Severe fracture of the maxillary alveolar process associated with extrusive luxation and tooth avulsion: A case report

Aim: The aim of this report is to present a case of severe fracture of the maxillary anterior alveolar process with substantial bone dislodgement associated with extrusive tooth luxation and avulsion. Background: Dentoalveolar trauma is a challenge to dentistry, especially in young patients, for it can lead to early tooth loss which compromises oral function, esthetics, self-esteem, and alter the long-term plan of care for the victim. Case Report: A 12-year-old girl with severe dentoalveolar trauma to the maxillary anterior region presented for emergency care for her injury. Treatment consisted of fracture reduction of the alveolar process, repositioning of the teeth that had suffered extrusive luxation, placement of a semi-rigid splint, and suturing of soft tissue lacerations. The traumatized teeth presented with pulpal necrosis and were treated endodontically. After 24 months of follow up, the fracture of the alveolar process was completely healed and the displaced teeth presented no signs of ankylosis or root resorption. Summary: First-aid care contributed remarkably to this case allowing the re-establishment of esthetics, function, and patient's self-esteem. In spite of trauma extension the treatment outcomes were favorable. Clinical Significance: Cases of dentoalveolar trauma should be evaluated on an individual basis. However, early emergency management and adequate follow-up can prevent further complications and contribute to treatment success.

Effect of induced diabetes mellitus on alveolar bone loss after 30 days of ligature-induced periodontal disease

Several studies have shown that diabetics are more susceptible to the development of severe periodontal disease. Currently, the use of animal models can be considered a feasible alternative in radiographic assessments of these two pathologies. The purpose of this radiographic study was to evaluate the effect of induced diabetes mellitus on alveolar bone loss after 30 days of ligature-induced periodontal disease. Sixty-four Wistar rats were randomly distributed into four experimental groups. Diabetes was induced in Groups II and IV, while periodontal disease was induced in Groups III and IV; Group I was used as control. In order to perform the radiographic assessment of the specimens, the rats were killed on the 3rd and 30th days of the study. Radiographic measurements were assessed with ANOVA and Tukey's test to determine statistically significant differences (p < 0.05). It was observed that Groups III and IV featured greater bone loss when compared to Groups I and II. Only the diabetic group with periodontal disease (Group IV) featured statistically significant greater bone loss when compared to the other groups. These results suggested that the alveolar bone loss resulting from the periodontal disease installation is greater when associated to the diabetes mellitus.

Effect of remifentanil hydrochloride administered via constant rate infusion on the minimum alveolar concentration of isoflurane in cats

Objective - To evaluate the effects of increasing doses of remifentanil hydrochloride administered via constant rate infusion (CRI) on the minimum alveolar concentration (MAC) of isoflurane in cats. Animals - 6 healthy adult cats. Procedures - For each cat, 2 experiments were performed (2-week interval). On each study day, anesthesia was induced and maintained with isoflurane; a catheter was placed in a cephalic vein for the administration of lactated Ringer's solution or remifentanil CRIs, and a catheter was placed in the jugular vein for collection of blood samples for blood gas analyses. On the first study day, individual basal MAC (MAC Basal) was determined for each cat. On the second study day, 3 remifentanil CRIs (0.25, 0.5, and 1.0 μg/kg/min) were administered (in ascending order); for each infusion, at least 30 minutes elapsed before determination of MAC (designated as MAC R0.25, MAC R0.5, and MAC R1.0, respectively). A 15-minute washout period was allowed between CRIs. A control MAC (MAC Control) was determined after the last remifentanil infusion. Results - Mean ± SD MAC Basal and MAC Control values at sea level did not differ significantly (1.66 ± 0.08% and 1.52 ± 0.21%, respectively). The MAC values determined for each remifentanil CRI did not differ significantly. However, MAC R0.25, MAC R0.5, and MAC R1.0, were significantly decreased, compared with MAC Basal, by 23.4 ± 79%, 29.8 ± 8.3%, and 26.0 ± 9.4%, respectively. Conclusions and Clinical Relevance - The 3 doses of remifentanil administered via CRI resulted in a similar degree of isoflurane MAC reduction in adult cats, indicating that a ceiling effect was achieved following administration of the lowest dose.

