Relationship between maxillary sinuses’ shapes and their contacts with upper jaw teeth roots according to computer tomography

Взаємозв’язок форм верхньощелепних пазух з їх контактами з коренями зубів за даними комп’ютерної томографії Черкес М.Б.1 ̧2, ORCID: 0000-0002-6553-974X, e-mail: maryana.cherkes@gmail.com 1Львівський національний медичний університет імені Данила Галицького Міністерства охорони здоров’я України, Львів, Україна 2Комунальне некомерційне підприємство «Міська дитяча клінічна лікарня міста Львова», Львів, Україна

The shape of the maxillary sinus is also very important in pathogenesis of various pathological conditions. According to the modern classification, the MS shapes are as follows: irregular, spherical, triangular, quadrangular [41].
The paper is focused on describing the technique for detailed studying the maxillary sinus on 2D and 3D visual models. To achieve this, DICOM Image Viewer software was used along with building a 3D model of the maxillary sinus on a PC. The model like this makes it possible to see the shape, size and configuration of the MS and measure its dimensions: 3D and linear ones [3,12,17,21,24,25,27,30,32,33]. The models of patients with teeth of the maxillary dental arch, as well as the ones with missing teeth of the maxillary dental arch, can be used to demonstrate the anatomical differences of the MS and connection of the tooth roots with the MS lower wall [9,10,15,18,19,20,26,34,36,39].
In spite of numerous contributions, this subject area is relevant since studying the morphometric parameters of the maxillary sinuses and their relationship with the roots of the teeth of the maxillary dental arch is an essential for diagnosis made by otolaryngologist or dentist for planning surgery on the sinuses, planning and fulfilling dental implant procedures, as well as choosing the strategy for patient management.
Purpose -establish a relationship between the shape of the maxillary sinuses and possible contacts of the roots of the maxillary dental arch in healthy mature men and women.
The study was performed based on the results of 102 CT series with normal maxillary sinuses variations in adults (55 women and 47 men) aged 21 to 65 years. The patients underwent cone-beam computerized tomography (CBCT) in the frontal and sagittal planes with the referral from otorhinolaryngologists or dentists associated with maxillary dental arch pathology, hypertrophy of palatine tonsils, hypertrophy of the adenoid vegetations, deviated septum, temporomandibular joint pathologies. аденоїдних вегетацій, викривленою перегородкою носа, патологіями, пов'язаними із скронево-нижньощелепним суглобом.

РЕЗУЛЬТАТИ ТА ЇХ ОБГОВОРЕННЯ RESULTS AND DISCUSSION
The examined patients had no pathologies that would affect the size or volume of the sinuses, neither had they history of pathological conditions that could have influenced the state of the sinuses (chronic or acute rhinosinusitis, polyposis, MS cyst formations), without pre-existing surgery.
The examination was performed by means of Point 3D Combi 500 tomograph at Medical 3D Diagnosis Center in Lviv. The software for visualization was Software Xelis dental. This tomograph is one of the premium computed tomographs which makes it possible to study the maxillofacial area with a high level of resolution and build 3D models of structures necessary to describe patients.
The paper belongs to the «description of case series» category whis is a type of study recognized by evidence based medicine and does not claim statistical significance of the results. The Student-Fisher test is not applied to samples of such volume.
When examining the computer tomograms of men and women in the study group, it has been found out how the shape of the maxillary sinuses (MS) affects the contact of the tooth roots with the cortical plate and the mucous membrane of the maxillary sinuses. The maxillary sinuses were studied in 2 planes: frontal and sagittal.
Six main shapes of the MS were defined: trapezoidal, square, round, oval, rectangular and triangular.
It was found that, in any form of the sinus, the frontal plane on all our computed tomograms of the left MS under study did not show any contact of the roots of the 23rd and 24th teeth of the maxillary dental arch with the mucous membrane of the maxillary sinus (Table 1).
