[Relation of the apexes of the maxillary tooth roots to the floor of the maxillary sinus on the basis of anatomic studies].
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OBJECTIVES: Low-level laser treatment has been advocated as a possible treatment for patients with paresthesia. An objectively verified improvement in sensory function is relevant if, at the same time, it is perceived as a subjective improvement by the patient. The aim of this double blind clinical study was to see if low-level laser treatment with a GaAlAs laser (820 nm, Rønvig, Denmark) resulted in objectively verified improvement in sensory function and whether this correlated with the patient's subjective evaluation subsequent to treatment. STUDY DESIGN: The 13 patients in this study had all undergone saggittal split ramus osteotomy resulting in either compression or traction of the inferior alveolar nerve as reported by the surgery notes. The material was collected from a consecutive series of patients at the Karolinska Hospital, all of whom had shown reduced sensibility at their final 2-year postoperative checkup. The patients were randomly divided into two groups; one (eight subjects) group received real low-level laser treatment (4 x 6 J per treatment along the distribution of the inferior alveolar nerve, at the following points extraoral: lateral third of lower lip, intraoral; buccally to the apex of the second premolar tooth and the apex of the second molar tooth; lingually in the region of the mandibular foramen; for a total of 20 treatments). The other group received an equivalent placebo treatment. The study was conducted in a double blind fashion for both patient and doctor as the low-level laser equipment had two settings, A and B, one of which was an unknown void setting. The degree of mechanoceptor neurosensory deficit was assessed by Semmes Weinstein monofilaments (North Coast Medical, USA) and the degree of thermoceptor neurosensory deficit was assessed by a Thermotester (Somedic, Sweden). The degree of subjective neurosensory deficit was assessed by means of a visual analogue scale. Both variables and the degree of subjective injury were comparable between the two groups before starting treatment. RESULTS: The patients in the real low-level laser treatment group experienced a subjective improvement in both lip (p = 0.01) and chin (p = 0.02) after completion of the course of treatment. In addition, this group showed a significant decrease in the area of mechanoperception neurosensory deficit (p = 0.01) compared with no difference in the placebo group. The real low-level laser treatment group exhibited a strong tendency toward improvement in mechanoreceptor neurosensory deficit in the areas of most damage for both lip and chin. This improvement was especially pronounced in the lip region (p = 0.06). No similar tendency was demonstrated in the placebo group. Neither group showed any significant change or tendency to improvement in thermoception on completion of the course of treatment. CONCLUSION: In conclusion GaAlAs low-level laser treatment results in both a subjective and objective improvement in mechanical sensory perception in long-standing neurosensory deficit in the inferior alveolar nerve.
The periodontal ligament is richly innervated with mechanosensitive afferent nerve fibers, and the location of the mechanoreceptive terminals within the ligament is of functional significance. In this study, we have obtained quantitative information on mechanoreceptor distribution in the lower canine teeth of the cat. Using light microscopy, we quantified the number of myelinated axons in the periodontal ligament at 1 mm, 3 mm, and 5 mm from the tooth root apex. Grouped axons and axons which were isolated in the cemental half of the ligament (and therefore putative mechanoreceptors) were identified. The mean total number of axons was 1290 (n = 20) at 1 mm from the apex, 1290 at 3 mm, and 814 at 5 mm. The distribution of axons around the tooth root circumference was found to be non-uniform. Near the root apex, the highest numbers of grouped axons were located distally and mesially, and in the middle region of the root, the highest numbers were found mesially. The highest numbers of isolated axons at the apical levels were located distally, and in the mid-root region, mesially. At all levels, the lingual region was the most sparsely innervated by both groups. There was a positive correlation between the number of grouped axons and the width of the ligament in the same region, but this correlation was much weaker for isolated axons, suggesting that their distribution does not result only from the volume of tissue. Variations in the number of axons and, to a lesser extent, the dimensions of the periodontal ligament were considerable.(ABSTRACT TRUNCATED AT 250 WORDS)
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OBJECTIVES: The dental development of permanent mandibular teeth in a small group of children with dystrophic epidermolysis bullosa (DEB) was assessed from radiographs and compared to a healthy, age-and-sex-matched control group. METHODS: This was a retrospective radiographic cross-sectional study. The sample consisted of a group of 44 children aged between 4 and 15 years with DEB and healthy, age-and-sex-matched controls. Two quantitative methods of assessing tooth formation were used: (1) a combination of information about tooth length and apex width; and (2) the use of tooth length to predict age. Panoramic radiographs were digitized in order to determine tooth length and apex width. Dental age was calculated, and the difference with real age was tested with Student's t-test. RESULTS: The dentition of both the DEB and control groups was slightly delayed. Using the first method, the delay was 0.34 +/- 0.87 years for the DEB group and 0.29 +/- 0.97 years for the control group. Using the second method, the delay was 0.49 +/- 1.18 years for the DEB group and 0.23 +/- 0.62 years for the control group. This delay was not statistically significant for either method. CONCLUSIONS: The dental formation of permanent mandibular teeth in the group of children with DEB was not significantly different to that found in the control group.
