Bone and tooth

La anestesia dental es un tema importante en la práctica cotidiana en las diversas especialidades odontológicas, motivo por el que nace la necesidad de hacer una revisión de las técnicas anestésicas actuales. Con base en nuestra experiencia nos dimos cuenta de que la practicidad de utilizar referencias anatómicas confi ables nos sirven de guía para obtener una mejor efi cacia al momento de anestesiar el nervio alveolar mandibular. Lo anterior se traduce en menor dolor posterior a la punción, menor dosis anestésica y una profundidad anestésica adecuada en tejidos blandos y duros, del mismo modo nos permite llevar a cabo diversos tratamientos con un margen de seguridad más amplio y disminuir los riesgos de toxicidad. Cabe mencionar que dicha técnica se ha incluido en la práctica clínica cotidiana en nuestra práctica privada en el Postgrado de Ortodoncia del Instituto Universitario Franco Inglés de México y en el Servicio de Cirugía Oral y Maxilofacial del Centro Médico «Lic. Adolfo López Mateos» en la ciudad de Toluca, Estado de México.
Palabras clave: Anestesia, dental, nervio alveolar mandibular.

Objectives Aim of this systematic review was to assess the effect of orthodontic treatment with fixed appliances on the tooth color of patients. Methods Nine databases were searched up to May 2017 for clinical cohort studies on the effect of fixed appliance treatment on tooth color. After elimination of duplicate studies, data extraction, and risk of bias assessment according to the Cochrane guidelines, random effects meta-analyses of mean differences (MD) or means and their 95% confidence intervals (CIs) were performed, followed by GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessment of the quality of evidence. Results Three nonrandomized and one randomized study with a total of 138 patients (46% male, 54% female) with average age of 15.7 years were included. Tooth color of treated patients was significantly altered during or after orthodontic treatment (4 studies; average of 3.2 E units; 95% CI = 2.0–4.4 E units), which was more than the variation among controls (1 study; MD = 1.9 E units; 95% CI = 1.7–2.2 E units). However, the quality of evidence was very low, due to the inclusion of nonrandomized studies, bias, and imprecision. Re-analysis of raw study data indicated that significant differences in clinically discernable treatment-induced color changes were seen between chemically and light-cured adhesives and among the various tooth categories. Conclusion Existing evidence of very low quality indicates that orthodontic treatment might be associated with alterations of tooth color, which are however not consistently clinically discernible. Treatment-induced color alterations might be dependent on bonding material and tooth type, but evidence supporting this is weak.

Abstract The use of tooth mark sizes to infer carnivore
types when analyzing the modification of faunal assemblages
has been criticized on the base of intense overlap in
tooth mark size among differently sized carnivores. The
present study analyzes this overlap and presents some critical
explanations for it. This work is based on the largest
collection of tooth pit dimensional data collected to date for
some of the most relevant carnivore types. The study empirically
shows that small and large carnivores can be clearly
differentiated when using tooth pit size, with a higher
discrimination when using tooth marks on dense shafts than
on cancellous ends. It is argued that most previous studies of
tooth mark sizes have reproduced a higher overlap probably
because sample sizes were small, and experiments were
carried out using small carcasses (which require a smaller
bite force) or for a combination of factors.

