Predicting Mandibular Third Molar Agenesis from Second Molar Formation

Svrha rada: Svrha rada bila je opisati kod djece razvoj kripte trećega donjeg kutnjaka (M3) i istražiti može li se prema razvoju korijena drugoga donjeg kutnjaka (M2) predvidjeti njegova ageneza. Materijali i načini: mandibularni M2 i M3 svrstani su u razvojne faze prema Moorreesu i suradnicima (1963.). Zatim je izračunat raspon srednje dobi faze kripte M3 te izabrane radiografske snimke s trećim donjim kutnjakom u fazi kripte (N = 150) i opisan raspon faze razvoja M2. Broj i vjerojatnost razvoja M3, kad se znao razvoj M2, izračunata je na temelju 1749 radiografskih snimki. Omjer vjerojatnosti razvoja M3 - ako je M2> u fazi razvoja R1 / 2 - izračunat je logističkom regresijom. Rezultati: prosječna dob faze kripte M3 bila je 8,84 godine, u rasponu od 5,47 do 12,55 godina. Nisu bile uočene znatne spolne ili etničke razlike. Kada je M3 bio u fazi kripte, raspon faza M2 bio je od polovice krune do tri četvrtine korijena, najčešće s potpunom krunom i jednom četvrtinom korijena. Kada je M2 bio u fazi razvoja R1 / 2, 99 posto pojedinaca imalo je vidljivu kriptu M3. Omjer vjerojatnosti ageneze M3 - kada je bio u fazi razvoja M2 R3 / 4 ili u kasnijoj - bio je 0,03 [95 % CI 0,02;0,05]. Zaključak: prosječna dob kripte M3 jest tijekom osme godine i najčešće se događa kada je susjedni M2 u fazi potpune krune ili u početnoj fazi korijena. Dok se je razvijao korijen M2, smanjila se vjerojatnost razvoja kripte M3. Nakon M2 u fazi razvoja R1 / 2, razvoj kripte M3 bio je malo vjerojatan.Objective: to describe the age of mandibular third molar (M3) crypt formation and investigate if root formation of the mandibular second molar (M2) can predict M3 agenesis. Materials and Methods. Mandibular M2 and M3 were categorised into developmental stages of Moorrees et al. (1963). The range and mean age of M3 crypt stage was calculated. Radiographs with M3 at crypt stage (N=150) were selected and the range of M2 formation stage described. The number and probability of M3 developing given M2 stage was calculated using 1749 radiographs. The odds ratio of M3 developing if M2 > R1/2 was calculated using logistic regression. Results. The average age of M3 crypt stage was 8.84 years [range 5.47 to 12.55]. No significant sex or ethnic differences were observed. When M3 was at crypt stage, the range of M2 stages was from crown half up to root three quarters, the most common being from crown complete to root one quarter. By the time M2 was R1/2, 99% of individuals had a visible M3 crypt. Odds ratio of M3 absence at M2 R3/4 or later stage was 0.03 [95% c.i. 0.02, 0.05]. Conclusion. The average age of M3 crypt was during the eighth year and most commonly occured when the adjacent M2 was at crown complete or early root stage. As the root of M2 developed, the likelihood of M3 crypt formation decreased. After M2 stage R1/2, the development of the M3 crypt was unlikely

Can human maxillary premolar crown dimensions discriminate between males and females?

Studies showed that odontometry can be used to analyse the influence of sexual dimorphism on the size of the teeth in specific ancestries. The aim of this study was to explore the bucco-lingual dimensions expressed as a ratio of human maxillary premolar crowns in males and females from polled ancestries. ethnicities If this measurement could discriminate sex, it would have application in forensic cases, mass disasters and archaeology where the number of mingled human remains is high and the ancestry ethnicity is unknown or multiple; Moreover, methodologies applied on radiographs or biochemical analysis in the laboratory is not always possible. The sample studied consisted of unworn premolars from 51 skeletal remains, 19 females and 32 males of known sex from collections: the Hunterian Museum, Royal College of Surgeons, England and the Natural History Museum, London and 100 archived orthodontic plaster casts of young adult dental patients (50 females and 50 males) of Royal London Hospital. Digital photographs were taken parallel to the occlusal surface and intercuspal distance and maximum bucco-lingual distance were captured using ImageJ 1.47v (U. S. National Institutes of Health, Maryland, USA), and the ratio of both distances calculated. Results were compared using a t-test and showed that for both upper premolars, the overall ratio was greater in males than females; however this was not significantly different to zero. The overall ratio for first premolar (P1) was less than second premolar (P2) in males and females. These findings show that maxillary premolar, measured in this way, are not significantly different and cannot discriminate between the sexes in this sample of different ancestries

