V-XVII a. Lietuvos arklių plaštakų ir pėdų osteometrinė analizė bei biologinio amžiaus nustatymas pagal dantų struktūrą ; Osteometrical analysis of metacarpal and metatarsal bones of V-XVII c. Lithuanian horse and biological age determination according to teeth structure
LITHUANIAN VETERINARY ACADEMY The research work has been carried out at the Lithuanian Veterinary Acad- emy, Department of Anatomy and Physiology, in 2002–2006. Research supervisor – Prof. at Incumbent dr. Linas Daugnora (Biomedical Sciences, Veterinary Medicine – 12 B), Lithuanian Veterinary Academy. Chairman of the Veterinary Medicine Council – Doc. dr. Albina Aniulien ė (Biomedical Sciences, Veterinary Medicine – 12 B), Lithuanian Veterinary Academy. Snieguol ė Veli čkait ė Members: Prof. dr. Bronius Bakutis (Biomedical Sciences, Veterinary Medicine – 12 B), Lithuanian Veterinary Academy; Prof. habil. dr. Vytautas Špakauskas (Biomedical Sciences, Veterinary Medicine – 12 B), Lithuanian Veterinary Academy; Prof. dr. Neringa Paužien ė (Biomedical Sciences, Medicine – 07 B), Kaunas University of Medical; OSTEOMETRICAL ANALYSIS OF Dr Laima Bal čiauskien ė (Biomedical Sciences, Ecology and Environmental Science – 03B), Institute of Ecology of Vilnius University. METACARPAL AND METATARSAL BONES OF V–XVII C. LITHUANIAN HORSE AND Opponents: BIOLOGICAL AGE DETERMINATION ACCORDING Dr. Ingrida Monkevi čien ė (Biomedical Sciences, Veterinary Medicine – TO TEETH STRUCTURE 12 B), Lithuanian Veterinary Academy; Doc. dr. Rimantas Jankauskas (Biomedical Sciences, Medicine – 07 B), Vilnius University.
Snieguol Veli č kait OSTEOMETRICAL ANALYSIS OF METACARPAL AND METATARSAL BONES OF VXVII C. LITHUANIAN HORSE AND BIOLOGICAL AGE DETERMINATION ACCORDING TO TEETH STRUCTURE SUMMARY OF DOCTORAL DISSERTATION BIOMEDICAL SCIENCES, VETERINARY MEDICINE (12B) KAUNAS, 2006
The research work has been carried out at the Lithuanian Veterinary Acad-emy, Department of Anatomy and Physiology, in 20022006. Research supervisor Prof. at Incumbent dr. Linas Daugnora (Biomedical Sciences, Veterinary Medicine 12 B), Lithuanian Veterinary Academy. Chairman of the Veterinary Medicine Council Doc. dr. Albina Aniulien (Biomedical Sciences, Veterinary Medicine 12 B), Lithuanian Veterinary Academy. Members: Prof. dr. Bronius Bakutis (Biomedical Sciences, Veterinary Medicine 12 B), Lithuanian Veterinary Academy; Prof. habil. dr. Vytautas pakauskas (Biomedical Sciences, Veterinary Medicine 12 B), Lithuanian Veterinary Academy; Prof. dr. Neringa Pauien (Biomedical Sciences, Medicine 07 B), Kaunas University of Medical; Dr Laima Bal č iauskien (Biomedical Sciences, Ecology and Environmental Science 03B), Institute of Ecology of Vilnius University. Opponents: Dr. Ingrida Monkevi č ien (Biomedical Sciences, Veterinary Medicine 12 B), Lithuanian Veterinary Academy; Doc. dr. Rimantas Jankauskas (Biomedical Sciences, Medicine 07 B), Vilnius University. Public defense of Doctoral thesis in Veterinary Medicine Science Council will take place at Lithuanian Veterinary Academy I auditorium 14 am on 30 th of November, 2006. Address: Til s 18 LT-47181, Kaunas, Lithuania. The abstract of doctoral dissertation has been send on 30 th of October, 2006 according to the confirmed address list. This dissertation is available at the libraries of the Lithuanian Veterinary Academy and Veterinary Institute of Lithuanian Veterinary Academy.