Effects of Long-Term FK 506 Therapy on the Alveolar Bone and Cementum of Rats

Cyclosporine (CsA) and tacrolimus (FK 506) exert complex, incompletely understood actions on bone. The objective of the study was to evaluate the effects of long-term tacrolimus therapy on the periodontium. Rats were treated for 60, 120, 180, and 240 days with daily subcutaneous injections of 1 mg/kg body weight of FK 506. After the experimental period, we obtained serum levels of calcium and alkaline phosphatase (ALP). After histological processing, the alveolar bone and cementum, as well as volume densities of bone (Vb) and osteoclasts (Vo), were assessed at the regions of the lower first molar. There was a tendency toward a statistically significant decrease in ALP levels with FK 506; however, serum calcium levels increased during the long periods. At 60, 180, and 240 days of treatment with FK 506, we did not observe Vb and Vo alterations. At 120 days of treatment, there was an evident decrease in Vb, but it did not show alveolar bone loss. We did not observe any alterations of cementum among rats treated with FK 506. It may be concluded that FK 506 administration did not induce side effects on the periodontium. © 2009 Elsevier Inc. All rights reserved.

Low caloric value of ethanol itself increases alveolar bone loss in ligature-induced periodontitis in male rats

This study aimed at morphometrically evaluating the influence of variable caloric values of ethanol consumption on alveolar bone loss in periodontitis in male rats. Thirty-six male rats were randomized into four groups of nine rats each, as follows: Test group A (low) - rats were fed an ethanol-containing liquid diet (ethanol representing 22% of total caloric value); Control group A - rats were fed a pair-fed control diet (ethanol replaced by isocaloric amounts of carbohydrate); Test group B (high) - rats were fed an ethanol-containing liquid diet (ethanol representing 36% of total caloric value); Control group B - rats were fed a pair-fed control diet for Test B. Following anesthesia, cotton ligatures were placed around the cervix of the right upper second molar. At eight weeks, the maxillary bones were removed and alveolar bone loss was analyzed by measuring the distance between the cementoenamel junction and the alveolar bone crest at buccal and palatal sites of the upper second molar. The unligated groups showed no significant differences between the bone loss values observed for the low and high caloric values of ethanol (p > 0.05). In the ligated groups, the rats receiving low caloric values of ethanol showed significantly greater bone loss compared to the isocaloric rats (p < 0.05); however, the rats receiving high caloric values of ethanol showed no significant differences compared to the controls. Analysis of the results demonstrated that, in male rats, ethanol itself affected ligature-induced bone loss when representing a low value in the total caloric value.

Influence of alcohol consumption on alveolar bone level associated with ligature-induced periodontitis in rats

Alcohol consumption is a risk indicator for periodontal disease. The purpose of this study was to morphometrically evaluate the influence of alcohol consumption on alveolar bone level associated with ligature-induced periodontitis in rats. Thirty-six female rats (Wistar, 120 days-old) were randomly divided into three groups that received a daily administration of a water diet (control, n = 12), a 10% alcohol diet (10% ethanol, n = 12) or a 20% alcohol diet (20% ethanol, n = 12). Four weeks after the onset of the experiment, cotton ligatures were placed around the cervix of the upper right second molar in six rats. The other 6 rats in each group remained unligated. The rats were sacrificed four weeks after ligature placement. The maxillary bones were removed and alveolar bone loss was analyzed by measuring the distance between the cementoenamel junction and the alveolar bone crest at 2 buccal and 2 palatal sites on the upper right second molar. Analyses between the ligated and unligated groups showed that the presence of ligature induced alveolar bone loss (p < 0.05). Unligated groups showed no significant differences between each other (p > 0.05). In the ligated groups, rats receiving 20% ethanol showed significantly greater bone loss compared to control rats or rats receiving 10% ethanol. These results demonstrate that alcohol consumption may increase alveolar bone loss in female rats in a dosedependent manner.

Time reconstruction and performance of the CMS electromagnetic calorimeter

The resolution and the linearity of time measurements made with the CMS electromagnetic calorimeter are studied with samples of data from test beam electrons, cosmic rays, and beam-produced muons. The resulting time resolution measured by lead tungstate crystals is better than 100 ps for energy deposits larger than 10 GeV. Crystal-to-crystal synchronization with a precision of 500 ps is performed using muons produced with the first LHC beams in 2008. © 2010 IOP Publishing Ltd and SISSA.

