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 433 records · Page 24Linked to original sources
PubMed1990

The association between palatal grooves in upper incisors and periodontal complications.

Palatal groove is a rare morphological defect of upper incisors, frequently associated with localized destruction of periodontal tissue with endodontic complications. In this study, a sample of 1,081 male, young adult subjects, aged 20 to 22, palatal grooving was recorded in 11 (1.01%) subjects, affecting 15 incisors. Among 634 adult subjects, aged 35 to 50, with periodontal disease, palatal groove was found in 5 (0.79%) incisors. Second incisors were more frequently (75%) associated with this anomaly. In the young adults, the mean probing pocket depth in the groove region and around other teeth of the intercanine area was 3.8 mm and 1.2 mm, respectively. In the group of periodontal patients, the mean probing pocket depth was significantly greater at the site of palatal groove (8.8 mm vs. 4.0 mm).

Adult↗
PubMed1998

Pain threshold values during periodontal probing: assessment of maxillary incisor and molar sites.

Probing pain threshold (PPT) assessments were conducted in the facial and oral sulci of maxillary central incisors and first molars of 10 periodontally healthy adults. All subjects were systemically healthy, free of pain, and reported no current medication usage. A computer-linked electronic probe, modified to deliver steadily increasing forces up to 200 grams, was used to collect the data. The system contained a subject operated "off-switch" which, upon activation, signaled the computer to record the subject's PPT. Assessments of each subject's PPTs were conducted on 3 separate occasions at 7-day intervals. Results indicated that the facial sulci of the incisors were the most pain sensitive. They displayed a mean PPT of 50.9 +/- 26.6 grams. The oral sulci of the incisors exhibited a mean PPT of 76.5 +/- 45.2 grams. Facial and oral sulci of the molars evidenced mean PPT values of 102.6 +/- 52.1 grams and 113.5 +/- 51.3 grams, respectively. These data suggest that sulci associated with incisor teeth are nearly twice as pain sensitive as sulci associated with molar teeth. In addition, facial sulci are significantly more pain sensitive than oral sulci. Data did not indicate a visit effect nor a side-of-mouth effect on PPT values.

Adult↗
PubMed1989

[Roentgenological study of the form of pulp cavities on upper central incisors].

The purpose of this study is to estimate the form of pulp cavities of upper central incisors using roentgenograms. Materials were fifty extracted upper central incisors. First, roentgenograms of these materials were taken from labio-lingual and mesio-distal directions. Then ten dentists read and traced the form of pulp cavities as shown by the roentgenograms, after which the percentage of readability was determined. Furthermore, the incisors were then cut in order to trace the actual form of pulp cavities and these tracings were compared with those made by the dentists as based on the roentgenograms. It was shown by this study that the tracings of pulp chamber at the dental cervix based on the roentgenograms taken from the labio-lingual direction and the tracings at the horn of pulp chamber based on the roentgenograms taken from the mesio-distal direction closely approximated the tracings of the cut materials. It was also found that readability of these points was 100% for all ten dentists. Based on these results, the two above mentioned points were designated as the datum points to be used when estimating the form of pulp cavities. Furthermore, the form of pulp cavities of the cut teeth was considered in order to determine the angle of the mesial and distal projection of the horn of pulp chamber against the datum plane of the dental cervix. In the above manner, a possible method of estimating the form of pulp cavities of upper central incisors using two roentgenograms was investigated.

Dental Pulp Cavity↗
PubMed1995

Y-shaped lower bilateral incisors. A previously undescribed oral malformation.

A case of Y-shaped lower bilateral central incisors found in an 18-year-old Japanese man is reported. Each of the central incisors had an abnormally high cusp located at the labial surface. The cause of this malformation of the lower central incisors is obscure, but we suspect that it was due to hyperplasia of the labial surface of the central lobe of the incisor during tooth development.