The timing of mandibular tooth formation in two African groups

Background: Ethnic differences in the timing of human tooth development are unclear. Aim: To describe similarities and differences in the timing of tooth formation in two groups of Sudanese children and young adults. Subjects and methods: The sample consisted of healthy individuals from Khartoum, Sudan, aged 2–23 years. The Northern group was of Arab origin (848 males, 802 females) and the Western group was of African origin (846 males, 402 females). Each mandibular left permanent tooth from first incisor to third molar was assessed from dental radiographs into one of 15 development stages. Mean ages at entry for 306 tooth stages were calculated using probit regression in males/females in each group and compared using a t-test. Results: Mean ages were not significantly different in most tooth stage comparisons between ethnic groups for both males (61/75) and females (56/76), despite a tendency of earlier mean ages in the Western group. Mean ages for most tooth stage comparisons between males and females (137/155) were not significantly different within ethnic groups suggesting low sexual dimorphism. Conclusion: The mean ages of most mandibular tooth formation stages were generally not significantly different between ethnic groups or between males and females in this study

Biological methods to assess unaccompanied asylum-seeking children's age

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children

Biological methods to assess unaccompanied asylum-seeking children’s age:Interim Age Estimation Science Advisory Committee

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children.<br/

Biological methods to assess unaccompanied asylum-seeking children's age

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children

Biological methods to assess unaccompanied asylum-seeking children’s age:Interim Age Estimation Science Advisory Committee

Report by the interim Age Estimation Science Advisory Committee (AESAC) on scientific methodologies for assessing the age of unaccompanied asylum-seeking children.<br/

Age estimation [editorial].

yesAssessing and interpreting dental and skeletal age-related changes in both the living and the dead is of interest to a wide range of disciplines (e.g. see Bittles and Collins 1986) including human biology, paediatrics, public health, palaeodemography, archaeology, palaeontology, human evolution, forensic anthropology and legal medicine. ... This special issue of Annals of Human Biology arises from the 55th annual symposium of the Society for the Study of Human Biology in association with the British Association for Biological Anthropological and Osteoarchaeology held in Oxford, UK, from 9–11 December 2014. Only a selection of the presentations are included here which encompass some of the major recent advances in age estimation from the dentition and skeleton

Malnutrition Has No Effect on the Timing of Human Tooth Formation

The effect of nutrition on the timing of human tooth formation is poorly understood. Delays and advancements in dental maturation have all been reported as well as no effect. We investigated the effect of severe malnutrition on the timing of human tooth formation in a large representative sample of North Sudanese children. The sample (1102 males, 1013 females) consisted of stratified randomly selected healthy individuals in Khartoum, Sudan, aged 2-22 years using a cross-sectional design following the STROBE statement. Nutritional status was defined using WHO criteria of height and weight. Body mass index Z-scores and height for age Z-scores of ≤-2 (cut-off) were used to identify the malnourished group (N = 474) while the normal was defined by Z-scores of ≥0 (N = 799). Clinical and radiographic examination of individuals, with known ages of birth was performed including height and weight measurements. Mandibular left permanent teeth were assessed using eight crown and seven root established tooth formation stages. Mean age at entry and mean age within tooth stages were calculated for each available tooth stage in each group and compared using a t-test. Results show the mean age at entry and mean age within tooth stages were not significantly different between groups affected by severe malnutrition and normal children (p>0.05). This remarkable finding was evident across the span of dental development. We demonstrate that there is little measurable effect of sustained malnutrition on the average timing of tooth formation. This noteworthy finding supports the notion that teeth have substantial biological stability and are insulated from extreme nutritional conditions compared to other maturing body systems

Accuracy of estimating age from cervical vertebral maturation and mandibular molar maturation

Age estimation is required for forensic cases such as minors without documentation and age disputed asylum seekers. Cervical vertebral maturation (CVM) is a potential method to estimate age, particularly when third molars are mature or absent. The aim of this study was to assess the accuracy of estimating age by maturation of the cervical vertebra, the mandibular second (M2) and third (M3) molars in a group of males. The sample consisted of lateral cephalograms of 60 boys from the Bolton-Brush online collection and 53 from Burlington online collection aged 10 to 15 years. CVM age was calculated from age category and mean age and transition age of CVM stages, calculated from raw data of 69 boys (aged 9 to 15 years) in Lamparski (1972). Dental age was calculated using mandibular second and third molar stages from Liversidge (2009). The mean difference and absolute mean difference between CVM age and dental ages and chronological ages was calculated. CVM and molar tooth stage assessment reliability was assessed by duplicate readings by the first author. CVM mean age was the most accurate method to estimating age (mean difference -0.49, SD 0.23, absolute mean difference 0.49 years). CVM has potential as a method of estimating age for this age group, particularly when M2 is mature or M3 is missing.National Council for Technological and Scientific Development (CNPq) from Brazi