M3 Teeth Research Articles

Effect of mandibular third molar tooth germ extraction on mandibular development: a retrospective study

Objective: To investigatethe effect of extraction of mandibular third molar (M3) tooth germon the development of the mandible in orthodontic patients, with a view to providing a reference for clinical M3 tooth germ extraction. Methods: One hundred and twenty-nine Angel class Ⅰ patients aged 10-16 years who attended the Department of Orthodontics Division 1, School & Hospital of Stomatology, Wuhan University from 1 January 2013 to 30 December 2021 and fulfilled the criteria for nativity were included. Those who had their M3 extracted in the Department of Oral and Maxillofacial Surgery were included in the study group, with a total of 66 cases; and those who did not have their M3 extracted were included in the control group, with a total of 63 cases. The average annual growth was calculated by tracing point measurements on cephalometric films before and after orthodontic treatment according to the Jarabak and McNamara methods, with measurements of the mandibular ramus height (Ar-Go'), mandibular body length (Go'-Me), and overall mandibular length (Co-Gn) values, respectively. The average annual growth of Ar-Go', Go'-Me, and Co-Gn were compared between the two groups for the overall sample of patients, patients of the same sex (male/female), patients of the same age group (A, B, and C), and patients of the same cervical vertebral maturation stage (stages Ⅱ, Ⅲ, and Ⅳ), respectively, to see if there was any difference in the average annual growth of Ar-Go', Go'-Me, and Co-Gn. Results: There was no statistically significant difference in the average annual growth of Ar-Go', Go'-Me, and Co-Gn between the study group [0.88 (0.40, 1.80), 0.67 (0.15, 1.18), and 0.86 (0.40, 1.90) mm, respectively] and the control group [1.08 (0.45, 1.60), 0.53 (0.25, 1.13), and 1.20 (0.46, 2.28) mm, respectively] (P>0.05). In addition, there was no significant difference in the average annual growth in the Ar-Go', Go'-Me, and Co-Gn between the groups for patients of the same sex group (male/female), patients of the same age group (A, B, and C), and patients of the same cervical vertebral maturation stage group (stages Ⅱ, Ⅲ, and Ⅳ) (P>0.05). Conclusions: Extraction of the mandibular third molar tooth germ has no significant effect on the development of the mandible in Angle class Ⅰ orthodontic patients.

Early Pleistocene Bovidae from Palan-Tyukan (Azerbaijan)

The Early Pleistocene site of Palan-Tyukan (MNQ18, ca 1.85 Mya) is located in Transcaucasia, northwestern Azerbaijan. In total, more than 300 mammalian bones were collected there by one of the authors (M.V. Sablin) in 1986 and 1990. The remains were laid close to each other in a 25 m2 lens-like accumulation, in a stratum of normally magnetized (the upper part of the Olduvai subchron) yellowish-grey Lower Apsheron loams. No any excavations have been carried here out since. The present study is based on the analysis of the Bovidae remains. The material is represented by fragments of skulls and horn cores, isolated teeth and bones of the postcranial skeleton. As a result of the revision of the collection, Leptobos (Smertiobos) cf. etruscus (Falconer, 1859), Gazellospira torticornis (Aymard, 1854) and Gazella cf. bouvrainae (Kostopoulos, 1996) were identified. The degree of the unworn M3 tooth hypsodonty of Leptobos, as well as the size and morphology of limb bones indicate a greater similarity with those of L. etruscus from Olivola and Tasso. The characteristics of the horn cores, as well as the upper teeth and limb bones of the medium-sized spiral-horned antelope from Palan-Tyukan indicate a greater similarity with those of the nominative subspecies G. torticornis torticornis. The dimensions and degree of flattening of the horn cores, as well as the parameters of the p4 tooth, are similar to those of the medium-sized gazelle G. bouvrainae, described from several Early Pleistocene localities of Greece. The taxonomic composition of the Bovidae association from Palan-Tyukan is consistent with the previously determined stratigraphic position of the locality, the fauna from which belongs to the Psekups faunal complex of Eastern Europe, correlated with the Late Villafranchian of Western Europe. The composition of these herbivores community testifies to the spread of savanna-like forest-steppe landscapes in the west of Transcaucasia during this period of the Early Pleistocene.

Use of third molar eruption based on Gambier's criteria in assessing dental age.

