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Prevalence of dental anomalies in orthodontic patients.

The prevalence of dental anomalies including agenesis, crown shape, tooth position, root shape, and invagination were examined in 111 orthodontic patients; 74.77 per cent of the patients exhibited at least one dental anomaly. Invagination was found to be the most prevalent anomaly, whereas supernumerary teeth and root dilaceration were the least frequent anomalies. Dental invagination and short or blunt roots were significantly more prevalent in females than in males. Implications for orthodontic treatment planning are discussed.

Adolescent↗

Pulpal blood flow assessed by laser Doppler flowmetry in a tooth with a horizontal root fracture.

Horizontal root fractures of both maxillary central incisors were diagnosed radiographically; neither responded to electric pulp testing nor to cold testing. The pulp of the right incisor was necrotic, whereas the pulpal status of the left incisor was uncertain. Pulpal blood flow of the teeth was measured with laser Doppler flowmetry. The blood flow of the left central incisor was 4.0. Eight months after the injury, a local anesthetic with a vasoconstrictor was administered to confirm pulp vitality. The blood flow of the tooth was decreased to 51% of the preanesthesia value after the local anesthesia. At 19 months after the injury, it responded to both the electric pulp test and cold test. Laser Doppler flowmetry is a noninvasive method of evaluating the blood flow status in human teeth, and it may provide a clinically reliable method of assessing pulpal vitality.

Adolescent↗

Prevalence of dilaceration in Jordanian adults.

AIM: The purpose of this study was to determine the prevalence of dilaceration in a sample of Jordanian dental patients. METHODOLOGY: The data were collected from examination of radiographs from a random sample of periapical films. In all, 4655 teeth from 814 dental records at the Faculty of Dentistry, Irbid, Jordan were evaluated. The films were viewed using a magnifying lens and an X-ray viewer. A tooth was recorded as having a dilaceration towards the mesial or distal direction if there was a 90 angle or greater along its long axis using a small ruler aligned along the pulp of the tooth. Dilacerated roots towards the buccal or lingual directions were determined by evaluating the appearance of a round opaque area with a dark shadow in its central region, cast by the apical foramen in which the root canal gave a 'bulls-eye' appearance. RESULTS: Dilacerations were recorded in 3.78% of the teeth examined. Mandibular third molar teeth were the most commonly affected (19.2%) followed by mandibular first molars (5.6%). The maxillary anterior teeth and mandibular incisors were least affected exhibiting dilaceration in approximately 1% of teeth. Two-thirds of the dilacerations were in the mandible and approximately 5% were in anterior teeth. CONCLUSION: Dilaceration is not common, but it is an important dental anomaly that affects all teeth. Recognizing the condition will facilitate endodontic, orthodontic and surgical treatment.

Adolescent↗

Restoration of endodontically treated molar with root fracture.

The management of an unusual and extreme tooth and root fracture has been presented and discussed. A somewhat unorthodox approach was used in preparing the fractured root surfaces to fit the cast gold crown instead of making a crown to fit a prepared tooth surface. Diagnosis and treatment planning is a key factor in treating unusual patients. All factors must be carefully considered. Condition of adjacent teeth, periodontal support, size and form of remaining tooth structure, and occlusion are all important considerations. With careful and proper study, simple and conservative restorations can frequently be made that will provide excellent service for extended periods of time.

Adult↗

In vivo and in vitro effects of an Er:YAG laser, a GaAlAs diode laser, and scaling and root planing on periodontally diseased root surfaces: a comparative histologic study.

