Diver's mouth syndrome: a field study

Reports of clinical presentations of diver's mouth syndrome and prevalence of at least one of its symptoms in many successive Joint Service (JS) diving expeditions prompted the author (who is an advanced diving instructor and an Armed Forces dental surgeon and has been present on, or organized, at least six JS diving expeditions in regions from cold temperate to tropical) to construct customized diving mouthpieces and investigate their effectiveness during intensive use in the field.

Programmed occlusal reconstruction in anticipation of tooth wear

A procedure is presented that developed posterior lateral contacts in group function, despite existence of an anterior canine disclusion. This procedure allows a smooth transition into group function as the canine is subjected to natural attrition.

An adjustable bone fixation system for sagittal split ramus osteotomy: preliminary report

After sagittal split osteotomy, osteosynthesis for stabilization of the fragments is usually performed by means of rigid or semirigid fixation to avoid maxillomandibular fixation (MMF). Sometimes, this leads to malpositioning of the fragments with resulting 'immediate relapse' or disturbances of the temporomandibular joints (TMJs) such as progressive idiopathic condylar resorption, which is the worst effect. We have therefore developed a new bone fixation system that allows three-dimensional adjustment even after fixation of the fragments. The special configuration of the system avoids intraoperative dislocation of the mandibular condyle. We have used the method successfully in 40 patients, 27 of whom had mandibular retrognathism and 13 of whom had mandibular prognathism. In particular, there has been no evidence of resorptive changes. There were no postoperative complications.

Occlusion and splint therapy

Control of occlusal contacts is important to the success of restorative dentistry. Tooth surface loss can contribute to a loss of stability in the occlusion. An occlusal splint is often part of pre-restorative management and can also have a valuable role in protecting both teeth and restorations from excessive loads and further wear.

The new dental-medical renaissance. Medically efficacious functional jaw orthopedics

Functional Jaw Orthopedics (FJO) is medically efficacious, exceptionally unique and unequaled in speed of a cure for a number of very common medical conditions currently only "managed" by modern medicine. This publication combines scientific citations and case presentations to show how and why dentists who advocate and provide early FJO treatment will lead a New Dental-Medical Renaissance into some of the most profound areas of medicine. Nocturnal enuresis (chronic bed-wetting) otitis media (ear infections), cor pulmonare, cognitive thought, vision, hearing, cardio-pulmonary dysfunction, and myocardial infarction have FJO dental-medical relationships. Early FJO treatment fulfills the ADA Code of Ethics which "calls upon dentists to follow high ethical standards which have the benefit of the patient as their primary goal: Do No Harm and Do Good."

Oral splints: the crutches for temporomandibular disorders and bruxism?

Despite the extensive use of oral splints in the treatment of temporomandibular disorders (TMD) and bruxism, their mechanisms of action remain controversial Various hypotheses have been proposed to explain their apparent efficacy (i.e., true therapeutic value), including the repositioning of condyle and/or the articular disc, reduction in the electromyographic activity of the masticatory muscles, modification of the patient's "harmful" oral behavior, and changes in the patient's occlusion. Following a comprehensive review of the literature, it is concluded that any of these theories is either poor or inconsistent, while the issue of true efficacy for oral splints remains unsettled. However, the results of a controlled clinical trial lend support to the effectiveness (i.e., the patient's appreciation of the positive changes which are perceived to have occurred during the trial) of the stabilizing splint in the control of myofascial pain. In light of the data supporting their effectiveness but not their efficacy, oral splints should be used as an adjunct for pain management rather than a definitive treatment. For sleep bruxism, it is prudent to limit their use as a habit management aid and to prevent/limit dental damage potentially induced by the disorder. Future research should study the natural history and etiologies of TMD and bruxism, so that specific treatments for these disorders can be developed.

Medical treatment of recurrent temporomandibular joint dislocation using botulinum toxin A

This paper describes a new technique for prophylactic treatment of recurrent mandibular dislocation using injection of botulinum toxin A (BtA) into the lateral pterygoid muscles. BtA temporarily weakens muscles by blocking acetylcholine release, and thus operates through a principle different from established treatments such as joint sclerosant therapy, eminectomy or Dautry's procedure. The patient suffered recurrent mandibular dislocations caused by tardive dystonia. We injected 75 mu BtA percutaneously into each lateral pterygoid muscle under electromyographic guidance. No further dislocations occurred over the subsequent 10 months, and follow-up continues. There were no immediate or delayed side effects. More experience is required before this becomes an established treatment. BtA is usually given in outpatients, and is less invasive or destructive than previous options. It may not be suitable if dislocation is due to lax ligaments or weak muscles. Operators must be aware that other BtA preparations require a different dose.

