Abstract: Paranasal sinuses are located in the mid of the craniomandibular complex, including maxillary sinus, frontal sinus, sphenoid sinus and ethmoidal sinus. Paranasal sinuses take up most of the craniomandibular complex and exploring the relationship between the sinus and malocclusion is helpful to estimate the stability of craniomandibular structure. And this relationship is gradually clarified with the development of finite element technology and imageology. The maxillary sinus volume is positively correlated with the size of maxillary body, that is, the average volume of maxillary sinus is bigger in Class Ⅱ than Class I and Class Ⅲ. Vertically, the function stimulation to the maxillary sinus bottom is insufficient in the increasedFMPA patients with the weak masticatory muscle strength, resulting in the lower position of the maxillary sinus bottom. The size of frontal sinus is closely related to the occlusion of anterior teeth. The normal overjet and overbite induce a smooth flow to the sinus so it is smaller. The research on the relationship between sphenoid sinus, ethmoid sinus and malocclusion is still lacking. To explore the mechanical relationship between the sinus, craniomandibular complex and the maxillofacial system is helpful to determine whether the relationship between the maxilla and mandible is balanced and stable, which has some guiding values for the occurrence, treatment and prognosis of malocclusion.

Key words: paranasal sinus, malocclusion, pneumatization