Arrest of root formation in a permanent maxillary central incisor subsequent to trauma and pulp necrosis to the primary predecessor

This paper reports a case in which a previous traumatic injury at the age of 2 and pulp necrosis to a primary incisor resulted in a rare injury to the permanent successor tooth. The radiographic examination at the age of 9 showed the arrest of root formation of the permanent maxillary right central incisor, which did not erupt. Tooth 11 was extracted and a functional removable space maintainer was prepared. At the age of 17, the patient received an anterior fixed prosthesis for re-establishment of the esthetics, phonetics and deglutition.

Atypical extraction of maxillary central incisors

This case report describes a Class I crowded malocclusion with an ankylosed maxillary central incisor that was in infraocclusion and labially displaced. The patient had wide maxillary teeth, and the option of extracting the maxillary central incisors followed by space closure, with lateral incisors substituting for the central incisors, was chosen. (Am J Orthod Dentofacial Orthop 2010;138:510-7)

Influence of Post and Resin Cement on Stress Distribution of Maxillary Central Incisors Restored with Direct Resin Composite

The current study evaluated the influence of two endodontic post systems and the elastic modulus and film thickness of resin cement on stress distribution in a maxillary central incisor (MCI) restored with direct resin composite using finite element analysis (FEA). A three-dimensional model of an MCI with a coronary fracture and supporting structures was performed. A static chewing pressure of 2.16 N/mm(2) was applied to two areas on the palatal surface of the composite restoration. Zirconia ceramic (ZC) and glass fiber (GF) posts were considered. The stress distribution was analyzed in the post, dentin and cement layer when ZC and GF posts were fixed to the root canals using resin cements of different elastic moduli (7.0 and 18.6 GPa) and different layer thicknesses (70 and 200 mu m). The different post materials presented a significant influence on stress distribution with lesser stress concentration when using the GF post. The higher elastic modulus cement created higher stress levels within itself. The cement thicknesses did not present significant changes.

Replantation of an avulsed maxillary primary central incisor and management of dilaceration as a sequel on the permanent successor

This case report outlines the sequel and possible management of a permanent tooth traumatized through the predecessor, a maxillary right primary central incisor that was avulsed and replanted by a dentist 1 h after the trauma in a 3-year-old girl. Three years later, discoloration and fistula were present, so the primary tooth was extracted. The patient did not come to the scheduled follow-ups to perform a clinical and radiographic control of the succeeding permanent incisor, and only returned when she was 10 years old. At that moment, the impaction and dilaceration of the maxillary right permanent central incisor were observed through radiographic examination. The dilacerated permanent tooth was then surgically removed, and an esthetic fixed appliance was constructed with the crown of the extracted tooth. Positive psychological influence of the treatment on this patient was also observed.

Enamel Defects in Maxillary Central Incisors of Infants With Unilateral Cleft Lip

Objective: To evaluate the presence of enamel alterations in deciduous maxillary central incisors of infants with unilateral cleft lip and alveolar ridge, with or without cleft palate, and to compare the occurrence and location of these alterations between the central incisor adjacent to the cleft and the contralateral incisor. Design: Intraoral clinical examination was performed after tooth cleaning and drying by a single examiner with the aid of a dental mirror, dental probe, and artificial light, with the child positioned on a dental chair. The defects were recorded in a standardized manner according to the criteria of the Modified Developmental Defects of Enamel Index. Setting: Hospital for Rehabilitation of Craniofacial Anomalies (HRAC) at Bauru, Sao Paulo, Brazil. Patients: One hundred one infants were evaluated. All were white, of both genders, aged 12 to 36 months and had at least two thirds of the crowns of maxillary incisors erupted. Results: Demarcated opacity was the most common defect at both cleft and noncleft sides, followed by diffuse opacity. The occurrence of hypoplasia at the cleft side was 11.8%. Most defects affected less than one third of the crown. Conclusion: The occurrence of enamel defects in deciduous maxillary central incisors of patients with unilateral cleft lip was 42.6%, mainly affecting the cleft side as to both number and severity.

