Long term outcomes of en-block autotransplantation of a tooth.

Repositioning of impacted teeth in the dental arch through en-bloc autotransplantation showed short-term efficacy of 89%. The objective of this study was to evaluate the technique for long-term efficacy. The analysis involved 23 teeth transplanted to the alveolar ridge through harvesting the tooth with the adjacent bone tissue. Development of the root was completed and the apical foramen was closed in all the teeth. The teeth were examined clinically and radiologically (CBCT) and compared to contralateral ones. The obtained data were analysed statistically. The efficacy of the procedure amounted to 81% including two teeth lost at an early stage and another two lost during follow-up. The mean age of patients upon performing the procedure was 29.8. The long-term follow-up amounted to the mean of 34.3 months. In the study group recession of 1-2 mm as well as 3-5 mm was found, which was not noted on the control group. In 11.1% of the study group teeth the external root resorption was observed. No transplanted tooth underwent root canal treatment, no periapical changes were observed at CBCT and 77.8% of those showed positive reaction to ethyl chloride. One case of ankylosis was observed in tooth 11 and in two cases increased mobility of the transplanted tooth was found. Regeneration of nerves as well as revascularization in the en-bloc autotransplantation proceeded with high predictability and the risk of ankylosis of the treated tooth seemed to be negligible. Gingival recession was observed more often in case of en-bloc transplantation compared to the control group. The long-term follow-up suggested that this the technique does not prevent external resorption in 100%.

Virtual Therapy with the NMDA Antagonist Memantine in Hippocampal Models of Moderate to Severe Alzheimer's Disease, in Silico Trials.

The variability in clinical trial results on memantine treatment of Alzheimer's disease remains incompletely explained. The aim of this in silico study is a virtual memantine therapy for Alzheimer's disease that provides a different perspective on clinical trials; An in silico randomised trial using virtual hippocampi to treat moderate to severe Alzheimer's disease with doses of memantine 3-30 µM compared to placebo. The primary endpoint was the number of impulses (spikes). Secondary endpoints included interspike interval and frequency; The number of virtual moderate-AD hippocampal spikes was significantly lower, at 1648.7 (95% CI, 1344.5-1952.9), versus those treated with the 3 µM dose, 2324.7 (95% CI, 2045.9-2603.5), and the 10 µM dose, 3607.0 (95% CI, 3137.6-4076.4). In contrast, the number of virtual spikes (spikes) of severe AD of the hippocampus was significantly lower, at 1461.8 (95% CI, 1196.2-1727.4), versus those treated with the 10 µM dose, at 2734.5 (95% CI, 2369.8-3099.2), and the 30 µM dose, at 3748.9 (95% CI, 3219.8-4278.0). The results of the analysis of secondary endpoints, interspike intervals and frequencies changed statistically significantly relative to the placebo; The results of the in silico study confirm that memantine monotherapy is effective in the treatment of moderate to severe Alzheimer's disease, as assessed by various neuronal parameters.

The Computer Simulation of Therapy with the NMDA Antagonist in Excitotoxic Neurodegeneration in an Alzheimer's Disease-like Pathology.

