In addition, a 4 cm wound should constitute a minor injury. Besides injury identification, injury identification should also be carried out. I don't know where the injury identification was done. If it is done in Jixi, it is required to do injury identification at the same time. Those who constitute minor injuries may be investigated for criminal responsibility. Of course, such cases can be settled by themselves, and it is up to you whether to pursue the criminal responsibility of the other party. But one thing, whether the other party is investigated for criminal responsibility or not, can not be exempted from civil liability for compensation.
This case involves many legal issues, so it is suggested to ask local lawyers to provide legal help.
The above answers are for reference only. I hope it helps you.