Stress distribution in the cervical region of an upper central incisor in a 3D finite element model

The aim of this study was to evaluate the stress distribution in the cervical region of a sound upper central incisor in two clinical situations, standard and maximum masticatory forces, by means of a 3D model with the highest possible level of fidelity to the anatomic dimensions. Two models with 331,887 linear tetrahedral elements that represent a sound upper central incisor with periodontal ligament, cortical and trabecular bones were loaded at 45º in relation to the tooth's long axis. All structures were considered to be homogeneous and isotropic, with the exception of the enamel (anisotropic). A standard masticatory force (100 N) was simulated on one of the models, while on the other one a maximum masticatory force was simulated (235.9 N). The software used were: PATRAN for pre- and post-processing and Nastran for processing. In the cementoenamel junction area, tensile forces reached 14.7 MPa in the 100 N model, and 40.2 MPa in the 235.9 N model, exceeding the enamel's tensile strength (16.7 MPa). The fact that the stress concentration in the amelodentinal junction exceeded the enamel's tensile strength under simulated conditions of maximum masticatory force suggests the possibility of the occurrence of non-carious cervical lesions such as abfractions.

Determination of pulp vitality in vivo with pulse oximetry

Aim To evaluate the use of pulse oximetry as a test for pulp vitality, by comparing in the same patient, the levels of oxygen saturation of the index finger and of the maxillary central incisor and canine teeth without clinically detectable pulp inflammation. Methodology Seventeen male and female patients aged between 26 and 38 years participated and a total of 32 maxillary central incisor and 32 canine teeth were analysed. Selection criteria required the teeth to have healthy crowns, or with restorations no more than 2 mm in diameter and no clinical and radiographical signs or symptoms of pulp or periapical inflammatory changes. The negative control group consisted of 10 root filled teeth. Measurements were first taken from the index finger of patients. Their teeth were then subjected to a thermal test with refrigerant gas and then to a vitality test with pulse oximetry. Data were analysed by Pearson`s and paired t-tests. Results There were no significant statistical correlations between blood oxygen levels in the index finger and in the teeth of the patient (P > 0.05). There was a statistically significant difference in the oxygen levels between the two tooth groups studied and the index finger (P <= 0.002). Mean oxygen values in the index finger of patients were 95% (SD = 1.6), oxygen values in the maxillary central incisor were 91.29% (SD = 2.61) and mean oxygen values in maxillary canine were 90.69% (SD = 2.71). Conclusion The method determined consistently the level of blood oxygen saturation of the pulp in maxillary central incisor and canine teeth and can therefore be used for pulp vitality testing. Further studies are required to assess the effectiveness and validity of pulse oximetry in determining pulp vitality in traumatized teeth.

Evaluation of the temperature of different refrigerant sprays used as a pulpal test

The temperature of different refrigerant sprays (Endo-Ice, Endo-Frost, Coolermatic and Sprayon Contact and Tuner Cleaner) used as pulpal tests were evaluated in vitro. A thermocouple placed inside the pulp chamber of a maxillary central incisor was used to register the temperature changes when the refrigerant sprays were applied with a cotton swab, for 10 s. Results indicate that Endo-Ice and Endo-Frost presented the lowest temperatures among the refrigerant sprays tested. Temperatures measured inside the pulp chamber, however, were statistically similar in all groups.

Expression of matrix metalloproteinases-2 and-9 and RECK during alveolar bone regeneration in rat

MMPs are endopeptidases that play a pivotal role in ECM turnover. RECK is a single membrane-anchored MMP-regulator. Here, we evaluated the temporal and spatial expression of MMP-2, MMP-9, and RECK during alveolar bone regeneration. The maxillary central incisor of Wistar rats was extracted and the animals were killed at 1, 3, 7, 10, 14, 21, 28, and 42 days post-operatively (n = 3/period). The hemimaxillae were collected, demineralized and embedded in paraffin. Immunohistochemical analysis was performed by the immunoperoxidase technique with polyclonal antibodies. On day 1, polymorphonuclear cells in the blood clot presented mild immunolabeling for MMPs. During bone remodeling, osteoblasts facing new bone showed positive staining for gelatinases and RECK in all experimental periods. MMPs were also found in the connective tissue and endothelial cells. Our results show for the first time that inactive and/or active forms of MMP-2, MMP-9 and RECK are differentially expressed by osteogenic and connective cells during several events of alveolar bone regeneration. This may be important for the replacement of the blood clot by connective tissue, and in the formation, maturation and remodeling of new bone.