Adolescent↗
PubMed2001

A comparison of the supra-alveolar pulp size of impeded and unimpeded mandibular rat incisors using micro-computed tomography.

The pulp space is almost totally obliterated in the incisal end of a mandibular rat incisor. Repeated shortening of the incisor has been shown to increase the pulp space below the alveolar bone level; however, little is known about that above the alveolar bone level. This study investigated the changes in the pulp space superior to the bone level after rendering the incisor unimpeded for a period of three weeks. A desktop micro-computed tomography scanning unit, which is non-invasive, non-destructive, accurate, less technique sensitive and less time consuming than conventional methods, was used to calculate the volume of the pulp space. The results showed that the pulp size increased 140% at a level 3 mm below the alveolar bone margin and more than 700% at a level 2.5 mm above the alveolar bone. Moreover, the bone level of the unimpeded incisor was found to move incisally 0.4-0.5 mm; while deposition of dentine on the mesial and distal aspects of the pulp space were affected differently to that on the buccal and lingual sides.

Animals↗
PubMed1982

The depth of the lingual fossa in permanent maxillary incisors of East Greenland Eskimos. II. Side asymmetry, sex differences, comparison of centrals and laterals and anthropologic aspects.

Maxillary incisor lingual fossa depth was measured on casts of East Greenland Eskimo dentitions. No directional side asymmetry was found. The present study is the only which shows mean lingual fossa depth to be significantly deeper in the female than in the male. Larger incisor strength in the females is functional as the females are known to use their incisors as tools. The present investigation shows that on the question of sex differences conclusions should be drawn for the examined population only, and that generalization to other populations should be avoided. Mean lingual fossa depths were significantly different for centrals and laterals, but the laterals demonstrate special lack of reduction in this population. Lack of reduction of incisors together with frequent agenesis of third molars demonstrate that the posterior dentition may reduce independently of the anterior dentition. Mean lingual fossa depth, and relative fossa depth, in East Greenland Eskimos clearly show Mongoloid values.

Anthropology, Physical↗
PubMed1998

SEM study of the development of rat incisor enamel hypoplasia under hypocalcemia induced by thyro-parathyroidectomy.

Several clinical studies have reported the presence of enamel hypoplasia in congenital hypoparathyroidism or hypocalcemia. In previous studies we showed that thyroparathyroidectomy (TPTX) induced perturbations of the ameloblast morphology and secretion, of the rod pattern and of the enamel surface at late secretory stage and beginning of maturation, and limited hypoplasia in the erupted enamel of rat incisor. The aim of the present study was to evaluate by SEM, the extent and evolution of the enamel alterations of thyro-parathyroidectomized rats during the maturation stage. Wistar rats were thyro-parathyroidectomized and sacrificed 57 days later. The incisors were dissected out and processed for SEM. The surface of the incisor was observed from the end of secretion/beginning of maturation to its incisal erupted end. Transverse sections were prepared to study the structural defects and the prism pattern at different stages. The results showed that the surface of the TPTX incisors presented large hypoplastic defects at the end of secretion/beginning of maturation and only small defects in the erupted part. Transverse sections showed that, at the transition from secretion to maturation, the enamel defects extended to the mid-thickness of the tissue. At the incisal end the defects were limited to the outer enamel. As it is difficult to understand how the large apical defects could recover to appear as small hypoplasia at the incisal end, these results raise new questions concerning: (1) the effect of a long term calcium deficiency upon the cellular activity of the ameloblasts, and (2) the capacity of the enamel organ to compensate structural abnormalities.

Animals↗
PubMed2005

[Socket healing after rat mandibular incisor extraction].

