Extraction of maxillary teeth The maxillary sinus is known for its thin floor and close proximity to the posterior maxillary (upper) teeth. The extraction of a maxillary tooth (typically a maxillary first molar which lies close to the lowest point of antral floor although any premolar or molar can be affected) is the most common cause of an OAC (which can then progress to an<unk>  as described above). Extraction of primary teeth are not considered a risk of OAC due to the presence of developing permanent teeth and the small size of the developing maxillary sinus. Other causes Other causes of an OAC are: maxillary fractures across the antral floor typically Le Fort I, displacement of posterior maxillary molar roots into antrum and direct trauma. An OAC can happen for many other more unusual reasons, such as acute or chronic inflammatory lesions around the tip of a tooth root which is in close proximity with the maxillary antrum, destructive lesions/tumours of the maxilla, failure of surgical incisions to heal (e.g. Caldwell-luc antrostomy), osteomyelitis of the maxilla, careless use of instruments during surgical procedures, Syphilis, implants and as a results of complex surgery (for example removal of a large cysts or resections of large tumours involving the maxilla.
Oroantral fistula
Liber pantegni
Omphalocele
Urachal fistula
Cimino fistula
Midline cervical cleft
Hypospadias
Iatrosophia