In the «trapezoid» shape, the most frequent contact with the mucous membrane of the MS is observed in the 27th root of the tooth of the maxillary dental arch, that is in 19 people (70.3% of cases), Fig. 1 The contact with the mucous membrane of the MS of the 25th and 28th roots of the maxillary dental arch is observed in 6 people (22.2% of cases). The root of the 26th tooth of the maxillary dental arch is in contact with the mucous membrane in 14 people (51.8% of cases).
Regarding the contact with the cortical plate of the MS tooth roots in the «trapezoid» shape, the most common was the contact of the 25th and 26th roots of the teeth of the maxillary dental arch, that is in 11 and 9 people, respectively (40.7% and 33, 3% of cases), while least oftenthe 23rd root of the tooth -in 2 people (7.4% of cases). The 24th, 27th and 28th roots of the teeth of the maxillary dental arch are in contact with the MS cortical plate in 7 people (25.9% of cases), 5 people (18.5% of cases) and 6 people (22.2% of cases), respectively (Table 1, Fig. 2).
In case of the round shape, the contact with the cortical plate is also uniform on the 25th and 26th root of the teeth -4 people each (44.4% of cases). The 24th and 28th roots of the teeth are in contact with the MS cortical plate in 2 people each (22.2% of cases), and while 3 people (33.3% of cases) the contact is on the 27th root of the tooth of the maxillary dental arch.
The most frequent is the contact of the 27th root of the tooth with the mucous membrane of the round shape of the MS -in 4 people (44.4% of cases), the least frequent is the contact of the 28th root of the tooth -in 1 person (11.1% of cases), while the 25th and the 26th root of the teeth are in contact with the mucous membrane in 2 (22.2% of cases) and 3 (33.3% of cases) persons, respectively (Table 1, Fig. 2).
In case of the oval shape, the most frequent contact with the MS cortical plate occurs on the 25th root of the tooth -in 5 people (71.4% of cases), the least oftenon the 23rd and 27th root of the teeth -1 person, respectively (14.3% of cases) and are generally absent in the 26th root of the tooth. The 24th and 28th roots of the teeth of the maxillary dental arch are in contact with the MS oval-shaped cortical plate in 3 (42.9% of cases) and 2 people (28.6% of cases), respectively.
The contact of the roots of the teeth with the MS mucous membrane is evenly distributed on the 26th and 27th teeth -6 people (85.7% of cases). The 25th and 28th roots of the teeth of the maxillary dental arch are in contact with the MS mucous membrane of the oval shave in 2 (28.6% of cases) and 4 people (57.4% of cases), respectively ( Table 1, Fig. 2).
In the rectangular shape, the contact with the MS cortical plate is the most common for the 25th and 26th roots of the teeth of the maxillary dental archin 13 (56.5% of cases) and 11 (47.8% of cases) people, respectively. The contact of the 24th root of the tooth with the MS cortical plate is the least common -in 2 people (8.7% of cases) and is completely absent with the 23rd root of the tooth. The contact of the 27th and 28th roots of the teeth with the cortical plate was observed in 7 people each (30.4% of cases).
The contact with the mucous membrane is most frequently observed in the 28th root of the tooth -12 people (52.8% of cases). For the 25th and 26th roots of the teeth, the contact is distributed equally -1 person (4.3% of cases) each. For 7 people (30.4% of cases), the contact was observed with the 27th root of the tooth (Table 1, Fig. 2).
For the triangular shape, the contact with the cortical plate of the 25th root of the tooth was most often observedin 17 people (56.7% of cases), and least often -for the 23rd and 24th roots of the tooth -4 people each (13.3% of cases). The 26th, 27th and 28th roots of the teeth are in contact with the cortical plate in 11 (36.7% of cases), 13 (43.3% of cases) and 12 (40.0% of cases) people, respectively.
