Evaluation of Parents' Performance and Beliefs in Dealing with Symptoms Associated with Tooth Eruption in Kashan

Background: It is widely believed that the growth of deciduous teeth can be accompanied by systemic and localized symptoms. This study was conducted in Kashan in 2019 with the aim of parents' performance and beliefs in the face of tooth eruption and its associated factors. Methods: This study is a cross-sectional study. The study population consisted of 290 parents with children aged 6 to 36 months who were referred to Kashan health centers who were selected by available sampling. The researcher-made questionnaire was completed by the participants and the data were analyzed using descriptive statistics and Fisher's exact Chi-Square test by SPSS 16 statistical software. P value < 0.05 was considered as a significant level. Results: The most common symptoms reported by parents include; Restlessness (78.6), chewing (70.0), loss of appetite (65.5), weight loss 55.2), fever (53.4), swelling, and redness of the gums (51.7), runny mouth (50.0). Most parents' beliefs came from those around them. There was a statistically significant relationship between parents' education with weakness and colds (p value < 0.01). There was a significant difference between parents' performance in controlling symptoms and their education (p value < 0.01). Conclusion: Although tooth growth is a physiological phenomenon, it can be accompanied by a series of local and systemic symptoms. Educating parents will improve their beliefs and help their children's health.

The Role of Wnt Signaling in Postnatal Tooth Root Development

Appropriate tooth root formation and tooth eruption are critical for achieving and maintaining good oral health and quality of life. Tooth eruption is the process through which teeth emerge from their intraosseous position to their functional position in the oral cavity. This temporospatial process occurs simultaneously with tooth root formation through a cascade of interactions between the epithelial and adjoining mesenchymal cells. Here, we will review the role of the Wnt system in postnatal tooth root development. This signaling pathway orchestrates the process of tooth root formation and tooth eruption in conjunction with several other major signaling pathways. The Wnt signaling pathway is comprised of the canonical, or Wnt/β-catenin, and the non-Canonical signaling pathway. The expression of multiple Wnt ligands and their downstream transcription factors including β-catenin is found in the cells in the epithelia and mesenchyme starting from the initiation stage of tooth development. The inhibition of canonical Wnt signaling in an early stage arrests odontogenesis. Wnt transcription factors continue to be present in dental follicle cells, the progenitor cells responsible for differentiation into cells constituting the tooth root and the periodontal tissue apparatus. This expression occurs concurrently with osteogenesis and cementogenesis. The conditional ablation of β-catenin in osteoblast and odontoblast causes the malformation of the root dentin and cementum. On the contrary, the overexpression of β-catenin led to shorter molar roots with thin and hypo-mineralized dentin, along with the failure of tooth eruption. Therefore, the proper expression of Wnt signaling during dental development is crucial for regulating the proliferation, differentiation, as well as epithelial-mesenchymal interaction essential for tooth root formation and tooth eruption.

The effect of biphasic calcium phosphate and demineralized bone matrix on tooth eruption in mongrel dogs

Background: Bone grafts can provide an optimal environment for permanent tooth to erupt and enhance the stability of the alveolar maxilla. Although autologous bone is an optimal source for osteogenesis, its inevitable donor site morbidity has led to active research on bone substitutes. This study was designed to evaluate the safety and feasibility of using biphasic calcium phosphate (BCP; Osteon) as a bone substitute in dogs. Methods: Bilateral third and fourth premolars of four 15-week-old mongrel dogs were used. All teeth were extracted except the third premolar of the right mandible, which was used as a control. After extraction of the premolars, each dog was administered BCP (Osteon), demineralized bone matrix (DBM; DBX), and no graft in the hollow sockets of the right fourth premolar, left fourth premolar, and left third premolar, respectively. Radiographs were taken at 2-week intervals to check for tooth eruption. After 8 weeks, each dog was sacrificed, and tooth and bone biopsies were performed to check for the presence of tooth and bone substitute particle remnants. Results: Four weeks after the operation, permanent tooth eruptions had started at all the extraction sites in each dog. Eight weeks after the operation, all teeth had normally erupted, and histological examination revealed BCP particles at the right fourth premolar. Conclusion: In all four dogs, no delay in the eruption of the teeth or shape disfigurement of permanent teeth was observed on gross inspection and radiologic evaluation. On histological examination, most of the BCP and DBM were replaced by new bone. Bone substitutes can be used as graft materials in patients with alveolar clefts.

