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Two cases in which all of the zinc oxide canal filling did not resorb are described. The histories emphasize the importance of careful monitoring of treated primary teeth. The cases described were monitored for more than five years.
Amelogenesis imperfecta (AI) is a hereditary defect in enamel formation affecting both primary and permanent dentition. Scanning electron microscopic investigation is one of the most effective methods in diagnosing and identifying the type of amelogenesis imperfecta. The aim of this study was to investigate the ultrastructure of different types of amelogenesis imperfecta enamel. The primary teeth of three children with AI aged 4, 10 and 11-years-old were studied by scanning electron microscopy and irregular enamel, irregularities in enamel crystallites, hypoplastic areas on the enamel surface were seen. Histopathological evaluation revealed predentin areas with irregular canaliculi between normal dentin and internal resorption areas in the pulp tissue. Conclusively, in amelogenesis imperfecta, enamel tissue is mostly affected besides minor defects in dentinal and pulpal tissue.
We examined unexfoliated primary molar teeth by scanning electron microscopy to study the resorbing internal enamel surfaces. They were fixed in a cacodylate buffered glutaraldehyde-formaldehyde mixture, treated with 2 percent sodium hypochlorite, washed, dehydrated with ethanol and air-dried, before sputter-coating with a 40 nm layer of gold. The examination with a Jeol 6100 scanning electron microscope revealed large areas of enamel resorption, characterized by closely adjoining honeycomb-like lacunae (concavities). In higher magnification, lacunae show enamel with various patterns of resorption: whereas in some regions, only the central portions of prisms are removed; in others, the prism sheath regions are seen below the other enamel structures. Also, regions showing a random pattern of resorption are observed. In addition, lacunae showing resorbing enamel prisms in longitudinal and other orientations are also observed. The results of the present study reveal, therefore, that in unexfoliated primary teeth, the odontoclasts first remove the coronal dentin and then reach and resorb large areas of enamel. Furthermore, the various patterns of resorption support the idea that removal of enamel by odontoclasts depends upon the orientation of enamel structures, rather than of the different degrees of mineralization suggesting that enamel structures do not possess different inorganic/organic composition.
Resorption of deciduous teeth is not continuous, but alternates with periods of repair or rest. Dentine surfaces in periods of rest or repair resume resorption by odontoclasts during physiological root resorption of the deciduous teeth. However, no observations of such dentine surfaces have been shown. The characteristic feature of the dentine surfaces resuming resorption remains unknown. Tartrate-resistant acid phosphatase activity (TRAP) was detected on human deciduous teeth. The root resorbing surfaces on these teeth were photographed with a whole-mount light microscope, and the photographed areas were serially sectioned into 0.5 micron semithin sections. Preodontoclasts and odontoclasts were three-dimensionally reconstructed. On root resorbing surfaces, areas with small scattered TRAP-positive cells were observed among areas with many TRAP-positive resorbing odontoclasts and TRAP-negative areas. The sections showed that areas with small scattered TRAP-positive cells have features similar to those of TRAP-negative areas, but there were three kinds of characteristic TRAP-positive cells: preodontoclasts, odontoclasts forming small lacunae, and preodontoclasts, and odontoclasts with cytoplasmic processes extending to the dentine surface, which is covered with cells. These results suggest that the areas with small scattered TRAP-positive cells could be at the stage of resuming resorption, and show that the presence of preodontoclasts and odontoclasts with cytoplasmic processes extending to the covered dentine surface is a characteristic feature of the dentine surface at this stage.
The periodontal ligaments from traumatized deciduous teeth, while undergoing rapid resorption, were analyzed biochemically for mucopolysaccharidase activity and for total glycosaminoglycan content of dentin and cementum. Enzyme activity was present only in resorbing teeth. A concomitant 65 percent decrease in glycosaminoglycans from these teeth occurred as well.
