The maxillary sinus is one of the four pairs of paranasal sinuses located in the skull. It is situated within the maxilla, or upper jawbone, and is the largest of the sinus cavities. These air-filled spaces help to lighten the weight of the skull, produce mucus, and contribute to voice resonance. The maxillary sinus is connected to the nasal cavity, allowing for drainage and airflow. Infections or blockages in the maxillary sinus can lead to conditions such as sinusitis, which causes inflammation and discomfort. Symptoms may include facial pain, nasal congestion, and headaches. Proper functioning of the maxillary sinus is essential for overall respiratory health and comfort.