Parkinson's disease - The dentist's role as part of the healthcare team.

Parkinson's disease is a neurodegenerative disease that results in patients exhibiting uncontrolled movements, changes in saliva production, and difficulty in swallowing and speech. Understanding the staging of the disease and the available therapies allows dentists to treat these patients safely and with compassion to meet their oral health care needs for an optimal quality of life. This appraisal discusses Parkinson's disease as it relates to clinically relevant facts to manage and treat the oral health care needs of these patients in the short and long term including general dental care recommendations. Important observations related to Parkinson's disease include disease causation,; stages, pharmacologic treatment, the effects on saliva, mastication, dysphagia, and aspiration pneumonia. Dental recommendations are made for the dentate, the partially edentulous, and the completely edentulous Parkinson's patients with a focus on late-stage concerns. Optimizing dental health will help maintain the quality of life as the disease progresses. In late stages of Parkinson's disease, dental treatment should focus on keeping the patient comfortable and out of pain.  While benign neglect is an often-used term, compassionate therapy in the late stages of Parkinson's disease is a more compelling term for defining the patient's needs.  Since dysphagia in Parkinson's patients has been underdiagnosed, neurologists must be aware of the important part that dentists play in the early diagnosis for these patients.  Early referral to a dentist is vital to mitigate the unfortunate consequence of the need for extensive dental care in late-stage patients.

Proposal regarding potential causes related to certain complications with dental implants and adjacent natural teeth: Physics applied to prosthodontics.

PURPOSE: Complications can and do occur with implants and their restorations with causes having been proposed for some single implant complications but not for others. METHODS: A review of pertinent literature was conducted. A PubMed search of vibration, movement, and dentistry had 175 citations, while stress waves, movement, and dentistry had zero citations as did stress waves, movement. This paper discusses the physics of vibration, elastic and inelastic collision, and stress waves as potentially causative factors related to clinical complications. RESULTS: Multiple potential causes for interproximal contact loss have been presented, but it has not been fully understood. Likewise, theories have been suggested regarding the intrusion of natural teeth when they are connected to an implant as part of a fixed partial denture as well as intrusion when a tooth is located between adjacent implants, but the process of intrusion, and resultant extrusion, is not fully understood. A third complication with single implants and their crowns is abutment screw loosening with several of the clinical characteristics having been discussed but without determining the underlying process(es). CONCLUSIONS: Interproximal contact loss, natural tooth intrusion, and abutment screw loosening are common complications that occur with implant retained restorations. Occlusion is a significant confounding variable. The hypothesis is that vibration, or possibly stress waves, generated from occlusal impact forces on implant crowns and transmitted to adjacent teeth, are the causative factors in these events. Since occlusion appears to play a role in these complications, it is recommended that occlusal contacts provide centralized stability on implant crowns and not be located on any inclined surfaces that transmit lateral forces that could be transmitted to an adjacent tooth and cause interproximal contact loss or intrusion. The intensity, form, and location of proximal contacts between a natural tooth located between adjacent single implant crowns seem to play a role in the intrusion of the natural tooth. Currently, there is a lack of information about the underlying mechanisms related to these occurrences and research is needed to define any confounding variables.

Making clinical sense of 3-dimensional metrology software programs.

Three-dimensional (3D) metrology software programs were designed to allow the user to capture and process the data from 3D scanners and other devices to measure, understand, and communicate inspection results to ensure manufacturing quality. Its use in dentistry has increased with concerns over how to make clinically significant decisions based on the data provided. The data produced by a commonly used software program was reviewed, and a rationale for interpreting that data was presented. The requirements for trueness, precision, and tolerance were also reviewed. In addition, contact was made with Oqton Tech Support, who is responsible for the Geomagic software program. The arithmetic average and the root mean square (RMS) do not identify the amount of deviation nor the direction and may not be helpful in determining how to use the data. RMS, and other statistical approaches, can show that there was a deviation but do not tell how much and in what direction. For prosthodontic studies, the 3D color map is the most efficacious method of determining the clinical significance of 3D metrology software.

Centric relation: A needed reference position.

