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This report presents an endodontic therapy in an unusual case of a patient who had wide crowns of both permanent maxillary central incisors. The right maxillary central incisor had two separate canals on a fused root and the left had a large root canal within one root.
Parents and dentists are forced to make a decision early in a young patient's life when it is learned that the lateral incisors are missing. For many years the treatment has been to either move the cuspids into the lateral incisor sites or retain the teeth in their natural environment and restore the defect with a bonded or fixed bridge. With the advent of new designs in dental implants and their abutments, it is possible to consider replacing missing single teeth with implant-borne prostheses. Often-times, because of the limited residual bone and proximity of adjacent roots, placing conventional cylinder or screw-type implants is difficult. This article demonstrates the advantages of using a tapered-step implant, immediate one-stage surgery, and temporization in replacing congenitally missing laterals.
This study investigated the ability of chlorine dioxide to eliminate Enterococcus faecalis from dentinal tubules of bovine incisors. Thirty-seven extracted bovine incisor roots were sectioned into seventy-four 5 mm disks. Standardized lumens were filled with either sterile Brain Heart Infusion Broth (contamination controls, n = 10) or BHI containing E. faecalis (1.0 x 10 cfu/ml). Disks were incubated in 5% CO2 at 37 degrees C for 72 h. To simulate endodontic instrumentation the lumens were again enlarged. Sixty disks were randomly divided into four experimental groups and filled with one of the following irrigants: 10% Clidox-S (chlorine dioxide), 13.8% BioClenz (chlorine dioxide), 5.25% Clorox, or saline. The disks were incubated for 30 min and were then frozen, pulverized, serially diluted in phosphate buffered saline, and plated on BHI plates in triplicate. Total colony forming units were counted macroscopically. Statistical analysis of the data was performed with a Kruskal-Wallis one-way ANOVA on ranks (p < 0.05, n = 60). Bacterial counts, expressed in log10 cfu/disk were as follows (">" denotes significant differences): Saline > Clidox-S = BioClenz > Clorox. All negative controls were sterile. Chlorine dioxide and NaOCL were both effective in eliminating E. faecalis from the dentinal disks within 30 min.
In 1965, the cleft palate team at Children's Memorial Hospital embarked on a new surgical-orthodontic protocol in the habilitation of newborn complete cleft lip and palate cases. It brought the orthodontic effort into focus at birth and in planned sequence to correspond with the surgical procedures of lip closure, maxillary alveolar stabilization by means of an autogenous graft of the authors' design, and complete palate closure, all within the first year of life. The purpose of this investigation is threefold: first, to review the authors' previous publications and assess growth, secondary surgical need, and lateral incisor status of teeth adjacent to the cleft in a series of patients who have all followed a precise, early surgical/orthodontic protocol; second, to compare these cases with other collaborative studies wherein this protocol was not used; and third, to report on an additional 82 cases with regard to secondary surgical need and the status of teeth adjacent to the cleft. Methods of assessment have included cephalometric radiography, periapical and occlusal dental radiography, computer-assisted tomography, plaster cast analysis, and intraoral and extraoral photography. The authors have demonstrated, along with other collaborative studies, that there is growth as good as other similar samples wherein there was no primary osteoplasty. In addition, the authors found their incidence of orthognathic surgery to be 18.29 percent; pharyngoplasty, 3.65 percent; and oronasal fistulas requiring surgical closure, 29.27 percent. In the case of unilateral complete clefts, 53.13 percent of those lateral incisors present adjacent to the cleft area were usable, and in bilateral cases, 57.77 percent were usable. The authors remain convinced after more than 35 years of following this successful protocol that early maxillary orthopedics and their technique of primary osteoplasty in planned sequence with lip and palate closure can produce a more favorable alignment of maxillary growth potential and, with comprehensive orthodontic treatment, can lead to teeth in a better overall occlusion than if these procedures had not been undertaken.
