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 1,027 records · Page 57Linked to original sources
PubMed2005

The effect of platelet-rich plasma upon implant stability measured by resonance frequency analysis in the lower anterior mandibles.

Using a one-stage surgical protocol, a total of 34 Brånemark Mk-III Ti-Unite implants with a length of 13 mm and a diameter of 3.75 mm were inserted in 10 edentulous mandibles. Of these, seven patients received four and three patients two interforaminal implants. All implants were followed with repeated stability measurements by means of resonance frequency analysis at different time interval: 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 days. In quadrant III platelet-rich plasma (PRP) was instilled locally before implant placement, while no PRP was added in quadrant IV to serve as control group (split-mouth design). Results showed no statistically significant difference between the two groups. Nonetheless, both groups (PRP+control) showed a highly significant reduction of the implant stability quotient (P<0.001) between days 0 and 4. However, no difference was noted between the two groups after day 4, it may be concluded that the instillation of PRP during implant placement in the lower anterior mandible did not add additional benefit.

Aged↗
PubMed1985

Growth behavior and lineage of isolated and cultured cells derived from giant cell granuloma of the mandible.

A central giant cell granuloma of the mandible was fractionated into its mononuclear and multinuclear cellular constituents. The cells were subsequently grown in tissue culture. Sections from the original lesion and the cultured cells were analysed histochemically and immunocytochemically. Acid phosphatase, non-specific esterase, Lysozyme and alpha-1-antitrypsin were employed as markers for cells of histiocytic origin and Factor VIII-related antigen served as an endothelial cell marker. The mononuclear cells were of 2 types; a spindle-shaped cell and a round macrophage-like cell. The giant cells and the macrophage-like cells had a limited life span in culture and survived for up to 2 and 5 weeks respectively. However, the spindle-shaped cells continued to proliferate with a doubling time of 48 h. The giant cells and the macrophage-like cells were identical in their staining characteristics and showed positive staining for all the histiocytic markers tested. In contrast, the spindle-shaped cells were negative for those markers. None of the 3 cell types stained positively for Factor VIII-related antigen. These findings suggest that the giant cells in giant cell granuloma of the jaw are reactive, fully differentiated end-cells that are probably derived from stromal macrophages. The histogenesis of the spindle-shaped cell is not yet known. It is also shown in this study that the histochemical and in vitro growth characteristics of the cells of central giant cell granuloma of the mandible are analogous to those of giant cell tumors of long bones.

Adult↗
PubMed1978

Sex and age differences in bone morphology of mandibles.

Histomorphometric analysis of mandibular specimens has been performed in order to demonstrate possible sex and age differences in percent bone mass and bone activity in the mandible. The material consisted of 32 autopsy specimens from the right premolar region of the mandibular body in subjects with sudden unexpected death and without known bone disease. The subjects were divided in a young group (20--43 years of age) and an old group (60--90 years of age); each group consisted of eight females and eight males. Microradiograms of buccolingual ground sections of 100 micron were used. Quantitation of (1) percent bone area of cortical and trabecular bone and (2) total bone surface/bone area and resorption surfaces/total bone surface in trabecular bone, were done by electronic point-counting. The analysis did not reveal any significant sex or age differences in the trabecular bone with respect to percent bone mass, trabecular coarseness and bone activity. In the buccal and lingual cortices a significant age difference was demonstrated, but there was no sex difference in percnet bone mass. Cortical porosity in mandibles clearly increases with increasing age, but seems to be independent of sex.

Adult↗
PubMed1982

Microradiographic and histomorphometric indices of mandibles for diagnosis of osteopenia.

Mandibular autopsy specimens of 100 Danish subjects without known systemic diseases were obtained. Microradiograms of 100-micrometer-thick undemineralized vertical buccolingual grounds cross-sections and these sections, stained with basic fuchsin, were used. Microradiographic and histologic readings of bone turnover foci on Haversian canal and endosteal-trabecular surfaces were compared and combined. The analyses show the following. 1) number/area Haversian canals with bone formation and resorption foci and total of Haversian canals are reproducible and representative measures for bone turnover, while estimation of % bone turnover surfaces on periosteal and endosteal-trabecular surfaces in biopsies of mandibles has no diagnostic value. 2) Percentage of bone mass and mean cortical width in standard locality indicate the level in group of mandibles. 3) the cortical variables of bone turnover are sex independent; number/area Haversian canals with resorption foci is age independent; number/area Haversian canals with bone formation foci, total of Haversian canals and percentage of subendosteal (Haversian canals + marrow spaces) are increased with age.

Adult↗
PubMed1995

Agenesis of permanent incisors in a mediaeval maxilla and mandible: aetiological aspects.

