Stages Of Dental Development Research Articles

Orthodontic treatment for posterior crossbites.

A posterior crossbite occurs when the top back teeth bite inside the bottom back teeth. When it affects one side of the mouth, the lower jaw may have to move to one side to allow the back teeth to meet together. Several treatments have been recommended to correct this problem. Some treatments widen the upper teeth while others are directed at treating the cause of the posterior crossbite (e.g. breathing problems or sucking habits). Most treatments have been used at each stage of dental development. This is an update of a Cochrane review first published in 2001. To assess the effects of orthodontic treatment for posterior crossbites. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 21 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE via OVID (1946 to 21 January 2014), and EMBASE via OVID (1980 to 21 January 2014). We searched the US National Institutes of Health Trials Register and the World Health Organization (WHO) Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication when searching the electronic databases. Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults. Two review authors, independently and in duplicate, screened the results of the electronic searches, and extracted data and assessed the risk of bias of the included studies. We attempted to contact the first named authors of the included studies for missing data and for clarification. We used risk ratios (RR) and 95% confidence intervals (CIs) to summarise dichotomous (event) data, and mean differences (MD) with 95% CIs to summarise continuous data. We performed meta-analyses using fixed-effect models (we would have used random-effects models if we had included four or more studies in a meta-analysis) when comparisons and outcomes were sufficiently similar. We included 15 studies, of which two were at low risk of bias, seven were at high risk of bias and six were unclear. Fixed appliances with mid-palatal expansionNine studies tested fixed appliances with mid-palatal expansion against each other. No study reported a difference between any type of appliance. Fixed versus removable appliancesFixed quad-helix appliances may be 20% more likely to correct crossbites than removable expansion plates (RR 1.20; 95% CI 1.04 to 1.37; two studies; 96 participants; low-quality evidence).Quad-helix appliances may achieve 1.15 mm more molar expansion than expansion plates (MD 1.15 mm; 95% CI 0.40 to 1.90; two studies; 96 participants; moderate-quality evidence).There was insufficient evidence of a difference in canine expansion or the stability of crossbite correction.Very limited evidence showed that both fixed quad-helix appliances and removable expansion plates were superior to composite onlays in terms of crossbite correction, molar and canine expansion. Other comparisonsVery limited evidence showed that treatments were superior to no treatment, but there was insufficient evidence of a difference between any active treatments. There is a very small body of low- to moderate-quality evidence to suggest that the quad-helix appliance may be more successful than removable expansion plates at correcting posterior crossbites and expanding the inter-molar width for children in the early mixed dentition (aged eight to 10 years). The remaining evidence we found was of very low quality and was insufficient to allow the conclusion that any one intervention is better than another for any of the outcomes in this review.

Maturation of teeth adjacent to dental agenesis site

Objective. The purpose of this study was to evaluate the developmental stage of teeth adjacent to the agenesis site in comparison to their antimeres. Materials and methods. Panoramic views of 39 patients with unilateral dental agenesis and 42 normal controls were evaluated. The dental developmental stage (normal or delayed) of the teeth adjacent to the agenesis site was determined for each patient using the Haavikko's method, while the overall dental age was determined by Becker's method. Results. No statistically significant difference was found in the developmental stage of teeth adjacent to the agenesis, compared to their antimere and to the same teeth in the normal control group. However, the prevalence of cases with no difference in development was almost double for the tooth distal to the agenesis site compared to the tooth mesial to the agenesis site in the hypodontia group (84.6% distal and 43.6% mesial; p < 0.001) and in the control group (83.3% distal and 52.4% mesial; p < 0.002). In most of the cases the tooth distal to the agenesis site was the 1st permanent molar. Conclusions. (1) No difference was found between the developmental stage of teeth adjacent to the agenesis site and their antimeres. (2) Teeth mesial to the agenesis site showed some delay in development compared to teeth distal to the agenesis site, in this study. (3) The 1st molars, which were in most of the cases the distal adjacent tooth to the site of agenesis, showed developmental stability. (4) Additional longitudinal studies are needed to examine the dental developmental pattern in patients with agenesis.