(1) Background: The use of uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists results in neuroprotective benefits in patients with moderate to severe Alzheimer's disease. In this study, we demonstrated mathematical and computer modelling of the excitotoxicity phenomenon and performed virtual memantine therapy. (2) Methods: A computer simulation environment of the N-methyl-D-aspartate receptor combining biological mechanisms of channel activation by means of excessive extracellular glutamic acid concentration in three models of excitotoxicity severity. The simulation model is based on sliding register tables, where each table is associated with corresponding synaptic inputs. Modelling of the increase in extracellular glutamate concentration, through over-stimulation of NMDA receptors and exacerbation of excitotoxicity, is performed by gradually increasing the parameters of phenomenological events by the power function. Pathological models were virtually treated with 3−30 µM doses of memantine compared to controls. (3) Results: The virtual therapy results of memantine at doses of 3−30 µM in the pathological models of excitotoxicity severity show statistically significant neuroprotective benefits in AD patients with moderate severity, 1.25 (95% CI, 1.18−1.32) vs. 1.76 (95% CI, 1.71−1.80) vs. 1.53 (95% CI, 1.48−1.59), (p < 0.001), to severe, 1.32 (95% CI, 1.12−1.53) vs. 1.77 (95% CI, 1.72−1.82) vs. 1.73 (95% CI, 1.68−1.79), (p < 0.001), in the area of effects on memory. A statistically significant benefit of memantine was demonstrated for all neuronal parameters in pathological models. In the mild severity model, a statistically significant increase in frequency was obtained relative to virtual memantine treatment with a dose of 3 µM, which was 23.5 Hz (95% CI, 15.5−28.4) vs. 38.8 Hz (95% CI, 34.0−43.6), (p < 0.0001). In the intermediate excitotoxicity severity model, a statistically significant increase in frequency was obtained relative to virtual memantine therapy with a 3 µM dose of 26.0 Hz (95% CI, 15.7−36.2) vs. 39.0 Hz (95% CI, 34.2−43.8) and a 10 µM dose of 26.0 Hz (95% CI, 15.7−36.2) vs. 30.9 Hz (95% CI, 26.4−35.4), (p < 0.0001). A statistically significant increase in frequency was obtained in the advanced excitotoxicity severity model as in the medium. (4) Conclusions: The NMDA antagonist memantine causes neuroprotective benefits in patients with moderate to severe AD. One of the most important benefits of memantine is the improvement of cognitive function and beneficial effects on memory. On the other hand, memantine provides only symptomatic and temporary support for AD patients. Memantine is prescribed in the US and Europe if a patient has moderate to severe AD. Memantine has also been approved for mild to moderate AD patients. However, its very modest effect provides motivation for further research into new drugs in AD. We are the first to present a mathematical model of the NMDA receptor that allows the simulation of excitotoxicity and virtual memantine therapy.

Aesthetic and functional restoration of the dental arch continuity in difficult cases of impacted teeth within the frontal segment.

Impacted teeth are a fairly common defect with the incidence ranging from 2.9 to 13.7%. Evaluation of the efficacy and safety of various treatment modalities in patients with impacted teeth within the frontal segment of the maxilla. The retrospective evaluation covered treatment outcomes in 81 patients with impacted teeth within the aesthetic segment. The subjects were divided into 3 groups. Patients with the impacted tooth uncovered and orthodontically repositioned in the arch were assigned to group 1. Group 2 consisted of patients with the impacted tooth qualified for extraction and the gap augmented and restored with an implant. Group 3 included subjects, who underwent en-bloc autotransplantation of the impacted tooth. In 38 group 1 subjects 47 teeth were uncovered with a mean efficacy of 58.1% (96.3% and 70% in patients below 18 yoa and adults, respectively). The excellent aesthetic treatment outcome was obtained in 75% and good in 25% of patients. In group 2 twenty-six adult subjects were treated with 100% efficacy. In 65.4% of patients, augmentation with a bone block was performed and in the remaining 34.6%, implantation and augmentation with bone granulate. In 88.3% subjects a satisfying treatment outcome was obtained. In group 3 eighteen teeth in a block were grafted with the efficacy of 88.9%. Excellent aesthetics was obtained in 56.25% of cases and good in 31.25%. Orthodontic repositioning of the impacted teeth in the arch in adult patients bears the risk of failure. Surgical treatment modalities in impacted teeth are effective and provide high aesthetics of the treatment outcome improved by prior orthodontic treatment of the concomitant malocclusion and augmentation of the vertical bone atrophy before implantation.

Alternative Methods of Repositioning Impacted Maxillary Canines in the Dental Arch-En Bloc Autotransplantation of a Tooth.

OBJECTIVES: Permanent anterior tooth impaction constitutes an esthetic and medical challenge. The treatment of choice is orthodontic-surgical alignment of the impacted tooth into the arch. The procedure often proves to be unattainable due to the impacted tooth's unfavorable position in relation to the adjacent teeth; therefore, the decision to proceed with it can cause severe and irreversible complications in the form of adjacent tooth resorption or occlusal plane derangement. We present a new treatment modality to be used for cases of impacted canines, which consists of en bloc autotransplantation of a fully impacted tooth to the correct position in the dental arch. MATERIALS AND METHODS: Our study recruited patients with an impacted anterior maxillary canine tooth and an unfavorable prognosis due to its position in the arch after previous unsuccessful conventional orthodontic-surgical treatment. After orthodontic preparation, the problematic tooth was excised en bloc with adjacent bone and positioned correctly in the dental arch. RESULTS: The transplanted teeth remained alive and achieved proper stability with physiological mobility. CONCLUSIONS: Autotransplantation of an impacted, live, permanent tooth en bloc with adjacent bone is a new treatment modality with efficacy confirmed by short-term follow-up. It is the treatment of choice in cases where it is impossible to reposition a canine tooth with an orthodontic appliance. In view of the gathered data, adequate assessment and qualification of patients was crucial and allowed for a reduction in complications after unsuccessful orthodontic-surgical repositioning of impacted teeth.