Prosthodontic treatment is difficult if the alveolar ridge is low or thin. To develop a method for alveolar ridge preservation after tooth extraction, we need an experimental model of a small animal, in which we can analyze the socket healing easily and quantitatively. The purpose of the present study was to establish such an experimental model. Ten weeks old male rats of Wistar strain were used. The edge of the right mandibular incisor was cut every three days three times and the incisor was extracted at three days after the final cut. The animals were sacrificed 0, 1, 2, 4, 8, 12 weeks after the extraction and the mandibles were dissected out. The length of the alveolar bone was measured on soft X-ray photographs and bone mineral content was measured with a dual energy X-ray absorptiometer (DEXA). Then, transverse sections of the alveolar bone were prepared. Periodic three-times cutting of the edge of the mandibular incisor made the extraction easy. Quantitative analyses of new bone formation in the socket and the resorption of the alveolar bone were possible with soft X-ray photography and DEXA. The histological findings corresponded well with the data from the soft X-ray photos and DEXA measurements. The present results demonstrated the possibility of simple and quantitative analyses of socket healing after the extraction of rat mandibular incisors. This experimental model would be useful for developing a method to prevent atrophy of the alveolar ridge after tooth extraction.

Animals↗
PubMed1976

Electrolyte concentration in the hypertrophic salivary glands of incisor-amputated rats.

The effect of periodic amputations of the lower incisors of the rat on the electrolyte concentration in the major salivary glands was studied. The incisor amputations caused a hypertrophy of the parotid, submandibular and sublingual glands. The resulting increased weight of the salivary glands was due to a higher dry mass. In general, the electrolyte concentration showed higher values in the salivary gland tissues of the incisor-amputated animals. Considering the parotid, submandibular and sublingual glands respectively, the Na+ concentration was increased by 47%, 50% and 14%; and Mg2+ concentration by 377%, 126+ and 376%. Inorganic phosphorus increased 45% in the parotid, 25% in the subnamdibular and was unchanged in the sublingual gland. K+ concentration increased in the submandibular (12%) and sublingual (100%) glands but decreased in the parotid (24%). The Na+/k+ ratio was higher in the parotid (82%) and submandibular (37%) glands and lower in the sublingual gland (84%). The electrolyte concen-ration changes are discussed in relation to the mechanism and type of stimulation promoted by the incisor-amputations on the major salivary glands of the rat.

Amputation, Surgical↗
PubMedDate not supplied

The fusion of three primary incisors: report of case.

The occurrence of a fusion of three primary incisors is rare. A two-year-old Japanese girl was brought to the pediatric dental outpatient clinic, Tokyo Dental College, to receive a caries-prevention treatment. The fused tooth consisted of the maxillary primary central incisors and right maxillary lateral incisor. Primary left lateral incisor erupted normally and the other primary teeth were erupted. The radicular pulp chambers were fused into one for three fourths of the length from the apex, and only one root. The hair and skin of the patient appeared normal and no systemic abnormality or congenital disease was noted in the medical history of the patient and her family. The occurrence of a three-tooth fusion, and no supernumerary tooth was confirmed.

Child, Preschool↗
PubMed2001

Congenitally missing maxillary lateral incisors and orthodontic treatment considerations for the single-tooth implant.

Implant restorations have become a primary treatment option for the replacement of congenitally missing lateral incisors. The central incisor and canine often erupt in less than optimal positions adjacent to the edentulous lateral incisor space, and therefore preprosthetic orthodontic treatment is frequently required. Derotation of the central incisor and canine, space closure and correction of root proximities may be required to create appropriate space in which to place the implant and achieve an esthetic restoration. This paper discusses aspects of preprosthetic orthodontic diagnosis and treatment that need to be considered with implant restorations.

Anodontia↗
PubMedDate not supplied

Fracture behavior of human mandibular incisors following endodontic treatment and porcelain veneer restoration.