The 26th and 27th roots of the teeth are evenly in contact with the mucous membrane -13 people each (43.3% of cases). The contact of the 25th root of the tooth was observed the least often -in 2 people (6.7% of cases). The 28th root of the tooth was in contact with the MS mucous membrane in 5 people (16.7% of cases) - Table. 1, Fig. 2.
In CBCT frontal plane, the most frequent contact with the cortical plate of the left MS is observed in the triangular and rectangular shape of the MS, that is: in the Ukrainian journal of radiology and oncology. 2021;29(3):31-50 ISSN 2708-7166 (Print) ISSN 2708-7174 (Online)
Контакт зі слизовою оболонкою ВЩП 14-го, 15-го, 17-го та 18-го коренів зубів ВЩЗР спостерігаємо у rectangular shape, the MS is in contact with the 25th root of the tooth in 13 people (56.5% of cases) and with the 26th root of the tooth in 11 people (47.8% of cases) and in case of the triangular shape, the MS is in contact with the 25th root of the tooth in 17 people (56.5% of cases), with the 26th root of the tooth -in 11 people (36.7% of cases), with the 27th root of the tooth -in 13 people (43.3% of cases) and with the 28th root of the toothin 12 people (40.0% of cases). The rarest contact with the MS cortical plate is observed in the oval and round shapes of the MS, namely: in the oval shape, the MS does not come into contact with the 26th root of the tooth while it comes into contact with the 23rd and 27th roots of the teeth -only 1 person each (14.3% of cases) and, in the round form, the MS does not come into contact with the 23rd root of the tooth while it comes into contact with the 24th and 28th roots of the teethonly 2 people each (22.2% of cases) - Table 1, Fig. 2.
Assessing the relationship between the roots of the teeth of the maxillary dental arch and the lower wall of the MS is very important for clinicians when planning any procedure (diagnostic or therapeutic) in order to avoid complications. Potentially, there are a great number of risks associated with tooth roots of the maxillary dental arch. For example, during a tooth implantation procedure, there is a risk of perforation of the sinus floor with surgical instruments. In case of sinusitis, patients often had primary procedures on the teeth of the maxillary dental arch, which caused inflammation of the MS.
Regarding the contacts with the mucous membrane of the left MS in the CBCT frontal plane, the most common contact is observed in the trapezoidal and triangular shape of the MS, that is: in the trapezoidal form, the MS is in contact with the 26th root of the tooth in 14 people (51.8%) and with the 27th root of the tooth -in 19 people (70.3% of cases), while in the triangular shape, the MS is in contact with the 25th and 27th roots of the teeth -13 people each (43.3% of cases). The rarely contact with the mucous membrane of the MS is observed in the square shape of the MS, namely: the MS does not come into contact with the 23rd and 24th roots of the teeth at all while it comes into contact with the 23rd and 27th roots of the teeth -only 1 person per each (16.7% of cases) and with the 26th and 26th roots of the teeth -3 people per each (50% of cases) - Table. 1, Fig. 2.
It is worth mentioning that standard dental panoramic radiography does not make it possible to determine the possible risks of perforation of the MS floor, that is why it is clearly recommended to use cone-beam computed tomography.
When analysing CBCT during our study, it has been found that it is very important to determine the contacts of the roots of the teeth of the maxillary dental arch with the MS cortical plate, and with its mucous membrane. It is known that microorganisms and toxic substances that are present both in the periapical areas of the tooth roots and in the MS itself can migrate through blood/ lymphatic vessels and there is a positive correlation between periodontal lesions and thickening of the maxillary sinus mucosa [42].
