Article

Measuring Rabbit (Oryctolagus cuniculus) Tooth Growth and Eruption by Fluorescence Markers and Bur Marks

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Rabbits (Oryctolagus cuniculus) and rodents possess continuously growing teeth, and dental problems are a major health issue in these species. Knowledge of tooth growth characteristics is required to adequately treat dental problems and advise owners concerning diets. Most research was performed using bur marks and measuring eruption and wear manually. However, this method cannot be applied to teeth less rostral than the first premolar; therefore, for evaluation of molars, other methods are needed. We evaluated the use of fluorochromes xylenol orange and calcein green to measure growth rates of rabbit teeth and compared this method to results obtained by manually measuring the distance between a bur mark and the gingival margin of the same tooth (eruption) and by measuring the distance between the bur mark and the apex of the same tooth on computed tomography scans (growth). Apical fluorochrome measurements correlated well with eruption and growth rates obtained with bur marks, whereas measurements coronal to the pulp cavity did not. Growth rates were approximately 1.9 mm/wk for maxillary and 2.2 mm/wk for mandibular incisors. Growth rates of premolars were 2.14 ± 0.28 mm/wk in rabbits on a grass/rice hulls/sand pelleted diet and 0.93 ± 0.18 mm/wk in rabbits on a hay diet. Growth of molars could only be assessed using the measurement in dentin on the wall of the pulp cavity, which does not account for the real growth. However, being similar to this measurement in premolars, one could hypothesize similar growth in molars as in premolars. We conclude that the application of fluorochrome staining can be used to measure tooth growth in teeth that are not accessible for bur marks or in animals that are too small to assess tooth eruption or growth by bur marks.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... In vivo markers were used to evaluate the mineralization process: 15 mg/kg tetracycline was injected to the rabbits, 24 h before the intervention, and 15 mg/kg of calcein the day before euthanasia, which was performed 28 days after the intervention. These markers were used afterwards to assess dentin growth by means of fluorescence microscopy [13]. ...
... Usually, the studied teeth are molars or incisors, the latter having the advantage of a better access to perform the perforation and place the bioactive molecules onto the pulp tissue. Note that rodent's incisors continuously grow; in this they are very different from human teeth [13]. Despite this fact, rodent's incisors have also been validated as a study model, useful for the evaluation of potential human dental pulp response [19][20][21][22]. ...
... Moreover, the fluorochromes have been conveniently used to determine dentin growth rates in rabbit incisors [13,23]. The fluorescence microscopic markers present the advantages of not being an invasive procedure and not causing toxicity [24]. ...
Article
Full-text available
Background: This study aimed to evaluate the area of dentin growth in rabbit incisors after pulp capping with plasma rich in growth factors (PRGF) compared with mineral trioxide aggregate (MTA) by fluorescence. Methods: twenty-seven upper and lower incisors of rabbits were divided into 4 groups: poor PRGF (F1) (n = 9 teeth), rich PRGF (F2) (n = 8 teeth), ProRoot MTA (positive control, n = 5 teeth), and untreated (NC) (negative control, n = 5). Fluorochrome markers were injected 24 h before surgery and the day before euthanasia, 28 days after the vital pulp therapy (VPT). Two transverse cuts were performed to every tooth: the first cut (A), 1 mm incisal to the gingival margin, and the second cut (B), 5 mm apical to the first cut. The sections were assessed with histomorphometric evaluation by fluorescence microscopy, comparing the dentin area between fluorescence marks and the total mineralized area. Results: The higher percentage of dentin growth was observed in the F2 group (B = 63.25%, A = 36.52%), followed by F1 (B = 57.63%, A = 30,12%) and MTA (B = 38.64%, A = 15.74%). The group with lowest percentage of dentin growth was the NC group (B = 29.22%, A = 7.82%). Significant difference (p < 0.05) was found between F2 group and MTA, also statistically significant difference has been observed comparing dentin growth areas of NC group with F1 and F2 groups. Conclusions: The application of PRGF rich and poor fraction as a pulp capping material stimulated dentin formation more intensively than MTA and NC.
... [10] There are many methods used to measure the eruption rate of the teeth, such as bur marks and radiographic, optical, and fluorescence markers, but the bur marks method is the easiest, less expensive, and reliable method for calculation of eruption rate. [11][12][13] The innovative advancement in the field of platelet-rich fibrin (PRF), such as injectable PRF (i-PRF), has paved the way for the usefulness in the uses of platelet concentrate. [14] This liquid form of PRF is prepared by using blood without any additives or anti-coagulant and at low-speed centrifugation (700 rpm for 3 minutes) in plastic tubes. ...