The purpose of this in vitro investigation was to determine whether the presence of sodium hypochlorite influences the accuracy of the Root ZX electronic apex locator. Forty, extracted, human teeth were mounted in an experimental apparatus. After achieving ideal access, working length measurements were obtained using the Root ZX. The canals were flushed with 2.125% sodium hypochlorite and measurements were again made with the electronic apex locator. Before measuring a third time, 5.25% sodium hypochlorite was then administered to each canal. Finally, the tooth was removed from the apparatus and the actual canal length was determined by measuring a file brought to the apical constriction (verified by direct visualization). No significant differences were found between the experimental groups. Overall, Root ZX measurements were within 0.5 mm of the actual length 83% of the time. The results of this study indicate that the Root ZX is not adversely affected by the presence of sodium hypochlorite.
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This open study was undertaken to investigate the outcome of autotransplanted teeth over a 6-year period. The subjects were 296 patients who underwent autotransplantation in the 6-year period September 1986-August 1992 and outcome was measured by considering root formation, occlusion, endodontal and periodontal complications. 18 patients were excluded because of inadequate notes or radiographs (n = 3) or because they were lost to follow-up (n = 15). The groups were divided into open apex and closed apex, and duration of follow up was 6 months-5 years. Aplasia was the indication for operation in 158 (77 percent) of the open apex group but only 10 (14 percent) of the closed apex group, whereas caries and associated disease was the most common in the latter (n = 45, 61 percent compared with 20, 10 percent). There were 24 complete failures, 12 in each group (p <0.01). Only 7 teeth in total developed full roots, and 159 showed incomplete growth. In the open apex group 112 teeth were in occlusal contact and 4 were extracted for severe infraocclusion. In the closed apex group there were 10 cases of mild infraocclusion, none of which required treatment. There were 7 cases of pulp necrosis in the open apex group, 4 of which required extraction. Two teeth in the closed apex group were extracted for endodontic reasons. Only 1 tooth (in the closed apex group) had to be extracted for periodontal reasons. Autotransplantation is a reliable method with a good prognosis for donor teeth with both open and closed apexes. The technique is applicable whatever the aetiology of the agenesis, and is worthy of consideration should there be a suitable donor tooth.
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A forty year old female patient developed paraesthesia of the right side of her lower lip following the placement of an extensive pin-retained amalgam restoration in her lower right second premolar tooth. Radiographs indicated that the mental foramen was close to the apex of this tooth and it was assumed that postoperative pulpitis and periapical inflammation had caused the paraesthesia through the effects of pressure on the mental nerve. The paraesthesia resolved following endodontic treatment of the lower second premolar tooth and the patient has had no further signs or symptoms.
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Using electron microscopy and morphometric analysis the number and size of axons entering the apex of the cat's mandibular canine tooth have been measured. The total number of axons varied from 761 to 1,903 between different animals but the maximum difference between right and left sides of the same animal was 353. From 56 to 79.6% of the axons were nonmyelinated; the difference in proportion between right and left sides never exceeded 6.4%. The mean circumference of myelinated axons ranged from 10.2 to 18.3 micrometers but again the right and left variation was much less and never exceeded 2 micrometers. In one tooth 38.8% of the myelinated axons were larger than 19 micrometers in circumference and thus outside the A delta range. The proportion was much smaller in other teeth but some "large" fibers were always present. Of all the nonmyelinated axons 19.7% showed some degree of axonal exposure to the extracellular space and 1.7% showed ax-oaxonal apposition. A small proportion of nonmyelinated axons showed evidence of apparent degeneration. Comparison of these data with those from studies at more coronal levels suggests that there is considerable branching and narrowing of fibers during their course through the dental pulp and that the degree of axonal exposure and apposition increases considerably. Some of the pulpal fibers are derived from larger axons than are normally associated with pain. The animal to animal variation in the parameters measured is considerable but right and left sides are similar.
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The endodontic treatment of teeth with severe Type 3 dens invaginatus, characterized by an infolding of enamel and dentin, extending deep into the pulp cavity near the root apex, may be complicated and challenging. Because of the bizarre root canal anatomy and widely open apex, a combination of nonsurgical and surgical endodontic treatment or extraction is the most common choice of therapy. This article describes a nonsurgical endodontic treatment of a tooth with severe Type 3 dens invaginatus and an associated large periradicular lesion. After complete removal of the invaginated central mass of hard tissue and long-term calcium hydroxide treatment, nonsurgical endodontic treatment was performed. Complete healing of the periradicular lesion was observed at 25-month and 74-month follow-up examinations.