Studies in zoo-archaeological Neolithic contexts is the study of early animal domestication in relation to humans transitioning into a more sedentary species. Research and documentation are vital for reconstructing the mechanisms behind the threshold event. In this thesis, teeth of Suidae have been documented, analysed and compared osteologically and interpreted cross-culturally. In addition, aDNA, isotope, coat colour and physical mammal size affecting factor studies are presented to contextualise this thesis. Primary osteological methods are Mandibular Wear Stage (MWS), Linear Enamel Hypoplasia (LEH) recordings and lower jaw third molar (M3) length measurement. These methods can detect biometric domestication markers. The analysed Suidae teeth are from the Middle Neolithic site of Ajvide, Gotland, Sweden. A collection of modern wild boar act as Control sample. These teeth are compared primarily with known domestic pig teeth sample statistics from the British Late Neolithic site of Durrington Walls, Wiltshire, United Kingdom. Results indicate that the Middle Neolithic Pitted Ware culture (PWC) on Gotland hunted during winter and kept limited numbers of captive wild boars as totemic animals (pets) possibly bound to land and ancestry. However, an exact reconstruction of the PWC pig pet keeping practices are uncertain due to human-pig relationships being highly dynamic. Intensified pig hunting, not pet keeping should be considered early domestication. Domestication carries with it detectable biometric markers, which seem to be rare in the Neolithic. The cross-cultural comparisons on traditional pig ‘low-intensity husbandry’ can attest to a human-pig relationship of hunter-gatherers keeping captive wild animals. The pig was not a staple food for the PWC and thus not intensively hunted, rather pigs were rare ritualistic commodities and likely highly praised. Perpetuating this human-pig relationship could have been maintained by PWC ‘big men’ that engaged in socio-political lavish giveaways at festivities and funerals, thus ‘hogging wealth’, but never domesticated the pig.

Background: The importance of tooth sectioning
is realized in disasters such as earthquake, airplane
crash investigation, terror, micro leakage studies, age
estimation etc. The objective of this study was to develop
a simple method to make thin sections (approximately
100 mm) from freshly extracted teeth.
Methods: One hundred and twenty human premolars
recently extracted for orthodontic purpose were used for
this study. The teeth were stored in 0.5% chorlaramine
for 2 weeks and were not allowed to dry at any stage
of the experiment. The teeth were thoroughly washed
in distilled water teeth and then were sectioned
buccolingually from crown to the root portion.
Results: A detailed embedding-cutting-mounting
procedure is described. The prepared thin ground
sections were then examined under a Polarised light
microscope for the enamel and the dentine, as well as
the caries lesions can clearly be distinguished.
Conclusion: This is an effective and efficient method
for preparation of ground sections in which the hard
tissue details are preserved.
IeJSME 2011: 5 (1): 27-30

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Addendum
Original Article:
Muneer Gohar Babar & Ma Angel Gonzalez. An alternative efficient technique for thin tooth sectioning.
IeJSME 2011; 5(1): 30-33.
The micrometer measurements of the thin sections should be expressed in μm, not mm.

In 1937, the German-Dutch paleontologist Gustav Heinrich Ralph von Koenigswald " von K " had a collector exploring the anticline of Sangiran (Pucangan) in Central Java. In the first days of January 1938 a maxillary with fresh breaks was found in the black clay, characteristic of palustral areas, of the lower part of the section that takes place over a long period and cross the Olduvai episode (1.95-1.78 Ma). Christine Hertler tells us that " Von Koenigswald urged his collectors to return to the site and search for further pieces. The search was successful and a few weeks later, a package arrived in Beijing containing seven large fragments of an almost complete cranium … but unfortunately there was no connection with the maxilla. " The anatomical descriptions of the posterior two-thirds of the braincase associated with the palate and teeth except the incisors of Skull IV was completed and submitted in September 1939 (figure 1). Figure 1. The Sangiran Pithecanthropus IV skull from Java, Indonesia. Note the prominent nuchal torus and the large canine (after Schwartz and Tattersall 2003) © Pierre-François Puech. The fossil was named Pithecanthropus IV, arguing that it presented a " link " between apes and humans. The canines are projecting and a precanine diastema is present, determining a gap between the upper canines and incisors considered as typical of apes having long lower canines fitting in this space allowing the jaw to close. Such a condition does not occur in Homo erectus but Thorne and Wolpoff (1981) suggested that it is also the case of the much later Sangiran 17 skull, there is no mesial wear facet present on the canine. Grover S. Krantz, in 1975, considered that it was " something of a mystery just how an erectus skull could show

