Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MANDIBLE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36Linked to original sources
PubMed2006

[The effect of the position of artificial premature on mandible moving track during opening movement].

PURPOSE: The purpose of this study was to observe the effect of the position of premature on track of mandibular incisal point during opening movement. METHODS: The changes of the track of mandibular incisal point along with the change of premature position were recorded by Arcus DigMa mandibular moving track analysis system. The relativity between the premature position and mandibular incisal point moving track on arrowy axis, vertical axis and horizontal axis was analyzed. Regression analysis was used for linear correlation between premature position and mandible opening moving track. RESULTS: The results showed that along with the retrusion of premature, the moving distance of mandibular incisal point tended to increase on arrowy axis, while decrease on vertical axis and lean to the contralateral side on horizontal axis. The linear regression equation of mandibular incisal point moving distance on vertical axis along with the premature position was: y=34.7095-0.1590x(1), delta=0.5549, P<0.001. CONCLUSION: The position of premature influenced the track of mandibular incisal point during opening movement significantly. With the retrusion of premature, the mandible opening moving track tended to be more posterior and shifting to the contralateral side, and the opening dimension tended to decrease. There was linear correlation between premature position and mandible moving track on the vertical axis.

Dental Occlusion↗
PubMedDate not supplied

A new device in immediately loaded implant treatment in the edentulous mandible.

PURPOSE: This article reports preliminary clinical results of the Speed Master system, a method for immediate loading of implants for the treatment of mandibular edentulism. MATERIALS AND METHODS: Fifteen patients with edentulous mandibles were consecutively included in the study. Each received 4 implants between the mental foramina placed using the system's surgical guides. Permanent fixed prostheses fabricated over premanufactured titanium bars were attached to the implants on the day of implant placement. The patients were followed for 15 to 27 months (mean, 19 months). Peri-implant tissues were periodically evaluated. Marginal bone loss was monitored with periapical radiographs using a computerized technique. Satisfaction was assessed by means of a questionnaire. RESULTS: The overall implant and prosthetic survival rates were 100%. At the time of the final follow-up visit, mean marginal bone loss was 1.11 mm, and bleeding on probing was not observed. Only 6.7% of the patients reported any discomfort during treatment, and all patients would recommend the procedure to others. DISCUSSION: The immediate loading of implants placed in the edentulous mandible with the Speed Master surgical and prosthetic protocol reduces treatment time and number of surgical procedures in comparison to classic delayed loading protocols. CONCLUSION: The rehabilitation of the mandible with an immediately delivered occlusally loaded hybrid prosthesis supported by 4 implants does not appear to jeopardize the success of the osseointegration and represents a viable treatment

Adult↗
PubMed2006

Immediate versus delayed functional loading of implants in the posterior mandible: a 2-year prospective clinical study of 12 consecutive cases.

The aim of this investigation was to evaluate the clinical success of immediately loaded implants versus implants loaded in a delayed fashion in the posterior mandible. Three implants were placed distal to the canines bilaterally in the edentulous distal mandibular ridges of 12 patients. One side was randomly selected for placement of three implants (delayed loading; control sites) with a progressive thread design for submerged healing, and after 3 months the implants were exposed and loaded with provisional splinted crowns, which were replaced 6 weeks later by the definitive restorations. Three additional implants (immediately loaded; test sites), of the same size were placed in the contralateral side of the mandible. The test implants had abutments placed and were loaded immediately using the same protocol as the control implants. After a mean loading period of 25.3 months, the patients showed normal mean clinical values without significant differences (P < 0.05) for test and control implants, respectively, as follows: Plaque Index: 0.4 versus 0.8; Sulcus Bleeding Index: 0.5 versus 0.3; probing pocket depth: 1.9 mm versus 2.1 mm; width of keratinized mucosa: 2.5 mm versus 3.3 mm; Periotest value: -3.7 versus -3.2. Twenty-nine of the examined sites showed no bone loss. After 2 years of loading in the posterior mandible, test and control implants had the same prognosis.

Bicuspid↗
PubMed1991

Biomechanical analysis of osseointegration of IMZ implants in goat mandibles and maxillae.

This study was designed to determine the effect of time on the biomechanical integration of cylindrical dental implants in the mandible and maxilla. A total of 136 IMZ dental implants was placed bilaterally in the endentulous maxillae and mandibles of 17 goats. Pullout tests were used to assess biomechanical integration at intervals from 2 to 24 weeks. This study indicated that there is a time-dependent, progressive increase in pullout force to 24 weeks. The forces were consistently higher for the mandible than the maxilla. Moreover, there was no correlation between the intraoperative stability of the implant and the postoperative pullout force.