To investigate the cytodifferentiation and degeneration of odontoclasts in physiologic root resorption, we studied deciduous incisors undergoing resorption in 6-month-old kittens by electron microscopy of ultrathin sections. The endogenous peroxidase activity within the cells was also examined by incubating the tissue slices in diaminobenzidine-H2O2 medium. The resorbing tissues, consisting of multinucleated giant cells, macrophages, granular leukocytes, fibroblasts and many blood vessels, were observed at the resorbing surface of the root dentine. Macrophages and granular leukocytes exhibited endogenous peroxidase activity, but mononuclear and multinucleated preodontoclasts and multinucleated odontoclasts did not. These preodontoclasts contained abundant mitochondria, a moderate amount of rough endoplasmic reticulum, stacks of Golgi membranes, lysosomes and numerous polyribosomes scattered throughout the cytoplasm. Many cellular processes extended from their cell surfaces by which the preodontoclasts appeared to fuse to one another during their multinucleation. Concomitant with the multinucleation process, the preodontoclasts developed numerous pale vacuoles throughout the cytoplasm. These vacuoles seemed to arise from some smooth endoplasmic reticula, perhaps representing Golgi-endoplasmic reticulum-lysosome, and the Golgi saccules. However, the preodontoclasts did not yet form a ruffled border and clear zones. When these preodontoclasts came into direct contact with resorbing dentine surfaces, they began to form the clear zones against dentine surfaces. Characteristically, numerous pale vacuoles were accumulated in the cytoplasm adjacent to the clear zone, then they penetrated into the cytoplasm of the clear zone, and with this, ruffles of the plasma membranes appeared. Through a further movement of more pale vacuoles towards the ruffled plasma membranes, the odontoclasts developed typical ruffled borders against the resorbing dentine surfaces. At this differential phase, little pale vacuoles appeared in the Golgi area, but the cisterns of the Golgi apparatus themselves reached their greatest extent during cellular differentiation. Fully differentiated odontoclasts frequently extended long broad cellular processes into the dentinal tubules exposed to the resorption lacunae. Although some odontoclastic processes penetrating the dentinal tubules contained vacuoles and lysosomal structures, most processes lacked any cytoplasmic organelles, and their cytoplasm resembled that of the clear zone. But these processes never exhibited ruffled-border-like structures.(ABSTRACT TRUNCATED AT 400 WORDS)
Coronal resorption of maxillary canines is a possible complication of long standing impaction. Degeneration of the enamel epithelium allows the connective tissues to come into direct contact with enamel. Irregular replacement of the pericoronal tissues and resorbed enamel by bone characterizes the histological picture. Inflammatory changes are rare. Resorption of enamel is slow and usually symptomless so that reported cases have usually been incidental radiographic findings in older patients. This report presents the early arrested development, ankylosis and resorption of the crown of a maxillary canine in a child 7.7-years-old. Arrest of crown development occurred between three and four-years-of-age. Radiographically the crown of the canine was incompletely formed and showed irregular resorption. Serial radiographs taken over a five-year period showed movement of the canine superiorly in relation to the hard palate which was taken as radiographic evidence for ankylosis of the resorbing maxillary canine in a growing child.
A bitewing radiograph obtained from a general dentist revealed an intracoronal radiolucency within an unerupted immature permanent second molar. This rare entity was successfully treated by surgical exposure and vital pulp therapy. Apexogenesis was confirmed radiographically and a permanent restoration placed at the time of eruption. Possible etiologies for this condition are discussed and recommendations for treatment are proposed.
An 18-year female patient with dysostosis cleidocranialis, treated for dental anomalies characteristic of her basic disease since the age of 12, is described. Delayed resorption of deciduous teeth and eruption of permanent teeth were recorded. At the age of 12, the patient had still had all deciduous teeth, with the exception of lower incisors and right upper mesial incisor. The presence of 11 succedaneous teeth, 7 in the maxilla and 4 in the mandible, had been recorded by X-ray. The treatment performed step by step is presented. Firstly, deciduous teeth were extracted, and a prosthesis for both the maxilla and mandible were constructed to stimulate eruption of permanent teeth. All supernumerary teeth from the jaws were also surgically removed. After the permanent tooth eruption had been accomplished, orthodontic treatment of these teeth was required and it has still been successfully performed. Thus, a conclusion is made that the treatment of dental anomalies should start at the time of normally expected deciduous tooth exfoliation.