En Bloc Autotransplantation of Retained Canine in the Mandible: A Case Presentation.

Missing canines compromise function and esthetics and therefore should be restored. In case of a retained canine, there can be a conservative approach of classic orthodontic eruption. If that is not effective, an alternative treatment method is to remove the retained tooth, followed by implant placement or transalveolar autotransplantation of the retained canine. En bloc autotransplantation of a retained canine, with surrounding bone, preserves canine periodontium and increases chances for revascularization and vitality of the transplanted tooth. This paper presents an en bloc autotransplantation of retained canines in the mandible in two female patients resulting in canine vitality after 1.5 years with proper pocket depth, physiologic tooth mobility, and positive reaction to ethyl chloride.

Allogeneic Bone Block Volume Preservation in Ridge Augmentation for Implants.

Allogeneic bone blocks are commonly used for bone augmentation in implant dentistry. Allogeneic bone blocks have the advantage of containing growth factors and the original human scaffold. A major disadvantage is the risk of substantial graft volume decrease due to resorption. The purpose of this study was to evaluate whether corticocancellous allogeneic bone blocks can predictably maintain graft volume to allow implant placement and esthetic restoration. A total of 141 allogeneic bone blocks were placed in 117 patients, allowing for 183 implants. The implant success rate was 96.7% after 6 to 96 months of follow-up.

Preparation of allogeneic bone for alveolar ridge augmentation.

Implant treatment is safe and predictable with sufficient amount and quality of bone tissue. In case of severely reduced bone tissue after a tooth was lost, augmentation of such tissue is necessary before implant embedment. Retrospective evaluation covered 380 alveolar ridge reconstructions. The study material consisted of human grafts prepared by the Department of Transplantology and Central Tissue Bank, Medical University of Warsaw. Presentation of laboratory procedures in the context of physical parameters of frozen, radiation sterilised, allogeneic corticocancellous material was presented. The preparation process makes it possible to obtain two types of bone material: granules and blocks. Women underwent 164 procedures with the use of bone granules and 61 augmentations with bone blocks. In case of men 122 packages of granules were used as well as 33 bone blocks. Based on the results an evaluation of usability of available allogeneic grafts was performed with reference to planned alveolar ridge augmentation procedures, which they were used for. 1. The opportunity to prepare allogeneic material of different textures allowed selection to meet augmentation requirements while providing biological safety. 2. Allogeneic granules should be used in multi-wall defects, such as a double, closed sinus lift and post-extraction socket augmentation. 3. Owing to their superior mechanical parameters, bone blocks were successfully used in extending the width and height of the alveolar ridge and in open sinus lifts with one-wall or two-wall defects and adequate location of the lamellar bone in a graft prevented substantial graft resorption.

Evaluation of treatment outcomes and clinical indications for antibiotic prophylaxis in patients undergoing implantation procedures.

PURPOSE: The use of antibiotic therapy during implantation to reduce the risk of an early implant failure is widely discussed among clinicists. However, half an hour after the procedure a quarter of patients show bacteremia which could decrease the efficacy of the surgery. Implant failure is associated with destruction of bone tissue within the alveolar process and may lead to an alternative but compromised treatment plan. The aim of the study was to evaluate the influence of perioperative antibiotic protection on success of implantation. MATERIAL AND METHODS: The retrospective study involved 1915 patients (females: 57.3%, males: 42.7%) with no systemic or local diseases, who required antibiotic therapy during surgical procedures. Group 1 comprised 203 patients with diagnosed vertical or horizontal bone atrophy within the alveolar ridge requiring reconstruction procedure before implantation. Group 2 included 1712 patients who did not need any surgical procedures before implantation. All the subjects took three types of antibiotics twice a day for 7 days. The data were statistically analyzed. RESULTS: A total number of 3309 implants were placed. Implantation efficacy in group 1 amounted to 98.53% and in group 2 it was 99.24%. Complications occurred most commonly after administration of cephalosporin which proved to be statistically significant for the patients who underwent augmentation with a bone block before the implant procedure (p 0.0209). CONCLUSIONS: Perioperative use of antibiotic therapy beneficially influences tissue healing, provides safety and success of the surgical procedure, as well as translates into high efficacy of implantation (99.52%).

