19 years; 2 males; 3 congenital onset B: control group without treatment ‐ n = 4; 11 to 17 years; 3 males; 2 congenital onset
Interventions	The intervention consisted of 16 minutes of training with a pre‐fabricated 'oral screen', 5 days per week. The 16 minutes were divided into 3 sessions: 3 minutes of active training with the oral screen. A teacher or parent of the participant pulled the oral screen for 5 seconds as much as possible without pulling it out of the mouth and then paused for 5 seconds as for (1) above 10 minutes of passive use of the oral screen inside closed lips to experience closed mouth and nasal breathing A sand glass or a timer was used as a reminder of time. A log book was used to record the training. The authors specified that it was preferable for training to be done at school during the day as individuals with myotonic dystrophy generally tired in the morning and in the evening, but that this was not always possible. Intervention was conducted at school (n = 4), home (n = 3), or mixture of 2 sessions at school and 1 at home (n = 1).
Outcomes	3 outcome measures were relevant to oropharyngeal dysphagia lip closure force and endurance lip mobility eating and saliva control questionnaire Outcome assessments of lip force and endurance measured with a calibrated lip force meter were conducted at school or in the participant's home every fourth week. Lip mobility measured using 3D motion analysis, and parental completion of a questionnaire of eating ability and saliva control was conducted at the clinic at baseline, immediately after the treatment and following the 16‐week non‐treatment period
Notes	There were inconsistencies between data tables in the Sjogreen study (specifically Tables 1 and 4 in the manuscript) on the outcomes reported on the parent questionnaire at baseline. Further, this study is at risk of selection bias given the very small sample size of participants per group
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	6 folded pieces of paper with information about subgroup allocation (A or B) were placed in a box. Participants were asked to pick a piece of paper to find out when they would start treatment. 2 children were enrolled later in the study and had the opportunity to choose whether they wanted to start treatment immediately or wait for 16 weeks, as the intervention interfered with the summer holidays
Allocation concealment (selection bias)	Low risk	Random assignment occurred after informed consent was obtained
Blinding of participants and personnel (performance bias) All outcomes	High risk	The nature of the treatment resulted in neither participant or personnel being blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	1 outcome assessor (speech language pathologist not involved in the study) was blinded for the entire study. 2 personnel outcome assessors (speech language pathologist and dental nurse) were not blinded, but were documenting objectively obtained measures (lip closure force, grip force and 3D video analysis of lip mobility). Parents of children also completed a questionnaire on eating and drinking difficulties. Parents could not be blinded to the intervention
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data were clearly reported in the manuscript. Few instances of missing data
Selective reporting (reporting bias)	Low risk	Individual data were reported for all outcome measures
Other bias	Low risk	No obvious further sources of bias

3D: 3 dimensional; ID: intellectual disability.