... Rabbits possess continuously erupting teeth displaying the total life cycle of teeth development from inception to maturity. [13,33] The use of platelet concentration that gives a wide range of growth factors and cytokinesis has increased the rate of tooth eruption and had the highest mean of eruption rate with a significant difference when compared to the control group. i-PRF week 1 showed a 107.3% increase in eruption rate, i-PRF week 2 showed a 144.7% increase in eruption rate, and i-PRF week 3 showed a 167.5% increase in eruption rate compared to the control group. ...
Article
Full-text available
Objective: This study aimed to evaluate the effect of the local injection of injectable platelet-rich fibrin (i-PRF) on the eruption rate of the teeth and evaluation of the effect of i-PRF on the number of odontoblast, cementoblast, osteoblast, osteocyte, and osteoclast cells. Materials and methods: The samples consisted of 20 male albino rabbits and were divided randomly into the control group (5 rabbits) and i-PRF groups (15 rabbits) sub-divided into week 1, week 2, and week 3 sub-groups. The labial surface of lower right incisors was marked by drilling a hole at the level of the free gingival margin in the mid-line of each tooth with a small round bur, and the eruption rates were measured by measuring the distance from the most apical point of the free gingival margin and the center of the hole with a digital caliper. i-PRF was prepared by centrifuging autologous blood of each rabbit at 1000 rpm for 5 minutes; then the i-PRF layer was collected. The control group received no treatment, whereas i-PRF groups received i-PRF in the following manner: For week 1 groups, a single dose was given at 0 day; for week 2 groups, double doses were given at 0 and 7 days; and for week 3 groups, three doses were given at 0, 7, and 14 days. At the end of experiments for each group, animal scarification was performed, and histological steps were performed. Results: There was a significant increase in the rate of tooth eruption in i-PRF groups when compared to the control group, and the eruption rate was increased in 107.3%, 144.7%, and 167.5% for week 1, week 2, and week 3, respectively. Concerning the histological finding, the i-PRF groups gave rise to a higher number of odontoblast, cementoblast, osteoblast, osteocyte, and osteoclast cells with a significant difference when compared to the control groups (P ≤ 0.05). Conclusions: Applying i-PRF significantly increased the rate of teeth eruption at all-time intervals. Platelet-rich fibrin injection can be an effective method for acceleration of teeth eruption.
... 52,53 Reference ranges of tooth characteristics in rabbits without dental disease have been published ( Table 2). [52][53][54][55] Tooth wear can decrease secondary to pain, congenital abnormalities, neoplasia, trauma, or inappropriate diet, which can increase tooth length and result in dental abnormalities. 52,53 Two studies compared the effects of pelleted diets with different degrees of Evidence-Based Advances in Rabbit Medicine abrasiveness and a whole grass hay-only diet on tooth eruption and attrition rate in domestic rabbits. ...
... Tooth growth was strongly related to tooth wear but differed correspondingly between diets and tooth positions. 54,55 As an interesting fact, tooth growth slowed down within its physiologic range in response to reduced attrition and wear. 55 In another study, the effects of 4 different diets (Timothy hay only; extruded diet with hay; muesli with hay; and muesli only) on length and curvature of cheek teeth via radiographs and eruption and attrition rates of incisors was evaluated in Dutch rabbits (n 5 32). ...
Article
Rabbit medicine has been continuously evolving over time with increasing popularity and demand. Tremendous advances have been made in rabbit medicine over the past 5 years, including the use of imaging tools for otitis and dental disease management, the development of laboratory testing for encephalitozoonosis, or determination of prognosis in rabbits. Recent pharmacokinetic studies have been published, providing additional information on commonly used antibiotics and motility-enhancer drugs, as well as benzimidazole toxicosis. This article presents a review of evidence-based advances for liver lobe torsions, thymoma, and dental disease in rabbits and controversial and new future promising areas in rabbit medicine.
... Furthermore dromedaries stand and grind their teeth for 8-12 h a day [100]. This prevents hypsodonty, the lifelong growth of teeth and molars, as occurs for example in rabbits [105]. Not correct Although dromedaries forage for 8-12 h a day, they do not have to travel long distances for water and food in Europe. ...
Article
Full-text available
The worldwide dromedary milk production has increased sharply since the beginning of this century due to prolonged shelf life, improved food-safety and perceived health benefits. Scientific confirmation of health claims will expand the market of dromedary milk further. As a result, more and more dromedaries will be bred for one purpose only: the highest possible milk production. However, intensive dromedary farming systems have consequences for animal welfare and may lead to genetic changes. Tighter regulations will be implemented to restrict commercialization of raw milk. Protocols controlling welfare of dromedaries and gene databases of milk-dromedaries will prevent negative consequences of intensive farming. In countries where dromedaries have only recently been introduced as production animal, legislators have limited expertise on this species. This is exemplified by an assessment on behalf of the Dutch government, recommending prohibiting keeping this species from 2024 onwards because the dromedary was deemed to be insufficiently domesticated. Implementation of this recommendation in Dutch law would have devastating effects on existing dromedary farms and could also pave the way for adopting similar measures in other European countries. In this paper it is shown that the Dutch assessment lacks scientific rigor. Awareness of breeders and legislators for the increasing knowledge about dromedaries and their products would strengthen the position of dromedaries as one of the most adapted and sustainable animals.