Dentigerous Cyst Associated with a Misaligned Maxillary First Premolar: A Case Report

Aims: The main goal of the following case report was to shed the light on the importance of thorough clinical, radiological and histological examinations in order to elaborate a final diagnosis of asymptomatic dentigerous cysts detected in unusual locations. Presentation of Case: A case of dentigerous cyst was identified accidentally in the maxillary left premolar region of an asymptomatic 14-year-old female post an orthodontic consultation. Histological examination of the tissue specimens following enucleation confirmed the diagnosis of a dentigerous cyst. Discussion: Dentigerous cysts are the second most common odontogenic cysts after radicular cysts. They involve impacted, un-erupted, permanent, supernumerary, odontomas and rarely deciduous teeth. Dentigerous cysts are usually painless but may cause facial swelling and delayed tooth eruption. Extensive maxillary involvement and childhood presentation are rare. Radio-graphic and histological examinations should be done to confirm the diagnosis of a dentigerous cyst. Conclusion: In our case, we showed the presence of a maxillary premolar dentigerous cyst that was removed by enucleation. The presence of dentigerous cyst is not always associated with a syndrome and its removal is very important to avoid future complications.

Comparison of rat tooth eruption in rats born from diabetic mothers

Background: Tooth eruption begins after crown and root formation and may be delayed by gestational diabetes mellitus. Metformin can control blood glucose levels through gluconeogenesis inhibition, and consuming thymoquinone for diabetic treatment will regenerate pancreatic β cells and reduce oxidative stress. Purpose: The objective of this study is to compare the tooth eruption in rats that were born with diabetes and are being treated with either metformin or thymoquinone. Methods: This study used 48 Wistar rats (Rattus norvegicus L.), and the rat sample was divided into four groups, including rats who were born from healthy mothers, rats who were born from untreated diabetic mothers, rats who were born from diabetic mothers that were treated with metformin and rats who were born from diabetic mothers that were treated with thymoquinone. Diabetes was induced by intraperitoneal injection of a single dose of streptozotocin (40 mg/kg BB). Each rat sample was taken with simple random sampling from different mothers, and body weight, blood glucose levels and levels of tooth eruption were recorded. Eruptions of the maxillary right first molar were measured from the cusp of the tooth to the alveolar epithelial lining. Results: Based on the measurements of tooth eruption, it was found that groups A, C and D were closer to mucosa on day 1, 7 and 14 than group B. Based on statistical analysis, there were significant differences (p = 0.03) between group B and groups C and D. Conclusions: Rats born from untreated diabetic mothers have more delays in tooth eruption than those born from diabetic mothers who are treated with metformin and thymoquinone. Thymoquinone has the potential to be an alternative to metformin because it has been shown to be similarly effective.

Hexavalent chromium exposure alters bone remodeling in the developing tooth alveolus and delays tooth eruption

Although it has been demonstrated that exposure of lactating rats to CrVI delays tooth eruption, the effects of CrVI exposure on bone remodeling in the developing alveolus during tooth eruption remain unknown. Our purpose was to analyze the effect of CrVI in the alveolus of the first lower molar of rats. Thirty-two suckling Wistar rats were divided into two groups. The experimental group received 12.5 mg/kg body weight/day of potassium dichromate dissolved in saline solution by oral gavage as of day 4 of the experiment; the control group received an equal dose of saline solution. Each group was divided into two sub-sets and euthanized at the ages of 9 and 15 days, respectively. Histochemical and histomorphometric studies of the bone surfaces of the developing tooth alveolus were performed. The percentage of bone formation surfaces was lower in experimental animals than in age-matched controls. The percentage of bone resorption surfaces was significantly lower in 9-day-old experimental rats than in controls and significantly higher in 15-day-old experimental rats than in controls. Exposure to CrVI during lactation alters the sequence of bone resorption and formation in the walls of the developing alveolus, both of which are necessary for tooth eruption, thus causing a delay.

