Naturalistic psilocybin use is associated with persisting improvements in mental health and wellbeing: results from a prospective, longitudinal survey

Introduction

The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain limited.

Methods

This prospective, longitudinal study comprised six sequential automated web-based surveys that collected data from adults planning to take psilocybin outside clinical research: at time of consent, 2 weeks before, the day before, 1-3 days after, 2-4 weeks after, and 2-3 months after psilocybin use.

Results

A sample of 2,833 respondents completed all baseline assessments approximately 2 weeks before psilocybin use, 1,182 completed the 2-4 week post-use survey, and 657 completed the final follow-up survey 2-3 months after psilocybin use. Participants were primarily college-educated White men residing in the United States with a prior history of psychedelic use; mean age = 40 years. Participants primarily used dried psilocybin mushrooms (mean dose = 3.1 grams) for "self-exploration" purposes. Prospective longitudinal data collected before and after a planned psilocybin experience on average showed persisting reductions in anxiety, depression, and alcohol misuse, increased cognitive flexibility, emotion regulation, spiritual wellbeing, and extraversion, and reduced neuroticism and burnout after psilocybin use. However, a minority of participants (11% at 2-4 weeks and 7% at 2-3 months) reported persisting negative effects after psilocybin use (e.g., mood fluctuations, depressive symptoms).

Discussion

Results from this study, the largest prospective survey of naturalistic psilocybin use to date, support the potential for psilocybin to produce lasting improvements in mental health symptoms and general wellbeing.

Fiberotomy enhances orthodontic tooth movement and diminishes relapse in a rat model

OBJECTIVES

Accelerated orthodontic tooth movement is triggered by procedures that include mucoperiosteum flap surgery and surgical scarring of cortical bone. Our aim was to test whether fiberotomy by itself will accelerate orthodontic tooth movement and diminish relapse.

MATERIALS AND METHODS

In 34 Wistar rats, alveolar bone resorption and molar tooth movement were measured after fiberotomy, apical full-thickness flap without detachment of gingiva from the roots, or no surgery. Orthodontic appliance was installed at time of surgery and activated for 14 days, generating movement of the first maxillary molar buccal and then removed.

RESULTS

Percent of sections in which alveolar bone resorption was detected was significantly higher (p < 0.05) after fiberotomy (27%) in comparison with apical flap surgery (12%) or no surgery (6%), after 30 days. Also, at the end of active phase, the molar moved significantly faster (p < 0.01) and twice the distance after fiberotomy (0.54 ± 0.33) in comparison with apical surgery (0.26 ± 0.12) or no surgery (0.3 ± 0.09). Sixteen days after the appliance was removed, only 12% relapse was recorded in the fiberotomy group, while almost total relapse in other two groups.

CONCLUSION

We conclude that fiberotomy solely accelerated orthodontic tooth movement and diminished relapse.

Influence of bone-derived matrices on generation of bone in an ectopic rat model

Most bone regeneration experimental models that test bone-derived matrices take place in conjunction with the native bone. Here, we compared the relative effectiveness of bone matrix components on bone-marrow-directed osteogenesis in an ectopic model. Cortical bone cylinders consisted of diaphysis of DA rat femurs. They were either demineralized (DBM), deproteinized (HABM), or nontreated (MBM). Fresh bone marrow was placed into cylinders and implanted at subcutaneous thoracic sites of 2-month-old DA rats. At designated times the cylinders were surgically removed from the animals. Microradiographs of DBM and histology of DBM and MBM cylinders demonstrated progressive increase in mineralized bone volume and its trabecular configuration. Bone filled the inner volume of DBM and MBM cylinders within 4 weeks, while in HABM cylinders mostly granulation tissue developed. In the DBM cylinders cartilage deposited within 10 days, while in the MBM cylinders bone was directly deposited. As early as day 3 after marrow transplantation, marrow cells interacting with DBM increased significantly the genes that express the cartilage and the bone phenotype. In conclusion, organic components of bone are needed for marrow-directed osteogenesis.

Molecular signaling in bone regeneration

Regeneration is the ability of cells to restore lost or damaged tissues and organs in adults by pathways that mimic developmental processes. Although many of the molecular mechanisms that control cellular differentiation and growth during embryogenesis recur during fracture healing, these processes take place in a postnatal environment that is unique and distinct from those that exist during embryogenesis. Bone tissue has a remarkable capacity of regeneration without scarring. This article highlights central biological and molecular processes that are crucial in embryonic bone development. Several animal bone regeneration models are described. The patterns of gene expression during the regeneration process in the different models are reviewed. Exploring the similarities and the differences in the molecular processes in different models will contribute to the understanding of their potential in the processes of bone regeneration and tissue engineering.

