Direct Resin Composite Restoration of Maxillary Central Incisors with Fractured Tooth Fragment Reattachment: Case Report

This article presents a clinical protocol to reconstruct two accidentally damaged maxillary central incisors using composite resin material and a fractured tooth component. A patient was referred to the clinic with fracture of the two maxillary central incisors. Clinical examination revealed that both teeth were fractured in the middle third of the crown and that the fractures involved enamel and dentin with no pulp exposure. The patient had also suffered a lower lip laceration. When the lip was evaluated, a fractured fragment of the maxillary right central incisor was found inside the wound. The missing part of the tooth was replaced via adhesive attachment. Due to the damage of the fractured part of the maxillary left central incisor, direct composite restoration of this tooth was performed. With the advent of adhesive dentistry, the process of fragment reattachment has become simplified and more reliable. This procedure provides improved function, is faster to perform, and provides long-lasting effects, indicating that reattachment of a coronal fragment is a realistic alternative to placement of conventional resin composite restorations.

A Proposed Methodology to Assess the Accuracy of 3D Scanners and Casts and Monitor Tooth Wear Progression in Patients

PURPOSE

The aim of this study was to detail and assess the capability of a novel methodology to 3D-quantify tooth wear progression in a patient over a period of 12 months.

MATERIALS AND METHODS

A calibrated stainless steel model was used to identify the accuracy of the scanning system by assessing the accuracy and precision of the contact scanner and the dimensional accuracy and stability of casts fabricated from three different types of impression materials. Thereafter, the overall accuracy of the 3D scanning system (scanner and casts) was ascertained. Clinically, polyether impressions were made of the patient's dentition at the initial examination and at the 12-month review, then poured in type IV dental stone to assess the tooth wear. The anterior teeth on the resultant casts were scanned, and images were analyzed using 3D matching software to detect dimensional variations between the patient's impressions.

RESULTS

The accuracy of the 3D scanning system was established to be 33 μm. 3D clinical analysis demonstrated localized wear on the incisal and palatal surfaces of the patient's maxillary central incisors. The identified wear extended to a depth of 500 μm with a distribution of 4% to 7% of affected tooth surfaces.

CONCLUSION

The newly developed 3D scanning methodology was found to be capable of assessing and accounting for the various factors affecting tooth wear scanning. Initial clinical evaluation of the methodology demonstrates successful monitoring of tooth wear progression. However, further clinical assessment is needed.

Repositioning of a pathologically migrated tooth using autologous platelet-rich plasma: a case report with 3-year follow-up

An intricate balance between the periodontal tissues and the forces of occlusion, tongue, and lips helps to maintain a tooth in its physiologic position within the dental arch. Disturbances in the equilibrium can cause a tooth to migrate pathologically, often requiring multidisciplinary treatment approaches. The present case demonstrates, for the first time, the use of autologous platelet-rich plasma to aid in tooth repositioning after pathologic tooth migration. A 25-year-old woman presented with extrusion and labial migration of the maxillary left central incisor, a diastema of 3 mm, and grade II mobility. Radiographic evaluation showed a deep, angular bone defect, extending to the apical third of the root, on both the mesial and distal aspects of the maxillary left central incisor. Comprehensive treatment consisted of nonsurgical and surgical periodontal therapy with autologous platelet-rich plasma. Without orthodontic intervention, the unesthetic diastema had completely closed by the end of 3 months postoperatively, and the results were stable at a 3-year follow-up examination. This successful, novel approach can be adopted as a conservative and time-efficient modality for management of unesthetic spaces caused by pathologic tooth migration.

