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PubMedDate not supplied

Dental implants in reconstructed jaws: patients' evaluation of functional and quality-of-life outcomes.

PURPOSE: To evaluate the quality-of-life aspect of treatment outcome following functional jaw reconstruction and dental implants in the maxilla or mandible. MATERIALS AND METHODS: This cross-sectional study used a questionnaire interview of 28 rehabilitated patients who received autogenous bone grafts from the ilium and endosseous implants (14 maxillary and 14 mandibular cases; 134 implants) for functional jaw reconstruction between 1988 and 1999. A questionnaire was developed to assess the quality-of-life outcome for those patients who had finished their rehabilitation at least 6 months prior to the interview. Responses to the questions were recorded by means of visual analog scales. RESULTS: In general, patients gave positive comments on the restoration of their orofacial appearance and function (mastication and speech). The majority (85.7%) found no problem in various daily social activities, including dining in public. DISCUSSION: The overall level of satisfaction with the treatment outcome and the degree of recommendation of the treatment to others were both favorable (mean scores 8.6 and 8.7 out of 10, respectively). CONCLUSION: Oral rehabilitation using functional jaw reconstruction can reach a satisfactory level of esthetics, function, and psychosocial well being of patients, thus improving their quality of life.

Activities of Daily Living↗
PubMed2003

[Retrospective analysis of 30 cases of mandibular ameloblastoma operated in the Ivory coast from 1992 to 2000].

OBJECTIVE: We analyzed a retrospective series of 30 cases of ameloblastoma operated in the Ivory coast from 1992 to 2000. PATIENTS AND METHODS: The following techniques were used--temporary reconstructions via the endobuccal approach using a Peri prothesis in 27 cases and a resin coated Peri prosthesis in one;-- definitive reconstructions using iliac bone grafts in 3 cases and rib grafts in 14. These reconstructions were performed in a second operation via a cutaneous approach to replace the Peri prosthesis. Thirteen patients were lost to follow-up for this second phase. Mean follow-up ranged from 6 months to 13 months (mean 9.9 months). RESULTS: Satisfactory outcome was acchevied when mouth opening was greater than 10 mm and patients with an acceptable cosmetic result no longer complained of mastication or phonation problems. There were four postoperative infections after bone graft reconstruction (two of them were immediate reconstruction). The resin coated Peri prosthesis led to a skin ulceration. DISCUSSION: This study demonstrated the interest of mandibular reconstruction in undermedicalized countries where indications are dominated by reconstruction after resection for ameloblastoma. The large number of patients lost to follow-up before the second stage bone grafts points out the need for immediate reconstruction using autologous bone. Further study in a larger series would be needed to determine the cause of failure after immediate reconstruction.

Adolescent↗
PubMed2003

Differential roles of periodontal mechanoreceptors of working-side posterior teeth in triggering nonworking-side temporalis activities.

The purpose of this study was to examine how the periodontal sensory inputs of working-side maxillary posterior, teeth affect nonworking-side anterior temporalis activities at the starting jaw position of the slow-closing phase in mastication. Six subjects with normal occlusion were asked to bite an incisal block to maintain the initial jaw position of the slow-closing phase and to generate jaw-closing muscle activities. Bipolar needle electrodes were inserted into the nonworking-side anterior temporalis to record spike discharges from a single motor unit. To stimulate the periodontal mechanoreceptors, mechanical stimulations were applied to the working-side maxillary first molar, first and second premolar in bucco-palatal, palato-buccal, and apical directions. Meanwhile, we examined changes in the discharge frequency of the motor unit activities of the nonworking-side anterior temporalis. We found that the palato-buccal stimulation to the working-side maxillary first molar and the apical stimulation to each working-side maxillary posterior tooth significantly increased the nonworking-side anterior temporalis activities; however, palato-buccal and bucco-palatal stimulations applied to the first and second premolar didn't. Thus, differential responses of the nonworking-side anterior temporalis are found by the working-side maxillary first molar and premolar stimulations. These findings may be due to some differences in function between molar and premolar.

Adult↗
PubMed2003

[An in vitro model for the simulation of approximal wear].