We have studied the variability of the buccal microwear pattern in the Homo habilis population from Olduvai Gorge (Tanzania) and East Rudolf (Kenya), as a dietary indicator in fossil hominin species, and its relationship to the age of the individuals analysed. The estimation of the age of the individuals was done by estimating the rate of dental occlusal wear of individuals of known age. The biodemographic population extinction pattern could be analysed, showing great similarities to that observed in other Paleolithic populations. In the studied sample, the results obtained show that the striation density of the buccal microwear pattern is not significantly correlated with the estimated age at death, despite a tendency towards an increase in the number of striations with age can be observed. Further analyses and greater samples are needed to draw meaningful results.KEYWORDS: Paleodemography – Buccal microwear – Hominins – Homo habilis

Teeth represent the hardest tissue in most living vertebrates. Their main function is catching prey and mastication of food. Therefore, they have a unique and delicate ultrastructure, typically with highly mineralized enamel on the outside and sober bone-like dentin inside representing the endodontium.
Bony fish, amphibians, reptiles and mammals (including humans), use calcium phosphate as tooth mineral.The tooth mineral in vertebrates is hydroxyapatite with some carbonate substitutions on phosphate positions, the so-called dahllite. An exception are cartilaginous fish including sharks which use
fluoroapatite as tooth mineral.We have shown recently that shark teeth contain fluoroapatite only in the outer layer, i.e. the enameloid (the enamel-equivalent in sharks, more appropriately called durodentin), but not in dentin. This enameloid is derived from cells of the tooth papilla and is different from true enamel of epithelial origin in bony fish and upper vertebrates. Here we report on a comprehensive study of the teeth of extinct sharks, sauropterygians, mosasaurs and dinosaurs where their ultrastructure and chemical composition were analyzed with high-end chemical and microscopic methods (elemental analysis, scanning electron microscopy, X-ray powder diffraction including Rietveld refinement, infrared spectroscopy). More specific teeth represent the hardest tissue in vertebrates and appear very early in their evolution as an ancestral character of the Eugnathostomata (true jawed vertebrates). In recent vertebrates, two strategies to form and mineralize the outermost functional layer have persisted. In cartilaginous fish, the enameloid is of ectomesenchymal origin with fluoroapatite as the mineral phase. All other groups form enamel of ectodermal origin using hydroxyapatite as the mineral phase. The high abundance of teeth in the fossil record is ideal to compare structure and composition of teeth from extinct groups with those of their recent successors to elucidate possible evolutionary changes. Here, we studied the chemical omposition and the microstructure of the teeth of six extinct shark species, two species of extinct marine reptiles and two dinosaur species using high-resolution chemical and microscopic methods. Although many of the ultrastructural features of fossilized teeth are similar to recent ones (especially for sharks where the ultrastructure basically did not change over millions of years), we found surprising differences in chemical composition. The tooth mineral of all extinct sharks was fluoroapatite in both dentin and enameloid, in sharp contrast to recent sharks where fluoroapatite is only found in enameloid. Unlike extinct sharks, recent sharks use hydroxyapatite as mineral in dentin. Most notably and hitherto unknown, all dinosaur and extinct marine reptile teeth contained fluoroapatite as mineral in dentin and enamel. Our results indicate a drastic change in the tooth mineralization strategy especially for terrestrial vertebrates that must have set in after the cretaceous period. Possibly, this is related to hitherto unconsidered environmental changes that caused unfavourable conditions for the use of fluoroapatite as tooth mineral.

Mineralized collagen fibrils (MCFs) are distinct building blocks for bone material and perform an important mechanical function. A novel experimental technique using combined atomic force microscopy and scanning electron microscopy is used to manipulate and measure the mechanical properties of individual MCFs from antler, which is a representative bone tissue. The recorded stress–strain response of individual MCFs under tension shows an initial linear deformation region for all fibrils, followed by inhomogeneous deformation above a critical strain. This inhomogeneous deformation is indicative of fibrils exhibiting either yield or strain hardening and suggests possible mineral compositional changes within each fibril. A phenomenological model is used to describe the fibril nano-mechanical behaviour.

