ABSTRACT
Mucous retention cysts (MRCs) of the maxillary sinuses are incidental findings in radiographs of the oral and maxillofacial structures. These cysts usually appear as rounded, dome-shaped, and soft-tissue masses, most often on the floor of the maxillary sinus. The aim of this study was to determine the prevalence of maxillary antral MRC and the effect of seasonal variation, sex and age in cone beam computed tomography (CBCT) images. Materials and Methods: In this simple, nonrandomized, cross-sectional study, CBCT images of patients were reviewed to evaluate the prevalence of MRCs and its location in the antrum, uni or bilateral, size, and season in which MRC occurred. The findings were analyzed using Statistical software SPSS and t-tests (P > 0.05). Results: A total of 765 CBCT images were evaluated (380 males and 385 females); 180 were suggestive of MRCs, 110 occurred in males (28.9%) while 70 (18.2%) occurred in females, which resulted in a prevalence of 23.5%. The peak prevalence of MRC was found in spring (41.6% of all radiographs), but there was no significant statistical difference between the occurrence of MRCs in different seasons (P > 0.05). Conclusion: This study showed no significant difference between the occurrences of MRCs in different seasons. There was no significant difference between male and female and different decades of life. Furthermore, there was no significant difference between the involvement of right and left maxillary sinuses and different walls of the antrum.
ABSTRACT
Context: Many synthetic bone materials have been introduced for repairing bone defects. Aim: The aim of this study is to comparatively evaluate the efficacy of nano‑hydroxyapatite (HA) and nano‑bioglass bone materials with their traditional micro counterparts in repairing bone defects. Materials and Methods: In this prospective animal study, four healthy dogs were included. First to fourth premolars were extracted in each quadrant and five cavities in each quadrant were created using trephine. Sixteen cavities in each dog were filled by HA, nano‑HA, bioglass, and nano‑bioglass and four defects were left as the control group. All defects were covered by a nonrestorable membrane. Dogs were sacrificed after 15, 30, 45, and 60 days sequentially. All 20 samples were extracted by trephine #8 with a sufficient amount of surrounding bone. All specimens were investigated under an optical microscope and the percentage of total regenerated bone, lamellar, and woven bone were evaluated. Statistical Analysis Used: Data analysis was carried out by SPSS Software ver. 15 and Mann–Whitney U‑test (α =0.05). Results: After 15 days, the bone formation percentage showed a significant difference between HA and nano‑HA and between HA and bioglass (P < 0.001). The nano‑HA group showed the highest rate of bone formation after 15 days. Nano‑bioglass and bioglass and nano‑HA and nano‑bioglass groups represented a significant difference and nano‑bioglass showed the highest rate of bone formation after 30 days (P = 0.01). After 45 days, the bone formation percentage showed a significant difference between nano‑bioglass and bioglass and between nano‑HA and nano‑bioglass groups (P = 0.01). Conclusions: Nano‑HA and nano‑bioglass biomaterials showed promising results when compared to conventional micro‑particles in the repair of bone defects.