Application of spiral computed tomography for determination of the minimal bone density variability of the maxillary sinus walls in chronic odontogenic and rhinogenic sinusitis

Нечипоренко А.С.1, 4, ORCID: 0000-0002-4501-7426, e-mail: alinanechyporenko@gmail.com Назарян Р.С.2, ORCID: 0000-0002-0005-8777, e-mail: rosnazaryan@gmail.com Семко Г.О.2, ORCID: 0000-0002-9465-224X, e-mail: ho.semko@knmu.edu.ua Лупир А.В.2, ORCID: 0000-0002-9896-163X, e-mail:lupyr_ent@ukr.net Юревич Н.О.2, ORCID: 0000-0001-7340-2850, e-mail: urevichi@ukr.net Фоменко Ю.В.2, ORCID: 0000-0002-2652-860X, e-mail: diacom1900@yahoo.com Костюков Е.О.2, ORCID: 0000-0003-0763-7859, e-mail: dr.kostukov@gmail.com Алєксєєва В.В.2, 3, ORCID: 0000-0001-5272-8704, e-mail: vik13052130@gmail.com

Background. There are many questions regarding the peculiarities of the course of odontogenic maxillary sinusitis, the likelihood of complications and the correct dosage of load during dental implantation. Purpose -to identify changes in minimal bone density in chronic odontogenic maxillary sinusitis and to compare it with chronic rhinogenic catarrhal maxillary sinusitis and physiological state of maxillary sinus. Materials and Methods. Our study involved 10 patients with chronic odontogenic maxillary sinusitis, 10 patients with chronic maxillary non-polyposis sinusitis of rhinogenic etiology, combined with hyperplasia of the sinus mucosa up to 1 cm. The control group comprised 10 patients with physiological condition of maxillary sinuses. In all subjects minimal bone density of superior, medial and inferior walls of maxillary sinus was analyzed. Results. The study showed that the maximum in physiological conditions is the minimal density of the upper wall of the maxillary sinus, the minimum is the lower wall. The minimal density of the lower wall was shown to undergo a statistically significant reduction in chronic catarrhal maxillary sinusitis only by 2%, the upper by 5%, the medial by 4% compared with the intact sinus, but with the odontogenic nature of maxillary sinusitis, this figure was 31% in the lower wall, 27% in the medial region. Only the density of the upper wall of the maxillary sinus remained quite stable, it decreased relative to the physiological one only by 6%. Conclusions. Minimal physiological densitometric parameters of lower, medial and upper walls were calculated. The reduction of minimal density of bone tissue in the cases of rhinogenic chronic catarrhal maxillary sinusitis. In the cases of chronic odontogenic maxillary sinusitis, maximum significant decrease of minimal density of both lower and medial walls is determined. INTRODUCTION На сьогодні надзвичайно гострою є проблема риносинуситів. Ця група захворювань уражує приблизно 10,9 % міського населення Сполучених Штатів Америки та 12 % населення Європи і потребує до 15 мільярдів доларів витрат щорічно Згідно ж до вітчизняних даних у рейтингу 20 найчастіших діагнозів, які встановлюють лікарі-отоларингологи, риносинусити знаходяться на першому місці. Кожний п'ятий пацієнт отоларинголога має даний діагноз [1].
To date, the problem of rhinosinusitis is extremely acute. This group of diseases affects approximately 10.9 % of the urban population of the United States and 12 % of the population of Europe and requires up to 15 billion US dollars in costs annually. According to the Ukrainian data, in the ranking of the 20 most common diagnoses, which are established by otolaryngologists, rhinosinusitis is in the first place. Every fifth patient has such diagnosis [1].
Chronic rhinosinusitis is a chronic inflammatory process of the nasal cavity and paranasal sinuses lasting more than 12 weeks [2]. Among all the diseases of the paranasal sinuses, the largest share falls on the impairments of the maxillary sinuses. The frequency of maxillary sinusitis is 59.97 % [3]. This is due to their maximum size, proximity to the location of the teeth and the high location of the natural junction [4]. In addition, the incidenсe of chronicity of maxillary sinusitis is 5 times higher than that of, for example, frontal sinusitis [5]. Up to 10% of all maxillary sinusitis are odontogenic, although it is estimated that they comprise even 40 % [6]. The progress of chronic odontogenic rhinosinusitis, as well as rhinosinusitis of other etiology is associated not only with pathological changes in the mucous membrane, but also with pathological changes in bone tissue, such as bone demineralization, disappearance of trabeculae, cortical destruction, focal sclerosis [7]. One of the most important prerequisites for the development of odontogenic sinusitis is a violation of the integrity of the Schneiderian membrane [8].
