All cases _______ children are dealt with in juvenile court.

• Concerning (preposition):
English Meaning - About something; involving someone or something.
Bangla Meaning - সম্পর্কে।
Example Sentences - He asked several questions concerning the future of the company.
- All cases concerning children are dealt with in juvenile court. (শিশুদের সংক্রান্ত সমস্ত মামলা কিশোর আদালতে মোকাবেলা করা হয়।)

Other options,
• Concern - উদ্বেগ।
Example - There is no cause for concern, he will come round soon.

• Concerned about/for - উদ্বিগ্ন হওয়া।
Example - I am concerned about your safety.

Source:
1. Oxford Learner's Dictionaries.
2. Accessible Dictionary by Bangla Academy.