METHODS VOLUMETRIC IMAGING JAW BONE TISSUE DENSITY

Pantus A. V.

DENTISTRY

Scentific article

For drafting a plan both of orthodontic and surgical treatment of bone tissue pathologies of dentofacial system, such criteria as patient’s age, concomitant somatic diseases, localization of the pathological process and the bone tissue condition at the site of injury are taken into account. The aim of the study was to optimize the method of spatial digital analysis of bone tissue density. Archival data of helical computed tomographic studies of 20 patients aged from 10 to 22 years with maxillofacial pathology were analyzed. For the purpose of diagnosis and treatment planning the spiral computed tomography of the facial skeleton was performed. Archived data were saved in the format dikom, analysis was performed in the software package MATLAB R2006a and Dikom Works 1.3.5. For mapping of the spatial location of density zones of bone tissue based on MATLAB R2006a software platform, there was worked out the mathematical algorithm of degree of matrix image obscuration with upper and lower limits that allows to select bone tissue of exact range of density and to perform the computer reconstruction regardless of tissues of another range of density. With the aim of further determination of the conformity of bone tissue density to some colour indexes, the axial slice of bone tissue image, marked in a range of colour spectrum of HSV, is divided into a number of images of a certain colour spectrum. Combining SSD reconstruction of each colour component that corresponds to a certain range of bone density, there was obtained three-dimensional reconstruction of the facial skeleton bones, marked with red colour, which corresponds to the bone tissue density of 2107-1369 Hounsfield units and with yellow colour with a density of 400-162 Hounsfield units. Analysis of the received image indicates the heterogeneity of density of skull bone tissue. Thus, bone tissue with density index of 2107-1369 Hounsfield units, marked in red, is localized mainly in the frontal area of the alveolar bone of the upper jaw, zygomatic-alveolar crest, forms the cortical layer of the angle, body and chin of the mandible. This colour is also responsible for marking the cementum and dentin of the teeth. Visualization of these areas is clear; their limits are easily obtained on the surface reconstruction of the facial skeleton bones. The performed analysis of data of computer-tomographic studies shows the correspondence between indicators of densitometric analysis and images of axial slices, spread out on the colour spectrum. Conclusions 1. The offered technique allows to visualize and divide the bone tissue, depending on the density, into a certain range of coloured spectra within each scan to identify better the areas with the highest and the lowest bone tissue density. 2. Possibility to isolate the layer of bone with a certain range of density allows to perform its reconstruction and follow its limits on the computer volumetric model. 3. This technique can be successfully used in maxillo-facial surgery, orthodontics, periodontics and implantology to determine the condition of the jaw bone in order to plan treatment activities.

bone tissue density, densitometry, Haunsfild units, computer diagnostic algorithm

• 1. Ославський О.М. Вплив передчасного видалення зубів на розвиток зубощелепних аномалій у дітей / О.М. Ославський // Одеський медичний журнал. –2010. – № 1 (117). – С. 47-50.
• 2. Сисоєв Н.П. Комбіноване лікування відкритого прикуса у дітей / Н.П. Сисоєв, Л.В. Чжан, Т.А. Кузнецова // Вісник стоматології. – 2009. – № 1. – С. 73-76.
• 3. Чуйкин С.В. Особенности этиологии, патогенеза и профилактики зубочелюстных аномалий у детей в регионе с неблагоприятными факторами окружающей среды / С.В. Чуйкин, С.В. Аверьянов // Стоматология детского возраста и профилактика. – 2009. – № 4. – С. 53-56.
• 4. Martínez-Lage J.F. Positional skull deformities in children: skull deformation without synostosis / J.F. Martínez-Lage, A.M. Ruíz-Espejo, A. Gilabert // Childs Nerv. Syst. – 2006. – Vol. 22, № 4. – P. 74-78.
• 5. Meikle M.C. Remodeling the Dentofacial Skeleton: The Biological Basis of Orthodontics and Dentofacial Orthopedics / M.C. Meikle // REVIEW CRITICAL REVIEWS IN ORAL BIOLOGY & MEDICINE. – 2007. –Vol. 86, № 1. – P. 12-24.
• 6. Obwegeser K. Unilateral hiperplasia and unilateral mandibular elongation. — Congenital Pathology of Facial Skeleton / K. Obwegeser // Temporomandibular joint Pathologi. – 1989. – Vol. 7. – P. 23-26.
• 7. Orofaciodigital syndrome type 1: clinicalcharacteristics of 2 cases and its diagnostics overlap with other malformation syndromes / E. Głuszkiewicz, A. Jezela-Stane, E. Marszal [et al.] // Case Rep. Clin. Pract. Rev. – 2006. – Vol. 7. – P. 39-43.

«Bulletin of problems biology and medicine» Issue 2 part 1 (128), 2016 year, 245-249 pages, index UDK 616.314-089+616.716