[Metric analysis of temporomandibular joint in asymptomatic persons by magnetic resonance imaging]. / Metricka analiza temporomandibularnog zgloba magnetskom rezonancijom u asimptomatskih ispitanika.

AIM: The objective of this study was to investigate the prevalence of anterior disk displacement and condyle position in volunteers free from clinical symptoms and signs of temporomandibular disorders. MATERIAL AND METHODS: Bilateral parasagittal T1-weighted magnetic resonance images of temporomandibular joints (TMJ) in 25 asymptomatic volunteers (age range 21-27, mean 23.4 years; 18 (72%) female and 7 (28%) male) were analyzed and metric measurements of disk and condyle position were investigated. Metric analysis of the position and relationship between the disk and the condyles were described using Kurita et al. method of measuring relative and absolute distances of reference points. On statistical data analysis, the left and right TMJs of each person were presented as two separate entities. The methods of nonparametric statistics were used. RESULTS: Anterior disk displacement was found in 5 (20%) asymptomatic volunteers (four of them female). Anterior displacement with unilateral reduction and anterior displacement without reduction unilaterally was present in two subjects each, whereas one volunteer had anterior displacement without reduction bilaterally. There was no difference in the calculated position of condyle between joints with and without disk displacement (Kruskal-Wallis test, p < 0.05). DISCUSSION: This study evaluated the prevalence of asymptomatic anterior disk displacement in symptom-free healthy volunteers and the condyle position in the glenoid fossa. Displaced disk is the main cause of temporomandibular pain; however, studies in asymptomatic volunteers also suggest it to be an anatomic variant. The relationship between dorsocranially positioned condyle and anteriorly displaced temporomandibular joint disk is a controversial issue. Metric analyses were only made in parasagittal plane. CONCLUSION: There was difference in the calculated disk position between joints with and without disk displacement, but this study found no difference in the calculated condyle positions according to the presence or absence of disk displacement.

Checking the occlusal relationships of complete dentures via a remount procedure.

Correct occlusal relationships are part of the successful prosthetic treatment of edentulous patients. Occlusal checking should be performed via a remount procedure because denture base materials and fabrication procedures cannot provide dimensionally accurate complete dentures. Occlusal errors caused by the adjustment of denture bases to the denture foundation after a certain period of wearing can also be corrected by means of remounting. The following remount procedures for complete dentures are described: fabrication of transfer casts, transfer of a maxillary denture with a facebow, centric relation record, and mounting of dentures with transfer casts in an articulator with a dental stone. Deflective occlusal contacts of denture teeth in centric occlusion can be eliminated by selective grinding and by tooth-guided excursive movements. In complete denture treatment, priority is given to anterior/canine-guided occlusion.

[Assessment tools in early detection of osteoporosis in dentistry]. / Dijagnosticke metode za rano otkrivanje osteoporoze u stomatologiji.

Osteoporosis, one of the major skeletal diseases in older age, is characterised by low bone mass and microarchitectural deterioration with a resulting increase in bone fragility and hence susceptibility to fracture. In this review we analyse the systemic and local factors associated with oral bone mass loss. Systemic factors most often correlated with the oral bone mass loss include osteoporosis, renal diseases, hormonal disorders, diet and the impact of different drugs on the bony structure. Chronic periodontal disease, early loss of teeth or the effect of inadequate prosthodontic appliance on the residual ridge are the local factors associated with mandibular bone loss. Different assessment tools for the assessment of mandibular oral bone loss have been proposed, such as DXA absorptiometry, quantitative computed tomography, intraoral microdensitometry, SCORE index and the assessment of the thickness and quality of the mandibular inferior cortical border. Qualitative and quantitative assessment of the mandibular bony structure is of great importance in all fields of dentistry - from periodontology to endodontics and prosthodontics, especially in dental implantology. It is important to make the correct indication prior to dental implant therapy, and taking into account the systemic and local factors mentioned above, assess both the actual quality and quantity of the mandible.

[Custom-made mouthguards and prevention of orofacial injuries in sports]. / Individualni sportski stitnik za zube i prevencija orofacijalnih sportskih ozljeda.

