Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “INCISOR”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed1985

The extent of the necrotic lesion in the apical end of the rat incisor pulp seen after Adriamycin administration.

The extent of the necrotic lesion produced by adriamycin in the apical end of the rat incisor was investigated. Male Sprague Dawley rats were injected intravenously with adriamycin (5 mg/kg body weight), and sacrificed by perfusion with a 2.5% buffered glutaraldehyde solution 1 d after injection. Controls injected with only physiological saline were treated in the same manner. One micron thick plastic serial sections were prepared from the apical end of the incisor, and a schematic representation of the entire lesion as seen in longitudinal section was reproduced from each fiftieth section. Cell destruction was observed for 2.2 mm within the pulp. The lesion extended further incisally in the lingual portion than in the labial portion. The bulbous portion of the odontogenic organ was not affected. This study indicates that the cytotoxicity of adriamycin appears to affect mainly proliferating immature precursor cells within the mesenchyma, and the preodontoblasts.

Animals↗
PubMed2001

Fracture strength and survival rate of endodontically treated maxillary incisors with approximal cavities after restoration with different post and core systems: an in-vitro study.

OBJECTIVES: This study compared the fracture strength and survival rate of endodontically treated crowned maxillary incisors with approximal class III cavities and different core build-ups. METHODS: Sixty-four caries free human maxillary central incisors were selected for standardized size and quality, endodontically treated and prepared with approximal cavities 3mm in diameter. Group 1 was restored with titanium posts, group 2 received zirconia posts, in group 3 the root canal was partially filled with a hybrid composite. In the control group, only the access opening was restored. All teeth were prepared for and restored with full cast metal alloy crowns and subsequently exposed to 1.2 million cycles in a computer-controlled chewing simulator with simultaneous thermocycling. In addition, the samples were loaded until fracture in a static testing device. RESULTS: One specimen with composite reinforced root canal did not survive the dynamic load test. The following median fracture strengths in Newtons for the different groups were: titanium post 1038, zirconia 1057, composite resin 750, control (no post) 1171. The fracture load in group 3 (composite resin) was significantly lower (P<0.05) than in the other groups. CONCLUSIONS: The reconstruction of endodontically treated single rooted teeth with approximal cavities can be successfully performed by closure of the endodontic and additional cavities with composite. Cementation of endodontic posts offers comparable but no advantageous fracture resistance. Enlargement of the root canal space after completion of endodontic treatment should be avoided and cannot be compensated for by injection of composite resin. Less catastrophic failures were observed without post reconstruction.

Chi-Square Distribution↗
PubMed1983

The effect of splinting upon periodontal and pulpal healing after autotransplantation of mature and immature permanent incisors in monkeys.

The effect of splinting upon periodontal and pulpal healing after autotransplantation of teeth with complete and incomplete root formation was studied in 16 green Vervet monkeys (Cercopithecus aethiops). 2 maxillary incisors were extracted in each monkey and autotransplanted to the contralateral socket. One of these teeth was stabilized with an acrylic splint for either 2 or 6 weeks, while the other incisor was non-splinted. The animals were sacrificed 8 weeks after autotransplantation and the autotransplanted teeth were examined histologically. The following histologic parameters were registered for each tooth: surface resorption, inflammatory resorption, replacement resorption (ankylosis), downgrowth of pocket epithelium, periapical inflammatory changes and extent of pulp necrosis. The histometric analysis demonstrated that splinting increased the extent of pulp necrosis and inflammatory root resorption compared to non-splinting. Furthermore, the extent of normal periodontium was decreased among the splinted teeth, when compared to the non-splinted teeth. It is concluded that splinting not only failed to improve healing but apparently exerted a harmful effect upon periodontal and pulpal healing after autotransplantation.

Animals↗
PubMed1997

Immunohistochemical localization of calbindin D28k in the periodontal Ruffini endings of rat incisors.

It was examined whether calbindin D28k (CB) might be located in the rat incisor periodontal Ruffini ending, an essential mechanoreceptor in periodontal ligament, by light- and electron-microscopic immunohistochemistry. Some thick nerve fibers showing CB-like immunoreactivity (LI) entered the lingual half of the periodontal ligament of the incisor and showed the dendritic terminal arborization. Electron-dense immunoreaction products indicating CB-LI were distributed diffusely in axoplasm of the axon terminals, no mitochondria, however, were not labeled. Neither cell bodies nor cytoplasmic extensions of the terminal Schwann cells exhibited CB-LI. CB was presumed to be involved in the maintenance of Ca2+ homeostasis in the mechano-electric transduction in mechanoreceptors in the periodontal ligament.