PURPOSE: Centric relation (CR) is a universally recognized term and an acceptable reference position with a long history of success. The problem is that there is little consensus as to its definition or the method of recording it, and this has created an uprising to abolish it. METHODS: A review of pertinent literature related to its definition, method of recording, anatomic considerations, and long-standing principles was conducted. RESULTS: Centric relation is an established term but there are valid concerns over its definition and method of recording. There is consensus on using it as a restorative position in a patient in need of full-arch reconstruction, and there is no substantive clinical research to contradict this. If a clinician decides to use a different position, it should have a different name. CONCLUSIONS: Centric relation is a reproducible reference position that can be utilized for diagnostic and restorative dental procedures with substantial scientific evidence to support that premise. There are numerous well-documented techniques, all of which are intermaxillary, that can replicate the position. There is little scientific evidence to support a premise as to where the exact position of the condyle should be in relation to the fossa.

Selecting a Virtual Articulator: An Analysis of the Factors Available with Mechanical Articulators and their Potential Need for Inclusion with Virtual Articulators.

The ever-expanding world of digital technology has produced many changes, including the availability of virtual articulators. The use of such digital technology requires an understanding of the features that have been available with different mechanical articulators. These features include such items as facebow, intercondylar distance, incisal guide table, condylar inclination, reference plane, lateral condylar inclination, immediate mandibular translation, and ability to verify a centric relation record. This paper reviews the adjustable features that have been available with different types of mechanical articulators so that clinicians can determine if these features should be included in the virtual articulators they choose to use. Regardless of whether one is utilizing a mechanical or virtual articulator, the rationale for which type of articulator to select is the same and is predicated on the needs of the patient, the occlusal philosophy of the clinician, and the required accuracy.

The Dahl Concept: Best Evidence Consensus Statement.

PURPOSE: In a series of publications, Dahl and Krogstad promoted an orthodontic technique for the treatment of severe wear of the anterior teeth that reportedly could induce intrusion of the anteriors and extrusion of the posterior teeth to allow space to restore the worn anterior teeth. The purpose of this Best Evidence Consensus Statement was to evaluate the existing dental literature related to the Dahl Concept. METHODS: A PubMed search limited to clinical studies, clinical trials, randomized controlled trials, systematic reviews, meta analyses, and journal articles, using the key words Orthodontics, Dahl appliance, Dahl concept and adult, revealed 11 citations, 9 of which were related. An additional 9 citations were culled from the reference lists in the aforementioned articles. RESULTS: The 20 articles that met the initial search criteria were evaluated and rated. The literature largely focused on the restorative materials that are commonly used to apply the Dahl technique. CONCLUSIONS: While there is low-level evidence from a few case series that demonstrated the ability to achieve enough space in the anterior region for the restoration of lost anterior tooth structure, there is no compelling evidence to support any theories as to how that space was achieved. In addition, there is no evidence to support the long-term stability of that position and the restorations. Negative position and restorative outcomes have been reported.

Revisiting rigid overdenture design following traditional removable prosthetic concepts: a case report.

The inability to place a sufficient number of implants posteriorly may limit tooth and soft tissue replacement because of the cantilever effects that would result from the unsupported prosthesis. Fabrication of a fixed removable overdenture that is implant retained and supported by both implants and soft tissue allows adequate replacement of teeth and soft tissue for optimal mastication and esthetics. This case report describes a design for implant overdentures that conforms to fundamental removable prosthetic principles by using a rigid bar with bilateral locking passive attachments. The rigid implant overdenture provides extra retention via the locking attachments while maintaining stability with proper extensions and full soft tissue support posteriorly. This removable implant overdenture design is a suitable treatment option for patients who desire the sensation of a fixed prosthesis but are unable to receive fully implant-supported prostheses.

In vitro shear bond strength of 2 resin cements to zirconia and lithium disilicate: An in vitro study.