Histopathological Study on the PTHrP-Induced Incisor Lesions in Rats

Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). The present study elucidates the histopathological characters of incisor lesions in the HHM rat model. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, maintained for 12 weeks, after which the mandibular incisors were collected. Incisor fractures were observed grossly. Microscopically, hypercalcified dentin, dentin niche with osteodentin, and thinning of dentin were observed. Hypercalcified dentin was observed as a basophilic line of calcified dentin without associated odontoblastic changes, whereas dentin niche and thinning of dentin occurred with osteodentin and loss of cell height, respectively. In contrast with hypercalcified dentin, which was distributed throughout the dentin, dentin niche and thinning of dentin were localized to the labial area of the apical and middle region, and to the labial and lingual areas of the middle and incisal region, respectively. These results suggest that hypercalcemia affected the entire calcification process resulting in hypercalcified dentin, and that high PTHrP concentrations affected selective populations of odontoblasts resulting in formation of dentin niche and thinning of dentin. The localization of dentin niche and thinning of dentin also suggest that PTHrP may also be involved odontoblastic development in the rat.

Prevalence of an unusual hypoplastic defect of the permanent maxillary lateral incisor in great apes

In this article, I describe a previously unreported maxillary lateral incisor defect (MLID) of the enamel in great apes and evaluate potential general causes (genetic, systemic stress, or localized disturbance), as well as examine differences in prevalence among the represented taxa. This defect occurred only on the labial surface of the maxillary lateral incisor and extended from the cervical-mesial quarter of the crown to the mesial edge of the cementoenamel junction (CEJ). The study sample consisted of 136 great ape specimens, including 41 gorillas, 25 chimpanzees, and 70 orangutans from the Smithsonian's National Museum of Natural History great ape collection. I used logistic regression to assess the prevalence of this defect in the sample and a binomial probability test for bilaterality. This defect of the maxillary lateral incisor is the second most common defect I observed in the study sample (30.1% of individuals affected), and was more likely to occur in individuals with linear enamel hypoplasia (LEH) and pit defects than those without these defects. Among specimens with both maxillary lateral incisors present, the defect was mostly bilateral. Pan and Pongo were significantly more likely to exhibit the defect than Gorilla. Between Pongo species, Pongo pygmaeus was significantly more likely to exhibit the defect than Pongo abelii. Between subspecies of Gorilla, although Gorilla gorilla gorilla exhibited the defect and Gorilla gorilla beringei did not, the difference was not significant. No sex differences were evident in this sample. The prevalence of this defect indicates it is not hereditary. The bilateral trend indicates a systemic cause, although the high inter-tooth specificity suggests a local disturbance and a combination of both is possible.

Combined Surgical Removal of a Supernumerary Tooth and Orthodontic Traction of an Impacted Maxillary Central Incisor

Impaction of permanent maxillary central incisors is a rare condition that can affect esthetics and oral function. The etiology of impaction is multifactorial and may be related to embryologic reasons, hereditary factors, mechanical obstacles, and pathologic elements, such as the presence of supernumerary teeth. The purpose of this report is to discuss the case of a 10-year-old patient who presented an impacted permanent maxillary right central incisor due to a supernumerary tooth. Surgical removal of the supernumerary tooth and orthodontic traction of the impacted central incisor by the closed eruption technique were performed. After 12 months, the permanent maxillary right central incisor was adequately positioned in the arch. The multidisciplinary treatment allowed the functional and esthetic rehabilitation to happen in a short period of time, thus reducing the patient's psychological impact caused by the lack of an anterior tooth.

Dental erosion: Prevalence and severity among 16-year-old adolescents in Troms, Norway

AIM

To study the prevalence, distribution and severity of dental erosion among 16-year-old adolescents in the Troms region of Norway.

MATERIALS AND METHODS

Study design: The participants were recruited through the Tromsø-study ("Fit Futures"), and 392 16-year-olds were examined for dental erosion using clinical intraoral photographs. Three calibrated clinicians used the Visual Erosion Dental Examination (VEDE) system to register and grade the dental erosive wear.

RESULTS

More than one third (38%) of the participants showed dental erosion on at least one tooth surface, 18% were limited to the enamel, while 20% of the adolescents showed erosive wear extending into the dentine. The occlusal surfaces of the lower first molars, and the palatal surfaces of the maxillary incisors were the most often and most severely affected. Of the participants showing dental erosion, 93% exhibited "cuppings" on the molars, with 48% limited to the enamel and 52% extending into the dentine. The highest prevalence of "cuppings" (73%) was found on the first lower molars, especially the mesiobuccal cusp of the teeth. The prevalence and severity of dental erosion was found to be higher in male than in female participants (p < 0.0001).