Animals↗
PubMed1998

Immunocytochemical detection of S-100beta in the periodontal Ruffini endings in the rat incisor.

Subcellular localization of S-100 protein, a kind of calcium binding proteins, was examined immunohistochemically in the Ruffini ending, a primary mechanoreceptor, in the periodontal ligament of the rat incisor. The periodontal ligament of the rat incisor was found to contain many S-100beta-immunoreactive (-IR) structures but no S-100alpha-IR elements. The S-100beta-IR structures ramified extensively to form Ruffini endings and were frequently associated with round cells, the terminal Schwann cells, which also showed S-100beta-like immunoreactivity. In many periodontal Ruffini endings, S-100beta-IR products were recognized in the cytoplasm of Schwann cells, but not in the axoplasm. However, some axon terminals which had fewer or shorter axonal fingers, were filled with S-100beta-IR products. The present findings indicated the existence of S-100beta, not S-100alpha, in axon terminals of the periodontal mechanoreceptive endings which were identified as type II Ruffini endings.

Animals↗
PubMed2000

Extraction of maxillary first bicuspids and mandibular lateral incisors, combined with orthognathic surgery to correct a severe class II skeletal malocclusion.

This is a case report of a 21-year-old female with a Class II Division 1 malocclusion. The maxillary arch was constricted with an associated anterior open bite. The lower facial height was excessive, and the mandibular plane angle was high. The treatment options were limited due to a previously extracted mandibular right lateral incisor. The patient was successfully treated by a surgical rapid palatal expansion procedure, extraction of the mandibular left lateral incisor, extraction of the maxillary first premolars at the time of a 3-piece Lefort 1 maxillary osteotomy procedure, and a bilateral sagittal split osteotomy advancement procedure.

Adult↗
PubMed2000

The use of the lingual arch in the mixed dentition to resolve incisor crowding.

In the mixed dentition, arch length preservation, maintaining the leeway space, can often provide adequate space to resolve lower incisor crowding. Yet the frequency of this occurrence is not known. To obtain this information, lingual arches were placed in the mandibular arches of 107 consecutive mixed dentition patients with incisor crowding to preserve arch length and make the leeway space available to resolve the crowding. Arch length decreased only 0.44 mm whereas the intercanine, interpremolar, and intermolar dimensions increased between 0.72 and 2.27 mm. There was adequate space to resolve the crowding in 65 (60%) of the 107 patients. If perfect arch length preservation had occurred, there would have been adequate space to resolve the crowding in 73 (68%) of the 107 patients. The correlation between leeway space and tooth size-arch size discrepancy was only 0.44.

Bicuspid↗
PubMed2004

Nonextraction treatment of a Class II malocclusion and impacted maxillary central incisor.

The multidisciplinary treatment of a patient with a Class II malocclusion and an impacted maxillary central incisor is presented. Nonextraction correction of the distoclusion was achieved through mandibular growth and protraction of the mandibular first molars. Closed-eruption surgical exposure of the incisor, combined with soft-tissue revision posteruption, resulted in significantly improved facial esthetics.

Child↗
PubMed1994

Variation in maxillary and mandibular molar and incisor vertical dimension in 12-year-old subjects with excess, normal, and short lower anterior face height.

Maxillary and mandibular molar and incisor vertical dimensions were evaluated in subjects who had excessive, normal, and short lower anterior face height in relation to upper face height. Sexual dimorphism was also investigated. The dentoalveolar heights were compared between Class I and Class II, dental and skeletal malocclusions. The sample was drawn from the Burlington Growth Centre sample and consisted of 188 male and 156 female subjects at age 12 years, for whom lateral head films were available. This sample was classified into excessive, normal, and short lower anterior face height, using the ratio upper anterior face height/lower anterior face height (UAFH/LAFH). The results showed that the dentoalveolar heights are significantly different between faces with excessive, normal, and short lower anterior face heights, except for the lower posterior dental height, which showed no difference between short and normal lower anterior face height subjects. All dentoalveolar heights are larger for male subjects except for the upper posterior dental height. Dentoalveolar heights are similar between Class I and Class II dental and skeletal malocclusions. The upper teeth present a higher correlation to the UAFH/LAFH ratio than the lower teeth. Stepwise regression analysis shows that 22% of the variation in the ratio is explained by the maxillary and mandibular molars and 41% is explained by the maxillary and mandibular incisors.