Several methods have been developed to evaluate attritional wear of restorative materials. A distinction was made between attritional wear in occlusal contact areas (OCA) and wear in contact-free occlusal areas (CFOA). Only limited data dealing with approximal wear in vitro are available. Using a new configuration of the computer-controlled masticator, approximal wear of two composites (P-50, 3M and Tetric Ceram, Ivoclar-Vivadent) was assessed in a two-body wear test after thermo-mechanical loading. Wear was quantified using a profilometer. In addition, micromorphology was assessed by SEM. Wear showed a non-linear pattern, which was comparable to occlusal abrasion. After the first loading cycle, wear increased significantly (p < or = 0.05), and subsequently decreased. After a 5-year-equivalent, the mean substance loss for composite specimens was 20.3 +/- 15.6 microns for P-50 und 17.5 +/- 3.1 microns for Tetric Ceram. Approximal wear between enamel surfaces was 3.9 +/- 4.3 microns. In another experiment, the influence of the approximal wear on an enamel bonding agent was assessed. After thermo-mechanical loading, specimens were immersed in a demineralisation gel. The protective potential of the sealant was assessed under a polarized light microscope. The results suggested that partial sealant loss could lead to caries-like demineralisation in the affected areas.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2004

[The biomechanical research on the different stress distributions between complete and defective dentition].

PURPOSE: To evaluate the stress distribution of crowns under mastication from the biomechanical respect, and observe the physical effects on different teeth through the interproximal contacts. METHODS: A healthy adult skull with both maxilla and mandible was selected, which had normal overbite and overjet, standard occlusal relationship, and tightly contacting with interproximal teeth. After preparation, a 1mm x 1mm strain foil was bonded on every crown. In centric occlusion, 20 kg vertical load was applied on it. The stress value of crown(GPa) was detected by the YJD-17strain gauge. There were three groups: group 1 with complete dentition, group 2 with the first molar missing, and group 3 with missing of right mandibular first molar, lateral incisor and central incisor. RESULTS: The stress value in complete dentition was 3.4641 in second molar, 0.5132 in second premolar, 1.0264 in canine, and 0 in others. In group 2, the stress value was 5.003 in second molar, 1.4113 in second premolar, the values of other teeth equal to that of group 1. In group 3, the stress value was 5.2603 in second molar,1.6679 in second premolar,3.2075 in canine, 0 in first premolar, respectively. CONCLUSION: In complete dentition, the occlusal strength is distributed through the contact area between interproximal teeth, therefore, the stress value of crown is low. However, in the area near the defective dentition, it will be obviously high.

Biomechanical Phenomena↗
PubMedDate not supplied

Effect of resilient liners on masticatory muscle activity of edentulous patients: clinical and electromyography studies.

This investigation evaluated how the soft lining of both maxillary and mandibular complete dentures influences the activity of the masseter and temporalis muscles. Electromyography was used to determine changes in muscle activity. The findings, expressed by Root Mean Square values, indicated an increase in muscle activity after insertion of dentures and prior to application of soft lining material. These activities decreased gradually throughout the 12-week evaluation period following the application of soft liner. Significant differences were noted between masseter and temporalis muscle activity during mastication of different types of food.

Analysis of Variance↗
PubMed2004

Saliva substitute in xerostomic patients with primary Sjögren's syndrome: a single-blind trial.

OBJECTIVE: To evaluate the efficacy of oral moisturizing gel (Oral Balance) in xerostomic patients with primary Sjögren's syndrome (SS). METHOD AND MATERIALS: Twenty-one xerostomic patients with primary SS were subjected to a single-blind trial in which the efficacy of Oral Balance gel in reducing xerostomia and xerostomia-related oral symptoms was compared with that of a placebo. Both gels were packaged identically and were indiscernible in appearance and taste. Xerostomia was confirmed for all the patients through measurement of stimulated whole saliva. Patients began using the Oral Balance gel three times a day for 90 days, and were then switched to a gel placebo to be used in the same way for the same length of time. Clinical response was evaluated through the patients' subjective assessment (improved, worsened, or unaltered) of both gels. RESULTS: Neither the Oral Balance gel nor the gel placebo affected the salivary output of the patients. The Oral Balance gel presented a substantial statistically significant advantage in the control of burning mouth, mastication, and swallowing. No statistically significant relief of the isolated sensation of oral dryness was established. CONCLUSION: Oral Balance is a useful tool in the management of dryness-related oral symptoms in primary SS, but there is room for enhancing the overall properties of topical preparations designed to reduce oral complaints in xerostomic patients.

Adult↗
PubMedDate not supplied

Use of image analysis in determining masticatory efficiency in patients presenting for immediate dentures.

Image analysis was used to determine masticatory efficiency and performance before and after placement of immediate dentures. Sections of cored carrot were used as the test food and the particle size of chewed expectorated food was measured using image analysis. Measurements were shown to be accurate and reproducible. Masticatory function of immediate-denture patients was also compared with a similar number of dentate individuals and experienced complete-denture wearers. Dentate subjects were significantly (P less than .01) more efficient at masticating the test food than were the complete- or immediate-denture wearers. The new method of measurement removes the necessity for the unpleasant and unhygienic sieving process previously used in this type of study.

Denture, Complete, Immediate↗
PubMedDate not supplied

A functional aspect of anterior attrition or flaring and mode of treatment.