LIETUVOS VETERINARIJOS AKADEMIJA Snieguol Veli č kait VXVII a. LIETUVOS ARKLI PLATAK IR P D OSTEOMETRIN ANALIZ BEI BIOLOGINIO AMIAUS NUSTATYMAS PAGAL DANT STRUKT R Ą Daktaro disertacijos santrauka Biomedicinos mokslai, veterinarin medicina (12 B) Kaunas, 2006
Disertacija rengta 2002-2006 metais Lietuvos veterinarijos akademijos Anatomijos ir fiziologijos katedroje. Mokslinis vadovas E. prof. p. dr. Linas Daugnora (biomedicinos mokslai, veterinarin medicina 12 B), Lietuvos veterinarijos akademija. Disertacija ginama Lietuvos veterinarijos akademijos Veterinarin s medicinos mokslo krypties taryboje: Pirminink Doc. dr. Albina Aniulien (biomedicinos mokslai, veterinarin medicina 12 B), Lietuvos veterinarijos akademija. Nariai: Prof. dr. Bronius Bakutis (biomedicinos mokslai, veterinarin medicina 12 B), Lietuvos veterinarijos akademija; Prof. habil. dr. Vytautas pakauskas (biomedicinos mokslai, veterinarin medicina 12 B), Lietuvos veterinarijos akademija; Prof. dr. Neringa Pauien (biomedicinos mokslai, medicina 07 B), Kauno medicinos universitetas; Dr. Laima Bal č iauskien (biomedicinos mokslai, ekologija ir aplinkotyra 03B), Vilniaus universiteto Ekologijos institutas. Oponentai: Dr. Ingrida Monkevi č ien , (biomedicinos mokslai, veterinarin medicina 12 B), Lietuvos veterinarijos akademija; Doc. dr. Rimantas Jankauskas (biomedicinos mokslai, medicina 07 B), Vilniaus universitetas. Disertacija bus ginama vieame Veterinarin s medicinos mokslo krypties tarybos pos dyje 2006 m. lapkri č io 30 d. 14 val. Lietuvos veterinarijos akademijos I auditorijoje. Adresas: Til s g. 18, 47181 Kaunas, Lietuva. Disertacijos santrauka isiuntin ta 2006 m. spalio m n. 30 d. pagal pat-virtint ą adres s ą ra ą . Disertacij ą galima peri r ti Lietuvos veterinarijos akademijos ir LVA Veterinarijos instituto bibliotekose.
INTRODUCTION The first horse burials in Lithuania were found in the coastal burial ground dated to the 2d4th centuries (Volkait -Kulikauskien , 2001; Michelbertas, 1984). Most abundant data were available from Central Lithuania where horse burials were known since the middle of the 1 st cen-tury. Horse skeletons found in Marvel burial ground (7th11th centuries) were most thoroughly investigated. Many publications were prepared based on this material (Daugnora, 1994; Daugnora, 1996; Bertaius, Daugnora, 1997; Bertaius, Daugnora, 2001). Horses remains uncovered in other places than burial grounds hill forts, cities or castles have been less in-vestigated by osteologists so far. The objects mentioned above must be stud-ied for comprehensive and more objective knowledge and view about the types of horses bred in Lithuania and in the neighbouring countries (Poland, Russia, Latvia, etc.) in the past. Date of archaeological material from the 5th century included many well preserved horse bones what enabled following up the evolution of the Lithuanian horse until today. Material about horse height, constitution and age is very rare. Metacarpal and metatarsal bones, and skull or at least the lower jaw with teeth could be pointed out as most valuable material. Teeth belong to the best preserved elements of excavations. Such factors as dentition or wear allow determin-ing the animal age. However solitary molars (as they found the most fre-quently) do not able to provide this kind of information. Therefore, the methods allowing determining the horse age according to the tooth height and number of cementum rings are very. The aim of the research The aim of the present work was to describe the whiter height, type and age of horses bred in the 5th17th centuries in the present territory of Lithuania and to specify and evaluate the methods of determining the bio-logical age of an individual. The tasks of the research 1. Determining the wither height of horses bred in the 5th17th centuries in the territory of Lithuania. 2. Determining the types of horses according to the relative width of metacarpus and metatarsus bones. 3. Assessment of the level of objectiveness of the methods used for de-termining the biological age according teeth structure. Originality of research: Osteological material from the 5th17th centuries excavated in Lithuania was analysed and the whiter height and type of the then bred horses. The age
5