A paleopathological maxilla and mandible with tooth agenesis were analyzed, focussing on the aetiology of the condition. The jaw material, derived from an adult mediaeval male, was examined by standard anthropological analyses, including radiography. In the maxilla there was agenesis of three permanent incisors and one premolar, and in the mandible of one permanent incisor and two permanent molars. Absence or marked reduction of the incisive foramen and the nasopalatine canal was found. The premaxillary area was reduced without general alveolar bone resorption. The pattern of tooth agenesis was similar to the pattern observed in contemporary individuals, except for the agenesis of one permanent maxillary central incisor. It is suggested that the pronounced lack of teeth in the maxillary anterior region is connected with deficient development of the premaxillary area of the nasopalatine canals and the incisive foramen. As the condition can be ascribed to deviations in the prenatal development, this investigation shows that embryological developmental patterns, which form the basis for the pattern of tooth agenesis, should be taken into account when evaluating dry bone pathology.

Anodontia↗
PubMed1998

Osseointegration in implant-embedded mandible in rats fed calcium-deficient diet: a radiological study.

OBJECTIVE: The purpose of the present study was to investigate osseointegration using radiographs of titanium (Ti) implants into the osteoporotic mandible of rats. MATERIALS AND METHODS: Rats were divided into three groups: first group, which were fed a standard diet throughout (control group), second group which were fed a Ca-deficient diet for only 1 week before implantation (group A), and those which were fed the Ca-deficient diet before and after implantation (group B). On the 7th and 42nd days after implantation, bone changes in those rats were examined by microradiographs and autoradiographs. RESULTS: On the 7th day after implantation, calcification of newly formed bones was lower in groups A and B than in the control group, 45Ca uptake was seen in surrounding bones adjacent to the implant, as well as throughout the mandible. On the 42nd day after implantation, trabecular bone in group A showed radiopacity as seen in the control group. In the alveolar crest and peri-implanted bones in group B, thin bone formation with active 45Ca incorporation was found. CONCLUSIONS: It is suggested that irrespective of the calcium deficiency status in rats, trabecular bones around the implant are restored to a healthy state to some extent by resuming an intake of a necessary amount of dietary calcium. In continued calcium deficiency, osseointegration with the implant and alveolar bone was still observed as in the healthy rats suggesting calcium deficiency is not always a factor to regulate osseointegration of mandibular endosseous implants.

Alveolar Process↗
PubMed2003

Histology of retrieved immediately and early loaded oxidized implants: light microscopic observations after 5 to 9 months of loading in the posterior mandible.

BACKGROUND: An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients. PURPOSE: The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading. MATERIALS AND METHODS: Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System TiUnite , Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry. RESULTS: Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 +/- 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 +/- 10.5% and a mean bone area value of 79.1 +/- 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 +/- 0.1% and 84.9 +/- 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 +/- 10.6% and 77.1 +/- 6.8%, respectively. CONCLUSIONS: The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.

Adult↗
PubMed2006

Clinical experiences with laser-welded titanium frameworks supported by implants in the edentulous mandible: a 10-year follow-up study.

BACKGROUND: Long-term follow-up studies for more than 5 years are not available on laser-welded titanium frameworks. PURPOSE: To report and compare 10-year data on implant-supported prostheses in the edentulous mandible provided with laser-welded titanium frameworks and conventional gold alloy frameworks. MATERIALS AND METHODS: Altogether, 155 patients were consecutively treated with prostheses at abutment level with two generations of fixed laser-welded titanium frameworks (test groups). A control group of 53 randomly selected patients with conventional gold alloy castings was used for comparison. Clinical and radiographic 10-year data were collected for the three groups. RESULTS: All patients followed-up for 10 years (n=112) still had fixed prostheses in the mandible (cumulative success rate [CSR] 100%). The overall 10-year cumulative success rate (CSR) was 92.8 and 100.0% for titanium and gold alloy frameworks, respectively. Ten-year implant cumulative survival rate (CSR) was 99.4 and 99.6% for the test and control groups, respectively. Average 10-year bone loss was 0.56 (SD 0.45) mm for the titanium group and 0.77 (SD 0.36) mm for the control group (p < 0.05). The most common complications for titanium frameworks were resin or veneer fractures, soft tissue inflammation, and fractures (12.9%) of the metal frame. Loose and fractured implant screw components were below 3%. CONCLUSION: Excellent overall long-term results with 100% CSR could be achieved with the present treatment modality. Fractures of the metal frames and remade prostheses were more common for the laser-welded titanium frameworks, and the first generation of titanium frameworks worked poorly when compared with gold alloy frameworks during 10 years (p < 0.05). However, on average more bone loss was observed for implants supporting gold alloy frameworks during 10 years. The reasons for this difference are not clear.