The relationships between patients' height, weight, age, body mass index, gender and presence of maxillary incisors and a series of laryngoscopic factors have been studied. These included the duration of laryngoscopy, maximally applied force, mean applied force and the integral of force over time. There was a positive correlation between height and weight and laryngoscopic factors. Sex and age also showed a positive correlation but these could be explained by differences in height, weight and the presence of maxillary incisors. This latter factor was the dominant patient characteristic influencing the measured laryngoscopic factors. Use of these laryngoscopic factors as a measure of difficulty of laryngoscopy is discussed.
The rodent incisor tooth is the site of five cell populations proliferating in harmony: amelocytes, odontocytes, pulp cells, endothelial cells and the periodontal ligament. Their proliferating regions are located in the apex tip, where the various cells originate. Cells displaced from the tooth origin at the apex toward the periphery, mature to perform their specified function. The proliferative events in the tooth are summarized in a conceptual model of the incisor proliferon. The proliferon is an oriented structure with an origin and periphery. It consists of four basic elements: parenchyma, connective tissue, blood vessels and nerve fibres, all interacting continuously. All four are indispensable in the definition of the proliferon.
The prime objective of this study was to develop and test a method of modelling the dental root canal system using a vinyl resin, type UCAR-VYHD. It also aimed to verify if the resin models allow a three-dimensional evaluation of those features of the pulpal morphology of human permanent mandibular incisor teeth, which might be associated with periodontal disease. One hundred and eleven freshly extracted teeth were studied. Pre-extraction clinical records and periapical radiographs were used to deduce the presence or absence of periodontal disease. Each extracted tooth was radiographed in two perpendicular planes before being opened by conventional orthograde endodontic technique, and photographed in a scanning electron microscope. The patent pulp space was then obturated with the vinyl resin. Scanning electron photomicrographs of the resin replicas and of the teeth were compared with the earlier radiographic images to correlate the morphological findings. The numbers of root canals and apical foramina were recorded. This study showed that in mandibular incisors with periodontal disease there was a relatively low incidence of lateral canals (7.2%). The modelling technique was found to be reliable, reproducible, and provided sufficient detail to allow three-dimensional analysis of root canal morphology.
AIM: To present the rare localization of a radicular groove on the buccal aspect of a tooth and to discuss the pathology and management of the concomitant endo-periodontal defect. SUMMARY: Bilateral buccal radicular grooves were found on the maxillary central incisors of a 60-year-old female Caucasian. One groove was associated with deep local pocketing resulting in pulp necrosis and the formation of a periodontal-endodontic lesion. After endodontic treatment of the affected tooth, periodontal surgery was performed during which an apicoectomy was carried out on the root-filled tooth. Both the buccal grooves were removed by grinding, the roots were planed with curettes and a guided-tissue regeneration technique applied using amelogenin (Emdogain, Biora, Sweden). Following a period of 2 years, re-examination showed excellent healing with the complete elimination of the periodontal pocket on both incisors and significant radiographic evidence of bone regeneration. KEY LEARNING POINTS: Deep radicular grooves can predispose to pulp necrosis and the establishment of combined periodontal-endodontic lesions. Evaluation of clinical signs and appropriate diagnostic tests are of paramount importance in order to prevent incorrect diagnosis and treatment. Endodontists must be capable of performing advanced periodontal regeneration techniques during endodontic surgery.
AIM: To report the multidisciplinary care of an unaesthetic geminated maxillary lateral incisor tooth, which allowed its preservation in the mouth. SUMMARY: Preoperative examination of an unsightly geminated maxillary lateral incisor (tooth 22) demonstrated two pulp chambers and open apices, with normal pulp sensitivity responses. At surgery, a periodontal mucoperiosteal flap was reflected and the distal part of the geminated tooth was removed. The exposed root canal of the preserved tooth was sealed with mineral trioxide aggregate (MTA). The extraction socket and osseous defect was grafted with decalcified freeze-dried bone allograft (DFDBA) before flap closure. During follow-up, distal caries in tooth 22 and a diastema between tooth 22 and 23 were managed with composite resin restorations. Forty-two months postoperatively, normal thermal and electrical pulp sensitivity tests confirmed pulp health. Convincing apexogenesis and dentinogenesis of the developing root was confirmed by radiographic examination. Acceptable periodontal health including 3-4 mm clinical probing depths was achieved. Optimizing aesthetics and occlusion was accomplished without orthodontic treatment.