Management of a permanent tooth after trauma to deciduous predecessor: an evaluation by cone-beam computed tomography

Impaction of permanent teeth represents a clinical challenge with regard to diagnosis, treatment plan, and prognosis. There is a close relationship between deciduous teeth and permanent teeth germ, and any injury in the deciduous dentition may influence the permanent teeth eruption. The extent of the damage caused to the permanent teeth germ depends on the patient age at the time of injury, type of trauma, severity, and direction of the impact. Conventional radiographic images are frequently used for diagnosis; however, recent developments in three-dimensional (3D) imaging systems have enabled dentistry to visualize structural changes effectively, with better contrast and more details, close to the reality. The cone-beam computed tomography (CBCT) has been used in the diagnosis and treatment plan of these impacted teeth. The purpose of the present case report is to describe a successful conservative management of a retained permanent maxillary lateral incisor with delayed root development after a trauma through the deciduous predecessor in a 9 year-old patient. After clinical and radiographic examination, a CBCT examination of the maxilla was requested to complement the diagnosis, providing an accurate 3D position of the retained tooth and its relationship to adjacent structures. The proposed treatment plan was the surgical exposure and orthodontic traction of the retained tooth. The lateral incisor spontaneously erupted after 6 months. Therefore, this case report suggests that permanent teeth with incomplete root formation have a great potential for spontaneous eruption because no tooth malposition or mechanical obstacles are observed.

Effects of accentuated and reversed curve of Spee on apical root resorption

Introduction: In this study, we evaluated the influence of intrusion mechanics with accentuated and reversed curve of Spee on root resorption of the maxillary and mandibular incisors. Methods: A sample of 60 patients with Class I and Class II Division 1 malocclusions having nonextraction treatment was divided into 2 groups with the following characteristics: group 1 comprised 30 deepbite patients, treated with accentuated and reversed curve of Spee intrusion mechanics, with an initial mean age of 12.8 +/- 1.23 years (range, 10.01-15.32 years), and group 2 comprised 30 patients with normal overbite treated without intrusion mechanics, with an initial mean age of 12.87 +/- 1.43 years ( range, 10.02-15.36 years). Pretreatment and posttreatment periapical radiographs were used to evaluate root resorption. The groups were compared by using the Mann-Whitney U test. Correlation between root resorption and tooth movement was investigated with the Spearman correlation coefficient. Results: The deepbite group treated with accentuated and reversed curve of Spee had statistically greater root resorption ( 1.87) than the normal overbite group ( 1.54), at P=.017. Changes in overbite and vertical displacements of the maxillary central incisor apices had significant correlations to root resorption ( r = 0.30, P =.019; r = 0.27, P =.037, respectively). Conclusions: Accentuating and reversing the curve of Spee in the archwires to correct deep overbite causes more root resorption than nonintrusive mechanics.

Holoprosencephaly and Holoprosencephaly-Like Phenotypes: Review of Facial and Molecular Findings in Patients From a Craniofacial Hospital in Brazil

Here we report on the clinical and genetic data for a large sample of Brazilian patients studied at the Hospital de Reabilitacao de Anomalas Craniofaciais-Universidade de Sao Paulo (HRAC-USP) who presented with either the classic holoprosencephaly or the holoprosencephaly-like (HPE-L) phenotype. The sample included patients without detected mutations in some HPE determinant genes such as SHH, GLI2, SIX3, TGIF, and PTCH, as well as the photographic documentation of the previously reported patients in our Center. The HPE-L phenotype has been also called of HPE ``minor forms"" or ""microforms,"" The variable phenotype, the challenge of genetic counseling, and the similarities to patients with isolated cleft lip/palate are discussed. (c) 2010 Wiley-Liss, Inc.