When examining and analyzing the right MS in the frontal plane, it has been found that in any form of sinus there is no contact of the 13th root of the tooth with the mucous membrane of the MS as well as no contact of the root of the 14th tooth with the MS mucosa in round, oval, rectangular and triangular shapes is detected (Table 2, Fig. 3, 4). Ukrainian journal of radiology and oncology. 2021;29 (3) Рис. 3. Вплив форми правої верхньощелепної пазухи на контакти з коренями зубів у фронтальній проекції КПКТ Fig. 3. Impact of the shape of the right maxillary sinus on the contacts with the tooth roots in the CBCT frontal plane

Triangular Rectangular
Oval
The contact with the mucous membrane of the MS of the 14th, 15th, 17th and 18th roots of the teeth of the maxillary dental arch is observed in 1 person (3% of cases), 9 people (27.3% of cases), 13 people (39.4% cases) and 6 people (18.2% of cases), respectively. Regarding the contacts with the MS cortical plate of the tooth roots in the «trapezoid» shape, the most common contact was observed on the 15th, 17th and 18th roots of the teeth of the maxillary dental arch, namely in 18, 14 and 13 people, respectively (54.5%, 42.4 and 39.4% of cases), and the least often -the 13th root of the tooth -in 3 people (12.1% of cases). The 14th and 16th roots of the teeth of the maxillary dental arch are in contact with the cortical plate of the MS in 6 people (18.2% of cases) and 7 people (21.2% of cases), respectively (Table 2, Fig. 3).
In the square form, the contact with the cortical plate of the MS most often occurs on the root of the 15th toothin 5 people (55.6% of cases) and slightly less at the 16th and 17th root of the teeth -4 people (44.4% of cases). The contact with the MS mucosa of the 18th tooth root was detected in 2 people (22.2% of cases). The roots of the 13th and 14th teeth do not come into contact with the cortical plate of the square MS at all.
The contact with the mucous membrane of the square MS is evenly distributed on the 16th and 18th roots of the teeth -3 people per each (33.3% of cases). The 14th and 17th roots of the maxillary dental arch are in contact with the mucous membrane in 1 person (11.1% of cases) and in 5 people (55.6% of cases), respectively, and no contact of the 15th root of the tooth of the maxillary dental arch is observed. 2, Fig. 3, 4).
In the round shape, the contact with the cortical plate is also uniform on the 13th and 14th roots of the teeth -1 person per each (14.3% of cases) and on the 17th and 18th roots of the teeth -2 people per each (28.6% of cases). The 15th root of the tooth is in contact with the MS cortical plate in 4 people (57.1% of cases), while in 3 people (42.9% of cases) the contact is on the 16th root of the tooth of the maxillary dental arch.
The roots of the teeth of the maxillary dental arch on the right are rarely in contact with the mucous membrane of the right round MS in the frontal plane, that is only 3 people (42.7% of cases) account for the roots of the 16th and 17th tooth, in 2 people (28.3% of cases)the root of the 18th tooth is in contact and in 1 person (14.3% of cases) -the root of the 15th tooth (Table 2, Fig. 3).
In the oval shape of the MS, the most frequent contact with the cortical plate occurs on the 16th root of the toothin 8 people (57.1% of cases), rarely -on the 13th and 14th root of the teeth -1 person per each, respectively (7.1%). cases). The 15th, 17th and 18th roots of the teeth of the MS are in contact with the cortical plate of the MS of the oval shape in 7 (50% of cases), 4 people (28.6% of cases) and 2 people (14.3% of cases), respectively.
The contact of the roots of the teeth with the mucous membrane of the MS is evenly distributed on 16 and 18 teeth -3 people (21.4% of cases). The 15th and 17th roots of the teeth of the maxillary dental arch are in contact with the mucous membrane of the MS of the oval shape in 1 (7.1% of cases) and 7 people (50% of cases), respectively (Table 2, Fig. 3).
The roots of the teeth are rarely in contact with the MS mucous membrane of the rectangular shape, namely: the contact of the roots of the 13th, 14th and 18th teeth is absent, while the 16th, 17th -6 people per each (42.9% of cases) and the 15th root of the tooth -in 1 person only (7.1% of cases) - Table. 2, Fig. 3.