Long-term outcomes of the use of allogeneic, radiation-sterilised bone blocks in reconstruction of the atrophied alveolar ridge in the maxilla and mandible.

Increasingly dental surgeons face the challenge of reconstruction of the height and/or thickness of the alveolar ridge as more and more patients wish to have permanent restoration of their dental defects based on intraosseous implants. Evaluation of human allogeneic bone tissue grafts in reconstruction of atrophied alveolar ridge as a pre-implantation procedure. The material comprised 21 patients aged 19-63, treated between 2009 and 2012 by the same surgeon. Restoration of bone tissue defects was performed with allogeneic, frozen, radiation-sterilised, corticocancellous blocks. The study included 26 grafting procedures with 7 procedures consisting in reconstruction of the alveolar ridge in the mandible and 19 in the maxilla. In all the cases the atrophied alveolar ridge was successfully reconstructed, which allowed placement of intraosseous implants in compliance with the initial treatment plan. After the treatment was completed the patients reported for follow-up annually. The average time of follow-up amounted to 39 months (28-50 months). None of the implants was lost during the follow-up period. There was one case of gingival recession causing aesthetics deterioration of the prosthetic restoration. In three cases the connector became unscrewed partially, which was corrected at the same visit. Frozen, radiation-sterilised, allogeneic bone blocks constitute good and durable bone-replacement material allowing effective and long-lasting reconstruction of the atrophied alveolar ridge to support durable, implant-based, prosthetic restoration.

Two-stage closed sinus lift: a new surgical technique for maxillary sinus floor augmentation.

Bone tissue atrophy may constitute a relative contraindication for implantation. The methods used in reconstruction of the alveolar ridge within the lateral section of the maxilla have been well known but not perfect. Presentation of the two-stage, closed sinus lift technique as well as efficacy evaluation of reconstruction of the alveolar ridge in the maxilla within its vertical dimension with the use of this technique. The total procedure was performed in 26 out of 28 patients qualified for the study. The height of the alveolar ridge at the site of the planned implantation was no <3 mm, the width of the ridge was no <5 mm. During the treatment stage 1 the sinus lift was performed for the first time. The created hollow was filled with allogeneic granulate. After 3-6 months stage 2 was performed consisting in another sinus lift with simultaneous implantation. The treatment was completed with prosthetic restoration after 6 months of osteointegration. In 24 out of 26 cases stage 1 was completed with the average ridge height of 7.2 mm. In stage 2, simultaneously with the second sinus lift, 26 implants were placed and no cases of sinusitis were found. In the follow-up period none of the implants were lost. The presented method is efficient and combines the benefits of the open technique-allowing treatment in cases of larger reduction of the vertical dimension and the closed technique-as it does not require opening of the maxillary sinus.

Global maxillary ridge augmentation with frozen radiation-sterilised bone blocks followed by implant placement: a case report.

Due to atrophy of the tissue within the alveolar ridge, implantation must sometimes be preceded by bone regeneration. The use of allogeneic material allows the surgeon to prepare grafts of any shape and amount; therefore it is a good alternative to autograft reconstruction in patients with extensive atrophy of the alveolar ridge. The patient with maxillary anodontia showed insufficient width of the ridge along its entire length, which prevented implantation. Therefore, alveolar ridge reconstruction was planned. Four frozen, radiation-sterilised bone blocks processed in the Tissue Bank in Warsaw were used for reconstruction of the alveolar ridge. The blocks were grafted to the area of molars, premolars and lateral incisors bilaterally. Three months after surgery a normal union of transplants with the recipient site was achieved. Six implants were embedded and following the 6-month integration period a permanent prosthetic restoration was successfully performed. During a 38-month follow-up none of the implants were lost and the aesthetic or functional condition of the prosthetic restoration did not deteriorate. Frozen allogeneic radiation-sterilised bone blocks constitute good, efficient and safe material used in reconstruction of the alveolar ridge in extensive bone atrophy. This is only one of possible grafting materials for reconstruction of extremely atrophic alveolar ridge.