P2X4 is up-regulated in gingival fibroblasts after periodontal surgery

Several studies have shown that surgical detachment of marginal gingiva close to the cervical cementum of molar teeth in a rat mandible is a distinct stimulus for alveolar bone resorption. Recently, we found that P2X4, an ATP-receptor, is significantly up-regulated in marginal gingival cells soon after surgery. We hypothesized that local release of ATP signaling through P2X4 elicits activation of osteoclasts on the alveolar bone surface. In this study, we identified intense immunoreactivity of gingival fibroblasts to P2X4-specific antibodies and a 6.4-fold increase in expression by real-time RT-PCR. Moreover, a single local application, at the time of surgery, of Apyrase (which degrades ATP) or Coomassie Brilliant Blue (an antagonist of purinoreceptors) significantly reduced alveolar bone loss. We propose that ATP flowing from cells after surgery can directly activate P2X4 receptors in the sensor cells of marginal gingiva through Ca(2+) signaling, or by direct activation of osteoclasts on the bone surface.

Effect of low intensity laser irradiation on surgically created bony defects in rats

Low intensity lasers have been used by clinicians to improve healing and reduce pain in humans. Lasing also results in new bone formation around hydroxyapatite implants and a significant increase in the total bone area. However, the exact mechanism of cell biostimulation by laser is still unclear. This study biochemically assessed the effects of low intensity laser (Gallium-Arsenide) using 4 and 22.4 mW cm(-2) power density on the bone healing process after surgically creating bony cavities in rat mandibles. Rats (n = 24) were divided into two groups each treated with specific energy, 4 or 22.4 mW cm(-2), for 3 min each day post-surgery. Surgical cavities were created on both sides of the mandible: the left served as an untreated control, the right was treated with laser. All rats were sacrificed after 1, 2 and 4 weeks of treatment. In the newly formed callus, accumulation of radiocalcium and alkaline phosphatase activity was measured to indicate osteogenic activity. One-way anova with repeated measures showed that the low intensity laser using 4 mW cm(-2) power density significantly increased radiocalcium accumulation from 2 weeks post-surgery, whereas 22.4 mW cm(-2) had no effect. No changes were noted in the activity of alkaline phosphatase with the laser treatment. These results suggest that laser therapy of low power density is effective on the bone healing process in artificially created osseous cavities by affecting calcium transport during new bone formation.

Insulin pump therapy vs. multiple daily injections in obese Type 2 diabetic patients

AIMS

To compare the efficacy of insulin pump treatment with multiple daily injections in the treatment of poorly controlled obese Type 2 diabetic patients already receiving two or more daily injections of insulin plus metformin.

METHODS

Forty obese Type 2 diabetic subjects (using insulin) were randomized to treatment with continuous subcutaneous infusion pump (CSII) (Minimed) or multiple daily insulin injections (MDI). At the end of the first 18-week treatment period, patients underwent a 12-week washout period during which they were treated with MDI plus metformin. They were then crossed-over to the other treatment for an 18-week follow-up period. Patients performed 4-point daily self blood-glucose monitoring (SBGM) on a regular basis and 7-point monitoring prior to visits 2, 8, 10 and 16. A subset of patients underwent continuous glucose monitoring using the Minimed(R) continuous glucose monitoring system (CGMS) at visits 2, 8, 10 and 16. A standard meal test was performed in which serum glucose was tested at fasting and once each hour for 6 h following a test meal. Glucose levels were plotted against time and the area under the curve (AUC) was calculated. HbA(1c), weight, daily insulin dose and hypoglycaemic episodes were recorded.

RESULTS

In obese Type 2 diabetic patients already treated with insulin, treatment with CSII significantly reduced HbA(1c) levels compared with treatment with MDI. An additional CSII treatment benefit was demonstrated by reduced meal-test glucose AUC. Initial reduction of daily insulin requirement observed in CSII-treated subjects during the first treatment period was attributable to a period effect and did not persist over time.

CONCLUSIONS

In the intent-to-treat analysis, CSII appeared to be superior to MDI in reducing HbA(1c) and glucose AUC values without significant change in weight or insulin dose in obese, uncontrolled, insulin-treated Type 2 diabetic subjects.

