The relationship between Angle type of occlusion and recorded Bennett angle values.

STATEMENT OF PROBLEM: The Bennett angle can be an important parameter to accurately record and program into an articulator during restorative procedures. Few data exist regarding the impact and association of a patient's occlusion types on their recorded Bennett angle values. PURPOSE: The purpose of this in vivo study was to investigate the effect of occlusion type on recorded Bennett angle values. MATERIAL AND METHODS: This study included 98 participants (26.0 ±5.2 years) divided into 4 study groups: Angle class I; Angle class II, division 1; Angle class II, division 2; Angle class III. All recordings were obtained using an ultrasound mandibular recording device with 6 degrees of freedom and a clutch was attached to the mandible. On each participant, 3 protrusive, 3 left laterotrusive, and 3 right laterotrusive movements were recorded. The recording device's software automatically calculated Bennett angle for each participant's left and right mandibular fossae and the data were statistically analyzed. RESULTS: One-way ANOVA did not show significant differences among different Angle classes of occlusion for the Bennett angle values. The average Bennett angle value for all participants was 7.7 degrees. CONCLUSIONS: The results of this study suggest that different Angle occlusion classifications do not appear to have an impact on recorded Bennett angle values. The average Bennett angle value in this study was found to be approximately 8 degrees. This information should be considered when programming average values into an articulator with respect to desired negative error (shorter cusp) during restoration fabrication.

Centric slide in different Angle's classes of occlusion.

The purpose of this study was to test the possible differences in centric slide values between different Angle's classes of occlusion. The study included 98 participants divided into four groups: Angle's class I, Angle's class II, subdivision 1, Angle's class II, subdivision 2 and Angle's class III. All recordings were obtained using an ultrasound jaw tracking device with six degrees of freedom. The distance between the maximum intercuspation (reference position) and the centric occlusion was recorded at the condylar level. Anteroposterior, superoinferior and transversal distance of the centric slide were calculated for each participant, and the data were statistically analyzed (analysis of variance and Newman-Keuls post hoc test). No statistically significant difference was found in the anteroposterior and transversal distance of the centric slide between tested groups, while Angle's class II, subdivision 2 showed smaller vertical amount of the centric slide compared to Angle's class I and class II, subdivision 1. None of the 98 participants showed coincidence of centric occlusion and maximum intercuspation. Our results suggest that coincidence of the maximum intercuspation with the centric occlusion should not be expected. Smaller extent of the vertical distance of the centric slide could be morphological and a functional expression characteristic of the Angle's class II, subdivision 2.

ADVERSE DRUG REACTIONS IN THE ORAL CAVITY.

Every medication may lead to adverse effects, even when used in standard doses and mode of application. In the oral cavity, adverse effects may affect every part of oral mucosa and are the result of medications taken either locally or systemically. Oral adverse reactions to drugs are not typical and therefore sometimes not easy to recognize. On diagnosing adverse side effects in the oral cavity, experienced clinician will usually diagnose the condition on the basis of detailed medical history and clinical finding. However, the only objective evidence for the offending drug is 're-challenge', i.e. exposure to the drug after its discontinuation. It carries a huge risk of anaphylactic reaction; therefore it has to be performed in a controlled hospital setting. Therapy is based on immediate exclusion of the offending drug and, if lesions are present in the oral cavity, topical or systemic corticosteroid therapy is prescribed. This article gives a review of patients with oral adverse drug reactions referred to the Department of Oral Medicine in Zagreb.

Movements of temporomandibular condyles during swallowing.

There have been studies that investigated mandibular movements and positioning during swallowing, but the results were inconsistent, and still the exact position of the condyles during swallowing is unknown. The purpose of this investigation was to study the kinematics of the mandible and the condyles, and to determine the actual movement paths and position of mandible and condyles during the process of swallowing. The study was performed on a sample of 44 dental students. Measurements were done with an electronic axiograph. After non-occlusing attachment was fixed in the mouth, every subject swallowed for five times from the rest position. The final swallowing position of the left and the right condyles was measured in the sagittal plane. The final swallowing position of the sagittal incisal point was measured in sagittal, frontal and horizontal plane, and data was statistically analyzed. The condyles showed average movement toward posterior (left 0.17 mm, SD 0.28, right 0.16 mm, SD 0.25) and superior (left 0.14 mm, SD 0.20, right 0.14 mm, SD 0.23). Anterior and/or inferior position had 20% of participants. The average sagittal incisal point movement during swallowing was toward anterior (0.30 mm, SD 0.53) and superior (0.81 mm, SD 0.84). The mean mandibular lateral movement was 0.1 mm (SD 0.1). The results of the study suggest that retrusion during swallowing is not the rule, although on average there is a slight tendency of condylar movement toward posterior. Swallowing can be used as auxiliary method for determining vertical dimension of occlusion.

ARTICULATOR-RELATED REGISTRATION AND ANALYSIS OF SAGITTAL CONDYLAR INCLINATION.

