A loose incisor in a 2.5 year old child is usually caused by trauma, but the possibility of calcium deficiency cannot be ruled out. You can use periodontal splints to fix the position under the guidance of the doctor’s advice, and you can also take calcium supplements to alleviate the problem. A loose incisor in a 2.5 year old child can be caused by trauma. If the loosening is caused by trauma, first go to the hospital for a radiographic examination to determine the cause of the loosening of the tooth. If the tooth is broken, it is important to differentiate between root fracture and intermediate fracture, and the intermediate fracture can be removed. If the tooth is dislocated, a periodontal splint can be used for cementation repair, and the damaged tooth may grow back over time. Loose incisors in 2.5 year olds can also be caused by a calcium deficiency, and once calcification is poor, the roots of the teeth may be less stable. If there is a calcium deficiency, you can give your child some calcium tablets or other calcium preparations under the guidance of your physician. Loose teeth need to see a doctor as soon as possible to identify the cause and treat the symptoms.