Use of complementary and alternative medicine among cancer patients in Israel

Complementary and alternative medicine (CAM) has gained in popularity among cancer patients in recent years. The present study assessed the patterns of CAM use among cancer patients in Israel. The design of the study was descriptive cross-sectional, and data were collected using a 27-item questionnaire. The sample consisted of 111 Israeli cancer patients who were part of a larger European study. Among the participants, past or current CAM use was reported by 32.4% (n=36). The most common therapies used included herbal medicine (22.2%), spiritual therapies (19.4%), visualization and relaxation techniques (16.7% for each), and vitamins/minerals (13.9%). Younger patients with higher education, higher annual income, and previous standard treatment were more likely to use CAM. The mean satisfaction and perceived effectiveness scores were 5.36+/-1.37 and 5.48+/-1.39, respectively, out of a maximum score of 7. The main benefits from CAM reported by patients included improvement in emotional and physical well-being (40% and 34.3%, respectively) and increased ability to fight the disease (31.4%), although 17.1% of patients reported no benefits at all from CAM. The main sources of information about CAM were friends/family and the media. Findings suggest that due to the relatively high use of CAM among cancer patients, this topic should be taken into account in a holistic approach to this patient population.

Combined local application of tetracycline and bisphosphonate reduces alveolar bone resorption in rats

BACKGROUND

Recent animal studies have shown that a combination of chemically-modified tetracyclines together with bisphosphonates, when delivered systemically, are synergistically effective in suppressing periodontal bone loss. In the present study, we explored the combined efficacy of local delivery of alendronate and tetracyclines in reducing alveolar bone loss.

METHODS

Eighty-six (86) male Wistar rats were used in these experiments. The flap was elevated using a special periosteal elevator, on both sides of the mandible, as described previously. A gelfoam pellet containing the drugs was applied between the alveolar bone and the mucoperiosteal flap, according to the experimental protocol. The rats were divided into 5 treatment groups: 1) alendronate; 2) doxycycline hyclate 10% (DOXY); 3) tetracycline hydrochloride 1% (TET); 4) alendronate + DOXY; and 5) alendronate + TET. In the operated control sites (C), saline was applied. The rats were sacrificed 21 days following the flap procedure. Sections of the mandibles (1.5 mm), in a buccal-lingual direction, underwent microradiography and were analyzed for bone loss.

RESULTS

DOXY alone was most effective in reducing bone loss. Alendronate was also effective in reducing bone loss as shown in previous reports. TET did not reduce bone loss significantly when used alone. In combination with alendronate TET was synergistically effective. The combined local treatment of alendronate + DOXY showed no additive effect.

CONCLUSIONS

In the present study, we found that tetracyclines can be most effective in reducing alveolar bone loss when applied locally. The combined local treatment of alendronate and tetracycline may have a synergistic effect.

Alveolar bone resorption following coronal versus apical approach in a mucoperiosteal flap surgery procedure in the rat mandible

BACKGROUND

In several publications, we have reported that a distinct resorptive phase of alveolar bone developed during 3 weeks following elevation of a mucoperiosteal flap in rats by a coronal surgical approach. In the present study, we compared the alveolar bone loss after mucoperiosteal flap surgery by a coronal approach (COR) to a surgical approach incising the mucosa close to the tooth apices and separating the mucoperiosteum toward the tooth crown (apical approach, AP).

METHODS

Eighteen Wistar rats were divided into 2 experimental groups; each group consisted of 9 rats. In the first group, COR was performed on both buccal and lingual aspects on the right side of the rat mandible, while the left side served as a sham-operated control. In the second experimental group, AP was performed.

RESULTS

In the AP group, the outer aspect (buccal or lingual) of the alveolar bone was slightly resorbed usually at the level where the mucosa was incised. In many sections, extensive modeling of new trabecular bone was seen, coronal to the surgical incision. On the contrary, the coronal surgical approach revealed an extensive resorptive phase, mainly of the periodontal aspect of the alveolar bone.

CONCLUSIONS

The results of this study show that periodontal surgery by a coronal surgical approach stimulates a burst of remodeling of the alveolar bone in a very specific pattern.

[Splinting--a review of the literature]

Early evidence for the use of splints can be seen in ancient civilizations, but the concept of Splinting teeth to support and immobilize teeth, by joining several teeth together continues to be a topic of controversy. Splints can be classified based on their purpose and duration of use, the way of fabrication, and the location of the splinted teeth in the jaw. The biomechanical mechanism of splint is related to the mechanism of tooth mobility. The indications for splint usage in the healthy and diseased periodontium are variable, among them are: prevention of mobility after acute trauma, for occlusal therapy, to allow function, to allow periodontal repair, in case of occlusal trauma, to prevent teeth drifting after orthodontic treatment or when a tooth is missing. Due to the many disadvantages splints have, splinting should be used cautiously, specially in splinting teeth and implants.