The mandibles of 78 Hereford cross Friesian steers all showing a full complement of temporary teeth were examined both visually and by radiography to determine whether it was possible to differentiate their various ages. All but one animal were slaughtered at the same weight (1020 lb-464 kg) and their ages at slaughter ranged from 1 year 3 months to 1 year 9 months. Differences were found between the mean ages for stages of resorption of the first temporary incisor roots, stages of first permanent incisor root formation and stages of second incisor crown formation, as determined by radiographic inspection. The results indicated that the age of a group of animals could be defined, but the age range within each development stage meant that it was not possible to define the age of individual cattle.
Undecalcified sections of 31 impacted third molars are examined histologically for signs of resorption. Resorption starts at small spots in enamel, progresses to dentin and may even penetrate the pulp cavity. The incidence of such resorption processes increases after the age fifty. A prerequisite for resorption is the loss of reduced ameloblastic epithelium. Histological examination reveals multinuclear giant cells and apposition of spongious bone to destroyed dental substances. The results is dental ankylosis. Because partially resorbed teeth or ankylosed teeth may lead to serious surgical difficulties, impacted wisdom teeth without any clinical symptoms and without pathologic radiological findings should always be extracted at a young age.
Histological examination of the deciduous teeth in two cases of segmental odontomaxillary dysplasia (SOMD) showed fibrous enlargement of the pulps, an irregular pulp/dentine interface displaying many pseudoinclusions and pulp stones. There were tubular defects in the coronal dentine from pulp horn to cusp tip, an irregular tubular structure to the circumpulpal dentine of the apical half, a focally deficient odontoblast layer and widespread external resorption. Together with the clinical features of unilateral maxillary enlargement, upper alveolar expansion in the distal segment, increased spacing and delayed eruption of the deciduous molars and absence of premolar teeth, these histological appearances allow distinction of this condition from fibrous dysplasia (FD), segmental hemifacial hypertrophy (SHH) and regional odontodysplasia (ROD).
Out of approximately 11 500 children, who had been referred to the Department of Paediatric Dentistry at the Institute for Postgraduate Education,Jönköping, Sweden, 97 individuals had a total of 123 mesiodentes. Their dental records and radiographs were analysed in order to study the clinical and radiographic features of the mesiodentes, to record the complications caused by them and to evaluate different forms of treatment. In the present study, the predominant location of the mesiodentes was palatally with 39 per cent in an inverted position. Arrest of the permanent incisors eruption, midline diastema and displacement or rotation of the incisors, were the most common complications found. On the contrary, no follicular cysts or resorption of either the mesiodens or the adjacent teeth were found. Fourty-three out of the 97 individuals were radiographically followed and no pathological findings were recorded. This study shows that the risk of complications caused by the mesiodentes seems to be very low and therefore a more restrictive attitude towards their surgical removal can be recommended.
An NIH conference on "Removal of Third Molars" debated the need for removal of asymptomatic impacted teeth with no evidence of pathology but stressed the need for long-range studies. The assumption is that "neglected" impacted third molars (ITMs) will sometime cause serious pathology. Examination of panoramic radiographs of 11,598 patients revealed 1,756 patients with 3,702 impacted teeth; average age 47 years, and an average retention period approximately 27 years. Dentigerous cystic changes occurred in about 30 ITMs (0.81%), internal resorption in 16 (0.43%), periodontal ligament damage and bone loss distal to the 2nd molar 166 times (4.48%), and pressure resorption of the 2nd molar 113 times (3.05%). No great surge in pathology occurred with increasing age. Some type of pathological change can be expected eventually in approximately 12.0% of an impacted 3rd molar population and 1.82% of the general population. A reappraisal of routine removal of ITMs might be indicated.