BACKGROUND AND OBJECTIVES: The aim of the present histologic study was to compare the in vivo and in vitro effects of an erbium: yttrium, aluminum, and garnet (Er:YAG) laser (ERL), combined with a fluorescent calculus detection system, a diode laser (DL) and scaling and root planing (SRP) on periodontally diseased root surfaces. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four single rooted teeth, considered for extraction due to severe periodontal destruction, were included in the study. Prior to extraction all mesial root surfaces were randomly assigned to the following treatment groups: (1) ERL combined with a calculus detection system with fluorescence induced by 655 nm InGaAsP DL radiation (160 mJ/pulse and 10 pulses/second under water irrigation) (ERL), or (2) GaAlAs DL (1.8 W, pulse/pause relation 1:10), or (3) SRP using hand instruments. Immediately after extraction, all distal root surfaces were treated with the same instruments under standardized conditions. For light microscopic investigation, a plastic embedding technique was used to cut the undecalcified roots into 30 microm thick crossections. The following parameters were recorded by on blind examiner: remaining debris, root surface morphology, and thermal side effects. RESULTS: Root surfaces instrumented with both, ERL in vivo and DL in vitro exhibited no detectable surface alterations. In contrast, ERL scaling in vitro and SRP in vivo/in vitro produced superficial microchanges in root cementum. However, irradiation with DL in vivo caused severe damages to the root surface (i.e., crater formation). There were no signs of thermal side effects in all laser treated groups. ERL provided subgingival calculus removal on a level equivalent to that provided by SRP. DL was unsuitable for calculus removal, since macroscopic inspection revealed the presence of large amounts of subgingival calculus. CONCLUSIONS: The present in vivo results showed that (i) ERL, combined with a fluorescent calculus detection system, provided a selective subgingival calculus removal on a level equivalent to that provided by SRP, and (ii) DL, using this power output, was unsuitable for calculus removal and altered the root surface in an undesirable manner.

Dental Calculus↗

Evaluation of an adjusted chi-square statistic as applied to observational studies involving clustered binary data.

A simple adjustment to the Pearson chi-square test has been proposed for comparing proportions estimated from clustered binary observations. However, the assumptions needed to assure the validity of this test have not yet been thoroughly addressed. These assumptions will hold for experimental comparisons, but could be violated for some observational comparisons. In this paper we investigate the conditions under which the adjusted chi-square statistic is valid and examine its performance when these assumptions are violated. We also introduce some alternative test statistics that do not require these assumptions. The test statistics considered are then compared through simulation and an example presented based on real data. The simulation study shows that the adjusted chi-square statistic generally produces empirical type I errors close to nominal under the assumption of a common intracluster correlation coefficient. Even if the intracluster correlations are different, the adjusted chi-square statistic performs well when the groups have equal numbers of clusters.

Chi-Square Distribution↗

[Apical root resorption during orthodontic treatment].

Pre- and posttreatment radiographs of 2050 orthodontically treated patients were examined and apical root resorptions of more than 2 mm were identified. 30 patients (211 teeth) were affected. Treatment characteristics and objectives of this group (with severe apical root resorption) were compared to a treated group of 30 patients (with no resorption) to determine clinical risk factors. Extrusion, but especially jiggling and a long treatment period were found to be significantly more frequent in the group exhibiting resorption than in the control group. Pathogenesis of treatment-induced root resorption is discussed in respect to histological results.

Adolescent↗

Light microscopic and SEM findings after orthodontic treatment--analysis of a human specimen.

AIM: The hard and soft tissue damage caused by orthodontic forces has so far, for obvious ethical reasons, been investigated in animal models primarily. However, the validity of these results as applied to humans remains controversial. The particular value of this study is that the maxilla of a young adult could be analyzed histologically. Thus it was possible to retrospectively study the effects of a routine orthodontic therapy using light microscopy. MATERIAL AND METHODS: The upper jaw of a 24-year-old patient was investigated. He had been in orthodontic treatment with a straight-wire-appliance using superelastic materials for 18 months. Both posterior segments were analyzed in the horizontal plane using the microsection method according to Donath (toluidine blue staining). Both central incisors were analyzed using a scanning electron microscope (SEM). The examination was performed qualitatively and histomorphometrically. RESULTS: 170 lateral root resorptions were found in the nine posterior teeth, while pressure sites and interference areas with the buccal and sinus cortical bone were predominantly affected. However, the extent of root resorption was minimal: mean length 979 +/- 766 microm, mean depth 208 +/- 133 microm. The lateral root erosions presented high repair potential: 55.6% of resorption length, and 28% of the depth were repaired in 76% of all lesions. CONCLUSION: The incidence of detected root resorptions seems high at first. However, the prognosis of the affected teeth is not critically impaired, due to the lesions' minor extent (length, depth) and their high repair capacity.