The effect of topical delivery of novel bisacylphosphonates in reducing alveolar bone loss in the rat model

BACKGROUND

Periodontal surgery stimulates osteoclast activity, leading to varying amounts of alveolar crest loss. We have established that topical application of 20 mg/ml of alendronate placed at the surgical mucoperiosteal site produced a striking reduction of alveolar bone loss in the rat model. The aim of this investigation was to examine the antiresorptive efficacy of 3 novel bisacylphosphonates topically delivered at the surgical site, in comparison to alendronate and etidronate which are in clinical use.

METHODS

Mucoperiosteal flap (MF) surgery was performed on the buccal and lingual aspects next to molars on both sides of the rat mandible. A gelatin sponge soaked in the bisphosphonate solution prepared by dissolving 20 mg of the bisphosphonate (alendronate, etidronate, VS-5, VS-6, ISA-13, SuBP) in 1 ml of saline was applied to exposed bone on the right side of the mandible (experimental, MF + BPs ) and the left side was treated with saline only (control, MF + S). Sections were evaluated for bone loss using microradiography pattern and amount.

RESULTS

The 3 novel bisacylphosphonates, VS-5 VS-6, and ISA-13 were more effective than etidronate, and less effective than alendronate. The most effective among this group was ISA-13 followed by VS-5 and VS-6.

CONCLUSION

We conclude that ISA-13-like alendronate is effective in reducing alveolar bone loss when delivered at surgical sites. Since ISA-13 is well absorbed through mucose tissues, we suggest that ISA-13 efficacy on reducing bone loss should be tested by its application on the mucosal tissue.

Effectiveness of local delivery of alendronate in reducing alveolar bone loss following periodontal surgery in rats

BACKGROUND

Mucoperiosteal flaps are used to access bone and root surfaces for debridement, pocket elimination, management of periodontal defects, and in regenerative procedures, as well as in implant surgery. Many reports show that periodontal surgery stimulates osteoclast activity with varying amounts of alveolar bone loss. Alendronate given intravenously significantly reduced alveolar bone loss in mucoperiosteal flap procedures. In the present study, we explored the effectiveness of different concentrations of alendronate, delivered at the surgical site at the time of surgery, in distant delivery in reducing alveolar bone loss.

METHODS

Following elevation of a mucoperiosteal flap next to molars of the rat mandible, a gelatin sponge soaked with different concentrations of alendronate (0, 1, 5, 20, or 40 mg/ml; experiment A) was applied to exposed bone on the experimental side. In the second group (experiment B), alendronate (0, 50, 200, or 400 microg) was topically delivered in the cheek submucosa on the left side (distant to the surgical site) in a small cut into which the gelatin sponge soaked with the drug was placed.

RESULTS

Topical application of 200 microg and 400 microg doses of alendronate at the time of surgery was significantly effective (P <0.001) in reducing bone loss. Generally, the percentage of sections with mild bone loss (V1, V2) increased with an increase in the dose of alendronate, while the percentage of sections with severe bone loss (H1, H2) decreased with an increase in alendronate dose. Topical application of 400 microg of alendronate had a systemic effect.

CONCLUSIONS

This study implies that topical delivery of alendronate at the time of surgery reduces bone loss in periodontal procedures involving mucoperiosteal flap surgery. The most effective dose is 200 microg for topical delivery at the surgical site and 400 microg for distant sites.

Disposition of alendronate following local delivery in a rat jaw

BACKGROUND

Recently, we have shown that local delivery of alendronate reduced significantly bone resorption activated by surgical separation of periosteum from bone. These results advocate the use of local application of alendronate in bone surgeries to prevent regional bone resorption at the surgery site. Here we investigated the efficacy of absorbtion of alendronate by the bone from a gelatin sponge soaked with radiolabeled alendronate applied topically at the surgical site.

METHODS

Following elevation of the mucoperiosteal flap next to premolars and molars of the rat mandible, a gelatin sponge soaked with 10 microl of radiolabled alendronate (1 microCi/mg) was applied to exposed bone on one side. The local absorbtion of alendronate and its disposition in the contralateral side of the mandible as well as in the tibia bone were analyzed.

RESULTS

The results show that 10% of total alendronate content of the gelatin sponge was absorbed in the bone locally (in the surgical site), while 0.2% was disposed in the tibia. Of interest is the fact that the surgical wound in the contralateral side increased the disposition of alendronate up to 2%. This finding is most likely the result of extravasation and diffusion of alendronate due to surgical wounding.

CONCLUSION

This study strongly supports our notion that local delivery of alendronate and its affinity to bone may become a very important treatment modality to prevent resorption of bone during dental and orthopedic procedures.