The biological aspects of determining the dental age of subadults represent an important interdisciplinary scientific link with applications in criminal law and in forensic anthropology and dentistry. In criminal procedural law, it is necessary to determine the exact age of an undocumented person in view of the application of the provisions on juvenile offenders and minor victims. Chronological age can be estimated from the development of the third molars, as these are the only teeth that develop at the age of 18. The aim of this study was to verify the applicability of the Gambier method based on the eruption of the third permanent molars in the mandible and maxilla, to contribute to forensic age assessment. The analyzed group that met the criteria consisted of 811 orthopantomograms (OPGs) (339 females and 472 males) between the ages of 13 and 25years. The OPGs were retrospectively analyzed according to the method of Gambier et al. (Int J Legal Med 133:625-632, 29), which refers to the eruption stages of the third molar. Differences between eruption stages of maxillary and mandibular third molars were statistically significant in both biological sexes. Intersexual differences in mean age were significant only at stage 3 for any M3 tooth and at stage 1 for mandibular M3. There were no statistically significant differences between the left and right mandibular and maxillary third molars, respectively. Differences between mandibular and maxillary M3 were significant only for stage 1 in males on the left side and for stage 2 in both sexes and sides. The method used allowed the best classification of individuals into minor and adult groups (based on phase D-90.41% of individuals, based on the third stage of the mandibular left third molar-86.29%). Based on the results obtained, we can assume that the method cannot be used alone in the initial examination of living individuals, since all four third molars must be assessed and there are no additional findings from practice.

Relationship Of Patient Knowledge Level About Wound Care After Molar Extraction 3 With The Success Of Patient Wound Care

Post-extraction of M3 tooth extraction is an effort to speed up the healing process and prevent and reduce pain and swelling. Pasien will be given instructions and education on how to take care of the possible tooth extractions. In-depth knowledge of the treatment of M3 tooth extraction wounds can be known in the instruction after removal. This study aims to determine the relationship between the level of patient knowledge about wound care after the removal of molars 3 with the success of wound care at the Dental and Oral Hospital, Padjadjaran University. This type of research is analytics. The research sample was taken by accidental sampling with a total population of 31 respondents who performed M3 tooth extraction at the Minor Surgical Poly of the Dental and Oral Hospital, Padjadjaran University. The results showed that respondents who had a level of knowledge of post-revocation wound care in the good category were 12 people (38.7%). The results of wound treatment of respondents after tooth extraction M3 in the normal wound healing category were 15 people (48.8%). There is a relationship between the level of knowledge of m3 tooth extraction wound care and the success of wound care p(0.03<0.05).

CHARACTERISTICS OF UPPER THIRD MOLAR IMPACTION IN BANDUNG CITY POPULATION

Background: The third molars (M3) are the most frequently impacted teeth because they are the last to erupt, so they often don’t get enough space to erupt. The characteristics of impacted M3 teeth can be different for each person. This study aims to provide a description of maxillary M3 impaction based on age, sex, classification, treatment, and anesthesia in Bandung City population. Method: This was a descriptive study using secondary data from medical records and panoramic radiographs at RSGM UNPAD with a purposive sampling technique. Determination of the characteristic impaction using a classification based on Archer, Shiller, Jung and Cho, and Killy and Kay, analyzed with ImageJ software by interobserver and intraobserver, and tested using Kappa statistics for reliability. Result: There were 134 impacted teeth from 102 impacted patients with 67 females (66.34%) and most cases occurred in 17-25 years old (60.4%); Class B, 82 cases (60.9%); distoangular angulation, 76 cases (56.72%); Class 3, 76 cases (52.24%); and one fused roots, 83 cases (64.93%). The most common procedure performed was odontectomy (87.25%) with local anesthesia (63.73%) Conclusion: Characteristics of upper M3 impaction in terms of position, angulation, and its relation to age and sex is needed for the diagnosis, so the management plan by the clinician is better and safer. Panoramic radiography can still be used to determine classification and diagnosis in preparing a treatment plan even though it has limitations.