Combining radiographic and histological data for dental development to compare growth in the past and the present

Background: Being able to estimate the age at death of fossil hominins enables meaningful comparisons of both dental and general growth, past and present.Aim: The aim of this study was to use data for modern permanent canine formation derived from separate histological and radiographic studies to estimate the age at death of an early African Homo erectus specimen (KNM-WT 15 000) with a developing permanent maxillary canine.Methods: Ground sections of 18 sexed modern human canines were used to reconstruct growth in tooth height along the enamel–dentine junction (EDJ) and onwards into root formation along the cement–dentine junction (CDJ). Daily rates of enamel and dentine formation were used to put a time scale to cumulative fractions of tooth height.Results: Age estimates for KNM-WT 15 000 averaged 7.89–8.8 years of age (range = 6.6–10.3 years) and were close to previous histological estimates for this individual (7.6–8.8 years).Conclusions: Stages of dental development in KNM-WT 15 000 were easily accommodated within this age distribution of a modern sample. However, body mass and stature estimates for KNM-WT 15 000 fell well beyond those reported for a modern sample of 438 Sudanese children aged between 7.0–10 years.

Root Resorption of Maxillary Incisors caused by Bilaterally Impacted Canines: An Evaluation by Cone-Beam Computed Tomography

ABSTRACT When root resorption of incisors occurs due to impaction of maxillary canines, several factors interfere in the treatment plan, such as the location and severity of root resorption, canine position, lack of space and dental development stage. The case of severe root resorption of permanent maxillary incisors caused by bilaterally impacted permanent maxillary canines and its multidisciplinary therapeutic approach in a 12-year-old girl is presented. After clinical and imaging examination, a treatment plan was outlined including preservation of primary canines, extraction of the permanent maxillary right canine and permanent maxillary left lateral incisor followed by its replacement with the orthodontically tractioned permanent canine and esthetic restoration of the permanent maxillary anterior teeth. One year after treatment, the result was satisfactory and the remaining teeth were still asymptomatic. The risk of root resorption in children with impacted permanent maxillary canines should not be neglected thus reducing subsequent complications. How to cite this article de Campos Neves ATS, Volpato LER, Oliveira TM, Palma VC, Tonetto MR, Bandeca MC, Borges AH. Root Resorption of Maxillary Incisors caused by Bilaterally Impacted Canines: An Evaluation by Cone-Beam Computed Tomography. World J Dent 2014;5(1):67-71.

Hand skeletal maturity and its correlation with mandibular dental development.

Objectives: Assessment of pubertal status and pubertal growth spurt in orthodontic patients has a considerable impact on the diagnosis, treatment plan and the outcome of orthodontic treatments. Hand-wrist radiography is routinely used to evaluate skeletal development. Some studies have shown that there is an association between bone development and different stages of dental calcification; therefore, the stages of dental calcification can be used as the first tool for diagnosis, in case there is an association. This study was performed with the aim to evaluate the association between the phases of dental development and the stages of skeletal maturity. Study design: In this study, a total of 52 patients (26 males and 26 females), referring to Mashhad School of Dentistry for orthodontic treatment, were evaluated; the subjects were within the age range of 9-14 years. Hand-wrist radiographic evaluation of skeletal maturation was performed using Fishman method. Also, the Demirjian method was used to identify the stages of dental calcification by panoramic radiographs. Independent t-test and Spearman correlation coefficient were used for data analyses. Results: The mean age of males and females was 11.05 ± 1.05 and 10.62 ± 1.12 years, respectively (p=0.156). The Spearman correlation coefficients between skeletal maturity indicators (SMIs) and developmental stages of mandibular left and right canines and second molars were significant in males only (p<0.05). Also, correlation coefficients were significant between adductor sesamoid ossification and mandibular right and left canines developmental stages in males (p<0.05). Conclusions: Findings of this study showed that the correlation between dental developmental stages and skeletal maturity only were significant in males; thus, different skeletal maturity patterns in males and females might be perceptible. Key words:Skeletal maturation, hand-wrist radiography, panoramic radiography.

