It is a common misunderstanding that infants do not have sinuses.
Many people do not understand what sinuses are. Thanks to the omnipresence of TV ads touting the latest quick fix for "sinus headaches," many people think they have sinusitis whenever they have the least bit of nasal congestion or facial pain. There are many other problems that can cause nasal congestion, postnasal drainage and facial pain/headache. Sinusitis is only one possible cause of such symptoms.
Assuming that your question was not simply a product of random curiosity, I would guess that one of two things may be true: (1) you have a baby who has been diagnosed with sinusitis, and you were surprised that this could be possible, or (2) your baby has nasal congestion or thick, discolored nasal mucus, and you are wondering if this could be a sinus infection. Quick answer to both concerns: sinusitis CAN occur in infants, but (as with adults) there are a number of other possible explanations for nasal congestion and thick nasal mucus.
Back to the anatomy lesson. Sinuses are best thought of as air pockets in the bones of the head. These air pockets are connected to the nasal cavities via narrow ducts. The sinuses are lined with a specialized tissue, mucosa, which produces mucus. The mucosal cells have tiny, finger-like projections called cilia which beat rhythmically, so as to push the mucus out of each sinus, into the nasal cavity. There is a constant flow of mucus out of the sinuses, into the nasal cavity, down the back of your throat, into your belly.
There are four areas that contain sinuses. There is a single maxillary sinus located in each cheekbone, immediately beneath the eye. The ethmoid sinuses are a honeycomb-like network of air pockets located between the eyes and the nasal cavities. The frontal sinus is located immediately above the nasal cavity. If you place your fingertip between your eyebrows, you will be pointing to the center of the frontal sinus. The frontal sinus extends above each eye, within the bone of each eyebrow. Finally, the sphenoid sinus is located deep within the head, immediately behind the ethmoid sinuses.
At birth, the ethmoid sinuses are present, as are the maxillary sinuses (although they are very small). The frontal sinus begins to appear at about age 2 or 3, and the sphenoid sinus begins to appear at age 3. These air pockets enlarge with the growth of the skull, so it is fair to say that the sinuses enlarge throughout childhood and early adolescence. Sinusitis (a bacterial infection of one or more sinuses) can occur at any age, but under the age of 10 the ethmoids are the most commonly infected sinuses.24It can be cured with the natural therapy and homemade therapy.
Link below for above1 year babies
Link below for above 3 year babies