Adult↗
PubMed1994

Muscle strength and mineral densities in the mandible.

Bone mineral density (BMD) in the femoral neck and lumbar spine was measured for 355 postmenopausal 48- to 56-year-old women and the BMD in five different regions in the mandible for 77. All 355 women were also classified according to the size of the masseter muscle. Both skeletal measures and the BMD of the buccal cortex distally from the foramen mentale were compared with the size of the masseter muscle. This study indicates that functional stress, caused by the masseter muscle, is involved in maintaining bone mineral density in edentulous regions of the mandible. Those individuals who are physically active or are bruxists may lose less mineral, after extractions of teeth, from those regions of the jaw bones where the muscles are attached.

Absorptiometry, Photon↗
PubMed1991

Soft tissue calcifications in the differential diagnosis of opacities superimposed over the mandible by dental panoramic radiography.

Not all opacities observed on panoramic dental radiographs are associated with the jaws. Two thousand six hundred and twenty-eight panoramic radiographs obtained from a single dental health clinic were evaluated for the presence of opacities associated with the mandible. Opacities were observed in 4 per cent of cases. The radiographic features of these opacities are presented. The importance of including soft tissue calcifications which may be superimposed over the mandible on panoramic views in the differential diagnosis is discussed. Information on the various soft tissue calcifications which can occur in this region is presented.

Adolescent↗
PubMed1978

Melnick-Needles syndrome: radiographic alterations in the mandible.

After the adventitious finding of bilateral loculations in the mandibular rami and erosion of the coronoid processes of the mandible of a patient with Melnick-Needles syndrome (osteodysplasty), the jaws of four other individuals with the same disorder were examined for similar changes. The coronoid process of the mandible was grossly hypoplastic in all patients, and the rami were markedly abbreviated. In four of the five patients the angle was rounded. In three of five patients, loculations of unknown nature were found in the mandibular rami. Several patients exhibited impacted molar teeth.

Adolescent↗
PubMed1991

Mandible position and activation of submental and masseter muscles during sleep.

Movement of the mandible could influence pharyngeal airway caliber because the mandible is attached to the tongue and to muscles that insert on the hyoid bone. In normal subjects and patients with obstructive sleep apnea (OSA) we measured jaw position during sleep with strain gauges, as well as masseter and submental electromyograms, airflow, esophageal pressure, oximetry, electroencephalograms, and electrooculograms. Jaws of patients with OSA were open more than those of normal subjects at end expiration and opened further at end inspiration, particularly at the termination of apneas when the masseter and submental muscles contracted. Masseter activation occurred only in patients with OSA and in a pattern similar to that of submental muscles. Jaw opening at end expiration could narrow the upper airway, whereas opening at end inspiration could reflect efforts to expand the airway with tracheal tug and with submental muscle activation and efforts to open the mouth to allow mouth breathing. Masseter contraction does not close the jaw but may serve to stabilize it.

Adult↗
PubMedDate not supplied

Deciduous tooth chronology in the mandible of the domestic pig.

Fetuses of known age, collected from 20 days' gestation to term, were used to characterize the chronology of deciduous tooth development within the right mandible of swine. Tooth development was first observed at 32 days' embryonic development, with the differentiation of the deciduous third molar. Bud stages for the remaining deciduous teeth differentiated within the period of 32 to 38 days of embryonic development. Although the initial histological appearance of these teeth covered a short period of time, it was apparent that each tooth continued to develop at its own rate. The deciduous second incisor and first molar reached a stage of enamel formation by the 80th and 86th day of fetal development. This is a much later stage than previously recorded for beginning enamel formation. The stages of tooth development and enamel formation for each tooth are summarized. A previous report on the distribution of the dental lamina and deciduous tooth development in the mandible of the domestic pig combined with the information presented in this report on tooth chronology provide much of the information required for future studies using the domestic pig in dental research. A fetus observed at the 74th day of development demonstrated a tooth bud for the deciduous first premolar. The development of this tooth was followed closely throughout the remainder of fetal development with the cap stage representing its most definitive form at 110 days' development. The suggested deciduous origin for this tooth could result in a reevaluation of the nomenclature for the dental formula of swine.

Animals↗
PubMed1977

The bilateral response of the temporal muscle in the rhesus monkey (Macaca mulatta) to short-term detachment of the muscle and increased loading of the mandible.