Effects of capsaicin in temporomandibular joint arthritis in rats

Temporomandibular joint (TMJ) arthritis was induced in female Lewis rats by unilateral injection of a suspension of heat-killed Mycobacterium butyricum in paraffin oil into the TMJ. Control rats received paraffin oil by the same route. Arthritic and control rats were pretreated either with capsaicin or denervation of the mandibular branch of the trigeminal nerve. Tissues were collected for neuropeptide extraction and analysed by radioimmunoassay and reverse-phase high-performance liquid chromatography. In all groups, the levels of substance P-(SP), calcitonin gene-related peptide- (CGRP) and neuropeptide Y- (NPY) like immunoreactivity (LI) were higher in the trigeminal ganglia than in the TMJs. In control rats, capsaicin significantly lowered the levels of SP-LI in the trigeminal ganglia and TMJ, but not CGRP-LI and NPY-LI. In the arthritic rats, capsaicin pretreatment significantly lowered the SP-LI and CGRP-LI in the trigeminal ganglia and TMJ, but not the NPY-LI. In the trigeminal ganglia the unilateral denervation significantly lowered SP-LI in control rats, and in arthritic rats SP-LI and CGRP-LI. On the denervated side of the arthritic TMJ, NPY-LI, SP-LI and CGRP- LI were significantly lowered as compared to the arthritic control rats and to the contralateral side. In this rat model, pretreatment with capsaicin and surgical denervation decreased the neuropeptide content in the trigeminal ganglia and the TMJ. The results clearly demonstrate a close interaction between increased neuropeptide release from sensory and sympathetic neurones after induction of arthritis in the rat.

Prevention of temporomandibular disorder-related signs and symptoms in orthodontically treated adolescents. A 3-year follow-up of a prospective randomized trial

Recommendations about the need for occlusal adjustment after malocclusion therapy are inconclusive. A total of 123 orthodontically treated healthy adolescents (88 girls, 35 boys; 14.8 +/- 1.7 years old) agreed to participate in the present study. The subjects were interviewed and examined for signs and symptoms related to temporomandibular disorder (TMD) and were randomly allocated to intervention (n = 63) and control (n = 60) groups. At base line, occlusal adjustment was carried out for the intervention group and repeated every 6 months thereafter as needed. Mock adjustments were performed for the control group. At the end of the 3rd year 118 subjects (96%) turned up for re-examination. The number of subjects with palpatory pain of the masticatory muscles, and with occlusal centric slides decreased significantly in the intervention group but not in the control group (P < 0.001). In conclusion, occlusal adjustment therapy may prevent the occurrence of TMD signs in orthodontically treated healthy adolescents.

Morphometric and morphological changes in the temporomandibular joint after orthognathic surgery: a magnetic resonance imaging and computed tomography prospective study

The possible morphological and morphometric changes in the different components of the temporomandibular joint (TMJ) after orthognathic surgery were analysed using computed tomography (CT) transverse scans and sagittal and coronal magnetic resonance imaging (MRI) images. Twenty-four patients with class III dentofacial deformity were studied. Nine had isolated maxillary osteotomies and 15 had combined maxillary and mandibular subcondylar osteotomies (MSO). Ten patients were studied as a control group. The patients were studied clinically, radiographically and with CT and MRI in four different phases in order to locate the position of the mandibular condyle in relation to the glenoid fossa. No statistically significant differences were found in the group of patients who had had isolated maxillary osteotomies throughout the four phases of the study. Patients treated by bimaxillary surgery showed different condylar movements after surgery. Intra-articular effusion was evident during the early postoperative period in patients treated by bimaxillary surgery. Although different changes in the position of the bony components of the TMJ occurred after MSO, these seemed to be transient, with no major alterations in the final outcome in the patients.

The short-term effect of autogenous auricular cartilage graft following discectomy on the osteoarthrotic temporomandibular joint in sheep

The aim of this experimental study was to determine the effect of auricular cartilage graft replacement on the progression of experimentally induced osteoarthrosis in sheep. Bilateral osteoarthrosis was induced in the sheep temporomandibular joint (TMJ). Three months later, discectomy and autogenous auricular cartilage grafting were performed unilaterally. At sacrifice, three months postrepair and six months postinduction of osteoarthrosis, it was found that the untreated side had extensive condylar osteoarthrosis and the grafted side showed evidence of fibrous repair. The graft prevented intra-articular adhesions and reduced degenerative changes, but there was a tendency towards graft perforation. Auricular cartilage grafting was effective in minimizing osteoarthrotic effects on the TMJ in the early stages after grafting.

Changes in condylar postition and occlusion associated with maxillary expansion for correction of functional unilateral posterior crossbite

The purpose of this study was to confirm that correction of functional posterior crossbite through maxillary expansion is associated with a change in condylar position and occlusal relationships, and to determine whether maxillary expansion is associated with autonomous increase in mandibular arch width. Pretreatment and posttreatment study models of 61 patients ages 4.1 to 12.0 years (mean 8.5 years, SD 1.5) were available after maxillary expansion with a Quad Helix or a Haas expander for correction of a functional posterior crossbite. Pretreatment and posttreatment tomograms were available for 22 of the patients. Tomographic evaluation revealed that the condyles moved posteriorly and superiorly on the noncrossbite side from before to after treatment (p < 0.05). No differences were observed on the crossbite side. Superior joint space was greatest on the noncrossbite side before treatment, whereas, conversely, it was greatest on the crossbite side after treatment (p < 0.05). Relative condylar position was more anterior on the noncrossbite side before treatment (p < 0.05), but similar on both sides after treatment. Molar and canine relationships were more Class II on the crossbite side before treatment (p < 0.01 and < 0.05, respectively) and similar on both sides after treatment. A significant reduction in midline deviation was seen from before to after treatment (p < 0.001). A small, but significant autonomous increase in mandibular intermolar width (p < 0.001) occurred concomitant with the maxillary expansion.