The triangular shape of the MS most frequently showed the contact with the cortical plate of the 15th root of the tooth -11 people (45.8% of cases), and least frequentlyfor the 13th root of the tooth -2 people (8.3% of cases). The 14th, 16th, 17th and 18th roots of the teeth are in contact with the cortical plate in 5 (20.8% of cases), 8 (33.3% of cases), 4 (16.7% of cases) and 9 (37.5% of cases) of persons, respectively.
The root of the 17th tooth is most often in contact with the mucous membrane in 19 people (79.2% of cases) and the root of the 16th tooth in 14 people (58.3% of cases). The roots of the 15th and 18th teeth are in contact in 4 and 6 people, respectively (16.7 and 20.8% and cases) - Table. 2, Fig. 3.
In the frontal plane of CBCT, the most frequent contact with the cortical plate of the right MS is observed in the triangular and trapezoidal shape of the MS, namely: in the triangular shape, the MS is in contact with the 15th root of the tooth in 11 people (45.8% of cases) while, in the trapezoidal shape, the MS is in contact with the 15th tooth root in 18 people (54.5% of cases), with 17th tooth rootin 14 people (42.4% of cases) and with 18th tooth rootin 13 people (39.4% of cases). Rarely, the contact with the cortical plate of the MS is observed in the square and round shape of the MS, that is: in the square shape, the MS does not come into contact with the 13th and 14th roots of teeth while it comes into contact with the 16th and 27th roots of teeth -in 4 people each (44.4% of cases) and, in the shape, the MS is in contact with the 13th and 14th roots of the teeth -only in 1 person each (14.3% of cases) and 2 people (28.6% of cases) is observed on the root of the 17th and 18th teeth of the maxillary dental arch ( Table 2, Fig. 3).
Regarding the contacts with the mucous membrane of the right MS in the frontal plane of CBCT, the most common contact is observed in the trapezoidal and triangular shape of the MS, that is: in the trapezoidal shape, the MS is in contact with the 16th root of the tooth in 17 people (51.5%)and the 17th root of the toothin 13 people (39.4% of cases), while in the triangular shape, the MS is in contact with the 16th and 17th roots of the teeth in 14 and 19 people, respectively (58.3 and 79.2% of cases). The least frequent contact with the mucous membrane of the MS is observed in the rectangular shape of the MS, that is: the MS does not come into contact with the 13th, 14th and 18th roots of the teeth and it comes into contact with the 15th one only in 1 person (7.1% of cases) and with the 16th and 17th roots of the teeth -6 people (42.9% of cases) - Table. 2, Fig. 3.
The most frequent contact of the roots of the teeth of the maxillary dental arch with the cortical plate is observed in the rectangular shape of the MS, while with the mucous membrane -in the triangular shape of the MS on the right (Fig. 3). Ukrainian journal of radiology and oncology. 2021;29(3):31-50 ISSN 2708-7166 (Print) ISSN 2708-7174 (Online)

Triangular Rectangular
Oval

Trapezoidal
The contact of the tooth roots of the maxillary dental arch with the mucous membrane The contact of the tooth roots of the maxillary dental arch with the cortical plate When analyzing cone-beam computed tomograms of the study group, it was considered appropriate to identify possible options for contact of the roots of the teeth with the maxillary sinus in the sagittal plane as well on the right and left, respectively. Since it is exactly the plane, where otolaryngologists often assess the state of the MS in both acute and chronic processes of the MS.
Regarding the left MS in the sagittal cone-beam section, it has been found that in any form of sinus there is no contact of the root of the 23rd tooth of the maxillary dental arch with the mucous membrane and the contact of the root of the 24th tooth is extremely rare, namely in the oval shape of the MS -in 1 person (7.1% of cases) - Table. 3, Fig. 6.