The phenomenon of occlusal wear has been generally reported, with no distinction being made between wear of the anterior or posterior teeth. This paper describes a group of patients without oral habits and exhibiting anterior tooth attrition or flaring with minimal posterior tooth attrition. The mandibular anterior movement patterns of the patients studied were evaluated using a Sirognathograph. These patterns appear to be the etiology for the anterior attrition or flaring present. A treatment mode allowing coexistence of this phenomenon with an anterior guidance that does not interfere with the mastication pattern is proposed. A hypothesis that might explain the clinical findings and a mode of treatment are described.

Adolescent↗
PubMed2004

Electromyographic evaluation of masticatory function in denture wearers in related to existing occlusal support.

The aim of this study was to clarify the relationship between partially edentulous pattern and the masticatory function in removable partial denture wearers. Eighty eight removable partial denture wearers and 7 subjects with intact dentition volunteered for this study. Using the Eichner's index, all subjects were divided into 6 groups. Electromyographic (EMG) activities of the masticatory muscle were recorded during chewing a piece of raw carrot. The masticatory function was analyzed by using the variation coefficient (VC) of the time parameter of EMG interval recorded during mastication. The association of the VC with group classification based on Eichner's index was analyzed using analysis of covariance with gender and age as the covariates. The result of the analysis revealed that the VC was significantly associated with group classification and the patients in groups without posterior occlusal supports exhibited significantly higher VC values than those in groups with posterior occlusal supports. These findings suggested that the reduced function in patients without the posterior occlusal contacts was difficult to attain improved and satisfactory outcome with removable partial dentures and that there is a significant need for posterior occlusal support for the preservation of masticatory function.

Adult↗
PubMedDate not supplied

[Comparative morphological studies of the structure of the articular disk of the temporomandibular joint].

Articular disks (DA) of mandibular articulations of several types of animals of different ages and both sexes (herbivora, carnivora, rodents and omnivora) were studied. Comparative macroscopy emphasized similarities with the DA of humans and other omnivora, as well as some peculiarities. DA is ellyptical in herbivora; its upper surface is divided into two facets by a transversal crest. DA is pinkish and square in carnivora; its posterior part is lacking. DA is half-moonish and white-nacreous in rodents; its upper surface presents a longitudinal crest. Microscopy evidenced some differences: the collagen fibrils are dominating in herbivora, while in carnivora the elastic ones. The rodents present rare elastic fibers; these animals and the ruminants show capillaries in the central part of the DA, while in other animals these are absent. Cells are mainly located in the upper superficial layers of DA. Relationships between form, histological structure and functions, mainly regarding the mastication types, are discussed.

Anatomy, Comparative↗
PubMed2005

Jaw tracking devices--historical review of methods development. Part I.

Chewing or mastication is one of the main functions of the stomatognathic system. The use of devices for quantitatively measuring mandibular motion has recently become more common in scientific and clinical use. Often, the goal has been to provide an objective basis for diagnosing musculoskeletal disorders of the jaws, to monitor the progress of active treatment methods or to evaluate prosthodontic treatment functional results. To better understand differences between various systems to record mandibular motion a review of recording methods presented over the years was made. To give fundamental description for development of existing methods review was divided in three parts. Part I includes analyses of methods using mechanical devices, photographic methods and roentgenographic methods, describing not only technologies by themselves, but also analyzing essential limitations, possible direction of the functional improvement and, specially, their scientific and clinical significance.

Dental Equipment↗
PubMed2005

Jaw tracking devices--historical review of methods development. Part II.

Chewing or mastication is one of the main functions of the stomatognathic system. The use of devices for quantitatively measuring mandibular motion has recently become more common in scientific and clinical use. Often, the goal has been to provide an objective basis for diagnosing musculoskeletal disorders of the jaws, to monitor the progress of active treatment methods or to evaluate prosthodontic treatment functional results. To better understand differences between various systems to record mandibular motion a review of recording methods presented over the years was made. To give fundamental description for development of existing methods review was divided in three parts. Part II includes analyses of electronic and telemetric methods, magnetometry and opto-electronic methods, describing not only technologies by themselves, but also analyzing essential limitations, possible direction of the functional improvement and, specially, their scientific and clinical significance.

Dental Equipment↗
PubMed2005

Dental arch relations analysed in a 14th century fossil skull of the Sao tribe, Cameroon.