Cephalometry↗
PubMed1996

Prevalence of tooth agenesis and peg-shaped maxillary lateral incisor associated with palatally displaced canine (PDC) anomaly.

Fifty-eight nonsyndromic North American white orthodontic patients with palatal displacement of one or both maxillary canine teeth were studied for associated tooth agenesis and peg-shaped maxillary lateral incisors. Agenesis of permanent teeth was identified by x-ray film analysis. Conical crown-size reduction (peg-shape anomaly) of the maxillary lateral incisor (l2) was determined by direct observation. Increases in absence of third molars and second premolars associated with the palatally displaced canine (PDC) anomaly were statistically very highly significant compared with normative data for tooth-agenesis prevalence. In contrast, the prevalence of l2 agenesis in the PDC sample showed no difference statistically compared with reference values. Reasons for this posterior site-specific suppression of tooth formation are not clear. The l2 peg-shape anomaly exceeded a 10-fold elevation in expression in the PDC sample, a very highly significant increase from normal prevalence. The findings are consistent with a hypothesis that the anomalies of tooth agenesis, tooth-size reduction, and PDC are biologic covariables in a complex of genetically related dental disturbances.

Adolescent↗
PubMed1998

Cortical bone remodeling/tooth movement ratio during maxillary incisor retraction with tip versus torque movements.

The validity of the postulate "bone traces tooth movement" was examined on 40 Angle Cl II cases. It was hypothesized that a 1:1 cortical bone remodeling/tooth movement ratio is preserved during maxillary incisor retraction. The sample was divided into retraction with tip (13 patients), retraction with torque (18 patients), and control (9 patients) groups. Two time point cephalograms were analyzed with two superimposition techniques, SN at S and a newly developed static tooth analysis, with the maxillary left central incisor serving as a reference object. In both retraction with tip and retraction with torque groups, the postulate bone traces tooth movement was not preserved and a bone remodeling/tooth movement ratio of 1:2 and 1:2.35 was obtained, respectively. In retraction with tip movement, the apical one third of the root tipped labially reducing the superior area of labial maxillaris by 19%. However, due to the compensating effect of the retraction movement, no apex approximation to the labial cortical plate occurred (eliminating the hazard of root resorption, dehiscence, or fenestration). In retraction with torque movement, the increase in both superior (28%) and inferior (65%) labial maxillaris areas was indicative for the hazard of root approximation to the palatal cortical bone. It is recommended to use the 1:2 bone remodeling/tooth movement ratio as a guideline to determine the biocompatible range of orthodontic tooth movements. Furthermore, a judicious interplay between the two modes of retraction can prevent major biologic impairments associated with the ratio and can extend the orthodontic range of treatment.

Bone Remodeling↗
PubMed2003

Variability of the carina-incisor distance as assessed by endoscopic ultrasound.

AIM: The purpose of this study is to demonstrate variability of the carina-incisor distance (CID), and define morphological factors associated with this. MATERIALS AND METHODS: The carina is clearly visualised on endoscopic ultrasound (EUS), and the CID was measured in 50 patients (29 men, 21 women) undergoing EUS for various indications (30 oesophageal cancer, 20 other) with Olympus UM-20 (used in 24 cases) or MH-908 (used in 26 cases) radial echoendoscopes. Patient height and weight were compared with CID using Pearson's correlation coefficient. RESULTS: Mean CID was 25.7 cm, with a range of 20.5-29 cm (SD +/- 1.99). There was no difference between the measured CID in the oesophageal cancer and non-oesophageal cancer groups, or between the two types of echoendoscope. There was highly significant positive correlation between patient height and CID (r = +0.750; P < or = 0.01). CONCLUSION: This study demonstrates considerable variability of the CID from 20.5-29 cm. It is no longer appropriate to assume a 'normal' carinal level of 25 cm in all patients. In this study, if the carina was accepted to lie at 25 cm, this would have led to radiation therapy missing macroscopic disease, a so called 'geographic miss', in nine of the 50 (18%) patients. We now routinely record the level of the CID, the upper and lower extent of the primary tumour and lymph-node metastases with reference to the incisor teeth. This is simple to perform and may assist in radiotherapy planning by reducing the geographic miss rate.

Adult↗
PubMed1999

Talon cusp affecting permanent maxillary lateral incisors in 2 family members.