However, despite such a prevalence of pathological processes, the severity of pathological changes in the sinus, social and medical significance, odontogenic sinusitis have not been fully studied yet. There are many questions regarding the peculiarities of their course, the likelihood of complications and the correct dosage of load during dental implantation.
Objective -was to identify changes in minimal bone density in chronic odontogenic maxillary sinusitis and to compare it with chronic rhinogenic catarrhal maxillary sinusitis and the physiological state of maxillary sinus.

Оригінальні дослідження
Original research genic maxillary sinusitis, 10 patients with chronic maxillary non-polyposis sinusitis of rhinogenic etiology, combined with hyperplasia of the sinus mucosa up to 1 cm. The control group comprised 10 patients with physiological condition of maxillary sinuses who were referred to CT for another cause, not related to diseases of the ENT-organs.
It should be noted that the group of odontogenic sinusitis included patients with violation of the integrity of the Schneiderian membrane and with the presence of a purulent process in the maxillary sinus. All patients underwent a full range of tests and treatment in accordance with the order No. 181 of the Ministry of Health of Ukraine of 24.03.2009 «On approval of protocols for medical care in the specialty «Otolaryngology».
The SCT scans were obtained from a Toshiba Aquilion-4 device. It is a multi-slice CT scanner with the feature of simultaneous data collection of 4 slices 0.5 mm thick and featuring high performance with a full revolution time of up to 0.4 s. The high-speed rotation mechanism and the fast system reconstruction unit provide accelerated data collection, which increases the scanner throughput.
All patients were equally divided by sex and age. The age of patients ranged from 30 to 50 years. To assess the minimal density of bone tissue during the CT study, Hounsfield scale was used, given that according to M. Hofner modern devices are able to cover 4096 shades of gray, which represent different levels of density in units of Hounsfield (HU) (water density is taken as 0 HU, and air as 1000 HU) [10]. The physiological density of the cancellous bone is characterized by values from 30 to 230 HU. The density in the area of the upper wall was calculated as significant for the development of intrabital complications [11], of the lower wall, which borders on the upper jaw and is of great importance in dentures for dosing the load during tooth implantation [12] and the medial wall adjacent to the nasal cavity and is important for endoscopic surgery [13].
Minimal densitometric indicators were calculated using the points maximally superficial to the sinus cavity: for the medial wall -in the area of natural junction, for the upper -on the border with the lateral one, for the lower -on the border with the medial one.
The obtained digital data were statistically processed on the personal computer Microsoft Office Excel 2010 (USA) by the methods of variation statistics. The conformity of distribution to normal was determined by the Shapiro -Wilk's test, which showed that the samples were close to normal distribution.
The check was performed using the program Attestat 12.0.5.
Thus, in the course of checking the conformity of the distribution to normal, it was found that the values of statistics W and the critical value W(ά) amounted in t he first study group to 0.98 and 0.67, in the second groupto 0.94 and 0.07, in the third -to 0.94 and 0.13. The results allowed not to reject the hypothesis of normal distribution.
In the course of the study, the minimal density of the upper, lower and medial walls of the maxillary sinus was calculated at all the above mentioned points -landmarks in physiological conditions, in the cases of chronic catarrhal maxillary sinusitis, in the cases of chronic odontogenic maxillary sinusitis. The results are presented in tables 1-3. Ukrainian journal of radiology and oncology. 2021;29(4):65-75 ISSN 2708-7166 (Print) ISSN 2708-7174 (Online)

Оригінальні дослідження Original research
The minimal density of the lower wall of the maxillary sinus was determined, which was equal to 128.7 ± 21.6 HU in physiological conditions, 88.4 ± 13.5 HU in odontogenic maxillary sinusitis, 126.9 ± 13.4 HU in chronic catarrhal maxillary sinusitis ( Table 1). The minimal density of the upper wall was also calculated -175.6 ± 23 HU, 166.9 ± 16.4 HU, 165.9 ± 26.9 HU (Table 3), as well as the minimal density of the medial wall -131.8 ± 23 HU, 127.4 ± 23.2 HU, 96.2 ± 19.5 HU according to the order above ( Table 2).
The study showed that the maximum in physiological conditions is the minimal density of the upper wall of the maxillary sinus, the minimum is the lower wall. The minimal density of the lower wall was shown to undergo a statistically significant reduction in chronic catarrhal maxillary sinusitis only by 2 %, the upper by 5 %, the medial by 4% compared with the normal sinus, but with the odontogenic nature of maxillary sinusitis, this figure was 31 % in the lower wall, 27 % in the medial region. Only the density of the upper wall of the maxillary sinus remained quite stable, it decreased relative to the physiological one only by 6 %.