STATEMENT OF PROBLEM: There is little evidence on how the multiple layers of zirconia (ZrO2) or glazed material will affect the shear bond strength (SBS) of different resin cements. PURPOSE: The purpose of this in vitro study was to compare the SBS of 2 resin cements with the different layers of a monolithic polychromatic ZrO2 ceramic, both glazed and nonglazed, and a lithium disilicate (LDS) ceramic. MATERIAL AND METHODS: One hundred and sixty-eight composite resin cylinders and 48 monolithic polychromic ZrO2 plates were prepared. Twenty-four were milled and sintered, and 24 were milled and sintered and had a glaze cycle applied with no liquid glaze. These plates and 12 LDS plates were mounted in autopolymerized acrylic resin. Bonding surfaces were polished, airborne-particle abraded, and cleaned ultrasonically. The different layers (cubic, hybrid, and tetragonal) of the ZrO2 plates were identified and marked. The plates were assigned to 2 cement groups: a self-adhesive, autopolymerized resin cement, and a dual-polymerizing, adhesive resin cement (DPRC). Bonding surfaces were cleaned and treated according to the cement manufacturer's instructions. Three composite resin cylinders were luted to the ZrO2 plates at the appropriate layer, and 2 cylinders were luted to each LDS plate. The specimens were stored in a moist environment for 24 hours at 37 °C. The SBS test was performed with a universal testing machine. Visual inspections of the debonded surfaces were compared under magnification. The data were analyzed with a 2-way ANOVA and a subsequent Student t test (α=.05). RESULTS: The 2-way ANOVA found no difference among luting agent and LDS and ZrO2. The SBSs of the nonglazed tetragonal and cubic layer to the ZrO2 were higher than to the surface exposed to a glazing cycle (P=.001). The bonded surfaces were examined tactilely and under ×3.5 magnification, followed by light and scanning electron microscopy and recorded as either adhesive, cohesive, or mixed. Almost all failures in the glazed ZrO2 were mixed and cohesive. However, more adhesive failures were observed in the DPRC group of nonglazed ZrO2. CONCLUSIONS: No differences were found between the 2 luting agents for the LDS. For the ZrO2 cubic and tetragonal layers, the DPRC had higher bond strengths to the nonglazed surfaces.

Angle's Classification-A Prosthodontic Consideration: Best Evidence Consensus Statement.

PURPOSE: This Best Evidence Consensus Statement evaluated the existing Angle's classification clinical literature to determine if the Angle's classification as historically determined in maximum intercuspal position (MIP) with hand held casts is coincident with the centric occlusion (CO) determined Angle's classification. In addition, it explored the value of using Angle's classification for edentulous patients MATERIALS AND METHODS: The search strategy was related to the focus questions and limited to Meta-analyses, Systematic Reviews (SR), Randomized Controlled Trials (RCT) and Clinical Trials. Searches were completed using the term Angle's classification and Boolean Modifiers (AND) with the key terms: dental occlusion, dental occlusion centric, centric occlusion, centric relation, maximal intercuspation, MIP, intercuspal position, and edentulous patient, retrognathia, determination, and prognathia. Additional related articles were culled from the reference lists in the articles found in the PubMed searches. RESULTS: The search identified 494 articles related to the selected terminology. Titles were reviewed and selected if related to the focus questions for further review. Seven papers could be identified that addressed the specifics of the questions. CONCLUSIONS: There is evidence that the Angle's classification for many patients will change when recorded in CO compared to the historical MIP determination/definition. A different Angle's classification recorded in CO is potentially a significant diagnostic finding for patients needing complete mouth rehabilitation. The current definitions of Angle's Classification are not useful in the management of edentulous patients.

Frankfort Mandibular Plane Angle: Critically Appraised Topic (CAT).

PURPOSE: The objective of this Critically Appraised Topic was to determine the level of evidence relative to the usefulness of the Frankfort mandibular plane angle in prosthodontic treatment. MATERIALS AND METHODS: The Patient Intervention Comparison Outcome (PICO) mesh heading received zero PubMed references, as did Frankfort Mandibular Plane Angle (FMA) as a determinant for dental occlusion and Frankfort Mandibular Plane Angle as a determinant of the occlusal scheme. Frankfort Mandibular Plane Angle alone received 168 PubMed citations that highlighted 2 DiPietro articles and a third from the orthodontics literature which was a Randomized Controlled Trial not relevant to the PICO. Four others, three prosthodontic and one orthodontic publication, were related to the PICO. A Google search revealed one additional article, which was a narrative review. RESULTS: Nine articles were related to the search, 2 of which were clinical trials that revealed no evidence to support the use of FMA as a diagnostic test. CONCLUSION: Based on the limited data presented above, there is a lack of evidence to support the use of FMA as a diagnostic procedure to predict outcomes, or dictate prosthodontic treatment.