PURPOSE: Because of existing controversy, the present study investigated the individual and combined effects of endodontic treatment and porcelain veneer restoration on the fracture behavior of human mandibular incisors. MATERIALS AND METHODS: Forty extracted intact human mandibular incisors were assigned to four groups of ten with a similar range of labiolingual widths at the cementoenamel junctions. Group A consisted of intact teeth; group B consisted of endodontically treated teeth; group C teeth were restored with labial porcelain veneers; and those of group D were endodontically treated and had labial porcelain veneers. All teeth were subjected to a slow continuous loading test at 30 degrees to the long axis of the teeth and 1 mm below the incisal edge on the labial side. RESULTS: Fracture forces were 415 +/- 220 N, 370 +/- 89 N, 420 +/- 128 N, and 448 +/- 156 N for groups A, B, C, and D, respectively. Root fracture was the most common mode of failure. There were no statistically significant differences between the groups in terms of fracture forces and modes of failure. CONCLUSION: Human mandibular incisors with endodontic treatment and/or porcelain veneer restorations were able to withstand the same magnitude of oblique loading as intact teeth. Endodontic treatment and/or porcelain veneer restoration did not affect the mode of failure of mandibular incisors.

Acid Etching, Dental↗
PubMedDate not supplied

Treatment of cariously involved fused maxillary primary lateral and central incisors.

A 3-and-a-half-year-old male child presented with fused cariously involved right maxillary primary central and lateral incisors as well as a previously traumatized non-vital left primary central incisor with a draining fistula. The child also had other restorative needs and the decision taken was to address all needs under a G.A. With respect to the fused incisors, these were split and root canals treatment was performed for all three incisors which were then restored with stainless steel crowns with esthetic facings.

Child, Preschool↗
PubMed2000

A biometric guide to prosthetic tooth positioning investigated in subjects with Class II division 2 incisor relationships.

A biometric guide for positioning of the maxillary central incisors in complete dentures is the incisor-incisive papilla distance. This distance was compared in dentate subject with either Class I or Class II/2 incisor relations. Maxillary casts were orientated parallel to the occlusal plane on an xy table, connected to a movable vertical arm. The distance from the posterior edge of the papilla to the labial incisor surface was measured. Results showed a mean difference of 2 mm between the groups, significant at the P < or = 0.001 level, however this distance would not appear to invalidate the conventional biometric guideline of 10 mm.

Adult↗
PubMed2001

Orthodontic-restorative treatment of chipped or worn incisors.

PURPOSE: To evaluate the shear bond strength of esthetic adhesive restorations for worn or fractured incisal edges. MATERIALS AND METHODS: On 30 human extracted incisors the edge was reduced and a bevel was prepared in the thickness of enamel. Then, the incisal edges were restored, using a different adhesive system in each of the three groups to which the sample teeth had been randomly assigned. Group A: Scotchbond Multi-Purpose Plus, in combination with phosphoric acid, and Z100 as a restorative material. Group B: Scotchbond 1 after etching with phosphoric acid, plus Z100. Group C: F2000, a compomer, in combination with its Primer/Adhesive. The differences in the bond strength values among the three groups were tested for statistical significance. Also, the resistance to load of the restored teeth was compared with that of 10 intact incisors (Group D) (controls). A statistical analysis was performed to test the significance of the differences. RESULTS: No statistically significant difference in shear bond strength was found between Scotchbond Multi-Purpose Plus (17.6 MPa) and Scotchbond 1 (14.8 MPa), whereas F2000 gave significantly lower bond strength values (10.1 MPa). As compared with intact incisors, the teeth restored with either Scotchbond Multi-Purpose Plus or Scotchbond 1 did not perform significantly differently under load. On the other hand, the incisors restored with F2000 gave, as compared with the controls, a resistance to loads significantly lower and of a questionable reliability from a clinical standpoint. SEM observations performed on some of the samples revealed that when phosphoric acid was used to condition the substrate, a deep and uniform demineralization of the enamel was effected, and a mechanically retentive interlocking was created at the interface between resin and enamel. The Adhesive/Primer of F2000 was unable to produce an equally retentive morphology.

Acid Etching, Dental↗
PubMedDate not supplied

The diagnostic value of lateral extraoral radiography for intruded maxillary primary incisors.