The importance of sports dentistry has become even greater due to the role that sports have in modern society. As the risk of sports-related injuries appears already in the period of children's play and is constantly present in various risk-related sporting activities, the role of dental profession has become extremely important. Custom-made mouthguards are the most highly recommended mouthguards used for successful prevention of orofacial and dental injuries. It is important to inform athletes of the best characteristics of a custom-made mouthguard such as retention, comfort, fit, ease of speech, resistance to tearing, ease of breathing as well as good protection of the teeth, gingiva and lips. The shape and surface of the mouthguard which encloses the teeth, the gingival and the hard palate can vary depending on the anatomical features of the athlete's jaw, his/her dental arch, the type of sports activity, as well as the materials used in the manufacture of the mouthguard. Mouthguards should not extend distally further than the first molars because some athletes complain of the vomiting reflex. In addition, mouthguards may interfere with breathing. They should reach the mucogingival border labially and extend a few millimeters palatally in order to provide the best protection for the labial gingival and good retention. The labial flange should extend up to 2 mm of the vestibular reflection. The palatal flange should extend about 10 mm above the gingival margin thus enclosing the greatest part of the anterior palate surface with a slight narrowing distally not further than the first molars. Materials used in the manufacture of mouthguards should satisfy a number of physical, mechanical and biological requirements. Essential properties of materials used in the manufacture of mouthguards include water absorption, density, thickness as well as temperature transmission, energy absorption and drawing strength (tensile strength) of custom-made mouthguards. Such materials should have an optimal consistency in order to cushion the traumatic impact. Currently, ethylene-vinyl acetate (EVA) is the most commonly used mouthguard material. An optimal thickness of the mouthguard is achieved by the application of vacuum forming pressure-lamination technique in two layers of a thermoplastic sheet of EVA copolymer and if needed, by placing two layers of protective air-cells against the critical area. Some investigations in the Croatian samples showed that the most common injuries in water polo occur in the orofacial region (96.4% of cases), of which 80% are injuries of lips, tongue and cheek. In the period from 1997 to 2005 the number of orofacial injuries increased by 62%. Dental trauma occurs in 7.6% of cases. In basketball players soft tissue injury in the orofacial complex was established in 69.4% and dental trauma in 11.3% of the respondents. In the selected sample of handball players, soft tissue injuries were established in 78.8%, dental trauma and loss of teeth in 13.6% and temporomandibular joint injuries in 6.8% of the cases. In tae-kwon-do players 88% of orofacial injuries were lacerations, but only 12% reported dental and temporomandibular joint trauma. Only a half of the examined professional basketball players wore mouthguards, and none of the examined tae-kwon-do players. Clinical value of intraoral custom-made mouthguards was proven. Dentists play the key role in the prevention and treatment of sports-related dental and orofacial injuries, collection and dissemination of relevant information, as well as promotion of research on the preventive procedures related to injuries of such a specific aetiology.

Psychologic status in patients with temporomandibular disorders.

PURPOSE: The aim of this study was to investigate diferrences in the prevalence of depression and somatization scores in temporomandibular disorder (TMD) patients. MATERIALS AND METHODS: One hundred fifty-four patients with single and/or multiple RDC/TMD diagnoses were classified into 7 groups based on Axis I criteria. Somatization and depression scores from the Symptom Checklist-90 were compared between groups. RESULTS: The results of this investigation indicate that patients with myofascial pain and arthralgia psychologically differed from those with disc displacement. These results were in accordance with findings that support the notion that the pain induces psychologic sequelae, at least in relation to depression and somatization. CONCLUSION: It was concluded that psychologic factors play an important role in etiopathogenesis of TMD, as demonstrated by an increase in levels of depression and somatization in TMD patients.

[Initial treatment of temporomandibular joint osteoarthritis]. / Inicijalna terapija osteoartritisa celjusnoga zgloba.

The diagnostic procedure and the initial treatment of a female patient suffering from temporomandibular disorder is described. Osteoarthritis and the discopathy of the temporomandibular joint were diagnosed both clinically and by magnetic resonance imaging. Anxiety was confirmed by measuring instrument State-Trait Anxiety Inventory. Pains in temporomandibular joints were removed after the initial treatment in which the occlusion splint had been used so that conditions for carrying out the definite occlusal treatment were fulfilled.