Pre-eruptive intracoronal dentine radiolucencies in the permanent dentition of Jordanian children

To determine the prevalence of pre-eruptive intracoronal dentine radiolucencies (PEIR) and subject factors or dental conditions associated with PEIR from orthopantograms (OPGs) in unerupted permanent teeth of children. OPGs were evaluated for 1,571 subjects (807 males, 764 females) with mean age (8.72 ± 2.5) years. Unerupted permanent teeth prior to emergence into the oral cavity were assessed. The Chi square test was used to determine statistical differences between the group showing and the group not showing the defect with regards to sex, stage of dental development, presence of developmental anomalies, and condition of primary predecessor teeth. Prevalence was (8.1%) by subject and (0.62%) by teeth. All subjects showed only one affected tooth per subject with no significant gender differences. The highest prevalence was in mandibular first premolars (3.02%). Most defects were noted in the mixed dentition stage (89.06%), mainly in the mandible (79.7%) as single lesions at a mesial location intracoronally, and a size of less than one-third of dentine thickness in (50%). Among all variables examined, PEIR defects were significantly associated with mixed dentition stage (p = 0.000) and decayed/filled primary predecessor teeth (p = 0.028). PEIR defects occur at a significant prevalence rate in unerupted teeth. Increased awareness and careful radiographic examination of unerupted teeth may improve early detection and treatment of PEIR defects in children.

Evaluation of skeletal and dental maturity indicators and assessment of cervical vertebral maturation stages by height/width ratio of third cervical vertebra

ObjectivesThis study was designed to evaluate: Relationship between skeletal maturity indicators and a dental maturity indicator for assessment of pubertal growth in patients and; Feasibility and reliability of using height/width ratio of the third cervical vertebra for objective assessment of CVMI stage. MethodsThe study was conducted on 120 children in the age group of 8–16 years, comprising of 60 males and 60 females. Informed consent and due precaution for radiation safety were followed. Lateral cephalogram for assessment of cervical vertebrae maturation stages, OPG for evaluating mandibular canine developmental stages, Radiograph of middle phalanx of middle finger of right hand for MP3 maturation were recorded. Height/Width ratio of third cervical vertebra in all subjects was also calculated. ResultsSignificant correlation was observed between MP3 stages and CVMI stages, whereas no correlation was observed between skeletal maturity indicators and dental developmental stages of mandibular canines. A highly significant correlation was observed between CVMI stage and height/width ratio of C3 vertebra in all subgroups of total population. ConclusionsSkeletal maturity indicators show significant correlation amongst them but not with dental maturity indicator used in the study. CVMI stage can be assessed objectively by calculating the height/width ratio of C3 vertebra.

Peroxisomes in dental tissues of the mouse

Patients with mild forms of peroxisomal biogenesis disorders show facial dysmorphism and exhibit dentition problems accompanied by enamel hypoplasia. However, no information is available on the role of peroxisomes in dental and paradontal tissues. Therefore, we studied the distribution of these organelles, their protein composition and the expression of corresponding genes during dental development and in mature decalcified teeth in mice. Perfusion-fixed heads of mice of different developmental stages (E13.5 to adult) were cut in sagittal direction into two halves and embedded in paraffin for serial sectioning and subsequent peroxidase-based immunohistochemistry or double-immunofluorescence preparations. Frozen, unfixed heads of newborn mice were used for cryosectioning and subsequent laser-assisted microdissection of ameloblasts and odontoblasts, RNA isolation and RT-PCR analysis. Our results revealed the presence of peroxisomes already in the bud stage of dental development. An increase in peroxisome abundance was noted during differentiation of ameloblasts and odontoblasts with the highest number of organelles in Tomes' processes of mature ameloblasts. A strong heterogeneity of peroxisomal enzyme content developed within differentiated dental cell types. A drastic down-regulation of catalase in maturing ameloblasts was noted in contrast to high levels of lipid metabolizing enzymes in peroxisomes of these cells. As known from the literature, differentiated ameloblasts are more prone to oxidative damage which could be explained by the low catalase levels inside of this cell type.

The evaluation of spontaneous space closure after the extraction of first permanent molars

In the UK, first permanent molars (FPMs) of poor prognosis are often planned for extraction so that second permanent molars (SPMs) erupt favourably to replace the FPMs. However, there is little published data to support this treatment strategy. The aim of this study was to assess the success of planned FPM extractions conducted 5years ago at a dental hospital in London. Two hundred and thirty-six SPMs from 63 patients were clinically assessed. The position of each SPM was recorded in relation to the second premolar, against patient Angle's classification and SPM radiographic development stage at the time of FPM extraction. Results were analysed using ordered logistic regression. At the time of FPM extraction, only 54% of SPMs were at the "ideal" stage of development (Demirjian's dental development stage E). Upper and lower arches yielded significantly different results with 92% of all upper extractions resulting in complete space closure regardless of SPM development stage. Only 66% of lower FPMs extracted at SPM stage E had complete space closure and no significant relationship was found between lower SPM development stage and its subsequent space closure. Space closure in both arches also appeared independent of patient Angle's classification. Although only over half the patients had FPMs extracted at the "ideal time", this did not appear to influence successful positioning of the upper or lower SPM. More research is required to investigate and confirm which predictive parameters have a significant effect on post-extraction orthodontic development, especially in the lower arch.