The purpose of this investigation was to study sagittal condylar inclination values within a uniform sample (Angle class I occlusion) using 'articulator-related registration' and Camper's plane as a reference plane. The study was performed on a sample of 58 Angle class I subjects (mean age 25.1, SD 3.1). Measurements were performed with an ultrasonic jaw tracking device with six degrees of freedom. After a paraocclusal tray was fixed in the mouth, each subject had to make three protrusive movements and three right and left laterotrusive movements. From protrusive movements the software of the device automatically calculated the left and the right sagittal condylar inclination values used for setting of the articulator. The mean sagittal condylar inclinationvalue was 41.0° (SD 10.5) for the right joint and 40.7° (SD 9.8) for the left joint. The maximum value was 65.0° for the right and 68.6° for the left joint, and the minimum value was 13.7° for the right and 21.7° for the left joint. The results of this study suggested the average articulator setting for sagittal condylar inclination for fully dentate adult subjects to be 40° in relation to Camper's plane. This is especially important for the articulators that are set up in relation to Camper's plane.

Measurements of the sagittal condylar inclination: intraindividual variations.

AIMS: Sagittal condylar inclination is an important parameter during fabrication of prosthetic restorations. Existing data about intraindividual variations of sagittal condylar inclination are scarce. The purpose of this study was to investigate intra- and interindividual variations of the sagittal condylar inclination, depending on the position of the condyle in the temporomandibular joint. METHODOLOGY: The study included 51 subjects with Angle's Class I occlusion (21-32 years of age, mean 25.1). Measurements were done using an electronic axiograph. After a paraocclusal tray was fixed in the mouth, every subject had to make three protrusive movements, from which the device's software calculated the mean left and mean right sagittal condylar path. The mean left and right condylar path of each subject was divided into three equal sequences, based on whole condylar path length. Condylar inclination values for the first, second and third movement sequences were calculated. RESULTS: Results showed significant differences between movement sequences (P < 0.05). For the left joint, condylar inclination values in the first condylar movement sequence demonstrated, on the average, 14.4% higher values compared to the second movement sequence, and 39.2% higher values than in the third movement sequence. For the right joint, the first condylar movement sequence demonstrated, on the average, 15.8% higher values compared to the second movement sequence, and 41.5% higher values than the third movement sequence. CONCLUSIONS: Results suggest that condylar movement in the sagittal direction is not uniform. Mean left and mean right condylar inclination values do not necessarily describe the actual condylar path, nor do they give adequate information for articulator setup. Left-right side condylar inclination differences greater than 10 degrees can be considered as normal.

Clinical view of the temporomandibular joint disorder.

Temporomandibular pain has a musculoskeletal origin because it occurs as a consequence of masticatory muscle function disorder and temporomandibular joint disorder. Most common diagnoses of disorders are disc displacement and osteoarthritis, but their comorbidity can also occur. Pain is the most common symptom, where chronic temporomandibular pain may con- tribute to the occurrence of psychological disorders in the patient population. Splint is the most widespread dental method of treatment but other, noninvasive methods of musculoskeletal pain treatment are also recommended. Electronic axiography is used for visualization of mandibular movements, in particular pathologic sounds in the joints. Mental health, although not so obvious in dental practice, can influence the need of a multidisciplinary approach to the patient with disorder of the temporomandibular joint.

Study of temporomandibular joint disorder in older patients by magnetic resonance imaging.

OBJECTIVES: To compare characteristics in older patients in a sample of the general population of those with temporomandibular joint disorder (TMJD). MATERIALS AND METHODS: A prospective study was carried out between 2001 and 2008 in patients with TMJD. The whole sample consisted of 141 patients divided in two groups: 31 patients aged over 60 (median age 67.9, ranging from 60 to 82) and the remaining 110 patients (median age 36.3, ranging from 12 to 59) who were seeking treatment. Clinical diagnostics was confirmed by MRI. Pain intensity was rated on a visual analogue scale (VAS 0-10). RESULTS: There was no statistical difference between average pain in older patients (6.2) and patients aged up to 59 (5.7) evaluated by VAS. There was a statistically significant difference (p = 0.002) in pain duration: older patients reported shorter duration of experienced pain (7.8 months) than patients aged up to 59 (12.2 months). CONCLUSION: In this study, it was found that 22% were older patients with TMJD. A higher level of anxiety was shown in both patients' groups, regardless of shorter pain experience in the older patients.

Prevalence of torus palatinus and torus mandibularis in the Split-Dalmatian County, Croatia.

Torus palatinus (TP) and torus mandibularis (TM) are non-pathological outgrowths of unclear etiology that develop from the jaw bone. The purpose of the present study was to report on the prevalence, shape and location of TP and TM in the population of the Central Dalmatian region, Croatia. The study comprised of 1679 subjects, 985 females and 694 males, age range from 9 to 99 years who were examined by clinical examination and analysis of the plaster casts. Torus palatinus was found in 42.9% subjects and torus mandibularis in 12.6% of the subjects. Spindle-shaped torus palatinus was the most frequent type (45.6%). The most frequent type of torus mandibularis was bilateral solitary torus mandibularis (35.4%). Furthermore, torus palatinus was found in 40.1% of the total number of females and in 46.8% of the total number of males, indicating a significantly higher prevalence in the male population (p = 0.006). Torus mandibularis was found in 11.3% of the female population and in 14.6% of the male population, again indicating significantly higher prevalence in the male population (p = 0.046). The results of this study show significantly higher prevalence of torus palatinus and torus mandibularis in the male subjects. Furthermore, no differences in the prevalence of either TM or TP regarding age were found.