This is the result of the orthodontic appliance for rapid palatal expansion ( RPE ). About 8mm maxillary width expansion was achieved in a month with one turn ( 0.25mm ) per day. It's not only correcting the posterior crossbite but also creating space for crowded teeth.
The gap between top front teeth showed that the RPE was working very well. But don't worry, the gap will be closed when we put braces on and start straightening the teeth.
The link below is how it looked when we started RPE.
https://www.riendental.com.au/single-post/2018/03/09/RPE---Rapid-Palatal-Expander