При трикутній формі ВЩП у сагітальній проекції найчастіше спостерігали контакти з кортикальною the 25th and 27th roots of the teeth -in 1 and 3 people (12.5 and 37.5% of cases ) respectively. The contact of the roots of the teeth with the cortical plate of the MS was evenly distributed on the 24th, 25th and 26th teeth -3 people (37.5% of cases), there was no contact with the 23rd root of the tooth, and in 4 people (50% of cases) there was contact of the cortical plate of the MS with the 27th root of the tooth of the maxillary dental arch (Table 3, Fig. 5).
In the square shape of the MS, the contact with its cortical plate is rare, that is: the roots of the 23rd, 24th and 28th teeth do not come into contact with it at all, while the 25th, 26th and 27th roots of the teeth -only in 1 person (25% of cases) each. The contact of the root of the 25th and 27th teeth with the mucous membrane of the square shape of the MS occurred in 2 people (50% of cases) each, the 24th and 26th roots of the teeth -1 person per each (25% of cases) and the 28th root tooth -in 3 people (75% of cases). The 23rd root of the tooth did not come into contact with the MS mucosa. (Table 3, Fig. 5).
In the round shape of the MS, both with the cortical plate and with the mucous membrane, no contact of the 23rd, 24th and 28th roots of the teeth was observed. The contacts of the 26th and 27th roots of the teeth were evenly distributed -1 person each (33.3% of cases) and the 25th root of the tooth came into contact with the mucous membrane in 1 person (33.3% of cases), while with the cortical platein 2 people (66.7% of cases) - Table 3, Fig. 5, 6.
In the oval shape of MS, the most frequent contact with the mucous membrane occurs on the 26th and 27th root of the teeth -in 7 and 8 people, respectively (50% and 57.1% of cases), the least often one -on the 24th root of the tooth -in 1 person (7.1% of cases). The 25th and 28th roots of the teeth of the maxillary dental arch are in contact with the mucous membrane of the MS of the oval shape in 3 (21.4% of cases) and 4 people (28.6% of cases), respectively. The contact of the 23rd root of the tooth with the mucous membrane of the MS is absent. The contact of the roots of the teeth with the cortical plate of the MS is evenly distributed on the 24th, 27th and 28th roots of the teeth -2 people per each (14.3% of cases). The 25th and 26th roots of the maxillary dental arch are in contact with the oval-shaped cortical plate of the MS in 5 and 4 people, respectively (35.7% and 28.6% of cases - Table 3, Fig. 5).
Проте, слід зауважити, що саме кругла форма ВЩП зустрічається найрідше у осіб зрілого віку з обстеженої In the rectangular shape, the contact with the cortical plate of the MS is the most common for the 26th root of the tooth of the maxillary dental arch -in 8 people (77.8% of cases). The contacts of the 23rd, 24th and 27th roots of the teeth with the cortical plate of the MS are the least common -1 person (22.2% of cases) per each, while the contacts of the 25th and 28th roots of the teeth with the cortical plate were observed in 2 people (22.2% of cases). The roots of the 23rd, 24th and 28th teeth do not come into contact with the mucous membrane of the rectangular shape of the MS at all, the roots of the 25th and 26th teeth -only in 1 person each (11.1% of cases). However, the 27th root of the tooth is in contact with the mucous membrane of the rectangular shape of the MS in 7 people (77.8% of cases) - Table. 3, Fig. 5.
In the triangular shape of the MS in the sagittal plane, the contacts with the cortical plate and the mucous membrane of the MS were most often observed. The cortical plate of the MS is most often in contact with the 25th root of the tooth -in 38 people (59.4% of cases), and least often is the 23rd root of the tooth -in 6 people (9.4% of cases). The 26th and 27th roots of the teeth are in contact -21 people each (32.8% of cases), while the 28th one, which is quite rare in other shapes, is in contact with the cortical plate of the triangular shape of the MS in 20 people (31.2 % of cases). The rarest contact was observed in 24 roots of teeth, that is in 13 people (20.3% of cases). The root of the 27th tooth is most often in contact with the mucous membrane -in 37 people (57.8% of cases) and the root of the 26th tooth -in 32 people (50% of cases). The roots of the 25th and 28th teeth are in contact in 7 and 15 people, respectively (10.9 and 23.4% and cases) - Table. 3, Fig. 5.