The Clinical Significance of Immediate Mandibular Lateral Translation: Critically Appraised Topic (CAT).

PURPOSE: The purpose of this Critically Appraised Topic was to investigate the possible clinical relevance of recording the immediate mandibular lateral translation. MATERIALS AND METHODS: A literature search limited to Clinical trials, Randomized Controlled Trials, Systematic Reviews, Meta Analyses, and using the PICO headings revealed no citations. Using the key words dental, occlusion, immediate side shift, also received no citations. Expanding the search criteria to include Journal Articles revealed 17 citations. Using dental occlusion, Bennett movement, revealed 21 citations. RESULTS: The cited articles were reviewed for relevance and duplicates were eliminated. The resulting 10 English language in vivo studies pertinent to the question were included. Other articles were culled from the author's library and the reference list of the aforementioned articles. There is no evidence on the prevalence of IMLT in patients in need of occlusal rehabilitation. There is agreement that the recording of the IMLT is reference point and recording instrument dependent. There is agreement that IMLT is observable on some patients and is minimal in magnitude. There is no evidence of any adverse clinical events as a result of not including IMLT in a restorative occlusal scheme. CONCLUSIONS: It is justifiable to question the necessity of attempting both to record immediate mandibular lateral translation on the average patient and reproduce it on an articulator.

Complete Denture Occlusion: Best Evidence Consensus Statement.

PURPOSE: The occlusal scheme required for an edentulous patient is controversial. The purpose of this Best Evidence Consensus Statement was to evaluate the existing complete denture literature related to occlusal schemes. MATERIALS AND METHODS: A literature search was limited to Meta-analyses, Systematic Reviews (SR), Randomized Controlled Studies (RCT) and Clinical Trials. Key Words were: Complete dentures, occlusion, harm; Complete dentures, occlusion alveolar bone loss; Complete dentures, occlusion, stability; Complete dentures, occlusion. Additional related articles were culled from the authors' library and reference lists in the articles found in the PubMed searches. RESULTS: Of the 165 articles that met the initial search criteria, 34 related to the focus questions and were evaluated and rated. CONCLUSIONS: There is strong support that the average denture patient, with good residual ridges and no neuromuscular problems, will function adequately with a properly fabricated complete denture regardless of the occlusal scheme. There is neither strong support for or against bilateral balanced occlusal schemes as it relates to patient satisfaction, preference or chewing ability. There is some support for increased alveolar bone loss with complete dentures that have a non-balanced occlusion. There is a need for bilateral balanced occlusal schemes for patients presenting with loss of stability and retention as a result of their presenting conditions (PDI III and IV).

Bruxism: Best Evidence Consensus Statement.

PURPOSE: The purpose of this Best Evidence Consensus Statement is to report on the prevalence, potential causes or association, treatment and cure of bruxism. MATERIALS AND METHODS: A literature search limited to Clinical Trials, Randomized Controlled Trials, Systematic Reviews and Meta Analyses, with the key words bruxism, and prevalence identified 22 references, bruxism and causation 21, bruxism, and treatment 117, and bruxism and cure none. RESULTS: Prevalence received 5 references which were relevant to the question researched. Causation received 11 relevant references, treatment 34 relevant references and cure none. Eighteen additional references were culled from the reference lists in the aforementioned articles. CONCLUSIONS: Due to variations in demographics and the dependence on anamnestic data, the true prevalence of bruxism in any specific population is unknown. There is moderate evidence that psychosocial factors such as stress, mood, distress, nervousness, and feeling blue are associated with sleep bruxism (SB) as well as caffeine, alcohol, and smoking. There is no consensus on what symptoms of SB or awake bruxism (AB) should be treated. There is some evidence that occlusal devices and bio feedback therapies can be utilized in SB treatment. There is conflicting evidence in the use of Botulinum toxin A and no compelling evidence for the use of drug therapy to treat SB. There is not an established cure for bruxism. The clinician is best served in using caution in the dental rehabilitation of patients with severe occlusal wear.