Adult↗

A radiographic evaluation of the response of previously avulsed teeth and partially avulsed teeth to orthodontic movement.

Orthodontic movement, as documented in this study, can be accomplished successfully in the case of completely avulsed and partially avulsed teeth which have been reimplanted. These teeth respond to normal orthodontic forces and duration of treatment time by conventional orthodontic techniques and retention. Apical root resorption does occur more readily in these teeth before, during, and after orthodontic treatment. Six of the eighty-one involved teeth were lost because of complete root dissolution. The involved teeth which were reimplanted immediately without pulpal treatment and their integrity protected as living tissue were successfully treated orthodontically with no known losses as of this writing. It will be interesting to observe the tissue response of these avulsed teeth in the years ahead. How will time and circumstances deal with these teeth?

Adolescent↗

The effects of space closure of the mandibular first molar area in adults.

There is little information regarding the orthodontic closure of remodeled, edentulous spaces in the posterior area of the mandible. The present study was undertaken to determine the dental and periodontal changes that occur when mandibular first molar areas are closed in adults. Fourteen adult patients were selected from private orthodontic practices. Pre- and posttreatment study models were used to measure the mesiodistal length of the edentulous space and the buccolingual width of the alveolar ridge. The amount of crown and root movement of the second molar and premolar was measured from lateral cephalometric radiographs. From pre- and posttreatment panoramic or periapical radiographs, the anatomic changes of the second molar and adjacent periodontium were also measured. Every case showed significant space closure (x = 6.2 mm) ranging from 2.7 to 11.5 mm. There was crestal bone loss (x = 1.3 mm) mesial to the second molar in all but five cases. These latter cases showed bone addition. As the molar moved mesially , the alveolar ridge increased in width an average of 1.2 mm. The adult patient who showed the greatest amount of space closure and the least amount of molar bone loss had (1) mesiodistal space of 6.0 mm, (2) buccolingual ridge width of 7.0 mm, and (3) mesial molar bone level 1.0 mm apical to the cementoenamel junction. The results of this study indicate that space closure is not only possible but may aid the treatment of certain cases. Space closure should be considered as a potential solution to the absence of mandibular first permanent molars.

Adult↗

Influence of orthodontic treatment on root development of autotransplanted premolars.

The aim of this study was to clarify whether orthodontic movement of autotransplanted premolars will affect the final root length of the transplants. A group of 29 autotransplanted premolars that had been orthodontically treated was compared with a group of 30 autotransplanted premolars that had not been orthodontically treated. Contralateral teeth in both groups served as controls. The root lengths of the transplants as well as the controls were measured on the radiographs immediately after transplantation and also after orthodontic treatment and complete root formation. The results demonstrated that there was no statistically significant difference between the original and final root lengths of the transplants in the two samples or between the contralateral teeth. The autotransplantation of the premolars resulted in an average shortening of 1 to 2 mm compared to the contralateral control teeth. Futhermore, orthodontic movement of the transplants appeared to have a tendency to shorten the final root length.

Adolescent↗

Root resorption in maxillary central incisors following active orthodontic treatment.

The purpose of this study was to determine if apical root resorption associated with orthodontic treatment continues after the termination of active treatment (that is, the removal of fixed appliances). A sample of 45 subjects who had experienced root resorption during treatment was selected from the orthodontic clinic at the State University of New York at Buffalo. The length of the maxillary central incisors was measured from lateral cephalometric radiograms taken before treatment, after active treatment, and after retention. From these data, the resorption occurring during and after active treatment was calculated. The mean amount of root resorption during active treatment was 2.93 mm. The mean amount of root resorption during the posttreatment period was 0.1 mm. There was a statistical difference between these two means using the Student's t test at the 0.05 level of significance. The reliability coefficient comparing the first tracings and measurements in the 19 cases that were retraced and remeasured was r = 0.993. The data from this radiographic study support the hypothesis that root resorption associated with orthodontic treatment ceases with the termination of active treatment. There was also evidence to suggest that when posttreatment root resorption does occur, it is not necessarily associated with large amounts of root resorption during the active treatment period. It is more likely associated with other factors, such as traumatic occlusion and active force-delivering retainers.

Adolescent↗