Overview of Radiological Studies on Visualization of Gubernaculum Tracts of Permanent Teeth

The eruption pathway from the dental follicle to the gingiva for permanent teeth is known as the gubernaculum tract (GT), a physiologic structure thought to play a role in tooth eruption. Cone beam computed tomography and multi-detector computed tomography have recently been used to visualize the GT, with the results indicating that this structure might be related to the normal eruption of teeth. By contrast, curved and/or constricted GTs may lead to abnormal tooth eruption. In addition, complex odontomas have been reported from within the GT or dental sac of unerupted permanent teeth. If an odontoma occurs within the GT, the tooth will not erupt normally. Moreover, the imaging characteristics of the GT from the top of the odontogenic mass to the alveolar crest are extremely useful for making a differential pathological diagnosis and for differentiating between odontogenic and non-odontogenic masses. Therefore, radiological studies on the GT have been attracting increasing attention. Given this background, the present review aims to clarify the imaging characteristics and review recent studies on the GT considering the importance of the research.

Identification of enamel knot gene signature within the developing mouse molar

In most mammals, the primary teeth develop in utero and the cells capable of contributing to hard surface regeneration are lost before tooth eruption. These cells differentiate through a series of reciprocal induction steps between the epithelium and mesenchyme, initially orchestrated by an epithelial signaling center called the enamel knot. While the factors secreted by this structure are of interest to the dental regeneration and development communities, its small size makes it difficult to isolate for analysis. Here we describe our work to identify the enamel knot from whole E14 molars using publicly available scRNA-seq data. We identified 335 genes differentially expressed in the enamel knot compared to the surrounding tissues, including known enamel knot marker genes. We validated expression of the most highly enriched enamel knot marker genes and identified 42 novel marker genes of the enamel knot which provide excellent targets for future dental regeneration investigations.

The Orthodontic Treatment Scheme for Primary Failure of Eruption Patient without PTH1R Mutation

Primary failure of eruption (PFE) is observed as a defect in the tooth eruption mechanism with the heterozygous mutations of parathyroid hormone receptor gene (PTH1R). The present study reported 2 families suffered from nonsyndromic tooth eruption disorder in successive generations. Genetic analysis and standardized assessments, including clinical and radiographic examinations, of the dental condition of all patients were performed to give a clear understanding of the disease. The mutation of PTH1R was detected in patient II-1 (Family I) by PCR and sanger sequencing. Sequencing analysis reviewed heterozygous presence of c.439C>T in exon 2 of PTH1R. According to the UniprotKB database, PTH1R is highly conserved among several mammalian species. RNA-seq was performed to further analyze the role of PTH1R in tooth development and eruption. It showed that during tooth development, the expression of PTH1R decreased in the early stage of tooth development in rat and mouse. However, the mutations of PTH1R were not detected in 2 patients from family II. With extensive analysis of the radiographs and physical examination, we attempted to use orthodontic methods to create enough room for tooth eruption, which shows therapeutic result to the submerged tooth. The results suggested new orthodontic scheme for the PFE patient without PTH1R mutation. Both clinical and genetic diagnosis should be considered in the treatment planning.

The Influence of Diet, Exercise and Education Level During Pregnancy on Child Cavities and Tooth Eruption

Objectives: This study’s objective was to evaluate if exercise during pregnancy, a healthy diet rich in polyunsaturated fatty acids and calcium, and the mother’s educational level influenced the dental health measures of caries risk and tooth eruption of their offspring. Methods: Women with children 6 years and younger completed questionnaires regarding PA and diet (PUFA-rich, calcium-rich (Ca) dairy foods) during pregnancy and education level prior to their child’s dental examination. T-tests were used to compare exercisers and non-exercisers; correlation and regression analyses were conducted to determine relationships and predictors of child dental health, respectively. Results: Eighty-two mother-child pairs were analysed. Exercisers had trends of increased PUFA (p=0.07) and Ca-rich dairy foods (p=0.12) to non-exercisers during pregnancy. Ca-rich dairy foods during pregnancy had positive associations with primary tooth count (p=0.004), mixed surface count (p=0.02), and tooth eruption (p=0.04). Controlling for maternal education and exercise, tooth eruption was predicted by PUFA summary and cheese consumption while dairy summary predicted primary tooth count; caries risk was predicted by maternal education; primary surface caries was associated with exercise duration. Conclusion: During pregnancy, calcium-rich dairy and PUFA-rich foods influenced child tooth eruption and thus tooth count, while exercise duration was associated with primary surface caries. Maternal education was associated with lower caries risk. Our findings support educating women on calcium intake and appropriate exercise levels during pregnancy, plus oral health counseling for their child.