The comparison of roof visibility of the mandibular canal between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness of the mandible

BackgroundAccurate detection of the mandibular canal is a difficult process despite cutting-edge radiographic methods. The present study analyses whether mandibular canal roof visibility is comparable to panoramic radiography (PR) and cone-beam computed tomography (CBCT) and, further, examines whether the visibility in PR and CBCT is dependent on cortical bone thickness in the mandible.MethodsThis study was conducted on a group of 343 selected patients. It incorporated anonymised data on 343 patients in which a CBCT and PR were available. The first stage examines whether the mandibular canal roof visibility is comparable to PR and CBCT. In the second stage, measurements of cortical bone thickness showed buccal and lingual in the P2, M1, M2 and M3 teeth areas, both to the left and right of the mandible in CBCT images.Statistical analysis was supported by statistical software (IBM SPSS 25; Armonk, NY, USA).ResultsThe mean age of the patients was 58.8 years with an almost equal gender distribution. When performing a McNemar test on the P2, M1, M2 and M3 on both the left and right jaws, the difference between the two image modalities, with regard to the visibility of the canal roof, was found to be significant (McNemar test, p < 0.001).Statistically (U test, p≥0.05), it follows that the thickness of the cortical bone of the mandible exerts no influence on the visibility of the roof of canalis mandibulae in PR and CBCT images.ConclusionWe conclude that the visibility of the mandibular canal in PR and CBCT rays is not identical, and that the thickness of the cortical bone in the mandible does not represent a factor affecting the visibility of the roof of the mandibular canal.

Evaluation of third molar agenesis associated with hypodontia and oligodontia in turkish pediatric patients.

To evaluate the association between third molar (M3) agenesis and hypodontia and oligodontia in pediatric patients by using panoramic radiography. Panoramic radiographs of 1,471 patients (899 females; 572 males) and 5,884 teeth were retrospectively evaluated. The age and gender of the patients were recorded. Patients ages 9-15 years old were included in the study. The mean age was 12.76. The agenesis of M3 teeth and the relationship between M3 agenesis and hypodontia and oligodontia were recorded according to findings from the upper and lower jaw, in both the right and left locations, along with the number of M3 with agenesis. Data were analyzed using chi-square and McNemar tests (p<0.05). A total of 1,319 (89.7%) patients had all M3 teeth present in the mouth, while the other 152 (10.3%) had congenital agenesis in one or more teeth. The number of teeth in which M3 agenesis was seen, in order of the number of missing M3 teeth, the percentages were 2.6% for one, 2.4% for two, 1.0% for three and 4.3% for four missing teeth.Hypodontia was detected in 37 patients and oligodontia was detected in 3 patients. The prevalence of M3 agenesis varies from one population to another. Two of the dental anomalies associated with M3 agenesis are hypodontia and oligodontia. In this study, M3 agenesis varied in terms of region and gender; hypodontia was also significantly higher in patients with missing mandibular M3.

Third molar agenesis: Prevalence and Association with agenesis of other teeth in a Turkish population.

Tooth agenesis is the congenital lack of one or more primary or permanent teeth and it is the most frequently seen dental anomaly. The prevalence of third molar agenesis is significantly higher than the agenesis of other teeth varying from 10% to 40% and shows geographical variance. The aim of this study was to investigate the prevalence of third molar agenesis and its association with other tooth agenesis of jaws. A total of 594 Turkish subjects with or without agenesis of third molars (M3) were included in the study. Dental records and panoramic radiographs were evaluated for M3 agenesis, hypodontia and hyperdontia. Significant differences in the prevalence rate of M3 agenesis between genders among with evaluation of coexistence of M3 and other tooth agenesis were determined by Fisher's exact test. The prevalence of M3 agenesis was determined as 28.7% with no statistically significant gender or location difference. Most common form of M3 agenesis involved one molar followed by two, four and three molars. Agenesis of other teeth was seen among both patient groups with and without M3 agenesis, without significant difference. Turkish population with M3 agenesis did not show increased prevalence of other tooth agenesis, indicating no association between occurrence of agenesis of other teeth and M3.

Морфотипическая изменчивость жевательной поверхности зуба М3 Myodes rutilus Pallas, 1779 (Arvicolinae, Rodentia) Среднего Приобья Тюменской области

Морфотипическая изменчивость жевательной поверхности зуба М3 Myodes rutilus Pallas, 1779 (Arvicolinae, Rodentia) Среднего Приобья Тюменской области

Factors predictive of the intensity of local anesthesia in mandibular third-molar surgery: A cross-sectional study