CONCLUSION

The results from this study indicate a high prevalence and severity of dental erosion among adolescents in Troms and stress the importance of information, early and effective diagnostics and implementation of prevention strategies.

Antagonistic Functions of USAG-1 and RUNX2 during Tooth Development

Supernumerary teeth and tooth agenesis are common morphological anomalies in humans. We previously obtained evidence that supernumerary maxillary incisors form as a result of the successive development of the rudimentary maxillary incisor tooth germ in Usag-1 null mice. The development of tooth germs is arrested in Runx2 null mice, and such mice also exhibit lingual epithelial buds associated with the upper molars and incisors. The aim of this study is to investigate the potential crosstalk between Usag-1 and Runx2 during tooth development. In the present study, three interesting phenomena were observed in double null Usag-1^-/-/Runx2^-/- mice: the prevalence of supernumerary teeth was lower than in Usag-1 null mice; tooth development progressed further compared than in Runx2 null mice; and the frequency of molar lingual buds was lower than in Runx2 null mice. Therefore, we suggest that RUNX2 and USAG-1 act in an antagonistic manner. The lingual bud was completely filled with odontogenic epithelial Sox2-positive cells in the Usag-1^+/+/Runx2^-/- mice, whereas almost no odontogenic epithelial Sox2-positive cells contributed to supernumerary tooth formation in the rudimentary maxillary incisors of the Usag-1^-/-/Runx2^+/+ mice. Our findings suggest that RUNX2 directly or indirectly prevents the differentiation and/or proliferation of odontogenic epithelial Sox2-positive cells. We hypothesize that RUNX2 inhibits the bone morphogenetic protein (BMP) and/or Wnt signaling pathways regulated by USAG-1, whereas RUNX2 expression is induced by BMP signaling independently of USAG-1.

Hexachlorobenzene-Induced Incisor Degeneration in Sprague—Dawley Rats

Hexachlorobenzene (HCB) was administered to female Sprague—Dawley rats in a 13-week toxicity study conducted for the National Toxicology Program (NTP). Groups of 10 rats were treated by gavage with 0.0, 0.03, 0.1, 0.3, 1.0, 3.0, 10, or 25 mg/kg HCB in corn oil 5 days/week for 13 weeks. Dose-dependent, region-specific, maxillary incisor degeneration was observed in animals given HCB at doses of 1.0 mg/kg/day and higher. Treatment with 1.0 mg/kg/day resulted in focal mesenchymal cell vacuolation and focal osteodentin formation within the pulp. Lesions were restricted to a short linear region subjacent to the odontoblast layer along the lateral aspect of the incisor at the level of the dentin-enamel interface. When observed in both incisors, lesions were bilaterally symmetric. Treatment with 3.0 mg/kg/day resulted in lateral and medial pulp lesions and focal odontoblast degeneration with dentin niche formation along the lateral incisor margin in some animals. Treatment with 10 mg/kg/day resulted in a higher incidence of lateral dentin niches and a low incidence of medial dentin niches. In animals treated with 25 mg/kg/day, a high incidence of bilaterally symmetric, lateral and medial, dentin niches were observed. The morphology and distribution of HCB-induced incisor lesions in rats are consistent with injury to a selective population of preodontoblasts.

[Aesthetic success in genioplasties procedures criteria]

Maxillomandibular dysmorphia may be associated with structural chin pathologies. Three-dimensional jaws displacements have limits. Specific genioplasty is an additional surgical mean for soft tissues profile normalization. Osteotomy line is examined according an incline angle and a possible lateral extension, as chin wing technique, improves facial shape. Cephalometric set-up with R line analyzes surgical chin movements and impact of lower incisors labial inclination on lower lip and mentolabial fold after advancement genioplasty. Micro-implant anchorage is a precious help to find lower incisors good position and optimum lower occlusal plane frontal shift in asymmetric facial pattern. Orthodontics criteria are essential factors to access an aesthetic success in genioplasties procedures.