Four cases of dentigerous cysts involving permanent incisors are reported. In each case the primary predecessor had been traumatized, was discoloured and suspected of being non-vital. Epithelial proliferation of the follicular tissues induced by chronic periapical inflammation of the predecessors is suggested as the most likely pathogenesis of cystic transformation in these cases. Regular radiographic review of discoloured primary incisors is recommended.
Odontomes associated with primary teeth are rare. This report describes two cases of compound odontome associated with impacted maxillary primary central incisors in patients aged 1 year 8 months and 1 year 2 months, the latter being the youngest to have been reported with the condition. The odontomes were removed under local anaesthesia. Histological examination revealed immature dental tissues in both cases, but no evidence of root formation. Case 1 revealed 'ghost cells' within the enamel epithelium. The impacted incisors erupted following removal of the odontomes; in Case 2 the crown had an unusual ridge on its labial surface, extending from the gingival margin to a few millimetres from the incisal edge.
We performed an intentional replantation of an immature lower incisor that had a refractory peri-apical lesion. The incisor was extracted and the peri-apical lesion was removed by curettage. The root canal of the tooth was then rapidly irrigated, and filled with a calcium hydroxide and iodoform paste (Vitapex(R)), after which the tooth was fixed with an arch wire splint. Five years later, no clinical or radiographic abnormalities were found, and the root apex was obturated by an apical bridge formation. A team of two dentists is essential to prevent a prolonged operation time, thus eliminating any of the causes of ankylosis. Furthermore, calcium hydroxide and iodoform paste, along with an arch wire splint retained with composite resin, led to good healing of the periodontal tissue after the intentional replantation. Our results indicate that intentional replantation is a useful method for an immature tooth with refractory peri-apical problems.
Caries of primary incisors is a common problem in paediatric dentistry in some countries. The restoration of primary incisors which have been severely damaged by early childhood caries or trauma is also a difficult challenge for clinicians. This case report describes an indirect technique for the restoration of primary anterior teeth using composite resin reinforced with a fibre-glass post. Over a one-year period, the crowns have demonstrated good retention and aesthetic results. The restorations were provided in two short chair-side sections, with satisfactory patient cooperation.
The relationship between condylar movements and incisor point movements during habitual maximum open-close movements were studied in 10 healthy male and 10 healthy female subjects. Jaw movements were recorded by means of an opto-electronic jaw movement recording system, OKAS-3D, capable of recording the six degrees of freedom at a sample frequency of 300 Hz. The lower jaw position of the lateral pole of the condyles was found by means of palpation. In order to analyse the movements, the opening and closing path of the incisor point were divided into ten equal intervals and the corresponding condylar displacement in each interval was calculated. A displacement index was obtained by normalizing the condylar displacement with respect to the maximum condylar displacement. Due to the normalization, the displacement index is not sensitive to possible errors in the location of the lateral condylar point. A clear condylar displacement was already recorded in the first movement interval, right at the start of opening (average displacement index in the first opening interval was significantly greater than zero, P < 0.0005). The condylar displacements in the start and the end interval of opening and closing were smaller than in the intermediate movement intervals (P < 0.00005).
