The school district is liable for negligence.  Negligence is the failure to exercise due care (that degree of care that a reasonable school district would have exercised under the same or similar circumstances to prevent foreseeable harm).Prior to filing a lawsuit for negligence against the school district, it may be possible to settle the case with the school district's insurance carrier.When your son completes his dental treatment and is released by the dentist or is declared to be permanent and stationary which means having reached a point in his treatment where no further improvement is anticipated, obtain his dental bills and dental report.  Your son's personal injury claim filed with the school district's insurance carrier should include these items.  Compensation for the dental bills is straight reimbursement.  The dental reports will be used to determine compensation for pain and suffering, which is an amount in addition to the dental bills.  The estimated cost of future treatment discounted to present value should be included. If the case is settled with the school district's insurance carrier, NO lawsuit is filed.  If you are dissatisfied with settlement offers from the school district's insurance carrier, reject the settlement offers and file a lawsuit for negligence against the school district.  You will need to be appointed guardian ad litem to file a lawsuit on behalf of your son because a minor cannot file a lawsuit himself.  If the case is NOT settled with the school district's insurance carrier, you will need to file the lawsuit for negligence against the school district on your son's behalf, prior to the expiration of the applicable statute of limitations or your son will lose his rights forever in the matter.