Sinuses

💥Order of appearance of the paranasal sinuses: MEFS (maxillary, ethmoid, frontal, sphenoid)
Maxillary and ethmoid present at birth.
Frontal and sphenoid develop later.

💥Frequency of sinusitis/ carcinoma in the PNS:
AgainMEFS (maxillary mc, sphenoid least common)

💥Order of appearance of the PNS on xray:
MESF
Max 4 to 5 mths
Ethmoid 1 yr
Sphenoid 4 yrs
Frontal 6 yrs.

💥Frequency of osteoma is FEMS.