of the excavated and present horses were determinate using the radiographic and computer tomography research methods and by counting rings of ce-mentum. MATERIAL AND METHODS The osteological and osteometric bone analysis was performed at the Laboratory of Osteology, Department of Anatomy and Physiology of the Lithuanian Veterinary Academy (LVA). The analysed osteological material was collected from the following ar-eas: Upper town of Kernav (13th15th century); Pakalnikiai (12th15th century); Obeliai (12th14th century); Taurapilis (5th6th century); Skub -tai (9th12th century); Plinkaigalis (5th6th century); Degsn Labotik s (5th12th century); Vilnius (14th the first half of the 15th century and the second half of the 15th 17th century) and Marvel (11th17th century ). The skulls of present horses whose age were known were collected in 19962002. The horses were used for the purposes of students training. The used oseological material was stored at the repositories of the Laboratory of Osteology, Department of Anatomy and Physiology of the LVA. Osteometry and determining of the horse height The minimal number of individuals (MNI) was determined by T. Whites (1953) method. According to the relative width of diaphysis of metacarpal and metatarsal bones (SD*100/GL) the horses were classified into types within A. Brauners classification. The wither height of horses was determined using the V. O. Vitts (Vitt, 1952) methods. The metacarpal and metatarsal bones were measured by A. von den Driesch (1976) method. The bones were measured with the calliper (precision 0.1 mm). Methods for determining the horse age The horse age was determined according to the wear of incisors using Goodys (1997) schemes and corrected according to tables given by Muyllei and others (1999), M. Levine (1982), I. A. Silver (1969), A. F. Klimov (1955), R. Getty (1955). Radiographic and computer tomographic images of teeth The excavated material often contained individual molars or fragments of jaw without incisors what made more difficult to determine the horse age. Using the radiographic and tomogramphic images the teeth were measured and thus the horse age determined. The lower jaws of present horses of known age were taken and teeth measured to correct the radiographic and computer tomographic methods. The biological age of horses was determined based on the teeth height data.
6
The height of teeth was statistically compared with the chronological age. The excavated horse teeth were also measured in radiographic imaging. The horse age determined by teeth measuring was compared with the horse age determined by other methods. The radiographic imagings were made at the LVA Dr L. Kriau č eli nas Clinics of Small Animals using Americomp spectra 325e apparatus (parameters of ray exposition 125 kV300 mA). The height of all molars between the masticator surface and furcation of the root and the length of teeth on the left side of the jaw were measured on the ra-diographic images. The computer tomograms were made at the Radiological Clinics of Kau-nas Medical University using 6-ply Siemens Spamatom Emotion and 16-ply General Electric Light speed multi-section computer tomographic scanners. The jaws were scanned by 2.5 mm thick layers. The height of all molars between the masticator surface and furcation of the root and the length of teeth on the left side of the lower jaw were measured on the computer tomo-graphy images. For correction of measuring data obtained from radiographic images and computer tomography, molars were chiselled from the lower jaw and their height, width and length were measured. The age of horses was determined according to the height of measured molars by M. Levine (1982) method. Histological examination of teeth Teeth sections were made at the Forensic Criminology Laboratory, Insti-tute of Forensic Medicine of Mykolas Romeris University. The first molars (M 1 ) from the lower jaw of present and excavated horses were taken for examination. Horizontal sections of the roots of horse teeth were made by methods described in the works of S. Trumpickait -Dzek č iorien (2000) and R. Bojarun (2003) and using microtome LEICA SP 1600. For determining the reliability of the data obtained histological prepara-tions of decalcinated teeth were made. These histological preparations were prepared by method described in C. Azorit et al. (2002). Statistical data analysis Statistical data analysis was carried out at the Department of Applied Mathematics of Kaunas Technological University using the SPSS 9.0 statis-tical analysis system for Windows. The following methods of statistical analysis were applied in the present work: 1. Descriptive statistics. Digital characteristics for analysed dimensions were calculated (frequencies, relative frequencies, minimal and maximal values, arithmetic mean and standard deviation (SD)). 2. Hypotheses about compatibility of actual and normal pattern of ana-