Animals↗
PubMed1991

Aesthetic improvements in free-flap mandible reconstruction.

Mandible reconstruction with free flaps has become a well-established technique. Efforts are now focused on obtaining superior functional and aesthetic results. Improvements in the quality of the latter are possible with a systematic approach to shaping the bone graft. Important elements in this approach have been defined based on experience in 50 consecutive cases. Preoperative studies include the lateral cephalogram and a transverse plane CT scan from which mandible templates are constructed. These templates are models of the mandible in two planes and are used to shape the bone with a high degree of precision. They allow the bone to be completely shaped while still attached by the pedicle at the donor site. The surgical specimen serves as an additional key visual reference and as a source of measurements to determine overall bone-graft length. Miniplates alone provide sufficient fixation to stabilize the bone as it is shaped segment by segment. Intermaxillary fixation is used only to prevent errors in total bone-graft length. Hemimandible and anterior defects represent two completely different bone-shaping problems. Although the bone-shaping methods described have been developed primarily with the fibula, they have been successfully applied to the scapula and radius donor sites as well.

Humans↗
PubMed1990

[In vivo radiotelemetric study of strain on the rabbit mandible].

Using strain transducer to measure bone strain and stress in vitro on-line techniques are more popular. In this article, the radiotelemetric method is selected for measuring living tissue mechanic properties. The angle of rabbit mandible serves as tested site. The transducer is minutely foil type electrical resistance strain gage. The measuring instruments are KYOWA telemeter for strain measurement MRT-200 series. When the mandible is in rest position, the tested site shows no change of strain; when the mandible acts without eating any food, small change of strain appear; when the rabbit mastication two kinds of food, the tested site shows the regular change of tension strain and compressive strain, the former is about 150 microstrain and latter is about 30 microstrain. The rates of strain are different when the animal mastication the different foods. Comparing with the on-line technique method, the radiotelemetric method has significant advantages, and is the better test way for studying mechanic properties of living tissue.

Animals↗
PubMed1990

Ameloblastoma of the mandible: report of extensive destruction within 4 years.

A multicystic ameloblastoma of the mandible is reported in a 54-year-old white man who presented with a complaint of an ill-fitting partial denture due to a swelling in the posterior mandible. This case demonstrates the aggressive character of an ameloblastoma, causing extensive destruction of the mandible in a documented period of less than 4 years.

Ameloblastoma↗
PubMed1990

[Retrusive joint function and stability range of the mandible].

In CO the mandible possesses a retrusive function, although this is hardly visible to the naked eye. Yet this function is equal in importance with the protrusive function for the mechanical stability of the mandible in CO while muscular forces are acting. It is theoretically concluded and empirically demonstrated herein that any force, whose line of action is within a certain area of stability, acts to secure the mandible in CO. The limits and range of this area as well as its clinical implications are discussed.

Biomechanical Phenomena↗
PubMed1989

Effects of hyperbaric oxygen treatment on bone healing. An experimental study in the rat mandible and the rabbit tibia.

This study was undertaken in order to investigate some of the factors important for bone healing. A simple and reproducible experimental model was developed for study of tissue reactions following mandibular osteotomy in the rat. Osteotomies were performed proximal to the entry of the inferior alveolar artery, alone or combined with different degrees of mucoperiosteal reflections. The maximal damage that was seen 10 days after surgery was bone resorption in the central portion of the mandibular corpus. The incisors were found to be more sensitive to vascular disturbancies than the molars. The tissue changes were most pronounced when the osteotomies were combined with mucoperiosteal reflections. In order to test different ways of reducing the damage induced and to initiate reparative events by altering local circulatory and metabolic parameters, hyperbaric oxygen (HBO), heparin, or dextran treatments were utilized. The HBO animals were placed in a pressure chamber and subjected to 2.8 ATA HBO, for 2 hours daily. The heparin was administered subcutaneously and dextran by i.v. infusion. Heparin treatment reduced morphologically determined tissue damage in the incisor pulp, odontoblasts and enamel organ. Dextrans had no ameliorative effects. HBO treatment reduced tissue damage in a manner similar to heparin, and also induced reparative events, such as osteodentin formation in pulps and early chondroid reactions in bone. The vascular bed (86Rb) and blood flow [( 125I]polyvinylpyrrolidone) in the mandible were determined at 10 and 30 days after surgery in animals with and without treatment with HBO. The operated right side was compared to the unoperated left side with respect to these two parameters. In HBO treated animals no difference could be seen between the operated and unoperated sides, whereas both a reduced blood flow and diminished vascular bed were seen in the operated side of the mandible in HBO-untreated animals. Alkaline phosphatase in serum (S-ALP) is considered to reflect the spillover of different isoenzymes from different tissues, and the activity of S-ALP is known to vary because of disease in the tissue from which it is derived. S-ALP was characterized biochemically. Separation and measurement of S-ALP isoenzymes was done using isoelectric focusing and optical densitometry. The S-ALP levels were determined before and after mandibular osteotomy and were compared in tissues of animals treated with HBO. A marked decrease in S-ALP was seen after osteotomy. HBO treatment, on the other hand, inhibited this S-ALP decrease, paralleling a reduced tissue damage in the mandible.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Influence of hypoproteinemia on the development of skull, mandible and teeth of the rats--metrical studies].