Preprosthetic therapy utilizing a temporary occlusal acrylic splint: a case report.

This case report describes the complex occlusal rehabilitation of a patient with signs and symptoms of temporomandibular disorders with utilization of an occlusal acrylic splint as a means of initial treatment for neuromuscular reprogramming and repositioning of the condyle within the mandibular fossa for occlusal stability, thus allowing adaptation to a new occlusal vertical dimension.

Registration and measurement of opening and closing jaw movements and rotational mandibular capacity by using the method of electronic axiography.

The aim of this study was to register and measure lower jaw movements, to analyse the measured length of opening and closing movements and to analyse the rotational mandibular capacity during the maximal opening of the mouth in the position of centric relation. Our objective was to determine the average values for each mandible and temporomandibular joint movement, as well as to determine the accuracy of electronic axiography, while diagnosing temporomandibular joint disorders. A statistical analysis was performed in order to evaluate whether significant differences between the length of the measured movements in asymptomatic and symptomatic subjects could be found. A symptomatic group consisted of 51 subjects with temporomandibular disorders. A control group consisted of 43 subjects without signs and symptoms of temporomandibular joint disorders. Each subject was registered by the GAMMA CADIAX system for registration of position and movement of the lower jaw, which consists of a conventional SAM axiograph, an electronic device for drawing curves by means of a computer. No significant differences were found between the groups of subjects for the measured variables. The results of the length of the mandibular and condyle movements, along with the rotational capacity of the mandible are important, in spite of unreliable indicators of temporomandibular joint function. Description analysis of a graphic recording of mandibular and TMJ movement remains an accurate evaluation method for the determination of TMJ dysfunction.

Incidence of temporomandibular disorders at tooth loss in the supporting zones.

Although the literature reports that occlusal disorders can be associated with temporomandibular disorders (TMD), their direct scientific correlation is still mainly unproved. The aim of this study was to establish the incidence of symptoms and signs of TMD and tissue-specific diagnoses in a population of subjects with tooth loss in the supporting zones. The study was conducted on 196 partially edentulous subjects (Eichner's class II and III) at the average age of 51.2. Manual functional analysis was used as a diagnostic procedure. Chi-square test for independent samples was used for establishing the significance of the differences between the variables. In the total sample, 16.3% of the subjects had symptoms and signs of temporomandibular disorders (TMD), while in 46.9% of the subjects a tissue-specific diagnosis of TMD was found. The most frequent tissue-specific diagnoses were osteoarthrosis and total or partial anterolateral disc displacement. A statistically significant difference between Eichner's class II and III was found for the tissue-specific diagnoses of myofascitis of the lateral pterygoid muscle, partial anterolateral disc displacement and capsulitis. The results of this study suggest that the incidence and intensity of TMD are higher in subjects with greater tooth loss in the supporting zones, regardless of their sex.

A study of the influence of occlusal factors and parafunctional habits on the prevalence of signs and symptoms of TMD.

PURPOSE: The purpose of this study was to investigate the prevalence of the clinical signs and symptoms of temporomandibular disorders (TMD) and the relationship between occlusal factors, parafunctional habits, and TMD in a young adult nonpatient population. MATERIALS AND METHODS: A questionnaire including data from a history and clinical functional examination was used in the study. All 230 subjects were male recruits, from 19 to 28 years of age (mean 21.3 years). RESULTS: Thirty-eight percent of the subjects reported at least one symptom, while in 45% of the subjects at least one sign of TMD was recorded. Temporomandibular joint clicking (40%) and pain on palpation (34%) were the most commonly recorded signs. Multivariate logistic regression analysis showed several weak but statistically significant correlations between the occlusal factors, parafunctional habits, and TMD in this nonpatient population. TMD signs were thus weakly correlated with malocclusion traits (angle Classes II/1, II/2, III, and cross bite), interferences in retruded contact position, midline discrepancy > or = 2 mm, < or = 10 contacts during maximal biting pressure, nonworking-side interferences, horizontal overlap > or = 5 mm, and parafunctional habits (teeth clenching and teeth grinding). CONCLUSION: Some association between occlusal factors and TMD signs was found. However, this association cannot be considered unique or dominant in defining subjects with TMD in the population.