To date, determining the bone density of the walls of the maxillary sinus can be key for diagnosing various forms of maxillary sinusitis. There are studies of the structure of the maxillary sinus in odontogenic sinusitis [14,15] and even determining the density during the development of mycetome in the sinus [16,17] according to cone-beam computed tomography. This study differs in the fact that it is devoted to the analysis and comparison of densitometric structure in maxillary sinusitis of both rhinogenic and odontogenic etiology. In addition, it is based on the results of spiral computed tomography, allowing to calculate in detail and accurately the values of bone density. Automatic processing of medical images is increasingly becoming key in their interpretation to obtain objective data for patient management [18,19], predicting the course of the pathological process [20,21], including in NS [22].
Pathological processes of the oral cavity have a variety of etiologies, often with impaired microcirculation [23], the development of bacterial complications [24], especially in the presence of harmful habits [24,25] and the influence of physiological [26] or adverse factors [27]. As can be seen from the study, the odontogenic nature of the development of pathological conditions in the sinus significantly reduces densitometric parameters, with the maximum in the area of the lower wall. Therefore, the question of pathogenic mechanisms resulting in changes with the development of odontogenic maxillary sinusitis is quite debatable. Thus, it is impossible to exclude a decrease in density as an etiological factor in the development of odontogenic lesions of the sinuses. This assumption can be confirmed by a detailed study of the SCT of patients in the control group, that had the tips of the tooth roots identified in the sinus and this did not lead to significant pathological changes in the maxillary sinus and was a variant of the physiological condition. Attention is drawn to the fact that in such individuals, even under physiological conditions, the bone density of the lower wall is slightly lower. Perhaps this explains the more rapid decrease in density with the development of odontogenic pathological processes. Thus, people with low bone density and the location of teeth roots in the maxillary sinus need maximum attention in terms of the development of odontogenic maxillary sinusitis and its complications. It is possible that this cohort of individuals should be recommended additional Визначено мінімальну щільність нижньої стінки верхньощелепної пазухи, яка дорівнювала: в фізіологічних умовах -128,7 ± 21,6 HU, при одонтогенному верхньощелепному синуситі -88,4 ± 13,5 HU, при хронічному катаральному верхньощелепному синуситі -126,9 ± 13,4 HU (табл. 1). Також обчислена мінімальна щільність верхньої стінки, яка склала: 175,6 ± 23 HU, 166,9 ± 16,4 HU, 165,9 ± 26,9 HU (табл. 3) і мінімальна щільність медіальної стінки: 131,8 ± 23 HU, 127,4 ± 23,2 HU, 96,2 ± 19,5 HU відповідно до наведеного вище порядку (табл. 2).
methods of testing and performing SCT before any medical and diagnostic procedures [28,29].
Changes of densitometric indicators in the cases of chronic maxillary sinusitis of rhinogenic and odontogenic etiology are also interesting. The most stable is the density of the upper wall of the maxillary sinus. It varies from 166.9 ± 16.4 HU to 165.9 ± 26.9 HU, which is only 1 %. The density of the lower wall (p <0.05) is significantly the most variable and decreases by 30% in the odontogenic nature of the disease in comparison with rhinogenic one. The density of the medial wall significantly (p <0.05) decreases by 24.5 %.
This method of bone density measurement can be supplemented by others [29][30][31] and studied in many pathological conditions and under the influence of certain substances [32][33][34], in the presence of features of individual development in childhood or adolescence [25,35,36] when the skeleton is formed or in elderly under the influence of hormonal disorders [26]. The results of this study are confirmed by our previous ones, in which density was calculated by method of uncertainty estimation [37].
Thus, the stability of the density of the upper wall of the maxillary sinus suggests that the risk of development of intraorbital complications is approximately the same as in the cases of both rhinogenic and odontogenic chronic maxillary sinusitis. The variability of the lower walls' density suggests the possibility of the infection spreading from the oral cavity to the maxillary sinus with the development of further complications in people without comorbidities [38], as well as those who have risk factors [39,40].
Of particular importance is the pronounced variability in the density of the lower wall of the maxillary sinus, which should be taken into account in dentistry when dosing loads during insertion of dental implants.
1. Calculation of minimal physiological densitometric parameters of the lower, medial, upper walls of the maxillary sinus showed the following results: 128.7 ± 21.6 HU 131.8 ± 23 HU, 175.6 ± 23 HU, respectively. Thus, the lower wall has the lowest density, and the upper one has the highest.
2. Chronic odontogenic maxillary sinusitis is associated with the maximum significant decrease in minimal density of the lower (31 % compared to the normal sinus and 30 % compared to chronic sinusitis of rhinogenic nature), as well as the medial wall by 27 % and 24.5 %, respectively.
3. The minimal density of the upper wall is relatively stable in all study groups of patients. It is reduced by only 5 % in chronic catarrhal maxillary sinusitis of rhinogenic nature and by 6 % in odontogenic form compared with the unchanged sinus.