7
lysed dimensions were checked using KolmogorovSmirnov criterion. The Wilcocksons criterion of signs was used for examination of dependent data sets. Statistical significance of the differences of metacarpal and metatarsal bones length in different localities and data on teeth height and length ob-tained from roentgenograms and tomograms was determined. 3. Correlation analysis. The strength of the link between the metatarsal bones length and width, chronological age of teeth and biological age de-termined by measuring teeth with the aid of trammel and in roentgenograms and tomograms, as well as between the number of cementum rings and chronological age was evaluated using Spidermans ranking correlation co-efficient. Hypotheses about significance of correlation coefficients (H o : cor-relation coefficient equals to zero) were checked. If zero hypothesis H o was rejected with significance value p<0.05 the correlation was considered sig-nificant. 4. Regression analysis was employed for assessment of relationship be-tween data sets. 5. The data were considered statistically significant when p<0.05. RESULTS Osteometry and whiter height of horse The length of metacarpal bones ranged from 170.2 mm to 250 mm (Ta-ble 1) and the length of metatarsal bones varied from 198.9 mm to 291 mm (Table 2). Table 1. Length of the horse metacarpal bones LocalityNofubmobnesrAvvaelruaegedSetavinadtiaordnMinMaxKernav 13 205,70 18,20 179,6 230 Vilnius 14ththe1st half of the 15th c. 5 207,1 17,5 188,0 229,9 tVhieln1i5utshth1e72thdchalfof8225,617,8200,0250,0. Obeliai 2 180,45 14,07 170,5 190,4 Taurapilis 2 205,4 6,65 200,7 210,1 Plinkaigalis 2 210,65 0,35 210,4 210,9 Pakalnikiai 12 199,25 16,37 180,5 220,4 Degsn Labotik s 3 190,3 20,05 170,2 210,3 Marvel 72 192,8 8,35 181 216
8
Table 2. Length of horse metatarsal bones y Number Max LocalitofbonesAveragedSetavinadtiarodnMinKernav 12 242 18,18 198,9 271,8 Vilniufst1he4t1h5tthhec1.st3241,315,9225,1256,8half o Vilnius the 2d half of the 15th17th c. 8 258,8 22,9 226,8 291,0 Obeliai 2 220 14 210,2 230 Taurapilis 2 240,7 0,28 240,4 240,8 Plinkaigalis 1 260,2 - - -Pakalnikiai 3 264,0 5,86 260,5 270,8 Degsn Labotik s 2 235,5 7,64 230,1 240,9 Marvel 48 234,14 8,83 219 258 Comparison of the length of horse metacarpal bones from Marvel with the items from Kernav , Vilnius (the 14ththe first half of the 15th century), Vilnius (the second half of the 15ththe 17th century), Pakalnikiai, Obeliai, Taurapilis, Plinkaigalis, Degsn Labotik s showed that according to Wil-cocksons criterion the differences of the length of the horse metacarpal bones from these localities were statistically significant (z=-3.779, p<0.001). Comparison of the length of metatarsal bones from Marvel with the items from Kernav , Vilnius (the 14ththe first half of the 15th century), Vilnius (the second half of the 15ththe 17th century), Pakalnikiai, Obeliai, Taurapilis, Plinkaigalis, Degsn Labotik s showed that according to Vilkoksons criterion the differences of the length of the horse feet bones from these localities were statistically significant (z = -3.779, p<0.001). According to the relative width of metacarpal bones (Table 3), horses of type III were dominant in Kernav though remains but all five types of horses were found. The data about Vilnius in the 14ththe first half of the 15th century were rare however they contain evidence about types IIII of horses. The material about Vilnius in the second half of the 15ththe 17th century contained remains of horse types III and IV. Only three metacarpal bones were uncovered in Obeliai. According to their size they belonged to horse type III. The horses buried in Taurapilis were of type IV, in Plinkai-galis III and IV, in Pakalnikiai dominated type III, and in Degsn Labotik s types II and V. According to the relative width of metatarsal (Table 4), type II and III of horses were dominant in Marvel and Kernav . The same types were found in the material from Vilnius (the second half of the 15ththe 17th century). Types II and III were dominant in Obeliai and 9