The amounts of plasma protein in eight groups of rats, A-H, was controlled by diet and a daily study was undertaken to investigate the effect that varying amounts of plasma protein have on body weight, the growth and development of body length, growth of the skull and mandible and development of the teeth. The following conclusions were obtained. 1. It was possible to keep the amount of plasma protein constant in each group by using a specially prepared diet containing differing amounts of casein. Also, when the rats with hypoproteinemia, due to a non-casein diet, were given food containing 24.5% casein, it was found that their plasma protein levels easily and quickly returned to normal. 2. Weight: Counting the first day of the experiment as 100, growth for group A (given a 24.5% casein diet) had reached 281.7% by the fifteenth week, whereas group H (fed a non-casein diet) reached a growth of only 48.5%--below half of day one of the experiment. On the other hand, each group which started out with a non-casein diet and later changed to a 24.5% casein diet recovered very quickly, but not to the extent of group A by the fifteenth week. Body length for all experimental groups increased from the first day to the third week, after which there was a tendency to approximate the body weight. 3. Effect of hypoproteinemia on skull growth: Growth was small for groups B and C whose plasma protein amounts were kept constant. Hardly any growth was seen in groups D and H. Groups E, F and G, whose plasma protein levels were restored, showed a high growth ratio after their diet was changed. Growth of the mandible showed a similar pattern. 4. A comparison of measurements for different parts of the skull indicated different patterns of growth and development for the upper and lower parts. For the upper part, the least growth was in the center followed by the rear area with the largest growth for the nasal bone at the front. The greatest growth ratio in the lower part of the skull was seen in splenoid and occipital bone lengths at the rear followed by the front area and central area. Growth of angular process length of mandible showed a very high growth ratio. 5. The amount of growth for each part of the skull from the largest to the smallest was found to be in the same order for both the upper and lower parts: the front, center and rear.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Relationship between muscular palpation and three dimensional incisal path at border movement of mandible].

Temporomandibular arthrosis was diversified phases of its development as well as complicated mode of its crisis, due to which no concrete clinical diagnostic procedure has been established yet. However, a close relation of occlusal disturbance with the crisis factor is suggested, and assessments have been made in the prosthetic dentistry, setting a viewpoint at the phases of mandibular movement. Particularly, incisal path at border movement of mandible is made the object for basic assessment since it exhibits intensified condition. On the other hand, importance is attached to Krogh-Poulsen's muscular palpation for diagnosis of the pain and contraction of the masticatory muscle which occur in temporomandibular arthrosis. However, though there is a close relation between the pain or abnormal contraction of the masticatory muscle and the phases of mandibular movement, these diagnostic procedures have been the studies which have dealt with the subjects separately. And no report is seen on the study made of the relation between the phases of incisal path at border movement of the mandible and Krogh-Poulsen's muscular palpation. Accordingly, with the purpose of investigating these relationships, the author has made assessment of the relationship between the result by Krogh-Poulsen's muscular palpation and the form (analogue form) of three-dimensional incisal path at border movement of the mandible summarized and standardized by TMJ gnathological instrument which is evaluated as a recording method with high clinical efficiency as a method with excellent reproducibility of mandibular movement and favorable manipulability. The subjects enrolled were patients with temporomandibular arthrosis and the so-called normal healthy subjects with normally functioning occlusion who are not conscious clinically of the abnormality of the stomatognathic system nor had similar anamnesis. And the following results have been obtained. 1. Results by Krogh-Poulsen's muscular palpation; 1) The 59 so-called normal healthy subjects were classified into 2 groups by Krogh-Poulsen's muscular palpation, and of these, the cases in whom no abnormality was observed were only 5, being 8.5%, and the cases in whom single or multiple test items showed abnormality were 54, being so high rate as 91.5%. The occurring frequency of 5 test symptoms in the 54 cases were; 22 cases with trismus-40.7%; 34 cases with temporomandibular sounds -63.0%; 20 cases with pain -37.0%; 36 cases with tenderness of the lateral pterygoid muscle -66.7%; and 25 cases with disturbance of lateral mandibular movement -46.3%.(ABSTRACT TRUNCATED AT 400 WORDS)