IntroductionPrimarily, the intensity of local anesthesia (LA) in mandibular third-molar (M3) surgery is governed directly by lipid solubility of the local anesthetic drug and indirectly by other physical characteristics. However, a patient's demographic, anthropometric, behavioral, and surgical factors may affect these physical characteristics and, therefore, indirectly influence the clinical actions of the local anesthetic drug used. The aim of this study was to investigate patients’ demographic, anthropometric, behavioral, and surgical variables that may predict for the intensity of LA in mandibular M3 surgery among healthy adult patients. Material and methodsThis cross-sectional study included 141 patients with unilateral mandibular M3 teeth indicated for surgical extraction under LA. Patients’ demographic, anthropometric, behavioral, and surgical potential predictor variables were recorded. Lidocaine (2%) with epinephrine (1:100,000) was administered to provide block anesthesia for mandibular M3 surgery. The overall intra-operative pain (intensity of LA) was the outcome variable and was evaluated by the patient after surgery, using a visual analogue scale (VAS). Data were analyzed using univariate analysis and multivariate regression analysis. ResultsThe final study population comprised 126 participants: 80 women and 46 men (mean age±SD=29.2±12.3 year). With multivariate regression analysis, age, smoking quantity, and “amount of local anesthetic used” were the only significant (P<0.001) predictors of the intensity of LA in mandibular M3 surgery. ConclusionsThis study suggested that an increase in age, smoking quantity and “amount of local anesthetic used” would predict an increase in the intensity of LA in mandibular M3 surgery.

Detecting direct inferior alveolar nerve – Third molar contact and canal decorticalization by cone-beam computed tomography to predict postoperative sensory impairment

BackgroundInjury to the inferior alveolar nerve (IAN) is a severe complication of third molar (M3) surgeries that may interfere with speech, chewing, and social interactions, all of which affect quality of life. Factors such as direct IAN-M3 contact and interruption of the mandibular canal border (decorticalization) diagnosed from cone-beam computed tomography (CBCT) images have been reported as risk factors, although their relation to postoperative sensory impairment is controversial. The purpose of this study was to assess the association between postoperative nerve injury and direct contact between IAN and M3 or canal decorticalization defined with CBCT. Materials and methodsSeventy-five patients with at least one M3 tooth (total of 126 teeth) in direct contact with the IAN were included in the study. All associations were confirmed with CBCT. Nerve injuries after surgery were confirmed and follow-ups were made with information given by patients, light touch, and pinprick tests. The relationship between sensory impairment and direct contact between IAN and M3 or canal decorticalization on CBCT images was statistically assessed. ResultsOne M3 extraction (0.8%) presented with postoperative permanent sensory impairment. No correlation between nerve injury and direct contact with the IAN or canal decorticalization on CBCT could be established. ConclusionThere is no association between nerve injury and direct IAN-M3 contact or canal decorticalization. Although orthopantomography is commonly used to plan M3 surgeries, consideration of CBCT as a viable alternative is warranted.

Cheek tooth erosion in male babirusa (genus Babyrousa)

The wear on the occlusal surfaces of male babirusa cheek teeth was evaluated in 53 skulls of Babyrousa babyrussa from Buru and the Sula Islands and 87 skulls of B. celebensis from Sulawesi, Indonesia. Based on the comparative lengths of their continually growing maxillary canine teeth, the skulls were divided into five ‘age categories’ (A–E). Numerical and symbolic codes representing tooth wear were applied to each pillar (cusp region) of the mandibular and maxillary permanent third and fourth premolar teeth, and the first, second and third permanent molar teeth. There was no significant difference between the tooth wear patters of skulls in groups A and B, or in groups C and D, and so these were amalgamated. There was close correspondence in wear patterns between each side of the mouth in both species and in each age group. The wear patterns of the mandibular and maxillary teeth, although not identical, were very similar, as were the wear patterns of both species. In group A+B for both species tooth wear was relatively slight, with the M1 teeth experiencing most relative wear. There was almost no wear of the M3 teeth. In group C+D substantial wear of upper and lower M1 was evident. In group E more widespread wear of the cheek teeth was seen, with increased severity of M1 tooth wear, yet there was comparatively much less M2 and M3 tooth wear. The pattern of cheek tooth wear of the Babyrousa spp. was different from that shown by Susscrofa. Differences in diet selection and processing were highlighted as potential contributing factors. The pattern of cheek tooth wear in male babirusa was not adequate for use to monitor their age.

Stage- and tissue-specific effect of cyclophosphamide during tooth development.