Pakalnikiai, IV in Taurapilis, III in Plinkaigalis, and II in Degsn Labotik s. The values of the length (GL) of metacarpal and metatarsal bones (Fig. 2) and the thinnest area of diaphysis (SD) arranged on different axes (Fig. 1) yielded the dispersion pattern of individual bone measurements. The data were widely dispersed. The data of individuals (points in the set) differed considerably from the data of main limb bone massifs. This implies that burials contained remains of different types of horses. The correlation coefficient of metacarpal bones length and width of diaphyses was high (r=0.68, p<0.01). The statistically correlation of length of metacarpal bones and width of diaphyses were significant (r=0.56, p<0.01). Table 3. Relative width of metacarpal bones diaphysis (SD/GL) Vilnius, Vilnius, Degsn LocalitynKaevr -vMealr -11st4othfhalfsh1ea5cltfohnofdObeliaiTpaiulirs-kaPilgina-lisnPiakkal--Labo- a iai tik s 15th c. 17th c. Width o diaphy-sis (SD/GL) accord-ing to Brauner Type I (up to 1 7,7 1 1 1 25 13.5%) Type II (13.5-1 7,7 9 12 2 50 4 26,7 14.5%) Type III (14.5-8 61,5 25 33,8 1 25 5 62,5 3 100 1 33,3 6 40 2 66,7 15.5%) Type IV (15.5-2 15,4 29 39,2 3 37,5 2 100 2 66,7 4 26,7 16.5%) Type V (16.5-1 7,7 10 13,5 1 6,6 1 33,3 17.5%) Total 12 100 74 100 4 100 8 100 2 100 2 100 3 100 15 100 3 100 10
Table 4. Relative width of metatarsal bones diaphysis (SD/GL) Vilnius, Vilnius, 14th -LocalitynKaevr -vMealr 1stohfalf21d5othfhalfObeliaiaTpaiulri-skaPilginal-isnPiakkaila-i-DtiLeagksb nos -15th c. 17th c. Width of dia-physis (SD/GL) accord-ing to Brauner Type I (up to 3 25,0 4 8.2 1 50 2 28,6 1 50 11%) II 5 41,7 25 1 50 2 100 (T1y2p%e)20 40,8 2 28,6 1 Type III (12-4 33,3 22 44,9 1 50 3 42,8 3 75 1 33,3 1 50 1 50 13%) Type IV (13- 3 6,1 2 66,7 14%) Total 12 100 49 100 2 100 7 100 4 100 3 100 2 100 2 100 2 100 Metacarpal and metatarsal bones were the most abundant and the best preserved items of archaeological material. Therefore, determining the height of horses was not a difficult task. The Lithuanian archaeological ma-terial from the 5th17th c. contained remains of horses whose wither height ranged from less than 112 cm to 160 cm (Table 5). Teeth measuring Radiographic and topographic images of 26 present horses were made order to find out which of the methods was more helpful in teeth measuring. Assessment of obtained measuring data by Kolmogorov Smirnov test re-vealed that normal distribution was obtained only for measuring tooth length p>0.5 and tooth height p>0.5 in computer tomograms. Statistical signifi-cance of the differences between measuring values from tomograms and roentgenograms was determined by Vilkoksons criterion. The obtained statistical significance value of the differences between tooth length values from roentgenograms and tomograms was p<0.001. 11
Metacarpus
40 35 30 25 20 170 180 190 200 210 220 230 240 250 260 Bone lenght, mm Vilnius 14 th -1 st half of 15 th c. Vilnius 2 d half of the 15 th - 17 th c. Kernav Marvel Pakalnikiai Fig. 1. Length of horse metacarpal bones (GL) versus width of hand diaphyses (SD) Metatarsus 40 35 30 25 20 15 190 200 210 220 230 240 250 260 270 280 290 300 Bone lenght, mm Vilnius 14 th - 1 st half of 15 th c. Vilnius 2 d half of the 15 th - 17 th c. Kernav Marvel Pakalnikiai Fig. 2. Length of horse metatarsal bones (GL) versus width of feet diaphyses (SD) 12
Statistical significance of the differences of tooth height data was p<0.001. The difference between the average tooth length values in roent-genograms and tomograms was 0.31 mm and as well as the average values of tooth height was 0.48 mm. The obtained results showed that teeth measuring results obtained from roentgenograms were more accurate. The tomographic method was also applicable but the average error of tooth width obtained by this method ranged from 2.8 to 8.7% and the average error of tooth length ranged from 7.7 to 11.5%. Table 5. Distribution of data in horse wither height, % ilnius taHoceciVogirthtdt,ingnKaevr- Pakal-ObeliairaTpaiuli-sPlgianlkisaiDegsn V14th2Vidlnhiaulsf- r-Laboti 1st half o cmnikiaik s15tohf1175tthfhc.vMeal c. <112 4 25 20 112120, very 16 20 22,2 6,2 36,1 small s1m20all128,322050806022,212,552,8128136, smaller 24 13,3 25 20 66,6 20 33,3 31 than av- ,3 11,1 erage a1v3e6ra1g4e4,2446,73,322,225144152, larger12,5than av-erage 152160, 12 5 large , n 25 15 4 5 3 5 9 16 72 Determining biological age according to the height of molars The determining of horses age was based on tooth height values obtained from radiographic and computer tomography images using calliper and re-13
