There are a few articles either using SI assessment (SIPTS) or sensory integration approaches but mainly looking a motor control. If I remember correctly they do not specifically look at tactile or oral issues. The other thing that I am always wary of is if the researchers are using the guidance re: the use of SI in research, as often sensory stimulation and modulation techniques are being referred to as SI therapy and as such when reading the research you end up comparing 'apples with pears,' instead of 'apples with apples.' I am aware from practice that many of us use play activities that increase the proprioceptive and tactile awareness around and in the mouth to help increase awareness of the lips, tongue and cheeks - as such there may be evidence in the SALT professional journals.