... The total number of teeth ranges from 26 to 28 [69]. Rabbit incisors grow continuously [330], which is of great interest for longitudinal mineralization studies [331]. ...
Article
Full-text available
Biomedical research seeks to generate experimental results for translation to clinical settings. In order to improve the transition from bench to bedside, researchers must draw justifiable conclusions based on data from an appropriate model. Animal testing, as a prerequisite to human clinical exposure, is performed in a range of species, from laboratory mice to larger animals (such as dogs or non-human primates). Minipigs appear to be the animal of choice for studying bone surgery around intraoral dental implants. Dog models, well-known in the field of dental implant research, tend now to be used for studies conducted under compromised oral conditions (biofilm). Regarding small animal models, research studies mostly use rodents, with interest in rabbit models declining. Mouse models remain a reference for genetic studies. On the other hand, over the last decade, scientific advances and government guidelines have led to the replacement, reduction, and refinement of the use of all animal models in dental implant research. In new development strategies, some in vivo experiments are being progressively replaced by in vitro or biomaterial approaches. In this review, we summarize the key information on the animal models currently available for dental implant research and highlight (i) the pros and cons of each type, (ii) new levels of decisional procedures regarding study objectives, and (iii) the outlook for animal research, discussing possible non-animal options.
... However, rodents possess long-crowned, continuously growing and open-rooted teeth 26 . Maxillary incisors of rabbits can grow up to approximately 1.9 mm per week depending on the type of food they are fed 27 . This physiological eruption of the incisors can cause the level and amount of force applied by the spring to change. ...
Article
Full-text available
The purpose of this animal study is to investigate the quantitative effects of extracorporeal shock waves applied at two different impulses and with two different applicators on orthodontic tooth movement. Thirty-five New Zealand rabbits were randomly divided into five groups (n = 7): the four experimental extracorporeal shock wave groups—focused/500 impulses, focused/1000 impulses, unfocused/500 impulses, and unfocused/1000 impulses—and the control group. Orthodontic tooth movement was achieved by application of reciprocal force between two maxillary incisors. In the experimental groups, animals received 500 or 1000 impulses of extracorporeal shock waves at 0.19 mJ/mm ² with focused or unfocused applicators depending on the group to which they belonged. These experiments were conducted on days 0, 7, and 14. Orthodontic tooth movement was measured with 0.01 mm accuracy at one-week intervals. On days 7 and 21, the bone-specific alkaline phosphatase levels were measured from blood samples. After 21 days, the animals were sacrificed and the area between the two maxillary incisors was stereologically examined. Orthodontic tooth movement in the focused/500 impulses and focused/1000 impulses groups was significantly increased compared to the control group. A significant difference in bone-specific alkaline phosphatase levels between the unfocused/500 impulses and control groups was found at 21st day. Stereological analysis showed that there were significant increases of the formation of new bone, connective tissue, and vessels in the experimental groups. The application of extracorporeal shock waves, especially with a focused applicator, could accelerate orthodontic tooth movement.
... Interestingly, the growth rate of the hypselodont teeth in these species [e.g. white rat (Rattus norvegicus) and rabbit (Oryctolagus cuniculus) is about 400-500, and 314 micrometers per day, respectively (Taylor & Butcher, 1951;Wyss et al., 2016)], similar to the African elephant's (Loxodonta africana) tusk's growth rate (about 470 micrometers per day) (Colyer & Miles, 1957;Miles & White, 1960). It must be noted that insufficient tooth abrasion in rodents and rabbits resulting from various causes such as insufficiently abrasive diet, can result in dental malocclusion and elongated (tusk-like) tooth formation (Müller et al., 2015;Samuels, 2009;Van Caelenberg et al., 2008;Williams, 1922). ...
Article
Full-text available
Objective The present review aims to: a) describe the features that support tusks in extra-oral position, and b) represent distinctive features of tusks, which provide insights into tusks adaptation to ambient conditions. Design A comprehensive review of scientific literature relevant to tusks and comparable dental tissues was conducted. Results The oral cavity provides a desirable condition which is conducive to tooth health. Therefore, it remains questionable how the bare (exposed) tusks resist the extra-oral conditions. The common features among tusked mammals indicate that the structural (e.g. the peculiar dentinal alignment), cellular (e.g. low or lack of cell populations in the tusk), hormonal (e.g. androgens), and behavioral traits have impact on a tusk’s preservation and occurrence. Conclusions Understanding of bare mineralized structures, such as tusks and antlers, and their compatibility with different environments, can provide important insight into oral biology.