Molar Incisor Hypomineralization

Molar incisor hypomineralization (MIH) is a developmental defect affecting teeth. High prevalence rates of MIH and its clinical implications are significant for both the patients and clinicians. A wide variation in defect prevalence (2.4-40.2%) is reported. It seems to differ with regions and various birth cohorts. Some of the recent prevalence studies are tabulated. Patient implications include hypersensitive teeth, rapid progression of caries, mastication impairment due to rapid attrition, and esthetic repercussions. Implications for clinicians include complexity in treatment planning and treatment implementation, poor prognosis of the restorations, difficulty in achieving pain control during treatment, and behavior management problems. Intention of this paper is to review the etio-pathogenesis, prevalence, clinical features, diagnostic features, and eventually present a sequential treatment approach, i.e., in accordance with current clinical practice guidelines.

Histopathological Study of Time Course Changes in PTHrP-Induced Incisor Lesions of Rats

Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). In the present study using HHM model rats, the time course of odontoblastic response to PTHrP and its relation to incisal fracture were elicited. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, mandibular incisors were collected at several time points. Microscopically 3 distinctive types of odontoblastic/dentin lesions were observed. Hypercalcfied dentin, which was reported as hypercalcemia-induced lesion in previous reports, observed in all areas of the dentin from week 5–10 samplings. Dentin niche, observed solely in week-10 sampling point, exhibited a nature identical to that of reparative odontoblast reported in the literatures of various cytotoxic agents. Since cytotoxicites were neither observed prior to the lesions nor reported as a role of PTHrP, the reparative response may have derived from highly sustained levels of PTHrP. Loss of columnar odontoblasts height was initially observed at week-5 time point in the middle section of the incisor. This primary loss of cell height prior to incisor fracture was considered to be the earliest response to the increased PTHrP levels of this model.

Association between Molar Incisor Hypomineralization in Schoolchildren and Both Prenatal and Postnatal Factors: A Population-Based Study

BACKGROUND

Although studies throughout the world have investigated potential factors involved in the occurrence of molar incisor hypomineralization (MIH), the findings are varied and inconclusive.

OBJECTIVE

The aim of the present study was to evaluate the prevalence of MIH and identify associated prenatal, perinatal and postnatal factors among Brazilian schoolchildren aged 8 and 9 years.

METHODS

A cross-sectional study was conducted with a randomly selected population-based sample of 1181 schoolchildren. Information on demographic and socioeconomic characteristics as well as prenatal, perinatal and postnatal aspects was obtained through questionnaires. The clinical examination included the investigation of MIH based on the criteria of the European Academy of Paediatric Dentistry. Dental caries in the permanent dentition and developmental defects of enamel (DDE) on the primary second molars were also recorded. Data analysis involved descriptive statistics, bivariate tests and Poisson regression with robust variance.

RESULTS

The prevalence of MIH was 20.4%. MIH was more frequent among children with dental caries in the permanent dentition (PR: 2.67; 95% CI: 1.98-3.61), those with DDE on the primary second molars (PR: 2.54; 95% CI: 1.87-3.45) and those who experienced asthma/bronchitis in the first four years of life (PR: 1.93; 95% CI: 1.45-2.56).

CONCLUSIONS

The prevalence of MIH was high and was associated with dental caries, the presence of DDE on primary second molars and the experience of asthma/bronchitis in early life. These findings could be useful in the identification of children in need of shorter recall intervals to prevent the consequences of MIH, such as enamel breakdown dental caries.

Examiner reliability in fluorosis scoring: a comparison of photographic and clinical methods

OBJECTIVE

To assess examiner reliability when scoring dental fluorosis in Malaysian children using clinical (Dean's Index) and photographic methods.

