CBCT Evaluation of Bony Nasal Pyramid Dimensions in Iranian Population: A Comparative Study with Ethnic Groups

Evaluation of diagnostic accuracy of cone beam computed tomography and multi-detector computed tomography for detection of anatomical variations in rhinoplasty

BACKGROUND

Different imaging techniques, such as multi-detector computed tomography (MDCT) scan and cone beam computed tomography(CBCT), are used to check the structure of the nose before rhinoplasty. This study aimed to evaluate the accuracy of two imaging techniques, MDCT scan, and CBCT, in diagnosing structural Variations in rhinoplasty for the first time.

METHODS

This diagnostic accuracy study was conducted on 64 rhinoplasty candidates who complained of snoring and sleep apnea or had a positive result in the examination with Cottle's maneuver or modified Cottle technique between February 2021 and October 2022 at 15- Khordad Hospital affiliated to Beheshti University of Medical Sciences. Before rhinoplasty, patients were randomly assigned to one of the CT and CBCT techniques with an equal ratio. Scans were assessed for the presence of Nasal septum deviation (NSD), Mucocele, Concha bullosa, and nasal septal spur by two independent radiologists. The findings of the two methods were evaluated with the results during rhinoplasty as the gold standard.

RESULTS

NSD was the most common anatomical variation based on both imaging techniques. The accuracy of CBCT for diagnosing Nasal Septum Deviation and Mucocele was 80% and 75%, respectively. The sensitivity, specificity, and accuracy of CBCT in detecting Concha bullosa were 81.3% and 83.3%, respectively. The Kappa coefficient between CBCT and intraoperative findings for diagnosing NSD and Concha Bullosa was 0.76 and 0.73, respectively (p < 0.05).

CONCLUSION

CBCT can be considered a suitable method with high accuracy and quality to evaluate the anatomical variations before rhinoplasty.

[Piriform aperture as a cause of nasal obstruction. Part I. Anthropometric characteristics in different populations (systematic review).]

The piriform aperture (PA) is anatomically an opening in the central part of the facial skull. To date, the piriform aperture, as an element of the static component of the internal nasal valve (INV) and as a possible cause of its dysfunction, has not received proper surgical attention. If PA is considered as a possible cause of nasal obstruction, then the main parameter is its width, which has a direct effect on the volume of the INV area. This parameter is the focus of the presented work. Despite the absence of generally accepted normative indicators for PA, we currently know the shape and size of the piriform aperture in different ethnic groups of the population, described in the article. As a result of the analysis of the presented research results, it was revealed that the width of the PA is influenced by the gender, age and ethnicity of the individual. The anthropometric data of the piriform aperture require further study, since they are of important reference value not only in the theory of medical research, but also in practical otorhinolaryngology, maxillofacial and plastic surgery, pulmonology.

Morphometric Study of Nasal Bone and Piriform Aperture in Human Dry Skull of Indian Origin

INTRODUCTION

Nasal bone and piriform aperture shows racial and geographical differences because of variable climate. The aim of this study was to evaluate the dimensions (maximal width and length), the size and the shape of the piriform aperture (PA) and their sexual dimorphism in North Indian adult.

MATERIALS AND METHODS

In this observational study, dimension of piriform aperture and nasal bone were measured using digital vernier caliper after assessing landmarks around the piriform aperture on the norma frontalis in Frankfurt plane in 40 skull of Indian orgin.

RESULTS

The mean width of the piriform aperture was 24.9±1.59 mm in males and 22.77±1.57 mm in females, the mean length was 29.57±3.28mm in females and 31.16±3.58mm in males. The difference between males and females was significant, and our data correlates well with the previously data acquired from humans skulls. Most of North Indian skulls have platyrhine type of piriform aperture (triangular to oval shape with pyriform aperture index of 0.79). Mean length and width of nasal bone were 17.58±2.47mm and 12.1±0.97mm respectively without sexual.

CONCLUSION

Shape and size analysis of the piriform aperture and nasal bone showed the existence of a significant sexual dimorphism. These results encourage us to go further with functional and imaging correlations. This study will also be helpful in forensic research and anthropology.