The term talon cusp refers to a relatively rare dental anomaly in which an accessory cusplike structure projects from the cingulum area or cement-enamel junction. The condition can occur in either maxillary or mandibular anterior teeth in both the primary and permanent dentitions. This article reports 2 cases of talon cusp affecting consanguineous first cousins: a case of bilateral talon cusps on the permanent maxillary lateral incisors of a 16-year-old girl, and a case of talon cusp on the maxillary permanent lateral incisor of an 11-year-old boy. The talon cusps caused clinical problems that were related to caries or occlusal interferences. The presence of the dental anomaly in 2 members of the same family suggests that genetic inheritance may be a causative (related) factor. Examination of relatives could facilitate early diagnosis of the talon cusp and aid in preventing carious and occlusal problems.

Adolescent↗
PubMed2003

BEN/DM-GRASP/SC1 expression during mouse facial development: differential expression and regulation in molars and incisors.

The cell adhesion molecule BEN/DM-GRASP/SC1 is expressed in a variety of tissues during embryogenesis. Here, we studied the expression pattern of BEN/DM-GRASP/SC1 in different organs involved in facial mouse development, especially in the developing teeth. BEN/DM-GRASP/SC1 was expressed in nose, whisker, gland, and tongue epithelia, as well as in myogenic mesenchyme. In molars, BEN/DM-GRASP/SC1 was firstly expressed in the condensed mesenchyme and thereafter expression was confined to mesenchymal cells of the dental follicle. In contrast, in incisors, transient BEN/DM-GRASP/SC1 expression was restricted to epithelium. In tissue recombination experiments, BEN/DM-GRASP/SC1 expression in mesenchyme was activated by molar, but not incisor epithelium.

Activated-Leukocyte Cell Adhesion Molecule↗
PubMed2005

[Extraction of the incisors in a dwarf rabbit].

The dwarf rabbit often suffers from dental malocclusion, particularly on the level of the incisors. A too short maxillary jawbone in these brachycephalic animals is the cause. The treatment of first intention consists in reducing the overgrowth using a diamond bur, but like the problem repeats quickly, an alternative consists in extracting the 6 incisors.

Animals↗
PubMed2001

Different treatment outcomes of two intruded permanent incisors--a case report.

Intrusive luxation involves the displacement of the tooth apically into the alveolar socket. This type of injury represents a very complex wound, involving disruption of the marginal gingival seal, alveolar bone, periodontal ligament fibers, cementum and the neuro-vascular supply to the pulp, which results in severely compromised healing and possible complications. The case presented is a report of a 60-year-old lady who fell and intruded her two maxillary central incisors. The healing outcomes of the two central incisors were markedly different from each other even though they sustained similar injuries.

Alveolar Process↗
PubMed2002

Rate of infraposition of reimplanted ankylosed incisors related to age and growth in children and adolescents.

In growing individuals, infraposition of a reimplanted, ankylosed tooth may disrupt normal alveolar development and compromise prosthetic treatment. The aims of this study were to analyze the rate of infraposition of ankylosed incisors in growing subjects and to provide guidelines for the timing of extraction. The subjects comprised 30 boys and 12 girls, selected consecutively from patients on annual post-trauma follow-up, and observed for periods ranging from 1 to 10 years. Only patients with one replanted ankylosed maxillary central incisor were included, the homologous teeth with healthy periodontal ligaments serving as controls. Growth intensity was evaluated from analyses of annual body height measurements. The following four periods were established: before the growth spurt, from initial to maximal growth spurt, from maximal growth spurt to the end and after the growth spurt. In 11 patients, cephalograms were taken at diagnosis and at extraction. Progression of infraposition varied individually. Diagnosis before the age of 10 or before the growth spurt was associated with very high risk of severe infraposition. In these cases the ankylosed tooth should be removed within 2-3 years. If ankylosis develops during the growth spurt, the tooth should be monitored regularly, but no intervention is indicated provided the adjacent teeth do not tilt and infraposition is minor or stable. Annual body height measurements, indicating the intensity of skeletal growth, are an aid to assessment. Cephalometric radiographs are important for evaluating the direction of growth of the jaws since there is a difference between horizontal and vertical growers.

Adolescent↗
PubMed2003

Treatment of a non-vital immature incisor with mineral trioxide aggregate (MTA).

- A case of severe crown fracture and luxation in the upper permanent incisors of a 9-year-old boy is reported. The treatment of one of the injured teeth included apexification with calcium hydroxide and endodontic treatment with gutta-percha obturation. The other incisor was also treated with calcium hydroxide, but as there was no apical stop after 3 years of treatment, it was decided to use a new root-end filling material: mineral trioxide aggregate (MTA). At follow-up 12 months later, the tooth was asymptomatic and radiographically showed the initial repair of the radiolucent apical lesion.

Aluminum Compounds↗