The validity and utility of disease detection methods and of occlusal therapy for temporomandibular disorders

Our evaluation of the clinical usefulness or devices for the diagnosis or treatment of temporomandibular disorders (TMD) led to the conclusion that the only current gold standard for TMD is a global clinical examination, because none of the instruments can be said to provide more than ancillary documentation and none have proven diagnostic validity or utility. Regarding the therapeutic efficacy of occlusal adjustment, we could find no comparative studies that test the efficacy of occlusal adjustment in preventing TMD. The studies we reviewed on the relationship of occlusion to TMD are not convincing, powerful, or practical enough to make any recommendations about a causal association.

Orthodontic treatment and temporomandibular disorders

The relationship between orthodontic treatment and temporomandibular disorders (TMDs) has long been of interest to the practicing orthodontist, but only during the past decade have a significant number of clinical studies been conducted that have investigated this association. This interest in orthodontics and TMD in part was prompted in the late 1980s after litigation that alleged that orthodontic treatment was the proximal cause of TMD in orthodontic patients. This litigious climate resulted in an increased understanding of the need for risk management as well as for methodologically sound clinical studies. The findings of current research investigating the relation of orthodontic treatment and TMD can be summarized as follows: (1) signs and symptoms of TMD may occur in healthy persons; (2) signs and symptoms of TMD increase with age, particularly during adolescence, until menopause, and therefore TMDs that originate during orthodontic treatment may not be related to the treatment; (3) in general, orthodontic treatment performed during adolescence does not increase or decrease the chances of development of TMD later in life; (4) the extraction of teeth as part of an orthodontic treatment plan does not increase the risk of TMD; (5) there is no increased risk of TMD associated with any particular type of orthodontic mechanics; (6) although a stable occlusion is a reasonable orthodontic treatment goal, not achieving a specific gnathologic ideal occlusion does not result in signs and symptoms of TMD; and (7) thus far, there is little evidence that orthodontic treatment prevents TMD, although the role of unilateral posterior crossbite correction in children may warrant further investigation.

The concepts prevalence, need for treatment, and prevention of temporomandibular disorders: a suggestion for terminology

The concepts active and passive treatment need and active and passive prevention need are suggested, to systematize some concepts used in discussions about temporomandibular disorders (TMD), to separate the treatment need figures from the prevalence figures, and to understand the great variation among TMD prevalence studies. On the basis of a summary of recently published papers and on a clinical 2-year follow-up study of 411 subjects, the suggestions seem to provide a reasonably good fit with clinical experience and earlier epidemiologic studies of TMD.

[Use of condyle positioning plate in sagittal split ramus osteotomy of mandible]

17 patients underwent an orthognathic operation. The condyle positioning plate was used in each sagittal split ramus osteotomy of mandible in order to maintain the condyle position. The results of postoperative X-ray examination showed that no obvious displacement of condyle in posterioranterior, and vertical dimension was detected in all joints and obvious horizontal condyle displacement were only found in two joints. Based on this work the author believe that condyle positioning plate is useful to position condyle during operation.

Occlusion and prosthodontics

Occlusion in prosthodontics is extremely important. Muscle dysfunction can interfere with prosthodontic restoration of occlusion. Occlusal interferences are the primary cause of the hyperactivity that cause muscle dysfunction. Occlusal interference can also place adverse stress on restorations and result in premature failures. Lateral stresses on restorations can cause cement failures, porcelain fractures, and solder joint failures. Our goal in prosthodontics is to restore occlusion that is occlusal interference free. This article gave an overview of how this can be done in phases. In Phase I, a diagnosis is made as to the presence or absence of muscle dysfunction. If it is present, the OIs are hidden. Occlusal splint therapy is needed to get rid of the muscle dysfunction so the OIs can be found. The occlusal splint diagnosis whether OIs are the cause of the dysfunction. The cure is to correct the occlusion. The restoration of the occlusion should be OI free. The various factors to consider in design and restoration of the occlusion were presented. After successful restoration of the occlusion, the recall appointments should include an evaluation of the occlusion. The PRI, COS, and clinical examination can all be helpful in diagnosing whether muscle dysfunction is developing and whether OIs are developing again as a result of the normal changes that can occur. Suggestions were made on how to slow these changes. This article was not meant to cover every aspect of prosthodontic occlusion in detail. The goal was to present an overview for readers to make a self-evaluation as to what areas of their practice might need to be improved to improve the restoration of the occlusion. All was not taught in dental school. As one practices and improves in skill, more knowledge and abilities must be sought through graduate and postgraduate education. Occlusion is too important for a successful practice and happy patients to be ignored. Time will make this obvious; however, the failures may be costly. The best approach would be to anticipate the failures and prepare yourself to reduce the risks. Occlusal interferences are truly the plague of dentistry.