Treatment of noninfectious intermediate and posterior uveitis with the humanized anti-Tac mAb: a phase I/II clinical trial

To evaluate the safety and potential therapeutic activity of humanized anti-IL-2 receptor mAb (Daclizumab) therapy in the treatment of patients with severe, sight-threatening, intermediate and posterior noninfectious uveitis, a nonrandomized, open-label, pilot study was performed. Patients with uveitis were treated with a minimum of 20 mg of prednisone, cyclosporine, antimetabolites, or any combination of these agents were eligible. Patients were weaned off their systemic immunosuppressive agents according to a standardized schedule, while ultimately receiving Daclizumab infusions every 4 weeks. Anti-IL-2 receptor antibody therapy, given intravenously with intervals of up to 4 weeks in lieu of standard immunosuppressive therapy, appeared to prevent the expression of severe sight-threatening intraocular inflammatory disease in 8 of 10 patients treated over a 12-month period, with noted improvements in visual acuity. One patient met a primary endpoint with a loss of vision of 10 letters or more from baseline in one eye and another patient discontinued therapy because of evidence of increased ocular inflammation. All patients were able to tolerate the study medications without the need for dose reduction. We report effective long-term use of anti-IL-2 therapy for an autoimmune indication. These initial findings would suggest that anti-IL-2 receptor therapy may be an effective therapeutic approach for uveitis and, by implication, other disorders with a predominant Th1 profile.

Local delivery of an amino bisphosphonate prevents the resorptive phase of alveolar bone following mucoperiosteal flap surgery in rats

Mucoperiosteal flaps are used to access the bone and root surface in a wide range of periodontal procedures and in implant surgery. We have demonstrated that the mucoperiosteal surgical flap of the rat mandible produces a transient burst of alveolar bone resorption similar to the clinical observations in humans. This resorptive activity, when coupled with local irritation factors, may cause confined alveolar bone loss. Recently, we have demonstrated that an amino bisphosphonate, which is used in preventing systemic bone resorption in osteoporosis and other bone diseases, reduces alveolar bone resorption in the rat model when administered systemically. In this study we evaluated the effect of local delivery of the amino bisphosphonate on bone resorption associated with mucoperiosteal flaps. Following mucoperiosteal flap elevation in the premolar and molar region of the rat mandible, a surgical pellet soaked with amino bisphosphonate was locally applied on the exposed bone surface and covered by flap. The results show that local delivery of amino bisphosphonate reduces significantly alveolar bone resorption activated by mucoperiosteal flap surgery. This study suggests that local application of amino bisphosphonate can be used as an adjunct in therapy for reducing bone resorption following surgery.

Physiologic occlusion vs pathologic occlusion and rationale for treatment

Treatment concepts in dentistry are generally based on a preconceived normal state derived from clinical observation and theories rather than scientific evidence. Before treatment is proposed, the clinician should observe physiologic signs and symptoms to determine the presence of a particular pathology. This article presents different theories of occlusion, diagnostic characteristics that can be used to distinguish between physiologic occlusion and pathologic occlusion requiring treatment, and guidelines for reconstructive occlusal therapy.

Diagnosis and mode of treatment for 'pseudo'-Class III patients and its effects on masticatory movements

This paper describes the treatment and functional analysis of 18 'pseudo'-class III patients. Clinical examination revealed IC-RC discrepancies, aesthetic aberrations and functional disturbances. The improvement of these parameters upon treatment was followed by sirognathographic recordings.

Inhibition of 2-5A synthetase expression by antisense RNA interferes with interferon-mediated antiviral and antiproliferative effects and induces anchorage-independent cell growth

It has been shown previously that the IFN-induced enzyme 2-5A synthetase is sufficient to induce antiviral and antiproliferative effects in transfected cells expressing the protein. In this study, the possibility that this enzyme is also essential in generating these biological activities was investigated. For this purpose, a plasmid, pMSas-NEO, was constructed. This plasmid carries an active neomycin-resistant gene. In addition, it contains a metallothionein promoter fused to an inverted 180-bp fragment derived from the 5' end of cDNA encoding the 43-kDa isoform of murine 2-5A synthetase. NIH/3T3 mouse fibroblasts were transfected with the plasmid, about 50 neomycin-resistant clones were isolated, and two, clone 11 and clone 22, were chosen for further studies. One clone transfected only with the neomycin-resistant gene, clone Neo, was used as a control. The results show that in the case of clone 11, the combined treatment of IFN and ZnCl2 reduced significantly the level of the IFN-induced 2-5A synthetase activity, the amount of the 40-, 43-, and 71-kDa 2-5A synthetase isoforms and the level of the 1.7-kb specific RNA transcript. An even stronger effect on these parameters was observed with clone 22 cells. No difference in PKR activity was evident under the same conditions with all three clones tested. Most important, the combined treatment of IFN and ZnCl2 reversed the IFN-mediated antiproliferative and antiviral activities, as determined by the kinetics of cell growth, thymidine incorporation, cloning efficiency, and infection with mengovirus. Strikingly, the growth of colonies in soft agar were observed in both clone 11 (small colonies) and clone 22 (large colonies) cells, particularly following treatment with ZnCl2. We conclude that 2-5A synthetase is an essential component in the IFN-induced biological activities and that interference with its function results in anchorage-independent growth of the transfected cells.