Safety and efficacy of bone wax in patients on oral anticoagulant therapy.

Cardiovascular conditions, apart from neoplastic diseases, remain the major cause of death in developed countries; therefore, the number of patients receiving oral anticoagulants is constantly increasing. Anticoagulant therapy considerably reduced mortality in patients with history of myocardial infarction among others. Although many interventions may be performed without withdrawal of the anticoagulant and tooth extraction was qualified as a procedure of low hemorrhage risk, a majority of dentists refer the patient to a cardiologist several days before the elective tooth extraction to withdraw anticoagulants. The aim of the study was to evaluate the efficacy and safety of bone wax used to stop bleeding after dental procedures in a group of patients on chronic anticoagulant therapy and find an answer to a question, whether it is justified to temporarily withdraw anticoagulants for this type of procedures. The study involved 176 patients on chronic anticoagulant therapy undergoing tooth extraction (154 subjects) or surgical extraction of a retained tooth (48 subjects). After the procedure, in each case the alveolus was filled with bone wax to stop bleeding. In all patients involved in the study bleeding from the alveolus was successfully stopped during the procedure. None of the subjects reported increased bleeding from the operational site after coming back home. Bone wax is a good, efficient, and safe material to block bleeding from the alveolus following tooth extractions, also in patients on chronic anticoagulant therapy. The study demonstrated that withdrawal or adjustment of anticoagulant therapy is not necessary before an elective tooth extraction.

Allogeneic materials in complications associated with pre-implantation restoration of maxillary and mandibular alveolar processes. A four case report.

There are numerous types of bone replacement materials used to regenerate atrophic alveolar processes before the elective intraosseous implantation. Properties of these materials differ one from another, therefore the choice of material should be thoroughly analysed as well as its type and texture in regard of intraoral conditions and the objective to be achieved. The study involved reconstruction of atrophic alveolar processes with allogeneic bone following unsuccessful use of synthetic and animal materials. The procedure of bone regeneration was performed with frozen bone block (case 1) and allogeneic bone granulate (cases 2, 3, 4) radiation-sterilised with 35 kGy prepared by the Tissue Bank. In all of the presented cases after 3-month implant reorganisation optimal width of the process was obtained, which allowed implant embedment (case 1) or correct implant submergence in the osseous tissue, when implantation took place at the same time (case 2, 3, 4). Allogeneic bone material both, in the form of a block as well as granulate, seems to be an adequate alternative for other materials used in order to widen the bone of the alveolar process, particularly in difficult, complicated cases, where the first regeneration procedure was not successful.

Analysis of effect of non-steroidal anti-inflammatory drugs on teeth and oral tissues during orthodontic treatment. Report based on literature review.

In view of high availability and diversity of non-steroidal anti-inflammatory drugs (NSAIDs) on Polish market it is important for orthodontists to be aware of NSAID effect on the range of orthodontic tooth movement as well as the risk of root resorption in the moved teeth and other adverse effects, which might occur within oral cavity. The disadvantages of NSAID non-selective inhibition of COX include common oral inflammatory conditions, gingival bleeding, and disturbances of salivary secretion. Both, the selective and non-selective COX inhibitors, meloxicam excluded, used to alleviate the pain of orthodontic tooth movement, impede the movement of teeth. Paracetamol, explicitly indicated by most authors as the safest NSAID, seems to be the drug of choice in view of no influence on the range of tooth movement, the risk of root resorption or other adverse effects within oral cavity.

Evaluation of safety and efficacy of radiation-sterilized bone allografts in reconstructive oral surgery.