METHOD

The upper central incisors of 111 children were examined both clinically and photographically for fluorosis status using Dean's index. Twenty children were re-examined after a two-week interval for intra-examiner reliability by a single examiner. In addition, two independent examiners and the clinical examiner scored 111 photographic images of the same children in a standardized manner. Fluorosis scores were compared individually between examiners for both clinical and photographic scoring. Examiner reliability was assessed using both simple and weighted kappa statistics at tooth level. Sensitivity, specificity, positive-negative predictive values and a Receiver Operating Characteristic (ROC) curve were also calculated to determine the accuracy of the test.

RESULTS

Across the three examiners, the prevalence of fluorosis (Dean's score ≥ 2) using photographs was lower (ranged from 23% to 26%) than the prevalence recorded by clinical examination (30%). The kappa score for intra-examiner reliability for the duplicate clinical examination was excellent (0.89). Inter-examiner reliability between the photographic method and the clinical examination (gold standard) for each examiner was substantial with weighted kappa values ranging from 0.74 to 0.77. The photographic method indicated higher specificity (99%) than sensitivity (79%) and the area under the ROC curve was also high (0.89) which suggests good accuracy of the diagnostic test.

CONCLUSION

These results suggest that photographic examination of fluorosis on central incisors can be recorded with good examiner reliability. The recorded fluorosis prevalence was lower using the photographic scores.

No association between gingival labial recession and facial type

OBJECTIVE

To evaluate if facial type is a predictor of the development of gingival recession.

METHODS

A cohort of 179 orthodontic patients (76 males, 101 females; age before treatment T S = 12.4 years, SD = 0.8) were followed until 5 years post-treatment (T 5 = 20.7 years, SD = 1.2). The presence of recessions was scored ('Yes' or 'No') by two raters on initial (T S), end of treatment (T 0), and post-treatment (T 5) plaster models. A recession was noted (scored 'Yes') if the labial cemento-enamel junction was exposed. The clinical crown heights were measured at T S, T 0, and T 5 as the distances between the incisal edges and the deepest points of the curvature of the vestibulo-gingival margins. Determination of the facial type was based on the inclination of mandibular plane relative to cranial base (Sella-Nasion/Mandibular Plane) and the proportion of posterior to anterior face heights (PFHs; SGo/NMe × 100 per cent) on pre-treatment cephalograms.

RESULTS

From T 0 to T 5, the number of subjects with recessions increased from 2 (1.1 per cent) to 24 (13.6 per cent), and the number of recession sites increased from 2 to 39. However, most patients had either one or two recession sites. The mean clinical crown height of mandibular incisors increased by 0.86mm (SD = 0.82, P < 0.001). Regression analysis showed that mandibular plane inclination had no effect on the development of gingival recession or on the increase of clinical crown heights of mandibular incisors.

CONCLUSIONS

Facial type is not a predictor of the occurrence of gingival recession.

A Guided, Conservative Approach for the Management of Localized Mandibular Anterior Tooth Wear

The successful management of the worn mandibular anterior dentition may present an awkward challenge to the dental operator. The purpose of this article is to describe a case report illustrating the use of a guided, three-dimensional protocol for the ultra-conservative and predictable restoration of the worn lower anterior dentition using direct resin composite. This technique utilizes information based on established biomechanical and occlusal principles to fabricate a diagnostic wax-up, which is duplicated in dental stone. This is used to prepare a vacuum-formed modified stent, assisting the clinician to place directly bonded resin composite restorations to restore the worn lower anterior dentition. The technique, described in 2012 and referred to as 'injection moulding' has the potential to offer optimal form, function and an aesthetic outcome in an efficient manner. CPD/Clinical Relevance: This article aims to describe an alternative technique to simplify the processes involved with restoration of worn lower anterior teeth.

The efficacy of Hybrid Hyrax-Mentoplate combination in early Class III treatment: a novel approach and pilot study

INTRODUCTION

The aim of the present study was to assess the skeletal, dental and soft tissue effects of a specific treatment protocol in consecutively treated patients who presented with a Class III malocclusion. Treatment involved the use of a Hybrid Hyrax (HH) in the maxilla, a Mentoplate in the mandible and the application of continuous intra-oral Class III elastics.

