1. braces correction: If the baby's teeth are uneven, you can consider braces correction. This can help to adjust the position and occlusion of teeth, thus improving the situation of eversion of lips.
2. Language therapy: Some children have unclear pronunciation or slurred speech due to poor oral muscle development. Speech therapy helps to enhance the motor ability of oral muscles and improve pronunciation and articulation.
3. Physical therapy: Physical therapists can help strengthen the athletic ability of oral muscles through massage, stretching and other means, thus improving the situation of valgus of lips.
4. Surgical treatment: In rare cases, surgery may be necessary. For example, if a child's cleft lip is serious, surgery may be needed to repair it.
It should be noted that for a four-year-old baby, the process of correction takes patience and time. Parents should closely cooperate with doctors, formulate appropriate treatment plans, and follow up regularly to monitor the treatment effect.