... The interaction of dental morphology, function and wear in lagomorphs has been explored paleontologically (Fraser, 2010;Koenigswald et al., 2010) and experimentally at different levels of resolution, ranging from macroscopic tissue loss (Meredith et al., 2015;Müller et al., 2014;Ness and Brown, 1956) down to microscopic wear traces (Schulz et al., 2013b). The rabbit"s (Oryctolagus cuniculus) hypselodont cheek teeth are more susceptible to wear than the hypsodont dentition of ungulates (Damuth and Janis, 2014) whilst growing at a flexible rate to compensate for crown loss (Wyss et al., 2016). Since this compensatory mechanism is not exact (Müller et al., 2014), differences in tooth wear can be detected at short-term intervals, and the expeditious wear and regrowth allows the use of these animals in a sequential experiment design. ...
Article
Full-text available
To differentiate the effects of internal and external abrasives on tooth wear, we performed a controlled feeding experiment in rabbits fed diets of varying phytolith content as an internal abrasive and with addition of sand as an external abrasive. 13 rabbits were each fed one of the following four pelleted diets with different abrasive characteristics (no phytoliths: lucerne L; phytoliths: grass G; more phytoliths: grass and rice hulls GR; phytoliths plus external abrasives: grass, rice hulls and sand GRS) for two weeks. At the end the feeding period, three tooth wear proxies were applied to quantify wear on the cheek teeth at macroscopic and microscopic wear scales: CT scans were obtained to quantify tooth height. Mesowear was scored adapted to this species, and 3D dental microwear texture analysis (DMTA) was performed on four antagonistic teeth. Both external and internal abrasives resulted in increased wear in all proxies compared to the phytolith and sand-free diet (L). The wear effect was more prominent on the maxillary than on the mandibular teeth. On the GRS diet, the upper third premolar had the largest decline in relative tooth height compared to others in the same tooth row. The impact of diet abrasiveness on the mesowear signal was only clearly visible for the most abrasive diet, most likely due to the limited sample size. DMTA was especially sensitive to phytolith changes in the diet, and surface roughness generally increased with increasing amounts of abrasive agents (L < G < GR < GRS) as expressed in an increase of most height and volume parameters. The fast pace of dental wear in this species led to some expected correlations between tooth height, mesowear and DMTA parameters, creating a distinct wear pattern for each diet. Animal models with high wear rates may be particularly suitable for investigations on functional interrelationships of different wear proxies.
... Furthermore dromedaries stand and grind their teeth for 8-12 h a day [100]. This prevents hypsodonty, the lifelong growth of teeth and molars, as occurs for example in rabbits [105]. Not correct Although dromedaries forage for 8-12 h a day, they do not have to travel long distances for water and food in Europe. ...
Article
Rabbits are cherished pets and valuable animals in various fields, including agriculture and science. The popularity of pet rabbits has surged, with various breeds such as the Lionhead Rabbit, Holland Lop Rabbit, Mini Rex Rabbit, Polish Rabbit, and Dutch Rabbit gaining traction. With proper diet and living conditions, rabbits can live up to ten to twelve years. However, domestic rabbits are prone to several infectious diseases, including parasitic, bacterial, and viral infections. The most common ailments in rabbits are skin conditions, respiratory infections, and digestive system issues. Understanding these common diseases is essential for maintaining the health and well-being of rabbits. This review article provides a comprehensive overview of the prevalent illnesses affecting rabbits, detailing their causes, symptoms, prevention methods, and available treatments.
Article
The treatment of facial abscesses of dental origin is difficult as jaw osteomyelitis in rabbits is mainly associated with a thick caseous pus that is particularly difficult to drain. Precise identification of the teeth involved in the infected site with the use of cone beam computed tomography (CBCT) was expected to ensure a favorable surgical treatment plan without a long-term local antibiotic strategy or local marsupialization. The first part of the study compared multi-planar reconstruction (MPR) and 3D reconstruction complemented by a maximum intensity projection filter (MIP). The surgical part of the study included rabbits with documentation of the treatment outcome for a period greater than one month after surgery and having had at least one post-operative CBCT demonstrating the achievement of surgical extraction. MPR is significantly more efficient than MIP techniques for alveolar bone (P < 10-7), spongious bone (P < 10-10) and apical elongation (P < 10-5) parameters. Nineteen of 20 surgical sites gave radiological confirmation of the success of the surgical plan. Eighteen of 20 of the abscess sites were clinically healed within one month. Seven out of 20 of the abscess sites presented evidence of one dental structure regrowth following the CBCT recheck. Two out of these seven cases presented with a concomitant persistent chronic facial fistula. Both cases healed after second-stage surgery to extract the tooth structure. The mean number of teeth extracted was 2.85, and seven of the 20 procedures included one incisor.
