Panoramic Radiographic Evaluation of Grafted Bone in the Maxillary Sinus Floor

Abstract

The purpose of this investigation was to clarify how bone resorption proceeded with the passage of time after bone was grafted to the maxillary sinus floor. Six cases (9 sinuses) underwent bone grafting to the maxillary sinus floor. Panoramic radiographs were taken of all cases preoperatively and at postoperative 1, 3, and 6 months. Measurements were taken of bone height from the alveolar crest to the original or new sinus floor in three regions (extended parts from the infraorbital canal, posterior surface of the zygomatic process, and maxillary tubercle) on the X-ray. For correction of magnification on the X-ray, the linear distances defined from anatomical landmarks were also measured, and the ratios of the bone heights to the linear measurements were calculated. The results were as follows
The ratios indicated that statistically significant decreases took place over 3 to 6 months after grafting to the extended part from the infraorbital canal, over 1 to 6 months after grafting on the extended part from the posterior surface of the zygomatic process, and over 1 to 3 months after grafting on the extended part from the maxillary tubercle. The decreases of ratios in the three areas from 3 to 6 months after grafting were slight as compared with the decreases from 1 to 3 months after grafting.But at the same time, the ratios, when computed on the preoperative and postoperative panoramic radiographs based on the bone height from alveolar crest to the original sinus floor in the three areas,almost never changed in any of the cases.
The findings suggested that resorption of grafted bone arose during the 3-month period after grafting in the first and second molar and maxillary tuberosity regions. In addition, bone resorption took place slightly over 3 to 6 months after grafting in the second premolar and the second molar regions.