Skeletal and functional effects of treatment for unilateral posterior crossbite

Unilateral posterior crossbite (UPXB) is a common malocclusion, frequently presenting a lower midline deviation, accompanied by Class II subdivision relationships in final closure and a very high prevalence of the reverse sequencing (RS) pattern of jaw movement. These features often persist even after the elimination of the crossbite. The purpose of the present study was to examine in detail the morphologic, skeletal, and functional effects of the treatment for this malocclusion category. The experimental group consisted of 24 children in the mixed dentition stage with UPXB who were treated with removable expansion plates and a control group of 10 age-matched children with normal occlusion. Longitudinal follow-up revealed a stable dental maxillary arch expansion of at least 1.5 mm but a complete elimination of crossbite in only 50% of the cases. The frequent persistence of Class II subdivision relations and lower midline deviation that were not due to functional mandibular shift was striking. The pretreatment posteroanterior (P-A) cephalograms indicated reduced facial and maxillary widths. After treatment, the achieved maxillary width increase was greater than expected with normal growth. Longitudinal assessment of the mandibular movement response revealed by the electrognathograph showed a high prevalence of RS, which was reduced after treatment. In conclusion, (1) a higher than expected prevalence of skeletal transverse aberrations at the maxillary and zygomatic levels were found in the UPXB group; (2) the removable expansion appliance induces transverse growth of the maxilla; and (3) an inherent pattern of jaw movement is characteristic to the UPXB and does not change significantly with orthodontic treatment.

The effect of bisphosphonate on alveolar bone resorption following mucoperiosteal flap surgery in the mandible of rats

Following elevation of a full thickness flap a transient burst of regional remodeling occurs. This phenomenon is termed in orthopedic surgery as regional accelerated phenomenon (RAP), beginning with accelerated resorption activity followed by a slow process of bone regeneration. Recently we have demonstrated that a mucoperiosteal surgical flap of rat mandible is producing a typical RAP process. Bisphosphonates are synthetic compounds that are taken up preferentially by the skeleton and suppress osteoclast-mediated bone resorption by a mechanism that is not yet fully understood. Amino bisphosphonate has been shown to inhibit active bone resorption without interfering with bone formation. In this study we evaluated the effect of amino bisphosphonate on bone resorption associated with a mucoperiosteal flap used as a resorptive model. We compared the effect of amino bisphosphonate in rats using IV administration with topical application at 3 dose levels. The results show that topical application of all 3 doses (0.15, 0.75, and 1.5 mg/ml) had no inhibiting effect on bone resorption after surgery, while IV administration at 0.5 mg/kg body weight significantly reduced the bone resorption. Interestingly, in the non-operated side, amino bisphosphonate increased mineral density.

Tooth contact during dynamic lateral excursion in young adults

Tooth contact in mediotrusion as well as the signs and symptoms of periodontal and mandibular dysfunction were recorded in healthy patients aged between 20 and 31 with Angle class I or II. Non-functional side contact (NFSC) was found in 94% of the patients, indicating that it is a common phenomenon. In cases of NFSC, the entire range of movement, and not only the final stage of tip-to-tip contact on the working side, should be recorded. Slight positive mobility with tooth faceting, as compared to the adjacent and contralateral teeth, was observed in 56 patients. There was no correlation between mediotrusion and mandibular dysfunction. The cumulative effects of NFSC are not well documented, and longitudinal follow-up studies should be carried out to clarify these.