Article
This chapter provides a description of taxonomy, type of dentition, number of teeth, dental formula, and skull and dental anatomy of lagomorphs, namely North American pika, antelope jackrabbit, eastern cottontail, and snowshoe hare. The greatest jaw force of lagomorphs is either at the incisors (gnawing) or at the posterior cheek teeth. When a rabbit chews, the incisors do not touch. Designed as a practical resource for treating exotic animals, the chapter is filled with instructive photographs and illustrations. Written for zoo and wildlife caretakers and veterinarians, veterinary dentists, veterinary technicians, and veterinary students, it is a practical resource that has information for the dental care of a wide range of animal species that are all too often neglected.
Article
Full-text available
DENTAL disease is common in pet rabbits and treatment is an everyday procedure in many practices, yet many practitioners are unsure about how to approach these cases because the results of dental procedures can be disappointing. Maloccluded teeth can regrow within weeks of shortening and eating difficulties can persist, or even get worse, after dental intervention. Repeated anaesthetics are often required and owners become disillusioned. The long oral cavity and narrow gape of rabbits hamper dental examination and intervention, and rabbits are perceived as high anaesthetic risks with a danger of spinal injury if the animal struggles. Skull radiographs are difficult to interpret without knowledge of normal anatomy or the pathological changes that are taking place. As a result, some clinicians recommend euthanasia for rabbits with dental disease because it is a simple solution to a difficult problem. This decision could be averted with a better understanding of normal dentition and the progression of dental disease in these animals, and many owners nowadays are prepared to make a substantial commitment, in terms of both time and money, to their pet. This article, the first of three discussing dental disease in pet rabbits, describes normal dentition, and the pathogenesis and aetiology of the condition in this species. Parts 2 and 3, to be published in the October and November/December issues of In Practice, will consider diagnosis and treatment, and jaw abscesses, respectively.
Article
Full-text available
Four domestic pet rabbits with dental pathology were presented at a university clinic. In addition to conducting physical examinations of the rabbits, radiographic and computed tomographic (CT) images of the rabbits' heads were obtained. Three rabbits were euthanized at the owners' request, and anatomic sections of the skulls were made. The observations of the anatomic sections, radiographs, and CT images are described. The abnormalities found on the radiographs and CT images were very similar to the findings on the anatomic sections. Compared to radiography, the CT images provided more details about the extent of the dental pathology, which is likely to be important for establishing a more precise prognosis and a more informed decision making process.
Article
Full-text available
To obtain a detailed anatomic description of the rabbit head by means of computed tomography (CT). 6 clinically normal Dendermonde White rabbits weighing 3 kg and raised for human consumption and 1 Netherland dwarf rabbit. The commercially raised rabbits were slaughtered in a slaughterhouse, flayed, and decapitated. The dwarf rabbit was euthanatized. Two hours later, each rabbit head was positioned with the ventral side on the CT table to obtain transverse and sagittal, 1-mm-thick slices. Dorsal images were obtained by placing each head perpendicular to the table. Immediately after the CT examination, 3 heads were frozen in an ice cube at -14 degrees C until solid and then sectioned at 4-mm-thick intervals by use of an electric band saw. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images. Anatomic sections were examined, and identified anatomic structures were matched with structures on corresponding CT images. The bone-window CT images yielded good anatomic detail of the dentition and the bony structures of rabbit skulls. The soft tissue structures that could be determined were not better identifiable on the soft tissue-window CT images than on the bone-window images. CT images of the heads of healthy rabbits yielded detailed information on the skull and some surrounding soft tissue structures. Results of this study could be used as a guide for evaluation of CT images of rabbits with various cranial and dental disorders.
Article
Full-text available
The use of fluorochromes in bone research is a widely accepted technique that dates back to the 1950s. Several pioneers, such as Harold Frost, have thoroughly investigated the potential of fluorochrome use for the study on bone formation and bone remodeling dynamics. Since the development of bone tissue engineering, a renewed interest in the benefits of fluorochrome use was perceived. Fluorochrome use in animal models makes it possible to determine the onset time and location of osteogenesis, which are the fundamental parameters in bone tissue engineering studies. There is, however, a lack of standardized procedures for using this technique. In addition, many types of fluorochromes exist and one could be confused upon selecting the appropriate type, the appropriate concentration, the route of administration, and methods of visualization. All these variables can potentially affect the outcome during fluorescence microscopy. This work aims at providing the bone tissue engineering researcher with an overview of the history, working mechanism, and the potential pitfalls in the use of fluorochromes in animal studies. Experiments using some of the more frequently used fluorochromes are explained and illustrated.