Occlusal Vertical Dimension: Best Evidence Consensus Statement.

PURPOSE: Patients in need of extensive prosthodontic treatment may need restoration of their occlusal vertical dimension (OVD) due to tooth wear, tooth loss, or changes that have occurred to existing prostheses over time. Prosthodontic treatment is based on the clinical application of the available evidence regarding interocclusal distance (IOD), the positional stability of rest vertical dimension (RVD), and the effect of altering the OVD. Hence, the purpose of this consensus document is to examine available data related to IOD, RVD, and alteration of the OVD. MATERIALS AND METHODS: The search was limited to Clinical trials, Randomized Controlled Trials, Systematic Reviews and Meta-analyses. Key words were healthy patient, mean, range, interocclusal rest distance; healthy patient, mean, range, freeway space; and dentistry, interocclusal gap, and no citations appeared. Dentistry, interocclusal distance, revealed 5 not relevant citations. Dentistry, inter occlusal rest space, and dentistry, interocclusal rest distance, both had the same single not relevant citation. Dentistry, freeway space revealed over 7,000 citations. Dentistry, occlusal vertical dimension, revealed 253 citations, 7 of which were related to the search question but only 1 which was different from the previous search. Mandible, rest vertical dimension, age changes, found 7 citations, none relative to the question. Expanding the search to include journal article found 260 citations with only one relevant to the question. Mandible, rest vertical dimension, alteration, harm revealed no citations; mandible, occlusal vertical dimension, alteration, revealed 15 citations, 1 of which was relevant; mandible, occlusal vertical dimension, changes, revealed 75 citations, none of which were relevant; mandible, occlusal vertical dimension, rehabilitation revealed 10 citations, none of which were relevant. Expanding the search strategy to include Journal article, mandible, occlusal vertical dimension, alteration, received 159 citations, 4 of which were relevant; mandible, occlusal vertical dimension, restoration revealed 208 citations, 1 of which was relevant. Numerous other articles were culled by going through the reference lists of the aforementioned articles. RESULTS: For IOD, 27 articles were found relevant to the search question, which confirmed a mean of 3.0 mm with ranges from 1 to 9 mm. Five articles revealed little evidence as to whether the RVD changes during life. For OVD, 20 articles, including 4 systematic reviews, revealed some evidence that skeletal growth continues from mid adolescence into mid adulthood; strong anecdotal evidence that some unopposed teeth will continue to erupt; no clinical evidence to support the concept that abraded teeth in occlusion in a patient with bruxism will undergo continuous eruption; and some evidence from clinical case reports that restoring OVD in patients with severe abrasion is a successful treatment. CONCLUSIONS: There is a range of dimensions for the interocclusal distance (IOD) with many normal dental patients functioning with a higher or lower IOD than the commonly used 3.0 mm average dimension. The resting vertical dimension (RVD) is a 3-dimensional range with little evidence related to changes in the RVD during life. However, aging can cause a decrease in muscle tone which could affect the RVD. The restoration of the OVD can be successfully accomplished if proper diagnosis and treatment planning are performed.

Occlusal Schemes for Implant Restorations: Best Evidence Consensus Statement.