Dental occlusal relations are rarely reported in paleo-anthropology. The manipulation of hemi-arch replicas, as well as the superimposition of drawings on calques traced from photographs, facilitated the description of the intra- and interarch relations. The occlusal interarch confrontation and the intermolar relation were observed and assessed in the horizontal, frontal and sagittal planes. Some measurements were helpful in the functional study. On the basis of knowledge in mandible kinematics a movement envelope of the first molar displacement during mastication was proposed. The dentition studied here was highly regular. It was a fine example of balanced wear for post-canine sectors. In spite of the lower canine extrusion, due to tribal mutilation of anterior teeth and to subsequent labret wearing, the interarch relations seemed not to have been altered.

Cameroon↗
PubMedDate not supplied

Prospective clinical trial comparing lingualized occlusion to bilateral balanced occlusion in complete dentures: a pilot study.

PURPOSE: The aim of this prospective comparative trial was to evaluate whether patients treated with complete dentures with lingualized occlusion (LO) exhibited more positive results than patients treated with complete dentures with bilaterally balanced occlusion (BBO). MATERIALS AND METHODS: Twenty-eight completely edentulous patients, ranging in age from 60 to 82 years (mean age 70.9), consented in writing to be participants in this trial. The first 14 patients enrolled in the study protocol were treated with complete dentures with LO, and the next 14 patients were treated with complete dentures with BBO. Baseline characteristics were measured prior to the trial. Main outcome variables involved subjective outcomes of general satisfaction, ability to masticate, and stability and retention of the prostheses; these were quantified with a 100-mm visual analog scale. Objective outcomes were masticatory performance and the number of adjustments. Statistical assessments of the 2 groups were compared using multiple linear regression analysis. The baseline characteristics were analyzed by Student t test and chi-square test. RESULTS: There were no significant differences between the groups at baseline. The height of the alveolar ridge exhibited significant correlations with masticatory performance (P = .02). The occlusal scheme exhibited a significant correlation with only the patient's retention satisfaction rating (P = .03). CONCLUSION: Despite limitations of this study attributed to the small sample size and lack of randomization, this pilot study found that edentulous patients fitted with complete dentures with LO experienced and expressed greater satisfaction with their denture retention. In addition, it was observed that a higher alveolar ridge resulted in greater masticatory performance.

Aged↗
PubMedDate not supplied

Immediate function with the zygomatic implant: a graftless solution for the patient with mild to advanced atrophy of the maxilla.

PURPOSE: In many edentulous maxillae, posterior alveolar atrophy calls for bone grafting. Patient treatment acceptance is increased by eliminating grafting using tilted implants, especially the zygomatic implant in combination with immediate function. The purpose of this study was to evaluate a protocol for immediate function (within 2 hours) of 2 zygomatic and 4 standard implants (Nobel Biocare) supporting a fixed prosthesis in the completely edentulous maxilla. MATERIALS AND METHODS: This clinical study included 14 patients with 83 immediately loaded implants (28 bilateral zygomatic and 55 premaxillary implants) supporting a complete maxillary denture converted to a fixed provisional prosthesis immediately following the surgical procedure. After 6 months of use, a new fixed metal-supported prosthesis was fabricated. RESULTS: Fourteen patients treated with immediate loading of zygomatic implants were followed for at least 12 months. All patients reported minimization of postoperative pain and security during speech, animation, and mastication. No failures occurred during the follow-up period. DISCUSSION: The patients in the study could have been candidates for sinus grafting. With the present concept these patients benefited from a less invasive procedure (1 surgical procedure and no grafting) and immediate rehabilitation (prosthesis attached directly after surgery). CONCLUSION: The high survival rate, increase in patients' immediate functional ability, and reduction of morbidity following the surgical procedure render this procedure a viable treatment option for the completely edentulous maxilla.

Atrophy↗
PubMed1991

[The stomatognathic function in a case of hemifacial hypertrophy--findings of mandibular movement].

We have been treating a girl with hemifacial hypertrophy since she was 5 years 8 months old. We analyzed her stomatognathic function, the dentition and occlusion, X-ray findings of TMJ, tooth contact and measurements of mandibular movement, at 9 years 2 months. The results were as follows: 1. The maxillary dental arch was almost symmetrical, but the mandibular one was complicatedly distorted in the up and down directions, and largely shifted to the left side. As a result the patient was able to occlude in the severe cross-bite condition of the area from incisors to left molars. 2. The patient had many tooth contact points on the right side and few on the left side when she bit at the intercuspal position and at the both lateral excursions. 3. From the analysis of the mandibular movements on the protrusion, lateral excursion and maximum open and close positions, it was suspected that the shift of right condyle was much less than the left one, and showed as almost rotating movement. 4. It could be concluded that the patient was accustomed to having more tooth contacts in the right dentition than in the left one because of the hypertrophy of the right half of mandible, so that she could only masticate with the right teeth also the anterior displacement of disk with reduction was resulted on the right condyle and the asymmetrical mandibular movement was noted.

Child↗