Article
Dental diseases are among the most important reasons for presenting guinea pigs (Cavia porcellus) and other rodents to veterinary clinics, but the aetiopathology of this disease complex is unclear. Clinicians tend to believe that the ever-growing teeth of rabbits and rodents have a constant growth that needs to be worn down by the mastication of an appropriate diet. In this study, we tested the effect of four different pelleted diets of increasing abrasiveness [due to both internal (phytoliths) and external abrasives (sand)] or whole grass hay fed for 2 weeks each in random order to 16 guinea pigs on incisor growth and wear, and tooth length of incisors and cheek teeth. There was a positive correlation between wear and growth of incisors. Tooth lengths depended both on internal and external abrasives, but only upper incisors were additionally affected by the feeding of whole hay. Diet effects were most prominent in anterior cheek teeth, in particular M1 and m1. Cheek tooth angle did not become shallower with decreasing diet abrasiveness, suggesting that a lack of dietary abrasiveness does not cause the typical ‘bridge formation’ of anterior cheek teeth frequently observed in guinea pigs. The findings suggest that other factors than diet abrasiveness, such as mineral imbalances and in particular hereditary malocclusion, are more likely causes for dental problems observed in this species.
Article
Although patterns of tooth wear are crucial in palaeo-reconstructions, and dental wear abnormalities are important in veterinary medicine, experimental investigations on the relationship between diet abrasiveness and tooth wear are rare. Here, we investigated the effect of four different pelleted diets of increasing abrasiveness (due to both internal [phytoliths] and external abrasives [sand]) or whole grass hay fed for 2 weeks each in random order to 16 rabbits (Oryctolagus cuniculus) on incisor and premolar growth and wear, and incisor and cheek tooth length. Wear and tooth length differed between diets, with significant effects of both internal and external abrasives. While diet abrasiveness was linked to tooth length for all tooth positions, whole forage had an additional effect on upper incisor length only. Tooth growth was strongly related to tooth wear and differed correspondingly between diets and tooth positions. At 1.4–3.2 mm/week, the growth of cheek teeth measured in this study was higher than previously reported for rabbits. Dental abnormalities were most distinct on the diet with sand. This study demonstrates that concepts of constant tooth growth in rabbits requiring consistent wear are inappropriate, and that diet form (whole vs. pelleted) does not necessarily affect cheek teeth. Irrespective of the strong effect of external abrasives, internal abrasives have the potential to induce wear and hence exert selective pressure in evolution. Detailed differences in wear effects between tooth positions allow inferences about the mastication process. Elucidating feedback mechanisms that link growth to tooth-specific wear represents a promising area of future research. J. Exp. Zool. 9999A: XX–XX, 2014. © 2014 Wiley Periodicals, Inc.
Article
Dental disease is considered as one of the, if not, the most common disorders seen in pet rabbits. This article provides a review of the scientific literature and an overview of the peculiarities of calcium homeostasis in the rabbit in an attempt to draw together current thinking on the cause of dental disease. A complete understanding of the aetiology and pathophysiology of rabbit dental disease is necessary for the veterinary practitioner to establish a proper therapeutic plan, prognosis and ultimately prevention of this common cause of morbidity and mortality in pet rabbits.
Book
In this unique book, Peter S. Ungar tells the story of mammalian teeth from their origin through their evolution to their current diversity. Mammal Teeth traces the evolutionary history of teeth, beginning with the very first mineralized vertebrate structures half a billion years ago. Ungar describes how the simple conical tooth of early vertebrates became the molars, incisors, and other forms we see in mammals today. Evolutionary adaptations changed pointy teeth into flatter ones, with specialized shapes designed to complement the corresponding jaw. Ungar explains tooth structure and function in the context of nutritional needs. The myriad tooth shapes produced by evolution offer different solutions to the fundamental problem of how to squeeze as many nutrients as possible out of foods. The book also highlights Ungar's own path-breaking studies that show how microwear analysis can help us understand ancient diets. The final part of the book provides an in-depth examination of mammalian teeth today, surveying all orders in the class, family by family. Ungar describes some of the more bizarre teeth, such as tusks, and the mammal diversity that accompanies these morphological wonders. Mammal Teeth captures the evolution of mammals, including humans, through the prism of dental change. Synthesizing decades of research, Ungar reveals the interconnections among mammal diet, dentition, and evolution. His book is a must-read for paleontologists, mammalogists, and anthropologists. © 2010 The Johns Hopkins University Press. All rights reserved.
Article
Dental disease is a common reason for presentation of a rabbit to aveterinary surgeon. A good understanding of the dental anatomy, physiology and the role that diet has in the health of the teeth is important to the management and prevention of this common condition in pet rabbits.
