The adjustable lateral cushion is a true preventive solution for flat head syndrome in infants from birth to 4 months. Whether dealing with flattening on one side of the back of the head (plagiocephaly) or flattening across the entire back of the skull (brachycephaly), the only truly effective treatment is to remove the pressure causing the deformation. Physiotherapy, osteopathy, and chiropractic care are justified to release neck tension and restore a full range of head movements. However, when bony flattening has already occurred, quick intervention with positional treatment is critical before the condition worsens and becomes irreversible. The lateral positioning cushion consists of two foam triangles connected together, allowing the child’s body to be semi-laterally positioned at a 45° angle. This positioning places the head on the chosen side. The larger triangle supports the child’s back; the lower arm rests on the top edge of the smaller triangle. For unilateral flattening, position the baby only on the side that avoids pressure. For general flattening, alternate sides daily or after each feeding. Initially, the cushion is used during the day under adult supervision. If deformation is severe, the pediatrician may recommend night use too. An adaptable Delta™ version is available depending on the child’s size. The earlier treatment starts, the quicker the recovery — after 5 months, cranial ossification makes recovery uncertain. Remove the cushion around 4½ months of age, when the baby starts rolling onto their stomach.