Bone grafting allows reconstruction of the atrophied or destroyed alveolar process. In orthopaedics and traumatology allogeneic grafting has been used to restore defects of osseous tissue for over 60 years. In order to improve safety of the graft recipient, sterilized allogeneic grafts have been use. The aim of the study was to assess the direct and long-term outcomes following augmentation of atrophied alveolar processes with the use of radiation-sterilized allogeneic bone grafts. Sixty-eight patients were surgically treated between 2004 and 2011: 29 underwent open sinus floor elevation, post-extraction alveoli augmentation was performed in 16 subjects and 23 underwent reconstruction of the atrophied alveolar process. Augmentation of bone defects used bone granulate in 63 patients and bone blocks stabilized with titanium screws in 5 patients. PRF membranes collected from the patient's blood were also used in all the procedures. In each of the cases optimal dimensions of the alveolar process were obtained allowing embedment of BIOMET 3I dental implant/-s. In all the patients the defects were successfully restored with implant-supported prostheses. Radiation-sterilized allogeneic bone grafts proved to be safe and effective for the patients and manageable for the surgeon constituting a good alternative to autogeneic material.

Relative nasopharyngeal patency index as possible objective indication for adenoidectomy in children with orthodontic problems.

OBJECTIVES: Although the harmful influence of nasopharyngeal obstruction on the facial skeleton has been demonstrated, clear criteria to qualify children with adenoid hypertrophy and malocclusion for adenoidectomy have not been established yet. METHODS: Retrospective analysis of 148 patients qualified for orthodontic treatment (77 females and 71 males) at the age of 9-11 years (the average age was 10 years and 3 months). X-ray images performed with the use of a cephalostat were scanned and submitted for cephalometric assessment. The study investigated the correlation between standard cephalometric parameters and the value of relative nasopharyngeal flow defined as the ratio of the nasopharyngeal flow to the dimension of the entire nasopharynx. In statistics Bartlett's test, Tukey's test and Pearson's correlation coefficients were used. RESULTS: The value of relative nasopharyngeal lumen ranged from 0.0943 to 0.5532 with no significant differences between genders. The subjects were divided into decile groups for investigating the correlation with cephalometric parameters. The study demonstrated statistically significant negative correlations between relative nasopharyngeal flow and the following parameters: the angle between lines NA and NB (ANB), the angle between lines SN and ML (SN/ML), the posterior/anterior facial height ratio (Post.Fac.H./Ant.Fac.H.), the difference between the maxillary and mandibular length (difference maxillary/mandibular), the mandibular length (Co-Gn) and the lower anterior facial height (Sn-Me). The correlations generally referred to middle deciles: from the 40th to 80th decile. An apparent lack of significant correlations in patients located below the 40th decile, which corresponded to the value of relative nasopharyngeal flow up to 18%, may indicate, that this value constitutes a threshold and further decreasing it exceeds adaptive capabilities of the body. CONCLUSIONS: Relative nasopharyngeal flow below 38% should constitute an indication for adenoidectomy, due to the exceeded adaptive capabilities of the body.

Patency of nasopharynx and a cephalometric image in the children with orthodontic problems.

OBJECTIVES: To study a possible impact of adenoidectomy on malocclusion on the base of cephalometry. METHODS: Retrospective analysis of 148 patients qualified into the orthodontic treatment (77 girls and 71 boys) at the age of 9-11 years (an average age: 10 years and 3 months). Material was divided into three groups, equalized regarding sex and age. The first one consisted of the patients after adenoidectomy, at the moment of orthodontic assessment without any organic pathology within a nasal cavity or nasopharynx. To the second group were included children who for different reasons were not a subject of adenoidectomy despite clinical diagnosis of adenoid hypertrophy. In the third group were patients whose only problem was malocclusion. X-ray pictures taken on a cephalostate were scanned and given to cephalometric assessment. In statistics Bartlett's test, Tukey's test and Pearson's correlation coefficients were used. RESULTS: The significant differences with respect to many skull parameters appeared among the groups. The inappropriate respiratory habits find their reflection mainly within anterior and lower anterior facial height, angle of mandibular plane, nasopharyngeal flow and dental parameters. An evident beneficial influence of adenoidectomy is observed within a period of 36-41 months after an operation. Nasopharyngeal flow is the most sensitive parameter indicating the respiratory conditions, and is strongly connected with the key cephalometric parameters. CONCLUSIONS: In cases of malocclusion of skeletal character, coexisting with adenoid hypertrophy, adenoidectomy should be carried out as early as possible.