Using NBD-phallacidin, which specifically binds to F-actin, we investigated changes in the localization of actin during the differentiation of ameloblasts, related epithelial cells and odontoblasts in rat incisors. In cryosections treated with NBD-phallacidin, intense fluorescence was observed in undifferentiated epithelial cells in the apical loop and at the proximal extremity of undifferentiated inner enamel epithelial cells. During differentiation, the distal extremity began to exhibit strong fluorescence. In cross-sections of secretory ameloblasts, the fluorescence took the form of polygons of uniform intensity at the proximal end, and of rectangles of non-uniform intensity at the distal end. At the distal end, the fluorescence was more intense at right angles to the long axis of the incisor. At the distal end, this pattern was established just before the appearance of the enamel layer. These patterns were maintained during the secretory stage of ameloblasts. The location, pattern and time of appearance of these sites were identical to those of the terminal webs in ameloblasts. NBD-phallacidin weakly labelled the peripheral cytoplasm of the cell body of ameloblasts, and also labelled Tomes' process. The cells forming the stratum intermedium were mainly labelled at their periphery (i.e. forming larger polygons), while the overlying epithelial cells exhibited labelling throughout their cytoplasm. Except for the terminal webs, the cell bodies of odontoblasts were weakly labelled throughout the period of differentiation. Young odontoblasts secreting predentin were first labelled on the terminal web, with the fluorescence becoming gradually more intense as the thickness of the dentin increased.(ABSTRACT TRUNCATED AT 250 WORDS)
Mottled permanent incisors were studied in a stratified convenience sample of 206 Lagos schoolchildren aged 15 years. The mouth prevalence of this condition was 32%, and the right-left symmetry of the mottled incisors occurred very approximately in only a third of those persons with mottling. The distribution pattern was similar to that observed in similarly aged children in non-fluoride communities, and also that observed in optimally fluoridated Anglesey, England. The cause of this type of mottling in unknown, but its distribution suggests that endogenous (possibly genetic) factors may be involved.
The main purpose of this study was to compare the diagnosis of mild enamel fluorosis as established by two scoring systems, that of Dean based primarily on quantitative aspects and that of Thylstrup & Fejerskov with a preferentially qualitative approach. A further aim was to study the prevalence of fluorosis in permanent maxillary incisors after intake of fluoride tablets for a minimum of 5 yr between 1/2 and 6 yr of age in accordance with recommendations from the National Swedish Board of Health and Welfare. Maxillary incisors were examined in 118 13-yr-old children; 49 constituted a tablet group and the remaining 69 a control group who had never consumed tablets. Scored according to Dean, the difference in enamel fluorosis between the two groups was statistically not significant at the 5% level, whereas the system of Thylstrup & Fejerskov did give a significant difference. The frequency of fluorosis was substantially lower than that resulting from consumption of drinking water in Uppsala, Sweden, containing 1-1.2 ppm F. A probable relationship was found between the scoring systems, particularly if the Dean score 0.5 ("questionable") was converted to score 1. To ensure correct diagnosis, the tooth surface should be exposed to prolonged drying and apply relevant criteria for the differential diagnosis of disturbances of other origin. The higher sensitivity of Thylstrup & Fejerskov's system relates to score 1, narrow white lines located corresponding to perikymata. Here there seems to be a risk of over- or underdiagnosing. Recommendations are given for epidemiologic surveys and for experimental trials of limited size.
Vitamin A deficiency (A-) is known to cause morphologic changes in tooth structures. However, its effects on glycosaminoglycan (GAG) distribution in dental pulp, and the role of retinoic acid (RA) in altering these effects are not clearly defined. Tissue changes induced by vitamin A deficiency and RA administration were evaluated histologically in incisors of rats fed on one of 3 different diets: a) vitamin A sufficient (A+); b) vitamin A deficient (A-); and c) vitamin A deficient supplemented with retinoic acid (A-/RA). Four weeks after the onset of vitamin A deficiency, all rats were killed and their 4 continuously erupting incisors evaluated histologically. A- rats had altered dentine and pulp with disrupted histodifferentiation of pulpal mesenchymal cells to normal odontoblasts. The frequency of these abnormalities in dentine and pulp was lower in A-/RA rats. The enamel organ was unremarkable in the 4-week deficient period. Using special stains, we noted that pulpal GAG accumulation in A- and A-/RA rats was limited to the lingual area, while in A+ rats, GAG were distributed throughout. These data suggest that vitamin A deficiency affects histodifferentiation of pulpal mesenchymal cells to odontoblasts, as well as GAG distribution in pulp. RA administration reduces the A- changes and therefore, appears to have some activity in dentinogenesis.