count using A. Levine (1982) method (Table 6). All molars in the lower jaw of 26 present horses (whose age was known) were measured. The smallest difference of biological horse age determined according to the height of second molars (P2) from the chronological age determined by measuring the teeth with a calliper was 2 years and the greatest difference 2.87 years. The correlation coefficient between the chronological and bio-logical age determined by measuring with a calliper was also high (r=0.809, p<0.01). The chronological age and biological age determined based on to-mograms were in no statistically significant correlation. The greatest difference of biological age average determined according to the third molars (P3) on tomograms was 2.4 years. The correlation coeffi-cient between the chronological age and the age determined using a trammel was high (r=0,854, p<0.01). The chronological age and age determined by teeth measuring on roentgenograms statistically significantly correlated (r=0.785, p<0.01). The correlation coefficient between the chronological age and age determined by tooth height on tomograms showed strong correla-tion of data r=0.723, p<0.05. The difference between the age determined according to the tooth height of fourth molars using a calliper and the chronological age was 2.05 years. The greatest difference was determined when the age was evaluated by measuring teeth on tomograms 2.20. The correlation coefficient between the chronological age and age determined by measuring teeth with a tram-mel was high (r=0.835 p<0.01). The correlation coefficient between the chronological and biological age determined by a trammel was also high (r=0.835, p<0.01). The difference between the average values of chronological age of first molars and biological age determined by measuring on tomograms was 2.87 years. The correlation coefficient between the chronological age and the age determined using a calliper was high (r=0.827, p<0.01). Statistically signifi-cant correlation was determined between the chronological age and age de-termined by measuring teeth on roentgenograms (r=0.827, p<0.01). The correlation coefficient between the chronological age and age determined by teeth measuring on tomograms was also high (r=0.777, p< 0.01). The absolute difference of chronological age of the second molars from the biological age determined by roentgenograms was 1.9 years and from the biological age determined by tomograms 2.4 years. The chronological and biological age determined by teeth measuring in all cases was in strong correlation.
14
Table 6. Results of determining the biological age of animals and dif-ferences from the chronological age StatiChro-DiffferenceHrfDroioflmferceihcnracole-HtfDrioffmerencenolo- rom chro-sticalindexgicalHsclhorgoicnaol-naoggenologicalage age age Average(P2) 8,5 6,88 2,00 6,85 2,08 7,20 2,87 N 26 26 26 26 26 15 15 Min 2,5 3 0 2 0 4 0 Max 17 13 10 14 9 11 9 Standard deviation 4,40 2,93 2,54 3,02 2,46 2,43 2,81 Average (P3) 9,76 8,86 1,29 9,14 1,57 9,40 2,40 N 21 21 21 21 21 10 10 Min 5 5 0 6 0 7 0 Max 17 15 8 15 8 16 8 Standard deviation 3,94 3,14 2,28 3,21 2,38 2,72 2,55 Average (P4) 9,76 8,38 2,05 8,24 1,95 9,00 2,20 N 21 21 21 21 21 10 10 Min 5 4 0 4 0 5 0 Max 17 16 9 15 9 15 8 Standard deviation 3,94 3,38 2,13 3,56 2,20 2,83 2,57 Average (M1) 8,5 6,88 2,00 6,85 2,08 7,20 2,87 N 26 26 26 26 26 15 15 Min 2,5 3 0 2 0 4 0 Max 17 13 10 14 9 11 9 Standard deviation 4,40 2,93 2,54 3,02 2,46 2,43 2,81 Average (M2) 9,76 8,43 1,76 8,29 1,90 8,70 2,40 N 21 21 21 21 21 10 10 Min 5 4 0 4 0 5 0 Max 17 14 9 14 9 13 8 Standard deviation 3,94 3,30 2,02 3,33 2,07 2,71 2,41 Average (M3) 9,76 9,00 2,00 9,14 2,33 9,00 3,00 N 21 21 21 21 21 10 10 Min 5 3 0 3 0 6 0 Max 17 20 9 20 9 13 9 Standard deviation 3,94 4,02 2,63 4,34 2,69 2,62 3,23 Hs biological age according to tooth height measured with the calliper; Hr biological age according to tooth height measured on radiographic images; Ht biological age according to tooth height measured on computer tomography images.