HDAC Inhibitor Trichostatin A Promotes Proliferation and Odontoblast Differentiation of Human Dental Pulp Stem Cells

Trichostatin A (TSA) is a potent histone deacetylase (HDAC) inhibitor with a broad spectrum of epigenetic activities known to regulate diverse cellular mechanisms, including differentiation of mesenchymal stem cells. In this study, we demonstrate that TSA promotes proliferation and odontoblast differentiation of human dental pulp stem cells (hDPSCs) in vitro and has the ability to enhance dentin formation and odontoblast differentiation in vivo during tooth development. We observed that TSA increased the expression of proliferating cell nuclear antigen and cyclin D1 in hDPSCs at a certain concentration and the activation of JNK/c-Jun pathway was essential for TSA-dependent hDPSC proliferation. Further, TSA accelerated mineral nodule formation in vitro and increased gene expression of dentin sialophosphoprotein, dentin matrix protein 1, bone sialoprotein, and osteocalcin. In addition, TSA significantly upregulated the levels of phospho-Smad2/3, Smad4, and nuclear factor I-C, while the specific inhibitor of Smad3 inhibits TSA enhancing mineralization differentiation of hDPSCs. HDAC3 is downregulated by TSA treatment, suggesting a possible mediator of TSA-dependent pathways among the members of HDAC family. Moreover, TSA-injected embryos exhibited increased dentin thickness, larger dentin areas, and higher odontoblast numbers in their postnatal molars with stronger dentin sialoprotein expression in immunohistochemical staining. These findings indicate that TSA may serve a key role in proliferation and odontoblast differentiation of hDPSCs in dental developmental stages and can be used as an accelerator in dental hard tissue engineering.

The Long-Term Effects of Mandibular Distraction Osteogenesis on Developing Deciduous Molar Teeth

Background. Many studies have demonstrated the effectiveness of mandibular distraction osteogenesis (MDO) in alleviating the micrognathia-associated upper airway obstruction but very few studies have focused on long-term dental outcomes. Objective. To report the effect of MDO on developing deciduous molars in the distraction area. Methods. A retrospective chart review was performed to identify patients with Pierre Robin sequence who underwent MDO with documented long-term dental assessments. Results. Ten children (mean age at surgery 69.8 days; 6 boys and 4 girls) were included for analysis. All patients underwent bilateral MDO with an inverted L-shaped osteotomy to avoid injuring tooth buds. The dental developmental stage was primary dentition in all children. Overall, 3 patients developed minor dental problems involving 4 molar teeth (2 root malformations and 2 shape anomalies) but they did not require any interventions. Conclusion. Significant primary molar developmental complications were not seen in our patients. The use of internal distractor device with an inverted L-shaped osteotomy seems to be a safe surgical approach in regards to dental outcomes.

Growth changes of the mandibular body with eruption of mandibular third molars: Analysis of anatomical morphometry and quantitative bone mineral content by using radiography

This study aimed to analyze growth changes in mandibular body morphology and quantitative bone mineral content (QBMC) with eruption of mandibular third molars (M3s) and the relationship between those variables and posterior mandibular body length. Linear and angular measurements were conducted using standard lateral radiographs of 37 dried mandibles in Hellman's dental developmental stages IVA (14 specimens) to VA (23 specimens). Cortical and trabecular basal bone mineral contents (CBMC and TBMC) in the mandible were expressed in millimeter titanium equivalent values using a titanium step wedge. The largest significant change in the mandibular body morphology was an increase in the horizontal dimension (M2DP'-Go': 7.59mm), followed by vertical dimension - total height of the mandibular body (THOMB: 4.96mm) and mandibular cortical width (MCW: 1.22mm). The gonial angle (GA) decreased significantly by 6.72° between stages IVA and VA. The mandibular cortical index (MCI) was classified only as C1 or C2 in each stage. Among 4 types of line profile, types 1 and 2 were most commonly observed in both stages. Mean values for CBMC and TBMC increased significantly between stages IVA and VA. Posterior mandibular body length (MeF'-Go') correlated positively with M2DP'-Go', THOM, MCW, and CBMC (r=0.816, 0.698, 0.595, and 0.507), respectively and negatively with GA (r=-0.582). These results demonstrated that the morphological changes in the posterior mandibular body and the QBMC increased significantly with M3 eruption, while the GA became significantly smaller. The posterior mandibular body length had a linear correlation with these variables.