OBJECTIVE: The aim of this research was to investigate the incidence of fully impacted teeth and their complications and to recommend suitable removal times for these teeth. METHOD AND MATERIALS: One thousand patients who were referred to the Oral Surgery Clinic, Faculty of Dentistry, at Atatürk University were intraorally examined, and fully impacted teeth were determined from radiographs. The locations of fully impacted teeth and the complications they caused were recorded. A total of 110 patients with fully impacted teeth were divided into three age groups: 16 to 19 years, 20 to 35 years, and older than 35 years. RESULTS: The incidence of fully impacted teeth was found to be 11.00%. The maxillary left third molars in females and the mandibular left third molars in males were the most frequently impacted teeth. Complications, such as pain, cysts, resorption of the impacted or adjacent teeth, infection, crowding, and axial changes in the position of the adjacent teeth, were associated with 28.42% of impacted teeth. Impaction was most frequent in the 20- to 35-year-old group. CONCLUSION: Extraction of fully impacted wisdom teeth before they cause complication is the ideal approach. However, in economically developing countries, such as Turkey, extraction of these teeth after complications occur is the most suitable approach because of restrictions in governmental budgets and the patients' poor socioeconomic conditions and fear of dentistry and oral
Usually supernumerary teeth in the maxilla are removed surgically, often due to retention of the permanent teeth in the region, but in certain cases the supernumerary teeth do not cause alterations in the eruption, position or integrity of the permanent dentition. This study was performed in order to review the indications for such surgical removal. The patient records of 208 patients with supernumerary teeth during the period of 1970-81 were reviewed retrospectively. Of these patients, 52 non-operated were furthermore examined clinically and radiographically in 1982; mean observation time 7.3 years (1-22 years). Results showed that none of the 52 non-operated patients had any symptoms or pathologic conditions related to the supernumerary teeth. In 37%, progressive resorption of the supernumerary teeth was seen, and in 24% the pericoronary space was markedly reduced compared to the first examination. The position and morphology was found to have influence on the prevalence of retention of the permanent incisors (p less than 0.0001). Widening of the pericoronary space during the observation period of the non-operated patients was not seen in any of the cases. Of the total of 262 teeth, 2 well-defined pericoronary cyst (pericoronary space greater than or equal to 5 mm) were found. From the present study, it is concluded that supernumerary teeth in the premaxilla may cause pathological conditions. However, each case must be considered individually concerning surgical treatment, and if no retention of permanent teeth or pathological conditions are present, observation with regularly radiographic controls is advisable. Enlarged pericoronary space (1-3 mm) does not alone seem to indicate surgical treatment.
In scanning electron microscopy (SEM) of the dental root surfaces human cementum resorption by giant multinucleated cells appeared similar in temporary and permanent teeth. Thus the resorbed zones were formed by associated Howship lacunae. On the lacunae walls, the openings of numerous tubules of the cementocytic lacunae were seen. Such aspects were noted during the physiological resorption of temporary teeth. The cementum surface of permanent teeth without pathology, presented frequently such resorption aspects around their apical regions as well as on other regions, the resorbed areas being more often not widespread. Similar resorption zones were observed in contact with paradental granulomas and along granulation tissue in cases of chronic periodontitis. Orally exposed cementum, after gingival recession, was mainly characterized by the disappearance of the typical dappled aspect of the cellular cementum and by the presence on the smoothed surface of numerous striate. The cementum wall of the periodontal pockets showed always the dappled aspect with the occasional presence of incipient calculus formation as well as calcified fibrillar elements. These calcified fibrils were either short covering the whole surface or were longer being disposed parallel to the surface in interwoven networks or in tufts. Cementum curetage followed by root planning removed the calculus completely. Before root planning, the presence of numerous striae were noted. They disappeared following the action of a rubber cup and an abrasive polishing paste. Ultrasonic scaling gave a relatively clean root surface. However, the cementum surface, apparently devoid fo calculus under visual examination, showed in places the presence of thin calculus layers under the SEM.
AIM: To examine the effects of inactive periods of force on the amount of tooth displacement and root resorption during experimental tooth movement in rats. SAMPLE: Sixty 11-week-old male Sprague-Dawley rats. METHOD: The maxillary first molar (M1) was moved mesially using a removable titanium-nickel alloy closed coil spring for 14 days. The rats were divided into four groups with, 0, 1, 4, and 9 hours of inactivation per day. RESULTS: Tooth displacement in the 0- and 1-hour groups was significantly greater than that in the 9-hour group. The area of root resorption in the 4- and 9-hour groups was significantly less than that in the 0- and 1-hour groups. There was no significant difference in root resorption between 0- and 1-hour groups, and also between 4- and 9-hour groups. CONCLUSION: The distance of tooth displacement gradually decreased as the inactive period increased, whereas root resorption suddenly decreased between 1 and 4 hours of inactive orthodontic force.