Performance of CMS muon reconstruction in cosmic-ray events

The performance of muon reconstruction in CMS is evaluated using a large data sample of cosmic-ray muons recorded in 2008. Efficiencies of various high-level trigger, identification, and reconstruction algorithms have been measured for a broad range of muon momenta, and were found to be in good agreement with expectations from Monte Carlo simulation. The relative momentum resolution for muons crossing the barrel part of the detector is better than 1% at 10 GeV/c and is about 8% at 500 GeV/c, the latter being only a factor of two worse than expected with ideal alignment conditions. Muon charge misassignment ranges from less than 0.01% at 10GeV/c to about 1% at 500 GeV/c. © 2010 IOP Publishing Ltd and SISSA.

Estudio histológico comparativo de la reparación ósea entre hueso alveolar y extra-alveolar en los cerdos sometidos a osteotomía con alta y baja velocidad, con refrigeración líquida

Taking into account the bone repair process in pigs has shown a greater similarity among the histological variables studied compared to other biological models, the present study has as its aim to evaluate the histological bone repair process of osteotomy performed on alveolar and extra-alveolar bones, using drilling tools with liquid refrigeration. Material and method: Eighteen Large White pigs weighing between 20 and 25 Kg were divided into three groups of six animals in order to evaluate the osteotomy repairs with low and high speed in the alveolar bone and threes in the extra-alveolar area, study periods of 7, 14 and 28 days. Results: It was observed that in the alveolar bone at the postoperative times of 14 and 28 days, the best repair results were in the osteotomy performed with low speed, while in the 7 day postoperative period, the results with high speed were slightly better, in alveolar areas as well as extra-alveolar areas. There no statistically significant differences between the alveolar and extra-alveolar bone repair process. Conclusions: The repair process, by means of microscopic analysis in the alveolar and extra-alveolar areas, are similar with better results observed in osteotomies performed with low speed drills in the 14 and 28 day study periods, and at 7 days postoperative the results with high speed drills and refrigeration were slightly better. Research works using pigs as an animal model are perfectly viable. © 2011 SECOM.

Conservative reconstruction of the smile by orthodontic, bleaching, and restorative procedures

The following is a clinical case report of a patient whose chief complaint was the presence of generalized spacing in the maxillary anterior segment following orthodontic treatment. After meticulous clinical analyses and discussions of the clinical procedures to be adopted, dental bleaching was performed in both arches with 10% hydrogen peroxide (Opalescence Trèswhite Supreme 10% Hydrogen Peroxide - Ultradent Products, Inc., South Jordan, USA) after the conclusion and stabilization of orthodontic treatment. Then, the orthodontic appliance was removed and the diastemas in the maxillary anterior teeth were closed with Amelogen Plus (Ultradent Products, Inc., South Jordan, USA) resin composite. It was observed that the association of orthodontic, bleaching, and restorative procedures was capable of restoring dental shape, function, and esthetics, allowing the patient to smile without hesitation.

Effect of dexmedetomidine on the minimum alveolar concentration of isoflurane in cats

This study reports the effects of dexmedetomidine on the minimum alveolar concentration of isoflurane (MAC iso) in cats. Six healthy adult female cats were used. MAC iso and dexmedetomidine pharmacokinetics had previously been determined in each individual. Cats were anesthetized with isoflurane in oxygen. Dexmedetomidine was administered intravenously using target-controlled infusions to maintain plasma concentrations of 0.16, 0.31, 0.63, 1.25, 2.5, 5, 10, and 20ng/mL. MAC iso was determined in triplicate at each target plasma dexmedetomidine concentration. Blood samples were collected and analyzed for dexmedetomidine concentration. The following model was fitted to the concentration-effect data: where MAC iso.c is MAC iso at plasma dexmedetomidine concentration C, MAC iso.0 is MAC iso in the absence of dexmedetomidine, I max is the maximum possible reduction in MAC iso, and IC 50 is the plasma dexmedetomidine concentration producing 50% of I max. Mean±SE MAC iso.0, determined in a previous study conducted under conditions identical to those in this study, was 2.07±0.04. Weighted mean±SE I max, and IC 50 estimated by the model were 1.76±0.07%, and 1.05±0.08ng/mL, respectively. Dexmedetomidine decreased MAC iso in a concentration-dependent manner. The lowest MAC iso predicted by the model was 0.38±0.08%, illustrating that dexmedetomidine alone is not expected to result in immobility in response to noxious stimulation in cats at any plasma concentration. © 2011 Blackwell Publishing Ltd.