PURPOSE: Numerous studies have focused on the various complications with implant-retained restorations and a common thread in these publications is the potential for occlusal overload. The purpose of this Best Evidence Consensus Statement on implant occlusal schemes was to review the literature to determine the level of scientific evidence upon which the articles are based. MATERIALS AND METHODS: Limiting the search to Clinical trials, Randomized Controlled Trials, Systematic Reviews, Meta-analyses, the key words: dental implants, occlusion, found no citations. Expanding the search to Journal articles found 1,483 results, 20 of which pertained to the question. Doing a similar search including Journal Articles, the key words: dental implants and occlusal scheme found 47 citations, 17 of which were pertinent to the question. RESULTS: After eliminating duplicates and non-relevant articles, 15 were included in the review. Nineteen additional articles were culled by going through the reference lists in the aforementioned articles. CONCLUSIONS: There is a lack of scientific evidence regarding the occlusal scheme utilized with implant restorations that will minimize or eliminate complications. In light of this lack of scientific evidence, the style of occlusion a practitioner utilizes with tooth or mucosal supported prostheses may be used with implant-supported restorations until compelling evidence dictates otherwise.

Light-Front Field Theory on Current Quantum Computers.

We present a quantum algorithm for simulation of quantum field theory in the light-front formulation and demonstrate how existing quantum devices can be used to study the structure of bound states in relativistic nuclear physics. Specifically, we apply the Variational Quantum Eigensolver algorithm to find the ground state of the light-front Hamiltonian obtained within the Basis Light-Front Quantization (BLFQ) framework. The BLFQ formulation of quantum field theory allows one to readily import techniques developed for digital quantum simulation of quantum chemistry. This provides a method that can be scaled up to simulation of full, relativistic quantum field theories in the quantum advantage regime. As an illustration, we calculate the mass, mass radius, decay constant, electromagnetic form factor, and charge radius of the pion on the IBM Vigo chip. This is the first time that the light-front approach to quantum field theory has been used to enable simulation of a real physical system on a quantum computer.

An in vitro assessment of the accuracy of new and in-use torque-limiting devices.

STATEMENT OF PROBLEM: Recent studies have shown that torque-limiting devices (TLDs) do not meet their torque targets and are affected by factors such as the use of the TLDs and the sterilization processes used. PURPOSE: The purpose of this in vitro study was to investigate the accuracy of TLDs currently in use in the Advance Education Program in Prosthodontics at the New York University College of Dentistry. MATERIAL AND METHODS: Five new and 46 in-use TLDs (Nobel BioCare) from the implant kits of the graduate students were evaluated. One investigator was trained and calibrated before testing and after every 10 evaluations. A 3-jaw chuck was mounted on the center of a cap testing device by using the provided mounting screws. A LOCATOR torque driver was clamped into the chuck, and a torque wrench driver was attached to it. The device was placed on a flat table with direct overhead lighting that allowed the investigator to have a consistent view of the notches on the TLDs. A piece of cardboard was attached to the device to ensure that the investigator could not see the readouts. The blinded researcher inserted the wrench and applied the appropriate torque force at the designated notches while another researcher recorded the results. Two readings were made for each TLD at 15, 35, and 45 Ncm. A 2-way ANOVA and an intraclass correlation coefficient to test for intraclinician reliability were performed by using a statistical software program (α=.05). RESULTS: Two TLDs were damaged and not tested. The 2-way ANOVA demonstrated no significant difference (P>.05) between graduate students in year 1, 2, and 3 or between the autoclaved and new TLDs. The intraclass correlation coefficient was 0.861 for 15 Ncm, 0.589 for 35 Ncm, and 0.764 for 45 Ncm. CONCLUSIONS: In this in vitro study, new and used TLDs all met the recommended torque values. No significant differences were found among groups, suggesting that autoclaving and use did not affect the accuracy of the TLDs tested.

An in vitro 3D evaluation of the accuracy of 4 intraoral optical scanners on a 6-implant model.