Article
AbstractComputed tomography (CT) is a well-recognized diagnostic tool in human and traditional companion animal medicine, and is beginning to find application in exotic companion mammals as well. In particular, CT is useful for evaluation of patients with dental disease, and aids diagnosis, determination of a more accurate prognosis, and planning of treatment. Although axial slices provide the most useful information, new reconstruction software allows images to be converted to virtual 3-dimensional forms, providing yet another imaging tool for the practitioner.
Article
The clinical crown length of rabbit teeth has not been well documented. The aim of this study was to determine the clinical crown length of incisor and cheek teeth, and the periodontal probing depth in young healthy rabbits without clinical signs of dental disease. Two groups of 20 male rabbits were measured, the first in 2007 and the second in 2008/2009. The measurements were taken with rabbits under general anesthesia using a periodontal probe. The average crown length (mm) of the mandibular third and fourth premolar, and maxillary second premolar teeth was 3.1 +/- 0.4, 2.6 +/- 0.4, and 1.5 +/- 0.4, respectively. The periodontal probing depth for the cheek teeth in the maxilla and the mandible was very similar (0.5 - 1.0-mm). There was a minor difference in the average crown length (mm) of the mandibular (6.4 +/- 0.6) and maxillary (6.1 +/- 0.9) incisor teeth. The periodontal probing depth (mm) was different when comparing maxillary (2.2 +/- 0.4) and mandibular (5.1 +/- 0.8) incisor teeth. The divergence in tooth length in individual rabbits and between the two groups was minimal. Measuring the crown length of the rostral cheek and incisor teeth with a periodontalprobe is easy to do in the rabbit and should be integrated into the clinical examination. The measurement results of this study can be used as a reference when trimming teeth.
Article
Xylenol orange is fixed in newly formed calcified tissues where it remains until removal of the bone mineral. It may be visualized in undecalcified histological sections in a similar way to the tetracyclines by means of its fluorescence. The fluorescence contrasts to that of known fluorescent dyes. Intravital bone labeling by Xylenol orange is achieved by parenteral administration of the dye. A dose of 90 mg/kg given as a 3% aqueous solution was found suitable. The general toxicity, local effect on calcification and resistance of the fluorescence to histological chemicals and long term excitation were assessed. It is noteworthy that the fluorescence of Xylenol orange is found exactly at the same site as that of tetracyclines, fluoresceins and Calcein blue. Xylenol orange is thus suitable for single or for polychrome sequential labeling.
Article
The present investigation studies the effects of persistently cutting one lower rat incisor out of occlusion. Within four days, the rate of eruption of the cut (unimpeded) incisor increased to 216% and that of the uncut (impeded) contralateral to 136% of the baseline rate. While the former remained high, the latter decreased gradually to about 90% within three weeks. The rate of attrition of the impeded incisor increased to 233% of the baseline rate within two days, then fell abruptly, and remained at a slightly lower level than the rate of eruption. Accordingly, the length of the erupted part of the impeded incisor decreased initially, but increased gradually after about four days. Measurements made on SEM micrographs of the series of transverse tooth segments obtained when cutting the incisor out of occlusion, showed that growth-related increase in mesiodistal tooth width was arrested from the 10th segment, dentin thickness decreased gradually to about 50% in the 12th segment, and enamel thickness, after an initial increase, decreased to about 80% in the 11th segment. The present study provides experimental evidence that accelerated eruption affects morphogenesis and histogenesis of the rat lower incisor. An impeded incisor, especially the contralateral, may not serve as an ideal control.
Article
Specific amplification and quantitation of nucleic acid sequences by the polymerase chain reaction (PCR) has been extensively used for the detection of viral infection and gene expression. Although successful amplification of DNA and RNA sequences extracted from paraffin embedded tissue have been described, there are presently no reports available regarding RNA analysis from bone and calcified tissues embedded in hydrophobic acrylic resin. Here we describe a general method for quantitation of specific mRNA sequences extracted from undecalcified bone sections, fixed in paraformaldehyde, and embedded in a hydrophobic acrylic resin. Total RNA was extracted from defined regions of single 50 microm sawed sections. These RNA preparations are suitable for quantitative PCR analysis of mRNA of different cytokines. In addition, the universally expressed housekeeping GAPDH mRNA proved to be useful as an amplification control and to correct for the degree of RNA degradation, which may vary considerably among samples. Reverse transcribed mRNA was amplified and quantitated in Real-Time PCR using a fluorescein labeled internal TaqMan probe.