The aim of this study was to investigate the toxic effect of cyclophosphamide (CPA) in the development of rodent molars. CPA was administered intraperitoneally in postnatal mice between Day 1 and Day 10, and the morphological phenotype was evaluated at Day 26 using micro-computed tomography and histological analysis, including cell proliferation and cell death analyses. M3 molars of the mice who received 100 mg/kg CPA treatment at Day 6 or M2 molars who received treatment at Day 1 resulted in tooth agenesis or marked hypoplasia. Histological observation demonstrated that CPA treatment at Day 6 resulted in shrinkage of the M3 tooth germs, with a significant reduction in the proliferation of apoptotic cells. Conversely, CPA exposure at Day 2, which occurs at around the bud stage of M3, resulted in crown and root hypoplasia, with reduced numbers of cusp and root. In addition, CPA exposure at Day 10, which is the late bell stage of M3, induced root shortening; however, it did not affect crown morphogenesis. The timing of CPA administration is limited to after birth. Therefore, its effect during the early stages of M1 and M2 could not be investigated. Defective phenotypes were evident in both crown and roots due to the effect of CPA. Interestingly, the severity of the phenotypes was associated with the developmental stages of the tooth germs at the time of CPA administration. The cap/early bell stage is the most susceptive timing for tooth agenesis, whereas the late bell stage is predominantly affected in terms of root formation by CPA administration.

About cases of pathology of the dental system In Archidiskodon meridionalis meridionalis (Nesti, 1825) from Georgievsk sand pit (Stavropol Territory, Russia)

Two cases of the dental system’s dysfunction in Archidiskodon meridionalis meridionalis found in the Georgievsk sand pit (Stavropol Territory, Russia; Early Pleistocene, Psekups Faunal complex) are described. One of the tusks is missing in one of the elephant’s skull, and its alveolus is overgrown. Probably, the tusk was broken off already in the alveolus at the adult animal, after which its growth process did not renew. On the skull from a skeleton of the second animal on the left upper jaw there is a disturbance of the M2 teeth change on M3 teeth. Tooth M2 is somewhat displaced lingually because of its falling delay. The anterior part of tooth M3 is beveled buccally relatively to the axis of the crown approximately at 104°. At the same time, the medial half of the first six enamel plates were significantly turned out laterally. On the other teeth noticeable changes were not noted. An obvious cause of this anomaly was a disruption of M3 growth rate and slowing of the rate of crown wearing and resorption of two posterior roots of M2. The described pathology was probably not a consequence of genetic predispositions, infection, or trauma. There are signs of osteodystrophy at separate bones of the skeleton.

Incidence and treatment of complications in patients who had third molars or other teeth extracted

The aim of this study was to compare the incidence of complications after extraction of third molars (M3) or other teeth, and to describe their management. We made a retrospective cohort study of patients having M3 or other teeth extracted, and recorded complications up to two years’ follow-up. A total of 142 complications developed after 2355 procedures (6%) – 7% after extraction of M3 compared with 5% after extractions of other teeth (p=0.024). The three most common complications were wound infection (2%), pain without apparent cause (<1%), and oroantral communication (<1%). Patients who had M3 extracted were at increased risk of complications compared with those who had other teeth extracted (Odds ratio (OR) 1.5, p=0.024), particularly for infection (OR 5.9, p<0.001) and hypoaesthesia (OR 8.4, p=0.027). Half of all patients with a complication were treated with antibiotics orally. The incidence of postoperative bleeding was 0.6% as a result of suboptimal management of antithrombotic drugs in extractions of teeth other than M3. Finally, optimal treatment of the complications was compared with the available evidence. Prevention and treatment of these complications could reduce the incidence, particularly of bleeding.

Agenesis of Third Molars among Turkish Children between the Ages of 12 and 18 Years: A Retrospective Radiographic Study.

The aim of this study was to investigate the agenesis of third molars (M3) in children with permanent dentition in a limited population in the province of Izmir, Turkey. The panoramic radiographs of 773 patients (457 females, 316 males) were evaluated retrospectively at the Dental Hospital of Ministry of Health in İzmir, Turkey. The patients' ages ranged from 12-18 years. The agenesis of M3 teeth was investigated according to maxilla and mandible and right and left distribution. In 593 of the patients (76.7%), all of the M3 teeth were present in the mouth; while in the other 180 (23.3%) patients, agenesis of a varying number of M3 teeth was identified. In 31 patients (4.0%), total M3 tooth agenesis was observed. A statistically significant relationship was not found between gender and M3 teeth (p=0.091). A statistically significant relationship was found between congenital M3 tooth agenesis and the maxilla (14.3%) and mandible (9.6%) (p<0.001). However, a statistically significant difference was not found between the right-left area of the jaw (p=0.100). As a result, while all M3 teeth were present in 76.71% of the population studied in the province of Izmir, agenesis of one or more than one M3 tooth was found in the other 23.29% of the patients studied.

