DETERMİNATİON OF THE ASYMMETRY OF THE LATERAL VİEW İN DİFFERENT FORMS OF THE SKULL.

S.A.  Aliyeva

doi:10.28942/jtcem.v5i1y2025.191

Abstract

The objective of this study was to investigate the degree of asymmetry manifested in the lateral view of facial skulls with varying shapes. The study examined signs of asymmetry in the craniometric parameters of 120 human skulls, representing various stages of postnatal development and exhibiting no deformities or injuries. Both the classical method of craniometry and the modern "fan" (yelpik) method were employed in the research. The results indicate that, regardless of shape, female skulls predominantly exhibit left-sided asymmetry in the measurements taken using the "lateral fan" technique. In female skulls with a medium-proportioned face, both left-sided asymmetry (ranging from a minimum of -0.01 to a maximum of -0.35) and right-sided asymmetry (ranging from a minimum of 0.04 to a maximum of 0.32) were recorded. In male skulls, regardless of shape, only left-sided asymmetry was observed in the "lateral fan" measurements—with the exception of the distance between the zygion and the lateral margin of the piriform aperture (Fl). The minimum value of left-sided asymmetry (-0.01) was observed in male skulls with medium-length faces, while the maximum value (-0.64) was observed in those with long faces.

Full article

Introductıon. In modern times, the activities of plastic and maxillofacial surgeons are aimed at early eradication of deformities, defects, and disproportions. Successful diagnostic examinations in the maxillofacial region and the selection of adequate treatment methods depend on the accuracy of the data on the regularity of the bone marrow localization of this region. However, in recent morphological studies, only evidence of facial features, structural features, developmental defects of the skeleton is found. In these studies, the asymmetry of the facial section of the skull was not taken into account. Changes in the soft tissues of the face as well as in the skull bones cause asymmetry. Although numerous studies are currently devoted to the asymmetries in the soft tissues of the face, asymmetry in the bone structures of different shaped skulls has not been studied. Materials and methods of research. The skulls from the craniological collection of the Museum of Human Anatomy and Medical Terminology of the Azerbaijan Medical University were used during the research. The skulls were deported (known by age and sex), with no deformities, no visible damage, and different ages of extraterretrial development. Asymmetry was rsearched in craniometric parameters of 120 human skulls. The research used the classical method of craniometry and the modern “Fan”method. Based on the classic craniometric method, the following craniometric paints were used to determine the size of the skull (Martin R., 1928):

1.Nazion (nasion) – connecting point of nasofrontal and internasal sutures. 2. Ziqion (zygion) – farest points of zygomatic bones; 3. Qnation (gnathion) – the most antrior convex point of the body of mandible; 4. Prostion (prosthion) – the most prominent point between central incisors dentes of the alveolar prosess of the maxillary bones . Using the indicated points, the width of the skull (the distance between the both zygion point of the skull), the morphological height (the distance between the nasion and the gnation), and the upper facial height (the distance between the nasion and the prostion) were measured. To determine the shape of the skull, the upper face index was determined based on the measurements mentioned.

The in upper face index is calculated as the relation of distance between nasion and prosthion to the zygomatic diameter (distance between both zygion points). According to R. Martini's (1928) classification, there are three types of skulls Ton the upper face index. he “”Fan” craniometric method was used to determine the asymmetry in the face skull. According to this method, three craniometric point are used in the facial section of the skull: 1. Nasion (N) - connecting point of nasofrontal and internasal sutures; 2. Prostion (Pr) - the most prominent point between central incisors dentes of the alveolar prosess of the maxillary bones; 3. Zygon (Zyg) farest points of zygomatic bones; Starting from this point and ending at the surrounding craniometric points. The face skull is divided into upper, lower, and lateral "fan" (images), The “lateral fan” consists of the distances between Zygion (Zg) with nasion (N), lateral margin of the apertura piriformis (Pl), the infraorbital foramen (Fio), prostion (Pr), gnation (Gn), gonion (Gon) (fig. 2). Following the general regulations for medical and biological research, the figures of our research were statistically analysed. The figures were calculated using variational statistics on PC / AT "Pentium-IV" using Statistical (StatSoft, 1999) and Microsoft Excel Windows-7 software packages. The minimum (min) and maximum (max) values, the average mathematical price (М±m), the variance coefficient (VC%), the reliability index (Rİ), the upper (UB) and the lower boundary (LB), are defined.

Research results and their discussion. The first and foremost research identified the shape of the skull. For this purpose, the upper height and width of the skull were measured and the upper face index was calculated. The results of our measurements showed that superior facial height 41,0-82,0mm, on averace 61,1±0,9mm (Rİ – 59,3-62,9%, VC – 16,1%), width of the facial skull 84,0- 128,3mm, on avarace 111,4±1,3mm (Rİ – 108,8-114,0%, VC – 12,8%), superior facial index 48,9-63,4mm, on averace 54,8±1,1 (Rİ – 52,6-57,0%, VC – 22,0%) was. The skulls studied in the research were subdivided into the upper face index. It was clarified how many percentages of facial forms occur. The distribution of the investigated material showed that the long face (lepten, upper face index more than 55) had 44 skulls, the middle face (mesen, upper face index 50 to 55) with 58 skulls, and the broad face (euryen, upper face). index (less than 50) was observed in 18 skulls. To determine the asymmetry in the different forms of the skull, measurements were made on the "lateral fan" in male and female skulls Almost half of the researched material (48,3±4,6%) was made of number of long size skulls. The study found that regardless of shape, female skulls had the most left-sided asymmetry at the sides of the "lateral fan". Regardless of the shape in the male skull except distance between zygion (Zg) point and lateral edge of the aperture piriformis (Fl) there is only left side asymmetry is observed all anther distance in “lateral fan” Regardless of the shape of the male skull, except the distance from Zygion (Zg) point to lateral edge of the aperture piriformis (Fl), only the left-sided asymmetry is observed at the “lateral fan”. According to the literature the asymmetry observed in the “lateral fan” may be due to the difference in tone of the nasal, mastication muscles on the right and left.

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References

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