In many patients with cerebral palsy, certain neonatal reflexes may persist long after the age at which they normally disappear. These primitive reflexes are usually modified or are progressively replaced as the subcortical dominance of the infant’s behavior is suppressed by higher centers of the maturing central nervous system. Three of the most common reactions, which a dentist should recognize, are the following: 1. Asymmetric tonic neck reflex. If the patient’s head is suddenly turned to one side, the arm and leg on the side to which the face is turned extend and stiffen. The limbs on the opposite side flex. 2. Tonic labyrinthine reflex. If the patient’s head suddenly falls backward while the patient is supine, the back may assume the position known as postural extension; the legs and arms straighten out, and the neck and back arch. 3. Startle reflex. This reflex, which is frequently observed in persons with cerebral palsy, consists of sudden, involuntary, often forceful bodily movements.  This reaction is produced when the patient is surprised by stimuli, such as sudden noises or unexpected movements by other people.  Note: Parachute reflex appears at 6-9 months and persists throughout life. Clinical importance: it is either absent or abnormal in spastic form of cerebral palsy.