Regional accelerated phenomenon in the mandible following mucoperiosteal flap surgery

Striking remodeling activity occurs adjacent to the site of injury in orthopedic surgery. This reaction has been described as regional accelerated phenomenon (RAP), as it speeds up the healing stage. The phenomenon is a transient burst of localized remodeling process following surgical wounding of cortical bone. We explored whether RAP occurs following mucoperiosteal flap surgery in the jaw bone. Mucoperiosteal flaps were performed on 60 Wistar rats, either only on the buccal aspect or both on buccal and lingual aspects of the mandible. The surgical procedure lasted an average of 30 seconds and the flap was readapted without sutures. The rats were sacrificed at 3, 7, 10, 14, 21, and 120 days. High resolution x-ray microradiography of 1 to 1.5 mm thick ground sections between premolar and molar regions of the mandible were analyzed and revealed large areas of radiolucency which correlated to massive resorption of the alveolar bone, as well as areas in the bone proper. The RAP was observed as early as 10 days in the treated side group. Striking resorption of the cortical bone, both on the surface and the bone proper, occurred on the periodontal aspect of the crestal bone leading to widening of the periodontal ligament space, where a mucoperiosteal flap was performed on the buccal aspect. The resorption was more prominent when a mucoperiosteal flap was performed both on the lingual and buccal aspect. The alveolar bone recovered almost to control levels 120 days after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional and morphological-occlusal aspects in children treated for unilateral posterior cross-bite

Morphological and functional aspects were investigated in children with unilateral posterior cross-bite (UPXB) before and after treatment. Sixty-five patients with Class I malocclusion with UPXB in the mixed dentition stage (mean age 8.8 +/- 1.6 years) served as the experimental group and 10 children of comparable age, with normocclusion or very mild Class I malocclusion (without UPXB) served as controls. The morphological aspects were examined on a longitudinal basis while the functional recordings, by means of a sirognathograph, were performed in a cross-sectional fashion. Complete elimination of cross-bite was maintained in 61 per cent and was accompanied by a dramatic reduction in the prevalence of functional mandibular displacement. However, the prevalence of mandibular midline deviation related to the maxillary midline as recorded in the intercuspal position was not affected. In addition, the high prevalence of Class II subdivision relationships which accompanied the UPXB in the intercuspal position was resolved in 50 per cent of the cases only. The sirognathographic recordings of the masticatory pattern showed a very high prevalence of a 'reverse sequencing' type pattern before treatment which was significantly lower following the elimination of UPXB, but still notably higher when compared with the controls. Reasons for these results are suggested and possible inter-relationships between the morphological and functional aspects are discussed.

The masticatory pattern as an adjunct for diagnosis and treatment

The sagitally-viewed masticatory pattern was investigated in 125 dentate patients. In 25 patients, the phenomenon of an incisal guided phase during mastication was observed. Clinical examination of these cases revealed slight to severe incisal attrition or various degrees of flaring. The hypothesis that the incisal guided phase contributes to this phenomenon and should therefore be taken into consideration during treatment is put forward.

A functional aspect of anterior attrition or flaring and mode of treatment

The phenomenon of occlusal wear has been generally reported, with no distinction being made between wear of the anterior or posterior teeth. This paper describes a group of patients without oral habits and exhibiting anterior tooth attrition or flaring with minimal posterior tooth attrition. The mandibular anterior movement patterns of the patients studied were evaluated using a Sirognathograph. These patterns appear to be the etiology for the anterior attrition or flaring present. A treatment mode allowing coexistence of this phenomenon with an anterior guidance that does not interfere with the mastication pattern is proposed. A hypothesis that might explain the clinical findings and a mode of treatment are described.

Splinting: a retrospective 17-year follow-up study

A retrospective 17-year, longitudinal study monitoring 66 patients with fixed partial denture and removable partial denture restorations revealed that perceptive splinting was beneficial and enhanced the longevity of the restoration. The study discussed the advantages and disadvantages of splinting, the survival rate of splints and splinted teeth, and the importance of oral hygiene and a periodic maintenance program.

Contribution of oral habits to dental disorders

Oral habits or parafunction may contribute to dental, periodontal, or neuromuscular damage. Such habits, of which the patient is often unaware, may cause considerable damage. Habits may be occlusal or non-occlusal, and may affect the dentition and/or the oral soft tissues. Drawing a patient's attention to the damage caused by some habits of which he or she is unaware often leads to cessation, whereas with certain conscious habits, such as nail or finger biting, success is much more limited.

Endodontic therapy as an adjunct for treatment of juvenile periodontitis: case report

The four first permanent molars in a 16-year-old girl with juvenile periodontitis were treated by selective grinding, tooth eruption, conventional periodontic treatment and endodontic therapy. The endodontic treatment was carried out as an elective procedure under ideal conditions, thereby pre-emptying the emergency treatment which would have been necessary following occlusal reduction. The two-year follow-up examination showed successful resolution of the original condition.

