This research aimed to determine the relationship between the maxillary posterior teeth and maxillary sinus floor (MSF), as well as the impact of nearby tooth loss on the space between MSF and posterior maxillary roots. A number of 120 digital panoramic radiographs were obtained from the archives of several clinics in Al-Najaf, Iraq, with the overall teeth examined in these radiographs including 236 of the 1^st premolars, 227 of the 2^nd premolars, 227 of the 1^st molars, and 231 of the 2^nd molars, from the right and left sides. The distances between the apices of the teeth and the maxillary sinus were determined. There are three categories of relationships between upper posterior teeth roots and MSF. These include type Os (root apex exists below or outside MSF), Type Co (root apex in contact with the MSF), and Type Is (root apex above or inside MSF). Type Os is the most encountered among premolars, Type Co is mostly encountered among the 2^nd molars, and Type Is, in the 1^st and 2^nd molars. The study finds no correlation between age, gender, and the distribution of maxillary posterior tooth roots attached to the MSF. The first premolars were the furthest from MS, while the first molars were the closest. The most frequent link between maxillary molar roots and the MS was the Co-relation for the 2^nd maxillary molar and the Is relation for the 1^st maxillary molar. There is a non-significant decrease in the distance between the apices of the 1^st maxillary premolar, 2^nd maxillary premolar, and 1^st maxillary molar and the MS before and after extraction.