PURPOSE: The purpose of the study was to assess the contribution of a lateral extraoral radiograph for diagnosing the relation between the root of intruded maxillary primary incisors and their permanent successors. METHODS: Three pediatric dentists examined intruded primary teeth 0-7 days after injury. The relations between the primary and permanent teeth were assessed in three separate steps: 1) evaluation of clinical signs only; 2) evaluation of a periapical radiograph (no lateral radiograph); 3) evaluation of a lateral extraoral radiograph. The clinical and radiographic signs used to assess the relations were recorded. The lateral extraoral radiograph was regarded as contributory to diagnosis if the assessment after the third step differed significantly from that made after the first and second steps. Ninety-three evaluations of 53 intruded teeth in 37 children were available for analysis. RESULTS: The lateral extraoral radiograph was found valuable for assessment of the primary incisor's root alignment in only 5% (5/93) of the evaluations in which neither the clinical examination nor the periapical radiograph were contributory. Four of these five cases were in children less than 20 months old. In all other cases, the lateral radiograph was not contributory for two main reasons: It could not be evaluated due to overlap of multiple intruded teeth and/or when the teeth intruded were lateral incisors, and when the clinical and periapical radiographs were sufficient for diagnosis. CONCLUSIONS: Lateral extraoral radiographs should not be used routinely in cases of intrusion of primary incisors. The operator should base his or her diagnosis on clinical findings and examination of a periapical radiograph. The lateral extraoral radiograph should be taken only when its expected contribution to diagnosis can be confirmed, as in cases of children younger than 20 months.

Child, Preschool↗
PubMed2003

Comparative morphology of incisor enamel and dentin in humans and fat dormice (Glis glis).

The structure of teeth in all living beings is genetically predetermined, although it can change under external physiological and pathological factors. The author's hypothesis was to indicate evolutional shifts resulting from genetic, functional and other differences. A comparative study about certain characteristics of incisors in humans and myomorpha, the fat dormouse (Glis glis) being their representative as well, comprised measurements of enamel and dentin thickness in individual incisor segments, evaluation of external enamel index, and also assessment of histological structure of enamel and dentin. The study results involving dormice showed the enamel to be thicker in lower than in the upper teeth, quite contrary to enamel thickness in humans. In the upper incisors in dormice the enamel is the thickest in the medial layer of the crown, and in the cervical portion of the crown in the lower incisors. The thickness of dentin in dormice is greater in the oral than in the vestibular side. These findings significantly differ from those reported in reference literature, but they are based on the function of teeth in dormice. Histological characteristics of hard dental tissues in dormice are similar to those in humans, with exception of uniserial structure of enamel and appearance of dentinoenamel junction.

Adaptation, Physiological↗
PubMed1992

Abnormal incisor teeth and body weight in the obese mouse (genotype ob/ob).

Inherently obese mice (genotype ob/ob) developed abnormal incisor teeth at 26 weeks of age. Up to that age, their teeth were indistinguishable by visual criteria, from those of lean (wild-type) litter-mate mice. Radiography and preliminary histology suggested impaction of the tooth in its alveolus (socket) due to the disorganized production of enamel and dentine. Incidence was high (92 per cent) in obese and zero in lean mice. Upper incisor teeth were more severely affected than lower. The severity of teeth lesions could not be correlated with age or body weight. Both sexes were equally affected. The onset of teeth lesions marked the end to the rapid rise in body weight characteristic of the obese mouse. An irregular fall in body weight ensued which could be alleviated by powdering the pelleted food. This indicated the fall to be a consequence of impaired function of the incisor teeth. Abnormality of the teeth was entirely prevented by feeding obese mice from weaning, a similar amount of food to that eaten by lean mice. The high circulating levels of adrenocorticosteroids in the obese mouse are suggested as a cause of the incisor tooth abnormality.

Age Factors↗