First sinus to develop -

Ans. is 'b' i.e., Maxillary "Development of the maxillary sinus begins by the 65th day of gestation, making it the first sinus to develop in utero _________Essential otolaryngologyo Most common sinus affected by sinusitis overall- Maxillaryo Most common sinus affected in adult- Maxillaryo Most common sinus affected in children- Ethmoido Least common sinus affected- Sphenoido Sinuses involved in order of frequency- Maxillary > Frontal > Ethmoid > Sphenoid