Humans↗
PubMed1989

[Metrical study on teeth and mandible in Macaca fuscata fuscata. 2. Principal component analysis].

Metrical investigation on teeth and mandible together was performed to understand the morphological relationship between these two components in Macaca fuscata fuscata. Measurements are 9 items from the mandible, 2 items from dental arch, and 8 mesiodistal diameters from teeth. Correlation matrix composed of 19 items, in total, was examined in males and females, respectively. Significant correlation coefficients were frequently seen among mandibular measurements and also among tooth measurements, but rarely seen between mandibular and tooth measurements. The only exception was a mesiodistal diameter of P3 which has a few significant correlations with mandibular measurements. Principal component analysis was also carried out based on the correlation matrix of 19 measurements. The first component was a size factor in which factor loadings were all positive. The second component was thought to be a factor of the mandibular size in which factor loadings were highly positive on the mandibular measurements and contrarily low on the dental measurements. It is concluded that there is no obvious correlation between general sizes of the mandible and the teeth in Macaca fuscata fuscata.

Animals↗
PubMed1989

[An experimental study on internal structures in the Japanese dentulous mandible].

Measurement of the human substantia compacta and spongy bone. For the sake of a fuller understanding of the structure of the human mandible, a study was made to clarify objectively the thickness of the substantia compacta, the ratio of spongy bone to the total substantia spongiosa, and the width of the spongy bone. Subjects were 11 human mandibles from individuals ranging in age between 35 and 64. All teeth from the central incisor through the second molar remained in place. Measurement was performed with a personal-computer-based image-processing system. Results 1. Width of the substantia compacta Measurement of the width of the substantia compacta showed the thickest part (3.32-3.35 mm) to be roughly at the center of the lingual side of the incisors. The second thickest (2.85-2.90 mm) was located at the buccal-alveolar part of the molars. The thinnest (1.26-1.27 mm) part was located at the labial-alveolar part of the incisors. The next thinnest part (1.74-1.75 mm) was located at the central lingual portion of molars. In the mandible base, thicknesses at all locations fell in the range of 2.76-2.98 mm, with little location-related variation observed. In the labial(buccal)alveolar region, the substantia compacta grows thicker from the mental region toward the molars. In the central lingual region, it grows thinner from the mental region toward the molars. 2. Ratio of spongy bone to total substantia spongiosa Measurements showed the highest ratio (80.9-81.4%) of spongy bone to total substantia spongiosa to be in the lower lingual side of the incisors. This was followed by the central lingual portion of the mental region (80.36%) and the labial side and central regions of the incisors (69.71-78.36%). The ratio was lowest (29.79%) at the first and second premolars. In general, the ratio was high in the incisor region and low near the premolars. No difference was observed between the buccal and lingual sides of the incisor and premolar regions, although in the molar region, the ratio was relatively higher on the buccal than on the lingual side. 3. Width of the spongy bone within the substantia spongiosa.

Adult↗
PubMed1977

The role of the mandible in mouse palatal development revisited.

Growth changes associated with formation of the secondary palate were studied in H-Velaz mouse embryos by morphometric measurement of medial sagittal sections of the heads between days 13 and 15 of embryonic development. Horizontalization of the palatine processes depends primarily on the length of the mandible and is effected by a shift of palatine process material into the supralingual space. The administration of 7.5 mg cortisone acetate im to the female on day 12, of 0.5 mg 6-aminonicotinamide im on day 14, or amniocentesis on day 14 significantly retards growth of the embryo in general and of the mandible in particular without significantly affecting deflexion of the skull base. The different spatial conditions created by disproportion between deflexion of the base and the length of the mandible cause irregularities in the course of horizontalization which lead, as a rule, to cleft palate.