METHOD

The treated group was comprised of seven males and seven females (mean pretreatment age 10.4 ± 1.7 yr, range 7.8-12.9 yr). Treatment changes were analysed on lateral cephalograms taken 6-12 months prior to commencing treatment (T1) and at the finish of the orthopaedic phase (T2). Where a normality assumption was met, a parametric paired-sample t-test was used to assess the change differences at T1 and T2. For non-normal data, a non-parametric Wilcoxon sign rank test for related samples was used to assess T1 and T2 differences. The level of statistical significance was set at p < 0.05 (2-tailed).

RESULTS

The average sagittal changes showed an improved SNA angle of 2.1 ± 2° (p = 0.002), an ANB angle of 1.9 ± 1.8° (p = 0.002), a Wits improvement of 3.4 ± 2.7 mm (p < 0.001) and an overjet reduction of 2.0 ± 2.2 mm (p = 0.005). There were no statistically significant correlations found between the age at T1, age at treatment start and age at T2 and the changes identified in the cephalometric variables (T2-T1).

CONCLUSION

The HH-Mentoplate Class III treatment protocol induced a mean Wits improvement of 3.4 mm in the maxillary and mandibular sagittal base relationship at the functional occlusal level. This was primarily achieved by sagittal maxillary skeletal protraction with negligible effects on the mandible, facial vertical dimension and the incisor angulations. A controlled clinical study with larger sample sizes and longer follow-up times is needed.

[Orthodontic failures in Class II cases]

In Class II treatment, as with all malformations, therapeutic failure can impact some or all of our treatment aims, whether occlusal, functional or esthetic. Using clinical cases, we will first define the concept of failure and the limits of what is acceptable in these different areas. We will then attempt to determine the main causes underlying our failures in order to better avoid them. An analysis of the literature and of the clinical cases demonstrates that our failures are most often caused by a misevaluation of the amount and direction of residual growth, poor control of the vertical dimension, inadequate management of functional problems, an inadequate position of the maxillary and mandibular incisors. In addition to these major treatment errors, one also encounters insufficient patient cooperation, which needs to be assessed and maintained in order to limit the number of failures and treatment drop-outs.

Frequency and distribution of teeth treated by single- and multiple- visit root canal treatment in a Nigerian population by differently skilled operators

BACKGROUND

Single visit root canal treatment (RCT) is being advocated around the world. This study profiles RCT in a Nigerian population and compares pattern of single versus multiple visit RCT to tooth type and skill level of the doctors.

METHOD

A retrospective study was carried out on RCT performed in one year by fresh graduates and postgraduate dentists. Records retrieved included patients' sex and age, tooth type, location in the jaw and whether single- or multiple-visit RCT was done.

RESULTS

Records of 705 teeth were reviewed, 54.6% belonged to females. Age range was 18-87 years, mean of 31.76 (± 12.31) years. Majority (70.1%) belonged to 20-39 years' age group. Most teeth were located in the maxilla (60.8%) and in posterior regions (73.6%). The most frequently root filled tooth was the mandibular first molar (20.7%) followed by maxillary central incisor (18.4%) then maxillary premolar (12.8%). However, all molars accounted for 47.3%, premolars 26.3% and incisors 25.0%. Canines (1.45%) were least frequently root-filled. Incisors (54.8%) were the teeth most frequently treated in single-visit followed by premolars (28.8%). Most frequently treated by multiple-visit were molars (51.0%). All doctors performed multiple-visit RCT in an approximately equal proportion but a significant percentage of single-visit RCT was carried out by senior doctors (71.2%).

CONCLUSION

The most frequently root filled teeth were mandibular first molars. Teeth most likely to be treated by single-visit RCT were incisors. Appropriate operator skill and experience is important in the decision to perform single-visit RCT. Single-visit RCT is advocated in the developing environment.