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Background: Nasal septum deviation (NSD) can cause serious anatomical and clinical complications. It can change the breathing pattern and thus alter the anatomy of the airway structures. Despite its importance, the association between NSD with the nasopharynx volume (NPV) has not been assessed before. Therefore, we aimed to investigate it for the first time. Methods: Archival CBCTs of 202 patients older than 17 years and without any history of trauma or pathology of the nasopharynx and without any orthodontic/orthognathic treatments were evaluated (129 women, 73 men, mean age: 36.24 ± 14.61 years). All included CBCTs must have been taken with a 12 × 8 field of view and fully covered the nasopharynx areas. The extent of NSD (°) and NPV (mm3) were measured. NSDs were categorized as mild (NSD ˂ 9°), moderate (9 ≤ NSD ≤ 15°), and severe (NSD ˃ 15°). Associations between sex, age, NSD, and nasopharynx volume were assessed using independent-samples t test, chi-square, one-way ANOVA, Tamhane post hoc test, Pearson and point-biserial correlation coefficients, and multiple linear regressions (α = 0.05). Results: Mean NSDs were 11.27 ± 4.69° (range 1–19.5), 11.58 ± 4.63°, and 10.70 ± 4.76° in the sample, females, and males, respectively (P > 0.05). Of females, 27.9%, 40.3%, and 31.8% had mild, moderate, and severe NSDs. These were 35.6%, 39.7%, and 24.7% in males (P > 0.05). Mean NPVs were 4.88 ± 1.49, 4.80 ± 1.43, and 5.04 ± 1.60 mm3 in the sample, females, and males, respectively (P > 0.05). Mean NPVs were 6.41 ± 1.21, 4.87 ± 0.73, and 3.30 ± 0.65 mm3 in mild, moderate, and severe NSD groups (all P values = 0.000). Mean ages were 27.06 ± 6.49, 29.80 ± 9.64, and 54.73 ± 8.45 years in mild, moderate, and severe NSD groups (severe group being older than the other two groups, P = 0.000). NSD was strongly, negatively correlated with NPV (R = − 0.793, P = 0.000). Sex was not correlated with NPV or NSD (P ≥ 0.189). Age was negatively and positively correlated with NPV and NSD, respectively (P = 0.000). Modeling NSD (β = −0.776, P = 0.000) as a predictor for NPV rendered age effect insignificant (P > 0.05). Conclusions: It was found, for the first time, that the more deviated the nasal septum, the smaller the nasopharynx volume. Aging might increase NSD and through it, reduce the nasopharynx volume. Sex might not affect NSD or NPV. [ABSTRACT FROM AUTHOR]

In recent years, the use of gold nanoparticles in radiation therapy has been introduced as a new approach in radiotherapy. The aim of this study is to investigate the effect of gold nanoparticles (GNPs) in plaque brachytherapy for choroidal melanoma using Monte Carlo (MC) simulation. MCNPX code was used for simulation of human eye, Pd (model 200) brachytherapy source and the 20 mm COMS eye plaque that was loaded with 24 Pd seeds and standardized by Collaborative Ocular Melanoma Study (COMS). The tumour was defined from the inner surface of choroid with 0.55 cm height and latticed with gold nanospheres and it was filled with different concentrations of 5, 10 and 15 mg/g GNPs, separately. Dose rate and dose enhancement factor in tumour and normal tissues of the eye (without gold) was examined for this case and compared with gold-water mixture of the same concentrations distributed in the tumour. The results show that with increasing the concentration of GNPs, the dose in the tumour increases and the dose to the normal tissues decreases. Furthermore, the time that is required to deliver the prescribed dose to the tumour decreases. In the gold nanosphere case for 5, 10 and 15 mg/g concentrations, the DEF in the apex of the tumour are 1.28, 1.46, 1.44 and at the distance of 6.5 mm in the normal tissue (outside the tumour) this factor would be 0.82, 0.73 and 0.68. The comparison between two cases of gold nanospheres and gold-water mixture shows that when the gold concentrations are defined as mixed with water, the dose enhancement in the first depths are higher than when the gold-nanoparticles are distributed inside the tumour. Furthermore due to more reduced particle flux for water-mixture case, by an increase in the depth the dose enhancement in gold-nanosphere increases compared with gold-water mixture case. [ABSTRACT FROM AUTHOR]