Implant removal by means of an expansion of the alveolar bony crest: Report of a clinical technique

Aim: To describe the adaptation of the Edentulous Ridge Expansion (E.R.E.) technique for implant removal. Material and Methods: The E.R.E. technique for the removal of failed implants is described in detail. A clinical case is also reported. In a patient carrying a full arch removable prosthesis in the upper jaw, sustained by two bars, two out of five implants were found to be fractured. Bucco-lingual partial-thickness flaps were used to access the fractured implants. The implants were subsequently removed applying the E.R.E. technique. Two recipient sites were prepared in the same position, using bone expanders, and two new implants were installed. Results: After 4 months of healing, the implants were integrated and a new bar was fabricated, and the old prosthesis readapted. Conclusion: The ERE technique may be successfully applied for the removal of failed implants, and the immediate or delayed reinstallation of new implants. © 2012 John Wiley & Sons A/S.

Performance of CMS muon reconstruction in pp collision events at √s = 7TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 pb-1 of data collected in pp collisions at s = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV/c is above 95% over the whole region of pseudorapidity covered by the CMS muon system, < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeVc is higher than 90% over the full η range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100GeV/c and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV/c. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation. © 2012 IOP Publishing Ltd and Sissa Medialab srl.

Alveolar bony crest preservation at implants installed immediately after tooth extraction: An experimental study in the dog

Aim: To evaluate the influence of deproteinized bovine bone mineral in conjunction with a collagen membrane, at implants installed into sockets in a lingual position immediately after tooth extraction, and presenting initial horizontal residual buccal defects <2 mm. Material and methods: The pulp tissue of the mesial roots of 4P4 was removed in six Labrador dogs, and the root canals were filled with gutta-percha and cement. Flaps were elevated, and the buccal and lingual alveolar bony plates were exposed. The premolars were hemi-sectioned, and the distal roots were removed. Implants were installed in a lingual position and with the margin flush with the buccal bony crest. After installation, defects resulted at about 1.7 mm in width at the buccal aspects, both at the test and control sites. Only in the left site (test), deproteinized bovine bone mineral (DBBM) particles were placed into the defect concomitantly with the placement of a collagen membrane. A non-submerged healing was allowed. Results: After 3 months of healing, one implant was found not integrated and was excluded from the analysis together with the contralateral control implant. All remaining implants were integrated into mature bone. The bony crest was located at the same level of the implant shoulder, both at the test and control sites. At the buccal aspect, the most coronal bone-to-implant contact was located at a similar distance from the implant margin at the test (1.7 ± 1.0 mm) and control (1.6 ± 0.8 mm) sites, respectively. Only small residual DBBM particles were found at the test sites. Conclusion: The placement of an implant in a lingual position into a socket immediately after tooth extraction may favor a low exposure of the buccal implant surface. The use of DBBM particles, concomitantly with a collagen membrane, did not additionally improve the outcome obtained at the control sites. © 2011 John Wiley & Sons A/S.

Arterial hypertension perpetuates alveolar bone loss

Few studies have focused on the impact of hypertension on the progression of periodontitis (PD). The purpose of this study was to evaluate whether hypertension affects PD by enhancing bone loss even after the stimulus for PD induction is removed. Ligature-induced PD was created on the first mandibular molars of spontaneously hypertensive rats (SHR) and normotensive rats (Wistar Kyoto-WKY). The animals were assigned to non-ligated controls (C) and PD groups: WKY-C, WKY-PD, SHR-C, and SHR-PD. After 10 days, five animals of each group were killed and the ligatures of the other animals were removed. On the 21st day (11 days without PD induced), the remaining animals were killed. The jaws were defleshed and the amount of bone loss was measured. After 10 days, the PD groups showed more bone loss than its controls (P < .05); SHR-PD = 0.72 ± 0.05 mm, SHR-C = 0.39 ± 0.04 mm, WKY-PD = 0.75 ± 0.04 mm, and WKY-C = 0.56 ± 0.04 mm. The cumulative bone loss on day 21 (0.94 ± 0.13 mm) was significantly worse than on day 10 only in SHR-PD group (P < .05). The final bone loss differences between PD and C groups accounted for 102% (SHR) and 26% (WKY) increase in comparison with the initial control levels. Hypertension is associated with progressive alveolar bone loss even when the stimulus for PD induction is removed and it may be speculated that host condition perpetuates alveolar bone loss. © 2013 Informa Healthcare USA, Inc.