15
The greatest difference of the biological age of the third molars from the chronological age was obtained when teeth were measured on topographic images (3 years) and the smallest when teeth were measured using a calliper (2 years). The correlation coefficient between the chronological age and biological age determined by a calliper was high (r=0.719 p<0.01). There was no correlation between the chronological and biological age determined by measuring teeth on computer tomography images. The presented data showed that the smallest differences from the chrono-logical age were obtained when teeth were measured using a calliper. The greatest differences were obtained when teeth were measured on computer tomography images. Determining the age of excavated horse according to the height of molars The age of all excavated horses was determined according to the wear of incisors (WI) and according to the shift from milk-teeth to permanent teeth (MPTS). The age of horses was determined based on tooth height values obtained from radiographic and computer tomography images measuring data obtained using a calliper and counted by A. Levine (1982) method (Ta-ble 7). All molars in the lower jaw of 16 exacvated horses were measured. The difference of age of horses determined by measuring the second mo-lars (P2) with a trammel and on roentgenograms from the age determined according to WI and MPTS was 2.13 years. The difference between the age determined by measuring teeth on a tomogram and the chronological age was 2.33 years. The correlation coefficient between the age determined ac-cording to WI and MPTS and the age determined by teeth measuring showed no correlation between these values p>0.05. However the data of individual measuring were in statistically significant correlation r=0.921, p<0.01. The smallest difference of 3.13 years was obtained between the age of the third molars determined according to WI and MPTS and the age deter-mined with the aid of a calliper. The greatest difference was obtained when teeth were measured on tomograms 3.56 years. The age determined ac-cording to WI and MPTS is in no correlation with the age determined by measuring the teeth height p>0.05. The greatest difference of 3.25 years was obtained between the age of the fourth molars (P4) determined according to WI and MPTS and the age determined by measuring tooth height on radiographic images. The age de-termined according to WI and MPTS is in no correlation with the biological age determined by measuring the teeth height p>0.05.
16
Table 7. Results of determining the biological age of excavated horses and differences from the chronological age - Difference Difference Age de Difference from the age from the StatisticalatcetcroomriWdniIendgHamfgrieonemddettahecre--agedidnetgetr-Hr determined index s ding to according to Ht mined ac-andcoWrIandWIandcoWrIandoMPTSMPTSMPTSMPTSAverage(P2) 8,25 9,60 2,13 9,87 2,13 9,73 2,33 16 15 15 15 15 15 15 Min 5 6 0 6 0 6 1 Max 16 15 8 15 8 15 8 STDV 3,70 3,07 1,88 3,09 1,96 2,96 1,88 Average (P3) 8,25 9,88 3,13 10 3,38 9,94 3,56 16 16 16 16 16 16 16 Min 5 6 0 6 1 6 0 Max 16 20 15 20 20 20 15 STDV 3,69 4,19 3,99 3,93 3,86 3,94 3,86 Average (P4) 8,25 9,50 3,13 9,75 3,25 9,50 3,13 16 16 16 16 16 16 16 Min 5 6 0 6 0 6 0 Max 16 20 15 20 15 20 15 STDV 3,69 3,67 3,84 3,69 3,80 3,62 3,76 Average(M1) 8,25 9,13 2,38 9,00 2,50 9,06 2,69 16 16 16 16 16 16 16 Min 5 6 0 6 0 5 0 Max 16 18 13 17 12 18 13 STDV 3,70 3,32 3,12 2,97 2,78 3,19 3,16 Average(M2) 8,25 9,69 2,69 9,19 2,94 9,38 2,94 16 16 16 16 16 16 16 Min 5 6 0 5 0 6 0 Max 16 15 9 15 9 15 9 STDV 3,69 2,77 1,96 2,76 2,32 2,55 2,32 Average(M3) 8,25 11,4 4,13 11,27 4,13 11,8 4,40 16 15 15 15 15 15 15 Min 5 7 1 7 1 8 2 Max 16 20 14 20 14 20 14 STDV 3,69 4,05 3,14 4,20 3,18 3,84 3,02 Hs biological age according to tooth height measured with the aid of calliper; Hr biological age according to tooth height measured on radiographic images; Ht biological age according to tooth height measured on computer tomography images. 17
The difference between the ages of the first molars (M1) determined accord-ing to WI and MPTS and the age determined by measuring teeth height with a calliper was 2.38 years. There were no correlation between the age of the first molars (M1) determined according to WI and MPTS and the biological age determined by teeth measuring p>0.05. The greatest difference of 2.94 years was obtained between the age of the second molars (M2) determined according to teeth height measuring on radiographic and computer tomography images. The average biological age determined by measuring with a calliper is 9.69 years. Its difference from the age determined by WI and MPTS was 2.69 years. Statistically signifi-cant correlation was established only between the age determined according to WI and MPTS and biological age determined by measuring with a tram-mel r=0.635, p<0.01. There were no correlation between the age determined according to WI and MPTS and the biological age determined by measuring the teeth height on tomograms, p>0.05. The difference between the average values of the age determined accord-ing to WI and MPTS and biological age determined by measuring the third molars (M3) with a calliper and on radiographic images was 4.13 years. There were no correlation between the age determined according to WI and MPTS and the biological age determined by teeth height measuring p>0.05. The greatest determined difference was between the age according to WI and MPTS and the biological age determined on the basis of tomograms. Counting of annual cementum rings in the teeth microstructure of present horses The main research results showed in Table 8. The annual cementum rings were counted on the teeth of 26 present horses based on 30 histological samples. The results of three counting methods of cementum rings corre-lated very high (r>0.968, p<0.01). This meaned that counting results of an-nual cementum rings were very objective and differences of counting pro-duced no major effect on the data. Therefore the correlation coefficient be-tween the age determined by annual rings and chronological age was high r=0.94, p<0.01. The absolute difference of the data set from the chronologi-cal age was 0.76 years on the average. The accuracy of age determined for older animals decreased; the difference of the whole data set was 0.76 years (8.78%). For young (up to 4 years of age) individuals this value was smaller 0.54 years (6.32%), for individuals aged up to 10 years 0.73 years (8.54%) and for individuals aged more than ten years 0.88 (10.3%).
