The impact of maxillary sinus mucosa cyst on transcrestal sinus floor elevation

Abstract

Objective By comparing the changes of mucosa cyst in maxillary sinus and the newly-formed bone around the implant in the cyst area after transcrestal sinus floor elevation surgery to evaluate whether transcrestal sinus floor elevation surgery is impacted by maxillary sinus mucosa cyst. Methods A total of 12 patients who lost upper molar supervened with alveolar bone insufficiency with maxillary sinus mucosa cyst were enrolled among patients. Sinus floor was elevated by transcrestal path and dental implants were placed simultaneously with the cyst untreated. A series of measures were taken to evaluate osteogenesis around the implant beneath mucosa cyst. Paired sample t test was used to compare the projection area changes of mucosa cysts before surgery and the day after surgery as well as six months after surgery in order to evaluate the interaction between surgical trauma and mucosa cysts. Results The bone around implants was formed well in the area where the mucosa cyst was. All the 14 implants got well osteogenesis after six months. The average height of maxillary floor in this study was (5.5 ± 1.4) mm. The average length implants protruded into maxillary sinus was (2.9 ± 1.3) mm. One year after, the thickness of maxillary sinus floor increased (1.8±1.0) mm. Projection area of mucosa cyst was calculated and analyzed based on the measurement. The area mucosa cyst before surgery was (201.2 ± 184.0) mm2, while the day after surgery was (133.6 ± 187.6) mm2, and six months after surgery was (134.5 ± 107.1) mm2. Statistical results showed that paired difference mean and standard deviation between surgery before and the day after was (67.5 ± 87.1) mm2, and then between surgery before and six months after was (66.6 ± 142.8) mm2. The standard deviation of paired difference between surgery before and six months after was significantly increased, indicating that the volume of mucosa cysts showed a variety of manifestations in six months after surgery. Projection area data of mucosa cysts were compared with before and the day after surgery by paired sample t test. Statistic results showed that the size of mucosa cyst shrieked significantly the day after surgery (t = 2.685, P= 0.021) . While the data were compared with before surgery and six months after surgery, Statistic results showed that the size of mucosa cyst did not change significantly (t= 1.617, P= 0.134) . Results of the matched t test indicated that sinus lift operation caused trauma to mucosa cyst in the short term. Nevertheless, mucosal cysts were not irritated to deteriorate in the long term. Conclusion The presence of mucosa cyst in maxillary sinus has little effect on the maxillary sinus floor lifting and osteogenesis around implant. Key words: Mouth mucosa; Cysts; Maxillary sinus; Dental implantation; Transcrestal sinus floor elevation