The electromyographic background activity of the temporal muscle was observed after short-term detachment of the muscle and with increased loads on the mandible. Detachment of the muscle increased its mean spike discharge within the first 24 days but without significant changes in the spectral components. Loading the mandible decreased both the spike discharge and spectral components.

Animals↗
PubMed1986

Size of the alveolar arch of the mandible in relation to that of the maxilla in 45,X females.

Length and width of the alveolar arch of the mandible and maxilla were determined from hard stone casts of 45,X females (Turner syndrome), female first-degree relatives, and population control females. Adjusted mean values (covariance adjusted for age, previous orthodontic treatment, and number of lost permanent teeth) for mandibular arch width were larger in 45,X females than in normal controls, both absolutely and, more clearly, in relation to the maxillary arch. The total absolute length of the mandibular arch was slightly reduced in 45,X females. The broader and shorter alveolar arch of the mandible in relation to the narrower but normal-length maxillary arch reflects imbalanced facial growth in subjects with one X-chromosome instead of the normal two.

Adult↗
PubMed1990

Long-term effects of orthodontic forces on the morphology of the rat-incisor socket and its location in the mandible.

The effect of orthodontic force application on the rat-incisor socket and mandible was studied on roentgenograms. A mean linguo-intrusive force of 19 +/- 0.6 g was applied continuously to the shortened left lower incisor for a period of two (group A) and four weeks (group B). A third group of rats, subjected to shortening of the left mandibular incisor only, served as a hypofunctional control (group C). A fourth group of normal rats constituted the intact control (group D). After a recovery period of three months, the animals were killed, and standardized roentgenograms of the cleaned mandibles were taken. Socket and mandibular dimensions were measured on magnified tracings of the roentgenograms. Comparison of groups A and B with the control groups, on the one hand, and of group C with group D, on the other, facilitated isolation of the hypofunctional factor. In groups A and B, the orthodontic forces caused changes in the parameters affected (i.e., socket area, alveolar bone thickness, mandibular dimensions) and not affected by hypofunction (i.e., socket angulation and location, anterior-socket length). The former findings implies modification of the adaptive capability of dental structures to functional demands. It is concluded that mechanical loading of the incisor for two to four weeks causes long-lasting changes in the socket and its surrounding bone.

Adaptation, Physiological↗
PubMed1995

Phenytoin at micromolar concentrations is an osteogenic agent for human-mandible-derived bone cells in vitro.

The present study sought to test the hypothesis that phenytoin acts on normal human-mandible-derived bone cells to induce osteogenic effects. To test the effects of phenytoin on bone cell proliferation, we measured [3H]-thymidine incorporation into cell DNA during the final four hr of a 24-hour incubation with phenytoin. Phenytoin at micromolar concentrations significantly stimulated the [3H]-thymidine incorporation in a dose-dependent, biphasic, manner with a maximal effect at from 10 to 50 microM. We confirmed the proliferative effect of phenytoin by counting cell number. To evaluate the effects of phenytoin on osteoblastic differentiation, we determined alkaline-phosphatase specific activity and found that phenytoin at micromolar concentrations significantly increased that activity in a dose-dependent manner, with maximal stimulation at approximately 1 microM. To investigate the effects of phenytoin on mature osteoblastic activities, we measured de novo collagen synthesis and osteocalcin secretion. Mitogenic doses of phenytoin significantly increased collagen synthesis and osteocalcin secretion in a dose-dependent, biphasic, manner, with the maximal stimulatory dose at from 5 to 10 microM. In summary, phenytoin at micromolar ranges increased (a) [3H]-thymidine incorporation and cell number, (b) alkaline-phosphatase specific activity, (c) collagen synthesis, and (d) osteocalcin secretion in monolayer cultures of normal human-mandible-derived bone cells. These observations are consistent with the premise that low doses of phenytoin act on human craniofacial bone cells to stimulate cell proliferation, differentiation, and mature osteoblastic activities to stimulate bone formation.

Alkaline Phosphatase↗
PubMed1999

Post-extraction remodeling of the adult mandible.

Following tooth loss, the mandible shows an extensive loss of bone in some individuals. This may pose a significant problem in the prosthodontic restoration of function and esthetics. The many factors which have been proposed as being responsible for the inter-individual variation in post-extraction remodeling mean that a perfunctory analysis of the literature, in which well-controlled, relevant studies are scarce, may not provide the whole story. This article reviews the local and systemic factors which may play a role in the post-extraction remodeling of the mandible. Since severe residual ridge resorption may occur even when the bone status in the rest of the skeleton is good and vice versa, it is concluded that local functional factors are of paramount significance. It is now essential to determine how they can be modified and applied to help maintain ridge height and quality in our aging, edentulous population.

Adult↗