Class I malocclusion treatment: Influence of a missing mandibular incisor on anterior guidance

This case report describes the orthodontic treatment of a patient with a deep-overbite Angle Class I malocclusion, agenesis of a mandibular central incisor, and 2 supernumerary teeth, which caused impaction of the mandibular first premolars. The 15-year-old patient also had a convex profile, maxillary dentoalveolar protrusion, and deficiency of space for the correct alignment of teeth. Therefore, treatment consisted of fixed appliance therapy, cervical headgear, extraction of the supernumeraries and the mandibular and maxillary first premolars, and mesiodistal reduction of the maxillary incisors to solve the arch perimeter discrepancy as much as possible with interproximal stripping. This method of treatment significantly improved the patient`s facial and dental esthetics and provided a good functional occlusion, despite the absence of a mandibular incisor, which generally impairs achieving adequate incisal guidance. (Am J Orthod Dentofacial Orthop 2010;138:109-17)

Diagnosis and treatment of extraction sockets in preparation for implant placement: report of three cases

This article addresses diagnostic parameters that should be assessed in the treatment of extraction sockets with dental implant placement by presenting three case reports that emphasize the relevance of the amount of remaining bone walls. Diagnosis was based on the analysis of clinical and radiographic parameters (e.g.: bone defect morphology, remaining bone volume, presence of infections on the receptor site). Case 1 presents a 5-wall defect in the maxillary right central incisor region with severe root resorption, which was treated with immediate implant placement. Cases 2 and 3 present, respectively, two- and three-wall bone defects that did not have indication for immediate implants. These cases were first submitted to a guided bone regeneration (GBR) procedure with bone graft biomaterial and membrane barriers, and the implants were installed in a second surgical procedure. The analysis of the preoperative periodontal condition of the adjacent teeth and bone defect morphology is extremely important because these factors determine the choice between immediate implant or GBR treatment followed by implant installation in a subsequent intervention.

Agenesis of maxillary lateral incisors and associated dental anomalies

Introduction: The objectives of this study were to evaluate the prevalence of dental anomalies in patients with agenesis of maxillary lateral incisors and to compare the findings with the prevalence of these anomalies in the general population. Methods: A sample of 126 patients, aged 7 to 35 years, with agenesis of at least 1 maxillary lateral incisor was selected. Panoramic and periapical radiographs and dental casts were used to analyze other associated dental anomalies, including agenesis of other permanent teeth, ectopia of unerupted permanent teeth, microdontia of maxillary lateral incisors, and supernumerary teeth. The occurrence of these anomalies was compared with prevalence data previously reported for the general population. Statistical testing was performed with the chi-square test (P<0.05) and the odds ratio. Results: Patients with maxillary lateral incisor agenesis had a significantly increased prevalence rate of permanent tooth agenesis (18.2%), excluding the third molars. The occurrence of third-molar agenesis in a subgroup aged 14 years or older (n = 76) was 35.5%. The frequencies of maxillary second premolar agenesis (10.3%), mandibular second premolar agenesis (7.9%), microdontia of maxillary lateral incisors (38.8%), and distoangulation of mandibular second premolars (3.9%) were significantly increased in our sample compared with the general population. In a subgroup of patients aged 10 years or older (n = 115), the prevalence of palatally displaced canines was elevated (5.2%). The prevalences of mesioangulation of mandibular second molars and supernumerary teeth were not higher in the sample. Conclusions: Permanent tooth agenesis, maxillary lateral incisor microdontia, palatally displaced canines, and distoangulation of mandibular second premolars are frequently associated with maxillary lateral incisor agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies. (Am J Orthod Dentofacial Orthop 2010;137:732.e1-732.e6)