Article
Measurements have been made of the eruption rates of the mandibular incisors of domestic rabbits, to examine the effects of shortening one or both incisors for a period of three weeks. Concomitant measurements were made of the rate of wear and the length of the incisors, and of a number of other values defining the occlusion of the lower incisors with the uppers. In occlusion the incisors erupt at rates around 280 mu /day. On being shortened their rates rise within a day to about 600 mu /day and are maintained at about 700 mu /day, while the incisor is kept out of occlusion. During such changes the growing base does not alter its position. Thus under these conditions eruption rate is an index of the rate of growth of tooth-forming tissues which, in turn, is controlled by the forces exerted, in biting, on the incisor tip. When eruption is prevented by the insertion of a pin through tooth and bone, the basal tissue does not stop growing; it becomes folded and the base of the socket may be resorbed. This indicates that the control of basal growth by occlusal pressure does not extend below a minimum level of eruption, which may be estimated as about 100 mu /day. The eruption rates of the right and left incisors of an animal tend to vary together when both are in, or out of, occlusion. Different factors hold the rates together under these two conditions, since there is no significant correlation between the rates of a shortened incisor and its unshortened fellow. There is no consistent relationship between the eruption rates of an incisor in occlusion and the potential rates it exhibits when erupting freely, although in either condition there is significant variance between the eruption rates of individuals During a period of experimental shortening, the eruption rates show peak values about 7 days after the incisor is taken out of occlusion. This phenomenon is not related to a change in level of a circulating substance promoting incisor growth; an incisor shortened during the period of peak eruption of its fellow behaves independently in that it shows peak values also about 7 days after being freed from occlusion. The incisor shortened second erupts faster than its fellow and this difference is maintained. During a period of experimental shortening, most operated incisors become proclinated and increase their radius of curvature, and such teeth usually show marked depression of their eruption rates in the following period, possibly through an increased proportion of the force of the bite being borne by the proclinated incisor.
Article
THE measurement of accretion-rates of bone by a non-toxic, non-radioactive, direct method based on the intravital marking of growing surfaces would be of value 1. I have been studying intravital staining of growing-bone surfaces in man, dogs, and rats, using many agents including alizarin red S, chlorazol fast pink 2, chlorazol sky blue, calcium fast purple, naphthamine brilliant blue RR and the tetracyclines. My aim was to be able to define microscopically the amount of growth in a stated time interval. By far the most satisfactory are the tetracyclines. Chlortetracycline, oxytetracycline and tetracycline are selectively incorporated into new bone deposits and can be identified by their fluorescence. They remain detectable for at least six months 3.
Article
Bone formation and remodeling in vivo can be assessed by polychrome labeling using calcium-binding fluorescent dyes. The number of fluorochromes, however, limits this technique due to the fact that with increasing number, fluorescent spectra inevitably overlap, which makes discrimination more difficult. In order to enhance discrimination, we performed spectral image analysis. Non-critical size defects of the femur of male Wistar rats served as a model for bone formation. Eight different fluorochromes (calcein blue, xylenol orange, calcein, alizarine complexone, doxycycline, rolitetracycline, hematoporphyrin, and BAPTA) were administered sequentially subcutaneously every third day starting at day 4 after surgery. Following, bone specimen were embedded in methylmethacrylate and analyzed by spectral image acquisition using a Sagnac type interferometer (ASI, Israel). Seven of the eight applied fluorochromes could be resolved using spectral image examination. With BAPTA, we present a new fluorochrome suitable for bone labeling. Due to the superior sensitivity of the spectral image acquisition, the thickness of the bone sections could be reduced so that 5 mum thick sections could be analyzed. Spectral decomposition and subsequent linear unmixing allows depiction of each individual fluorochrome without interference of any other, enabling a reliable and superior morphometric analysis of labeled regions.
Article
Fluorochrome sequential labelling of mineralizing tissues is commonly used in different fields of clinical and basic research. Recently we improved polychrome fluorescent sequential labelling of bone by applying spectral image analysis to discriminate seven different fluorochromes. Although basic mineralization processes of bone and teeth follow comparable principles, the respective tissues differ in terms of matrix composition and mineral assembly. The aim of this study therefore was to investigate the feasibility of this new technique for polychrome sequential labelling of teeth and to demonstrate the advantages in the field of dentistry. Furthermore, the exact labelled area of each fluorochrome could be measured, even in regions of overlapping fluorochromes. The technique presented may provide a basis for further investigations of mineralization processes of different anatomical dental structures.
Untersuchungen zu Fütterungseinflüssen auf die Entwicklung der Incisivi bei Kaninchen, Chinchilla und Ratte
  • P Wolf
  • J Kamphues
Wolf P, Kamphues J. Untersuchungen zu Fütterungseinflüssen auf die Entwicklung der Incisivi bei Kaninchen, Chinchilla und Ratte. Kleintierpraxis. 1996;41(10):723-732.