Teeth of early generations of Early Pleistocene elephants (Mammalia, Elephantidae) from Sinyaya Balka/Bogatyri site (Sea of Azov Region, Russia)

Based on study of a series of early generations' teeth DP4/dp4 – M1/m1 of elephants from the Late Villafranchian–Early Galerian locality Sinyaya Balka/Bogatyri (Taman peninsula, Russia) the variability of their characteristics is established. There is no clear normal distribution of main diagnostic dental parameters in the sample. This confirms the assumption of the possible presence of two elephant taxa in the structure of Taman Faunistic complex from south Eastern Europe, which was made earlier on the basis of the M3 teeth. The main part of the collection is represented by remains of the late meridionaloid elephant subspecies Archidiskodon meridionalis tamanensis, typical for late Early Pleistocene of Eastern Europe and neighboring regions. Individual specimens of the sample may refer to other form of elephants with similar morphological teeth characteristics, probably to Phanogoroloxodon mammonthoides. Though the lesser diagnosticity of early generation teeth in comparison with the M3/m3, it was found that they can be used when determining the taxonomic forms of elephants, even for the meridionaloid elephant subspecies.

Chalicotheriidae (Mammalia, Perissodactyla) from the Lufengpithecus locality of Lufeng, Yunnan Province, China

Shihuiba in the Lufeng Basin, Yunnan Province, China, is a very important hominoid locality. Chalicotheriidae from this locality are referred to Anisodon yuanmouensis based on the size and morphology of the cheek teeth. This species has a variable protoloph on upper molars, a markedly ‘three-lophed’ structure on P4, longer M2 than M3 and narrower lower cheek teeth than other species in this genus. Including specimens described in this paper, this species has been found from the Yuanmou and Lufeng basins in Yunnan Province, China and the Irrawaddy Formation in Myanmar. Relationships within Anisodon are proposed wherein Anisodon salinus constitutes a sister group with Anisodon yuanmouensis. The absence of Anisodon to the north of the Tibetan Plateau likely indicates the uplift of the plateau to an elevation which prevented the free immigration of anisodonts during the Mid-Late Miocene. The appearance of Anisodon in the Lufeng hominoid fauna confirms a subtropical forest local environment.

Age estimation in fossil hominins: comparing dental development in early Homo with modern humans

Background: Previous studies have used molar tooth eruption as a comparative marker of maturation in early fossil hominins. However, tooth eruption and tooth formation are independent maturational processes.Aim: To determine whether estimates of age for entering a stage of dental development in three early hominin fossils fell within the distribution of a modern human sample.Methods: This study used a comparative model of dental development to identify the stages of dental development most likely to provide information about length of the growth period in early fossil hominins. Age estimates for stages of dental development in fossils were superimposed onto a normal distribution of the same radiographically defined stages derived from a sample of 6540 children of diverse geographical origin.Results: Both within the dentition of S7–37, from Sangiran, Java, but also for stages of two other specimens (KNM-WT 15000 from Kenya and StW 151 from South Africa), all age estimates for later stages of tooth formation fell within the modern sample range.Conclusions: A pattern appears to exist in early Homo where, both within and between developing dentitions, age estimates for stages of P4, M2 and M3 tooth formation fell consistently among the more advanced individuals of the modern human sample.

Variations of the tooth morphology of the Woolly Mammoth Mammuthus primigenius (Blumenbach, 1799) (Mammalia: Elephanthidae)

Cases of variations in the morphology of isolated upper teeth M3 of Mammuthus primigenius (Blumenbach, 1799) from the south-east of West Siberia and Yakutiya are described. The anomaly of M. primigenius tooth from Yakutiya is expressed in changing of the tooth crown shape and position of dental plates in M3. Development of the anomaly was probably associated with a delay of loosing the tooth of the previous generation (M2) and disorder of the formation of M3 at the stage of its mineralization. Two M3 teeth from Novosibirsk Province are characterized by changing of the wearing surface and root shape. One of them shows two wearing surfaces in parallel to initial masticatory surface, shifted lingually. The upper part of the root is bent buccally, that is connected with the falling out of the tooth from the alveolus. The appearance of such a change, presumably, is connected with a mechanical injury of the cheek region of skull. The reconstruction of the formation of this tooth anomaly in M. primigenius was carried out. The second of these teeth also has a wrong position of the masticatory surface, which has a gradual curvature from nearly perpendicular (to enamel plates) in the anterior part of the tooth to about 45° in the posterior plates.