6-Aminonicotinamide↗
PubMed1978

Frozen autogenous mandible as an immediate replacement graft.

A study in animals was designed to examine the feasibility of grafting autogenous frozen mandible. Two groups of animals were used. In the first group, periosteum was elevated from the bone before resection. In the second group, the periosteum was removed with the resected specimen. Osteogenesis was shown by clinical, radiographic, fluorescence, and histologic studies in both groups of animals. The same technique was performed in nine humans with carcinomas that involved the mandible. The results were encouraging. We believe that immediate or delayed reconstruction with autogenous frozen mandible in a patient undergoing ablative surgery of the head and neck with involvement of the bone may offer the patient, as well as the surgeon, another acceptable treatment modality.

Animals↗
PubMed1979

[Position of the mandible, range of movement and temporomandibular joint noises in edentulous patients (proceedings)].

The authors present studies on lateral displacements and ranges of horizontal and vertical movements of the mandible. Theyy used a new device--deviatiometer (fig. 1--4)--for measuring the position and the movements of the mandible. They stated no significant differences in the frequency of temporomandibular joint noises with regard to sex, age, lateral displacement of the mandible and ranges of movements. Consequently, temporomandibular joint noises should not be overvalued in the edentulous patient.

Humans↗
PubMed1988

[Stress distribution in mandible induced by occlusal force in different horizontal mandibular positions].

The objective of this study was to investigate the stress distribution in the mandible induced by occlusal forces in a various different horizontal mandibular positions identified as neutroclusion, distoclusion, mesioclusion, and laterally shifted occlusion. A three dimensional Finite Element Method (3D-FEM) was applied to an artificial model of a simulated mandible constructed as a homogeneous, isotropic and elastic body. This model was divided into 480 elements with 785 nodes. The right and left heads of the mandibular condyles and the occlusal surfaces of the posterior teeth of the model were restrained. These restraints acted against the loading of the masticatory forces which consisted of a pair of masseter, temporal, and also the lateral and medial pterygoid muscles. The stress distributions analyzed by 3D-FEM were graphically demonstrated on a three dimensional display system. The data obtained were summarized as follows: I. Neutroclusion (1) Tensile stress appeared along the anterior border of the ramus, and compressive stress appeared along the angular portion of the ramus. (2) Compressive and tensile stress appeared on the external and the internal surfaces of the anterior portion of the mandibular body. II. Distoclusion and mesioclusion (1) As the position of the mandible was moved distally, the absolute values of the stress tended to increase on the same areas which is the external and the internal surfaces of the anterior portion of the mandibular body. (2) Compressive stress which appeared on the occlusal surfaces of the posterior teeth was very great in distoclusion. At the same time, the stress that appeared on the heads of the mandibular condyle was also great in mesioclusion. III. Right laterally shifted occlusion (1) Tensile stress appeared along the left sides of both of the left and right rami, and compressive stress appeared along the right side of both of the left and right rami. (2) A great amount of stress appeared on the left occlusal surfaces of the posterior teeth and on the left portion of the mandibular body. From these results, it was determined probably that the mandibular morphogenesis was influenced by a series of stress factors which were induced by the forces of the masticatory muscles.

Bite Force↗
PubMed1987

Effect of prenatal ethanol exposure on the growth of rat mandible skeletal units.

To study the effect of prenatal ethanol exposure on the growth of the skeletal units of the rat mandible, female Sprague-Dawley rats weighing 220-240 g were assigned to 1 of 3 different groups. One of the groups received ethanol in the drinking water (up to 10% v/v) for at least 15 days prior to mating, then 20% (v/v) throughout gestation. A balanced diet was supplied ad libitum. A second group was pair-fed with the first group. In addition, an amount of corn starch calorically equivalent to the amount of ethanol consumed by that group was offered. The remaining group formed the normal control and received food and water ad libitum. All groups were offered food and water ad libitum after delivery. Total caloric intakes in the first 2 groups. were 67.8% of that of the normal control group. The average off-spring weight at birth for rats given ethanol was 17% lower than that of normal control rats. There was no significant difference between the average weights of the offspring of pair-fed and normal control rats. During the ensuing 3 weeks, the weight of the offspring of alcoholic rats showed no indication of catching-up. All skeletal units of the mandible of the offspring of ethanol-treated females differed significantly from those of the control group. These differences varied between 2% and 16%. The skeletal units of mandibles of the pair-fed group did not differ significantly from ad libitum controls. The mandibular width was similar in all 3 experimental groups.

Animals↗