A review of published sources for age at death in cattle

A survey of the literature for information relevant to estimating age at death in cattle has added detailed data on the age at which particular stages of dental development have been observed, based on sources where direct observations were certainly made. The information is of general interest for archaeozoology and, moreover, has enabled refinements to be made to existing methods for ageing cattle dentition using tooth eruption and wear (Jones and Sadler 2012). The survey presents summaries of published work on longevity in cattle, and on variation in eruption and wear.

Mouth breathing children and cephalometric pattern: Does the stage of dental development matter?

ObjectiveTo test the hypothesis that there is no difference in the cephalometric pattern between mouth breathing children with primary dentition and mixed dentition. MethodsCephalometric measurements of 126 mouth breathing children (MB) were compared to 126 nasal breathing controls (NB). Both groups were divided into deciduous dentition (mean age 4 years, 8 months) and mixed dentition (mean age 7 years, 9 months) groups. ResultsA statistically significant difference was observed in the dentofacial patterns of MB children compared to NB children. The total length of the mandible was smaller in MB compared to NB children. However, this difference was found only in subjects with mixed dentition. The length of the mandibular corpus is similar in MB and NB children, although older MB children with mixed dentition had significantly smaller measurements. The lower anterior facial height was higher in MB compared to NB children, but this difference was evident only in younger children with primary dentition. Mandibular plane angle, Y-axis angle and lower anterior facial height to total anterior facial height ratio were greater, and posterior facial height to total anterior facial height ratio was smaller in MB than NB children, indicating that mouth breathers had a more vertical facial growth pattern. However, no differences were found in the vertical growth pattern associated with the stage of dental development. The ANB angle was not associated with the maturational status of occlusion. Linear measurements and the gonial angle were significantly different between children with primary and mixed dentition, but such differences were associated with normal vertical growth. ConclusionsThe present investigation rejected the null hypothesis and showed significant cephalometric differences between primary and mixed dentition MB children. Mouth breathing children in the mixed dentition have a smaller mandible (in terms of total length and corpus length) than nasal breathers. In children with primary dentition, the lower anterior facial height is higher in MB than in NB children. There was no significant association between the stage of dental development of mouth breathing children (either in the primary or mixed dentition) and the other cephalometric patterns.

Diagnosis and treatment of missing upper lateral incisors part 2

The aim of this second article is to outline the management and treatment options for patients with missing upper lateral incisors at various stages of dental development. The joint orthodontic-restorative multidisciplinary teams are best placed to manage these challenging cases. Clinical Relevance: There are various treatment options for the management of patients with absence of one or both lateral incisors. The orthodontic practitioner needs to be aware of the pros and cons of different options.

Permanent teeth development in a Spanish sample. Application to dental age estimation

The purpose of this study is to clarify the chronology of different stages of dental development, according to Demirjian, in a sample of Spanish children, which will enable us to build a database that will be used as a reference in regard to the dental development of individuals of our socio-geographic environment. In the same studied sample, a calculation of the dental age according to Demirjian was carried out. This study was conducted in a final sample consisting of 1010 orthopantograms, corresponding to Spanish children (485 boys and 525 girls) ages 2-16. Comparing the age of onset of the different stages among the children, evidence was found that girls had an earlier general development than boys. These differences were only statistically significant in teeth and concrete stages. The canine teeth revealed greater gender dimorphism, with significant differences in all stages compared with the upper canines. The method proposed by Demirjian for dental age calculation resulted in a significant overestimation of dental age in relation to the chronological age in boys (average of 0.87 years) and girls (average of 0.55 years). Data from this study may be used as reference for dental maturity, as well as a standard for estimating age in Spanish children.

