The myotonic Dystrophy Support group in England has announced the date of the 2013 conference near London in 2013. I attended this conference a few years back and it is excellent!  The date is June 8, 2013 Here are some of the details:

Although Oral facial weakness is commonly documented in myotonic dystrophy in congenital and juvenile forms the consequence and outcomes in Children had not been well documented. A study from 1997 gives additional information on this subject. 56 Children and adolescents from Sweden were survey and evaluated 18 with severe congenital form, 18 with moderate congenital form, 18 with childhood juvenile form and 2 with classical form
Here is part of this information:

Ability to understand Speech
This was moderately or severely reduced in 30 or the 56 patients studied
Speech intelligibility reduced   60%
No Speech                               9.3%

Muscle Function in Speech
Moderate or severe reduction in strength
Lip motility             76%
Tongue Motility      52.2%
Lip Force              69.2%
These issues  cause probelms with production of bilabial and dental constants. Bilabial constants use both lips. Dental constants are ones that use the tongue against the roof of the mouth.

.
Eating and drinking Difficulties
Difficulty in getting food off spoon with lips         20.4%
Takes long time to swallow bites of food            20.4%
Food and Liquids leak out of corners of mouth 16.7%
Food gets stuck in gums                                   14.8%
Swallows large pieces of Food w/o chewing      9.3%
Chokes on food                                                    7.4%
Coughs when receiving liquids                            7.4%
Presses tongue forward when swallowing        7.4%
Food or liquid go up through nose                      5.6%

Facial Expression
Mildly affected             9 Children
Moderately affected    25 children
Severely affected      25 children
49 had an open mouth at rest
37 had wide open mouth at rest

Speech
14 Mildly reduced speech
21 Moderately reduced Speech
9 severely reduced speech
5 No Speech <10 words
Congenital children had more severe reduced intelligibility

Click below for the full scientific study

OralFacial Dysfunction in Children with Myotonic Dystrophy
Developmental Medicine and Child Neurology 2007, 49 18-22

Children with DM1 should therefore be referred to a speech and language pathologist early to get support for optimal development of feeding and communications.