18
Table 8. Results of determining biological age of present horses and 18 difference from the chronological age 16 StatisticalindexChrono-vAavlereagoefDeterminedAbsoeluftreodmiftfheer-14 logicalcemeuntumbae ageringsiologicalgchernocnologicalage Average (all) 8,54 8,13 8,63 0,76 12 N 26 26 26 26 Min 2,5 1,3 1,8 0 10 Max 17 15,7 16,2 2,8 Standard deviation 4,40 4,44 4,43 0,84 8 Average (up to 4 years) 3,2 2,16 2,66 0,54 6 N 5 5 5 5 Min 2,5 1,3 1,8 0 4 Max 4 3,3 3,8 1,7 Standard deviation 0,57 0,77 0,77 0,73 2 Average (410 years) 6,55 6,66 7,16 0,73 0 2 4 6 8 10 12 14 16 N1111 11 11 Min 5 5,1 5,6 0 Max 9 11 11,5 2,8 Fig. 3. Mutual dependence of annual cementum rings on the teeth of Standard deviation 1,04 1,57 1,57 1,01 present horses (axis X) and chronological age (axis Y) . Broken line marks Average individual cases and solid line stands for cubic regression. (more than 10 years) 13,4 12,74 13,22 0,88 N 10 10 10 10 Min 10 8,5 9 0 and T d a i b f l f e e r 9 e . ncReefsruoltmstohfedcehtreornmoilnoignigcabliaogleogicalageofexcavatedhorsesMax 17 15,7 16,2 2,2 Standard deviation 2,37 2,37 2,40 0,76 Absolute dif- Arithmetic Age Dependence between the number of cementum rings and chronological accord- Average Deter- ference from difference age used a non-linear character: the highest correlation was obtained using StatisticalindexiWnIgatnodcneummenetruomflmoiniecdalbaigoe-ctotehrrdemiainnggeetdodaec-W-Ifardcoectmoerrtdhmieinngaegtdoecubic (Y = b 0 +b 1 X+b 2 X 2 +b 3 X 3 ) (Fig. 3) regression model (r=0.943). MPTS rings g d MPTS WI and MPTS an Counting of annual cementum rings in the tooth microstructure of Average(all) 10,81 10,58 11,08 0,68 -0,26 excavated horses N 8 8 8 8 8 The age of excavated horses was determined according to the shift of Min 5 4,3 4,8 0 -2,2 milk teethpermanent teeth (MPTS) and wear of incisors (WI). Cementum Max 16 15,5 16 2,2 1,2 rings were counted in 8 histological samples (40%). The obtained results Standard deviation 4,72 4,86 4,86 0,91 1,24 (Table 9) correlated highly. The correlation coefficient is r>0.922, p<0.01. Different r i n models showed that the determined interdependence TheagesdeterminedbycountingcementumringsandbyWIandMPTSusedan-lineegarrecshsaroacter:thehighestcorrelationwasobtainedusingcubicalso correlated highly r>0.946, p<0.01. The average difference between the on ages determined according cementum rings for the whole data set and ac- regression models (Y = b 0 +b 1 X+b 2 X 2 ) (Fig. 5.) (r = 0.942) and (Y = cording WI and MPTS was 0.68 years. b 0 +b 1 X+b 2 X 2 +b 3 X 3 ) (Fig. 4). 19 20