Functional occlusal patterns during lateral excursions in young adults.

STATEMENT OF PROBLEM: A valid system for assessing and classifying functional occlusion has not been established. The prevalence of anterior protected articulation is not known. PURPOSE: The purpose of this study was to quantify the prevalence of various functional occlusal contact patterns, including anterior protected articulation, among dental students. MATERIAL AND METHODS: Occlusal contacts were examined during lateral excursions from the maximal intercuspal position to the canine-to-canine position in 100 young adults. A combination of 3 common clinical methods was used: a visual examination, articulating paper, and feedback from the participants. RESULTS: Data from 3 classification systems were analyzed: (1) Occlusal contacts on the working side only ­ canine protected articulation was present in 25% of laterotrusions; anterior protected articulation was present in 18.5% of laterotrusions. Group function was present in 56% of laterotrusions. Other schemes were present in 0.5% of laterotrusions. (2) Contacts on both the working and the nonworking side. (3) Contacts on the working and nonworking side during both right and left laterotrusion. Nonworking side contacts were present in 33% of the participants. Nonworking side interference was present in 1 participant. CONCLUSIONS: The prevalence of anterior protected articulation found in this study was high enough to allow anterior protected articulation to be considered one of the fundamental working side occlusal contact patterns. More studies will be necessary to confirm this finding.

A complex haptic exercise to predict preclinical operative dentistry performance: a retrospective study.

A reliable test of manual dexterity could potentially have utility in dental education. Recently, haptic technologies have emerged that may offer a means of testing manual dexterity in the preclinical setting. The purpose of this study was to determine whether performance on a complex haptic simulator exercise was associated with preclinical operative dentistry practical examination scores or the Perceptual Ability Test (PAT) scores of the Dental Admission Test. All thirty-nine first-year dental students enrolled in the Operative Dentistry preclinical course at the Stony Brook University School of Dental Medicine completed a haptic exercise consisting of a single manual dexterity test (D-circle), repeated eight times in succession during a single session at midterm. A score reflecting accuracy and time to completion of each trial was calculated automatically and resulted in a success or failure for each trial. Preclinical operative dentistry practical examinations consisting of plastic tooth preparations given at three time points during the course were scored by four calibrated and masked course faculty members. Examination scores were compared with students' performance on the haptic test using linear regression. Number of failures during a single session on a complex haptic exercise was found to be a significant predictor of examination performance in the preclinical setting. These results suggest a role for haptics in identifying students with potential learning challenges in the preclinical stages of dental education. Identification of students with manual dexterity problems at an early stage may allow for early intervention to prevent failure.

Oral lichenoid lesions and allergy to dental materials.

BACKGROUND: Dental materials, oral hygiene products and food additives may cause contact allergic reactions in the mouth with varied clinical presentation. Oral lichenoid lesions (lichen planus-like lesions) can be induced by hypersensitivity to dental restorative metals, acrylates, flavorings and other substances. AIM: The aim of this study was to demonstrate contact allergy to dental materials in patients with oral lichenoid lesions using patch tests. PATIENTS AND METHODS: Routine patch tests with two sets of allergens - "European Standard" and "Dental Screening" (Chemotechnique Diagnostics, Sweden) supplemented with pulverized amalgam, iridium, indium, menthol, sorbic acid and platinum were done on a set of 25 patients with lichenoid lesions located on the buccal mucosa, tongue and lips. Application and interpretation of the tests were conducted according to ICDRG (International Contact Dermatitis Research Group). RESULTS: 15 (60 %) patients showed sensitization to 1 or more allergens, with a total of 31 positive reactions. The greatest frequency of positive reactions was to dental metals, with a total of 27 positive reactions. The order of tested metals according to frequency of positive reactions was mercury (6/25/24 %), amalgam (6/25/24 %), nickel (4/25/16 %), palladium (4/25/16 %), cobalt (3/25/12 %), gold (2/25/8 %), chrome (1/25/4 %), indium (1/25/4 %). The clinical relevance of the results with regard to the material's presence in the mouth was demonstrated in 11 (44 %) patients. In 9 patients, replacement of the positively tested materials led to healing or to significant regression of mucosal changes. CONCLUSIONS: The results of the patch tests showed the possible contribution of contact sensitization in the pathogenesis of lichenoid manifestations in the oral cavity. Due to the premalignant character of these lesions, replacement of positively tested materials and follow up of these patients is advised.

Case report: restoration of edentulous mandible with 4 BOI implants in an immediate load procedure.

Dental implants for insertion from the lateral aspects of the jaw bone have been described repeatedly, since 1972. Long term results have been reported. Due to their design, BOI-Implants (basal osseointegration) can be installed even in those cases, where the vertical bone supply is reduced. This applies to the distal areas of the maxilla and the mandible. Furthermore, BOI-implants allow immediate loading as long as a balanced masticatory function can be achieved and maintained. This paper reports on the steps taken to install a full lower bridge in 4 BOI-implants and restoration in a patient with a circular bridge. The bridge was made from CoCr-Alloy and covered with acrylic resin. This treatment technique reduces costs and treatment time by about 50% compared to conventional techniques.

The spectral analysis of syllables in patients using dentures.

Changes in the oral cavity resulting from the loss of teeth and the ensuing reconstruction of a set of teeth by dentures (partial or complete) may cause changes in the speech and voice of the patient. The aim of the present investigation was to study the changes in speech and voice in patients suffering from teeth loss and the degree of speech improvement using dentures. Voice and speech parameters of a set of tested syllables were analysed in 10 patients at the 2nd Clinic of Stomatology. The analysis was carried out by means of an FFT, SoundForge 5.0 programme. Differently expressed acoustic changes in both consonants and vowels were ascertained in a percentage of the patients under examination. These concerned especially the sibilant ("s", "(see text)"), labiodental ("f", "v") and vibrating ("r", "(see text)") consonants. Changes in the FFT spectrum and air leakage in constrictive consonants were also found. In some patients the vowels, especially the closed ones ("i", "u"), may change their fundamental frequency and show noise admixture manifested as a blurred delimitation of the formants. A denture should, inter alia, render it possible for the patient to produce the same articulation to which he/she had been accustomed before the loss of teeth. For the construction of dentures the most important factors from a phonetic point of view appear to be the following: overbite, overjet, the height of the plate, the thickness of the palatal material, the incisor position, and the modelling of the ruga palatina on the hard palate. In case of wrong denture construction the acoustic changes may continue, resulting in the patient's stress load dependent upon sex, age, psychic condition and seriousness of the problem.