STATEMENT OF PROBLEM: Although numerous studies have been performed on the accuracy of intraoral scanners, determining the clinical significance of the results is problematic. PURPOSE: The purpose of this in vitro study was to evaluate the trueness and precision of 4 intraoral optical scanners (IOSs) on a 6-implant model and provide a method to help determine clinical significance. MATERIAL AND METHODS: A polymer mandibular edentulous model with 6 hexagonal scan bodies (Ritter) was fabricated, and a control scan was made by using an industrial laser line probe (FARO Edge HD Arm). Four IOSs (True Definition, TRIOS, CEREC Omnicam, Emerald Scanner) were used to scan the same model 5 times: the 20 standard tessellation language (STL) files were individually imported to a 3D inspection software program (Geomagic Control X) and superimposed over the computer-aided design (CAD) control scan. The tolerance was set at a limit of ±0.01 mm. RESULTS: None of the tested scanners were true even 10% of the time at the ±0.01-mm tolerance, and the Emerald scanner was true less than 5% of the time. Within scanners, results were precise, showing variations of no more than 2% over repeated scans. When a ±0.05-mm tolerance was selected, the percentage within tolerance increased dramatically. This made the performance of the scanners to appear better but obscured valuable information. The 3D color map was the best method for understanding the data. The color maps showed how much was within tolerance and, equally important, the amount and direction of out of tolerance, providing an easily understandable qualitative and quantitative image. CONCLUSIONS: No statistical or clinical differences were found among the scanners tested. The 3D map was the best method for observing the data.

MH-ICP-MS Analysis of the Freshwater and Saltwater Environmental Resources of Upolu Island, Samoa.

The elemental composition of freshwater and saltwater samples around the South Pacific island of Upolu, Samoa has been investigated together with other indicators of water quality. Up to 69 elements from Li (3) to U (92) are measured in each sample, analyzed by Mattauch-Herzog-inductively coupled plasma-mass spectrometry (MH-ICP-MS). One hundred and seventy-six samples were collected from surface freshwater sources (24 rivers, two volcanic lakes, one dam) and from seawater sources from the surface to 30 m depth (45 inner reef, reef, and outer reef locations) around Upolu Island, including river mouths and estuaries. Principal component and hierarchical clustering correlation analyses were performed on quantile normalized log transformed elemental composition data to identify groups of samples with similar characteristics and to improve the visualization of the full spectrum of elements. Human activities, such as the use of herbicides and pesticides, may relate to observed elevated concentrations of some elements contained in chemicals known to have deleterious obesogenic effects on humans that may also cause coral reef decline. Furthermore, the salinity of some saltwater samples tested were very high, possibly due to climate variability, which may additionally harm the health and biodiversity of coral reefs.

Does the Stomatognathic System Adapt to Changes in Occlusion? Best Evidence Consensus Statement.

PURPOSE: The purpose of this Best Evidence Consensus Statement was to evaluate the existing literature on the stomatognathic system's ability to adapt to occlusal changes. MATERIALS AND METHODS: The search term stomatognathic system was not useful as it resulted in over 400,000 results nor was the search term temporomandibular joint adaptation with 738 results due to the large number of references not related to the topic. The terms stomatognathic system adaptation to occlusal changes (186 results), teeth flexion (139 results), muscle adaptation to dental occlusion (278 results), and occlusal changes and neuroplasticity (11 results) provided the best selection of articles related to the topic. Limiting the above searches to systematic reviews and randomized controlled clinical trials resulted in multiple publications that were related to the question.9-13 Other literature reviews, data-based publications, and expert opinion resources have been included due to their relationship to the question. RESULTS: From the extensive list of search results, 242 articles were determined to be potentially related to the focus question and were evaluated with 56 being included in this paper. It was determined that the stomatognathic system adapts to occlusal changes through the temporomandibular joint, muscles, teeth and bone. The dynamically modified periosteum on the articulator surfaces of the condyle and fossa has a unique load-bearing morphology with 3 subarticular layers of fibrocartilage that absorb and dissipate both peak (impact) and sustained loads. Adaptability of the TMJs and muscles can be documented through studies where artificially produced occlusal interferences were placed in patients and those study participants with normal temporomandibular joints (TMJs) adapted fairly well whereas those with a previous history of temporomandibular disorders (TMD) did not adapt as well. CONCLUSIONS: Available evidence indicates patients generally adapt to the occlusal change inherent in orthodontic treatment, mandibular advancement surgery, and the use of mandibular advancement devices. The head and neck muscles also adapt to occlusal changes in patients without a history of TMD. The dentition adapts to changes through the bone and periodontal ligaments as well as the ability of teeth to undergo slight flexion under masticatory loading. This article is protected by copyright. All rights reserved.