The specimen Garusi 1 is referred to Australopithecus afarensis but, because A. afarensis remains represent a wide geographic and a broad time range, measures have been used for the examination of evolutionary trends.
In the Phil. Trans. R. Soc. B volume 365 n°1556, dated 27 October 2010,  Carol V. Ward, J. Michael Plavcan and Fredrick K. Manthi have explored the “Anterior dental evolution in the Australopithecus afarensis–anamensis lineage”. One abstract sentence on page 3333 is: “During the course of the Au. anamensis–afarensis lineage, significant changes appear to occur particularly in the anterior dentition, but also in jaw structure and molar form, suggesting selection for altered diet and/or food processing. Specifically, canine tooth crown height does not change, but maxillary canines and P3s become shorter mesiodistally, canine tooth crowns become more symmetrical in profile and P3s less unicuspid. Canine roots diminish in size and dimorphism, especially relative to the size of the postcanine teeth. Molar crowns become higher. Tooth rows become more divergent and symphyseal form changes. Dietary change involving anterior dental use is also suggested by less intense anterior tooth wear in Au. afarensis. These dental changes signal selection for altered dietary behaviour and explain some differences in craniofacial form between these taxa”
We present here the description and measurements of the maxillary first premolar of Garusi I.

Aims: To evaluate the reliability and reproducibility and calculating arch discrepancy measurement using cone-beam computed tomography (CBCT) and comparing it to measurements obtained using the 2D Digital Method.
Material and Methods: Traditional dental plaster casts were obtained from 50 patients and then digitalized, so as to be able to measure them using the Digital Method. Likewise, CBCTs were undertaken on those same patients using the Dental Picasso Master 3D® and the images obtained analysed using the InVivoDental program.
Results: Determining the regression lines from both measuring methods, as well as the difference in values between them, shows how the two methods are comparable, despite the fact that the measurements analysed presented statistically significant differences.
Conclusions: The three-dimensional models obtained from the CBCT are as accurate and reproducible as the digital models obtained from plaster casts for calculating arch discrepancy measurement. The differences existing between both methods were clinically acceptable.

This presentation provides an update on prehistoric Southwest dog pathologies from the Museum of Northern Arizona’s curated faunal collections. Our zooarchaeological analysis of healed cranial lesions and tooth wear has not only expanded on earlier research accomplished in previous years but it has redefined the prehistoric dog’s role in the agricultural Southwest. Typically, domesticated dogs are identified as beasts of burden, which has inhibited sufficient and further analysis of the relationship between humans and dogs. Our research identifies that a lack of postcranial healed fractures and tooth wear evidence for dogs consuming human-like diets indicates that these animals may have been close companions of humans. In addition, the pathologies present on these canids convey a more dynamic and complex relationship between humans and dogs in the Southwest, one that had not previously been addressed by archaeologists. By combining zooarchaeological analysis with a chronology based on associated ceramics, we are able to describe the life of dogs in the Southwest in a more holistic manner. This information allows us to expand our understanding of how dogs were treated in Northern Arizona and creates a better potential to connect archaeological research with the interests of the public.

This paper examines caries prevalence in Tobolsk group of Siberian Tatars who left the Ostrovnye Yurty
burial ground (19th – early 20th centuries).
The observed caries frequency and the caries rate adjusted using proportional correction factor (PCF)
were 3.3% and 11.6%, respectively. The high value of the latter one points to a large caries prevalence in the
population under study.
Estimates of PCF calculated separately for each sex evidences a higher rate among males than in
females (14.3% and 7.8% respectively). I also found that the rate the PCF adjusted caries rate was higher in
the «matures» age category both in male and female groups than in younger age categories. Caries frequencies
were greater on posterior teeth that on the anterior ones in all age groups of both.
Caries frequency in the population under study was greater than that hunting and fishing societies of
West Siberia, it is similar to that in the Russian population of the Urals (Verkhoturie, Kamensk-Uralsk, Revda),
and close to that in the contemporaneity Selkup group of Vargananzhino and Ust-Balyk. Therefore, I may
infer that there existed similar food patterns in all aforementioned groups.
The author recommends use of PCF, which accounts for caries on teeth lost antemortem as well as
postmortem, hence generating a more differentiated and realistic estimates about caries frequency in past
populations.