Effect of occlusal bite-raising splint on electromyogram, motor unit histochemistry and myoneuronal dimensions in rats

Composite resin bite-raising splints were fabricated on both sides of the upper jaw in rats. EMG activity of the deep masseter muscle was monitored continuously for 24 h before and up to 4 weeks after treatment. Together with the EMG activity, measurements of the neuromuscular junction area and muscle fibre histochemistry were made. EMG activity showed great variability immediately after splint fabrication. Some of the animals showed increased EMG activity, while others exhibited less activity 48 h after splint application. Overall, the fluctuation lasted for about 4 days, and after approximately 7 days all the animals exhibited decreased EMG activity, followed by a gradual increase in activity towards baseline levels. The neuromuscular junction territory increased significantly 5-10 days after splint application. Histochemical characterization of the deep masseter muscle revealed that it contained the three main types of muscle fibre: slow oxidative (SO), fast-oxidative-glycolytic (FOG) and fast glycolytic (FG). The frequency distribution of fibre types did not change after bite-raising splint treatment. These findings indicated that splint treatment in rats is effective in reducing EMG activity, while the muscle type characteristics remain stable. The effect of lower activity on the motor end-plates suggested that the neuromuscular junctions are quite sensitive to functional changes.

Functional and esthetic rehabilitation of an adolescent cleft lip and palate patient

Many patients with clefts that also affect the alveolar ridge present with congenital absence of the permanent maxillary lateral incisors. This paper describes the treatment of an adolescent cleft lip and palate patient whose missing and unesthetic maxillary incisors were replaced by a combination of fixed and removable partial dentures.

Severe vertical overlap: a modified method of treatment

Severe vertical overlap may predispose the patient to abnormal function, improper mastication, excessive stress, and functional problems such as bruxing, clenching, and craniomandibular disorders. This report describes the establishment of a new occlusal relationship by using the potential of posterior tooth eruption with the Hawley bite plane or the canine platform method. It was used in patients with a full complement of teeth or with some missing teeth. Patients treated by either the Hawley bite plane or the canine platform demonstrate a stable and long-lasting new occlusal relationship. The method described is efficient, inexpensive, and convenient to the patient.

Various methods in achieving anterior guidance

The anterior teeth are essential for esthetics, phoentics, and mastication and are equally involved in protecting posterior teeth. A 10-year longitudinal study of treatment modalities was conducted for overbite-overjet occlusal relationships. Comprehensive treatment combining orthodontics, occlusal adjustment, and selective restorations minimized the need for extensive restorative dentistry. The treatment of selected patients with a 10-year postoperative evaluation was discussed.

A novel method to study directed cell migration in culture

Directional migration of gingival fibroblasts was elicited in a cell culture system using reconstituted type I collagen fibers as a source of the putative chemoattractant. The rate of migration was expressed as Migration Index which turned out to be dependent on and directly related to the distance between the cells and the collagen. It is believed that this method enables one to study many different phenomena associated with extracellular matrix and cell interactions.

The functional range of tooth contact in lateral gliding movements

The dynamic contact pattern of teeth in lateral glide movement was recorded in 72 individuals, 19 to 35 years of age, with normal tooth alignment and Angle class I molar and canine relationship. The lateral glide movement was divided into three stages to simulate the total range of events in lateral glide movement naturally demonstrated by the patient. This study has shown that lateral glide movement is a complex movement in which the nature of tooth contact is altering in location, direction, and number of teeth participating. Consequently the restoration of an occlusion in accordance with a given concept does not always apply to all patients.

Re-attachment of periodontal ligament by collagen in experimentally-induced alveolar bone dehiscence in dogs

Fifty-four bone dehiscences were made in nine dogs by reflecting mucoperiosteal flaps on the labial aspect of lower and upper incisors and premolars and removing alveolar bone. One half of the dehiscences were treated with native enriched collagen solution (ECS) prepared from acid-soluble dog-skin collagen. Six weeks later, histologic sections were prepared from both the ECS-treated and untreated control sites. Re-attachment was promoted by the ECS preparation; there was arrest of epithelial migration apically and formation of new bone and cementum, as well as proliferation of fibrous connective tissue that became attached to the newly-formed cementum. This effect could be due to an influence of ECS on the chemotaxis of connective-tissue cells and to an anti-migratory (barrier) effect on gingival epithelium.

Cessation of epithelial cell movement at native type I collagen-epithelial interface in vitro

Two foci of gingival epithelial cells from the dog were grown in culture in dishes which were coated with gingival epithelial extracellular matrix (GEEM). A streak of native, reconstituted type I collagen fibers had been placed at the midline of the dish between the two foci. The epithelial cells spread and proliferated in all directions, but their motility ceased at the collagen-epithelial interface, where they piled up and formed several layers. It is concluded that type I collagen may serve as a biological barrier to stop undesirable epithelial cell movement in vivo.