It was interesting to discover the fact that even the 23rd root of the tooth is in contact with the MS, which is often missed by clinicians, believing that it is the 23rd-24th roots of the teeth that rarely come into contact with the MS. However, our study has proved that it is in the sagittal plane of CBCT that the contact of the 23rd root of the tooth is clearly recorded in 6 people, and, in 13 people, the 24th root of the tooth of the maxillary dental arch is in contact with the MS.
In the sagittal plane of CBCT, the most frequent contact with the cortical plate of the left MS is observed in the triangular shape of the MS, namely -the sinus is in contact with the 25th root of the tooth in 38 people (59.4% of cases), and with the 26th, 27th and 28th tooth roots -in 21, 21 and 20 people, respectively (32.8%, 32.8% and 31.2% of cases).
The rarest contact with the cortical plate of the MS is observed in the round shape of the MS, i.e. the MS does not come into contact with the 23rd, 24th and 28th roots of the teeth and it comes into contact with the 26th and 27th roots of the teeth -only 1 person per each (33.3% of cases) - Table. 3, Fig. 5, 6.
Regarding the contacts with the mucous membrane of the left MS in the sagittal plane of CBCT, the most common contact is observed in the triangular shape of the MSin 37 people (51.8% of cases) contact is on the 27th root of the tooth and 32 in people (50% of cases) -on the 26th root of the tooth. The least frequent contact with the MS mucous membrane is observed in the square, round and rectangular shape of the MS, i.e.: the MS does not come into contact with the 23rd, 24th and 28th roots of the teeth and it comes into contact with the 25th and 26th -only 1 person each - Table. 3, Fig. 5, 6.
Analyzing the contacts of tooth roots with the specific shape of the right MS in sagittal plane, it has been found that in any shape of sinus, there is no contact of the 13th tooth root with the mucous membrane and the one of the 13th, 14th tooth roots with the cortical plate in square, round and rectangular shapes of the MS.
However, it is worth pointing out that the round shape of the MS is the least common in adults from the examined group of patients -from 2.9 to 8.8% of cases from the entire study group.
In case of the «trapezoidal» shape of the MS, the most frequent contact with the MS mucous membrane in the sagittal plane is observed in the 17th root of the toothin 5 people (62.5% of cases) - Table. 4, Fig. 7.
The contact with the mucous membrane of the MS of the 14th, 15th, 16th and 18th roots of the teeth of the maxillary dental arch is observed in 1 person (12.5% of cases), 2 people (25% of cases), 3 people (37.5% cases) and 1 person (12.5% of cases), respectively. Regarding the contacts with the cortical plate of the tooth root MS in the «trapezoidal» shape, the contact of the 18th root of the tooth of the maxillary dental arch was most often observed, i.e. in 4 people (50% of cases), the 14th, 15th and 16th roots of the teeth contact equally -3 people (37.5% of cases) per each, while the 13th and 17th roots of the teeth -2 people (25% of cases) per each - Table. 4, Fig. 7.
We consider it reasonable to focus on the contact of the 18th root of the tooth with the MS in the sagittal shape in 4 people (50% of cases), since it is very important to take into account when planning surgeries and other diagnostic interventions.
In the square form of the MS there is also no contact with the cortical plate of the 16th root of the tooth and only 1 person has contact of the 18th root of the tooth (50% of cases). Two people had contacts of tooth roots with the cortical plate of the 15th and 17th teeth, which was equal to 100% of such detected cases. Only the root of the 16th tooth (50% of cases) is in contact with the mucous membrane of the MS in its square shape. Table 4, Figure 7.