Fluoride content of Ready‐to‐Feed (RTF) infant food and drinks in the UK

The level of Fluoride exposure needed to cause dental fluorosis is not known precisely. An awareness of total F intake from all sources, especially during the critical stages of dental development during infancy and early childhood, is important in preventing the development of dental fluorosis. The aim of the study was to measure F content of ready-to-feed (RTF) infant drinks and foods in the UK. In total, 122 infant foods were analysed for F concentrations, in triplicate, indirectly by an acid diffusion method and 25 infant drinks analysed directly using an F-ion-selective electrode after addition of TISABIII. The median (range) F concentration was 0.110 (0.030-0.221) μg/g for breakfast cereals, 0.112 (0.040-1.200) μg/g for savoury meals, 0.056 (0.030-0.379) μg/g for desserts, 0.044 (0.020-0.191) μg/g for fruits, 0.196 (0.040-0.397) μg/g for baked goods, 0.069 (0.050-0.148) μg/ml for juices, 0.016 (0.009-0.030) μg/ml for milks and 0.041 (0.022-0.069) μg/ml for waters. The median (range) F concentration of all RTF infant foods and drinks by recommended age of consumption was 0.029 (0.010-0.245), 0.088 (0.020-0.500), 0.108 (0.100-0.510) and 0.108 (0.060-1.200) μg/g for infants from birth, 4+ month, 6+ month and 10+ month, respectively. The results suggest that the F concentrations of UK-marketed RTF infant foods, drinks and formula milk are not sufficiently high to be a risk factor for dental fluorosis, if consumption is within the limits recommended for infants and young children.

L’implant dentaire biologique : mythe ou réalité ?

The currently available options for tooth-loss are prostheses, implants, or surgery (auto-transplantation). They all have their limitations. The emergence of tissue engineering, 15 years ago, was made possible by a better knowledge of the various stages of dental development, and the mastery of stem cell differentiation. It opened a new alternative approach for tooth regeneration. Even if animal experiments have demonstrated that it was possible to obtain a biological tooth from stem cells, two major issues remain to be discussed. Is it possible to use induced pluripotent stem cells instead of embryonic stem cells, which raise an ethical problem? Is it possible to reproduce a dental crown with an adapted shape and colour? Or should we consider the simpler creation of a biological root secondarily covered by a ceramic prosthesis? Our study mentions the main landmarks and the key cells involved in the embryological development of the tooth, establishes a mapping and a list of the various types of stem cells. It details the various methods used to create a biological implant.

A New Yardstick for Rating Dental Arch Relationship in Patients with Complete Bilateral Cleft Lip and Palate

To develop yardsticks for assessment of dental arch relationship in young individuals with repaired complete bilateral cleft lip and palate appropriate to different stages of dental development. Eleven cleft team orthodontists from five countries worked on the projects for 4 days. A total of 776 sets of standardized plaster models from 411 patients with operated complete bilateral cleft lip and palate were available for the exercise. The interexaminer reliability was calculated using weighted kappa statistics. The interrater weighted kappa scores were between .74 and .92, which is in the "good" to "very good" categories. Three bilateral cleft lip and palate yardsticks for different developmental stages of the dentition were made: one for the deciduous dentition (6-year-olds' yardstick), one for early mixed dentition (9-year-olds' yardstick), and one for early permanent dentition (12-year-olds' yardstick).

Fluoride concentration in dentine as a biomarker of fluoride intake in European roe deer (Capreolus capreolus) – An electron-microprobe study

ObjectiveFluoride concentration in dentine has been recommended as the best marker for the level of chronic fluoride intake and the most suitable indicator of an individual's total body burden of fluoride. We analysed fluoride concentrations in the dentine of cheek teeth of European roe deer from fluoride-polluted habitats to retrospectively assess the level of fluoride uptake into the tissue. Thereby, we tested the hypothesis of the existence of mechanisms that limit fluoride intake of individuals and fluoride exposure of forming dental hard tissues during the late foetal and early postnatal periods in the species. DesignUsing electron-microprobe analysis, fluoride profiles were obtained on sectioned P4s, M1s, and M3s from individuals exhibiting pronounced dental fluorosis. Fluoride concentrations were compared between early formed (peripheral) and late-formed (juxtapulpal) dentine both within single teeth and amongst the three different teeth studied. ResultsPeripheral dentine of the M1, which is formed during the late foetal and early postnatal periods, exhibited markedly lower fluoride concentrations than juxtapulpal dentine of the same tooth and both, peripheral and juxtapulpal dentine of P4 and M3 that are formed post-weaning. ConclusionsOur study provides strong support for the hypothesis that in the European roe deer the prenatal and early postnatal (pre-weaning) stages of dental development are (largely) protected against exposure to excess fluoride. This is attributed to the operation of certain protective mechanisms during these periods.