In the round shape, the contact with the cortical plate is observed only for the root of the 16th tooth (50% of cases), while with the mucous membrane, the contacts are evenly distributed on the 16th and 17th root of the teeth -1 person (50% of cases) and in 2 people (100% of cases) the 15th root of the tooth is in contact ( Table 4, Fig. 7).
In case of the oval form of the MS, the most frequent contact with the mucous membrane occurs on the 16th and 17th root of the tooth -in 13 and 11 people, respectively (54.2% and 45.8% of cases), least often -on the 14th root of the tooth in 1 person (4.2% of cases). The 15th and 18th roots of the teeth of the maxillary dental arch are in contact with the mucous membrane of the MS of the oval shape in 3 (12.5% of cases) and 4 people (16.7% of cases), respectively. The contact of the roots of the teeth with the cortical plate of the MS is evenly distributed on the 16th and 17th roots of the teeth -7 people (29.2% of cases) each. The 13th, 14th, 15th and 18th roots of the teeth of the maxillary dental arch are in contact with the cortical plate of the MS of the oval shape in 2 (8.3% of cases), 3 (12.5% of cases), 8 (33.3%) cases) and 4 people (16.7% of cases), respectively (Table 4, Fig. 7).
In case of the rectangular shape, the contacts of the 13th, 14th roots of teeth are absent with a cortical plate of the MS as well as with the mucous membrane. There is no contact with the mucous membrane of the 15th root of the tooth either. The contact with the cortical plate is the most common for the 15th root of the tooth of the maxillary dental arch -in 11 people (78.6% of cases). The contact of the 16th and 17th roots of the teeth with the cortical plate of the MS occurs in 6 people (42.9% of cases), while the contact of the 18th root of the tooth -in 8 people (58.1% of cases).
For the triangular shape of the MS in a sagittal plane, the contacts of roots of teeth were observed most often in all forms. The root of the 15th tooth most often came into contact with the cortical plate -in 30 people (57.7% of cases). The 16th and 18th roots of the teeth were in contact with the cortical plate -17 people each (32.7% of cases), and the 13th, 14th and 17-1 roots of the teeth -in 5, 8 and 16 people, respectively (9.6, 15.4 and 30.8% of cases).
The 17th root of the tooth most often came into contact with the MS mucosa -in 28 people (53.8% of cases). The contact of the 16th and 18th roots of teeth was quite common -in 21 and 12 people, respectively (40.4 and 23.1% of cases). The 15th root of the tooth was in contact with the mucous membrane in 9 people (17.3% of cases). The 13th and 14th roots of the teeth were never in contact with the mucous membrane of the triangular shape of the MS (Table 4, Fig. 7, 8).
In the sagittal plane of CBCT, the contact with the roots of the teeth was hardly observed in the square and round shape of the MS. In the square shape of the MS, the 13th and 14th roots of the teeth do not come into contact with its cortical plate at all, and with the mucous membrane there is no contact of all tooth roots, except the 16th, in 1 person only. Regarding the round shape of the MS, there is no contact with the cortical plate in all tooth roots, except the 16th one (in 1 person), and with the mucous membrane the contact is absent in the 13th, 14th and 18th root of the teeth and is present in 16th and 17th root of the tooth -1 person per each (Table 4, Fig. 7, 8).
The study was aimed to establish the relationship bet-ween the shape of the maxillary sinuses and possible contact of the tooth roots of the maxillary dental arch in healthy adults without acute pathological conditions of the MS, so it could be affirmed that CBCT showed significantly higher reliability in diagnosis and its verification than 2D radiography.

СПИСОК ВИКОРИСТАНОЇ ЛІТЕРАТУРИ REFERENCES
the MS, the contact with the cortical plate is absent in all roots of the teeth except the 16th, and with the mucous membrane the contact is absent in the 13th, 14th and 18th root of the teeth.