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 253 records · Page 14Linked to original sources

Bone that best matches the properties of the mandible.

OBJECTIVE: The main advantage of primary oromandibular reconstruction using free vascularized bone-containing flaps is improved oral function from (1) the maintenance of mandibular and soft tissue architecture and (2) dental rehabilitation through osseointegrated implants. Bone dimensions, volume, quality, and the ability of the bone to withstand masticatory forces are important factors in achieving successful osseointegration. Previous studies have objectively examined the dimensions of bones used in oromandibular reconstruction, but few have addressed their biomechanical properties. The purpose of this study was to compare the dimensional and biomechanical properties of the bones commonly used in oromandibular reconstruction with those of the mandible. METHODS: Eleven formalin-fixed cadavers were used. The mandibles, fibulae, iliac crests, scapulae, clavicles, second metatarsals, radii, and anterior ribs were harvested. Measurements of the dimensions of the bones were made with calipers at multiple sites. Three-point break strength and screw pulling force tests were then performed on all of the bones. RESULTS: The fibulae, iliac crests, and clavicles had dimensions that best matched those of the mandible. The three-point break strength and screw pulling force tests were consistently the highest for the mandibles and fibulae, followed by the clavicles, scapulae, iliac crests, metatarsals, radii, and ribs, in that order. CONCLUSIONS: The fibula is the bone that best matches the properties of the mandible.

Aged↗

The appearance of foramen in the internal aspect of the mental region of mandible from Japanese cadavers and dry skulls under macroscopic observation and three-dimensional CT images.

The lingual canal with foramen displays different appearances on the internal surfaces of mandible as confirmed by macroscopic observation and computerized tomography (CT). The lingual canal was observed in the inside of mental region run to the outside of lingual foramen, which is extend internally from mandibular canal in right and left sides of the mandible in cadavers (13 sides out of 88 sides) and in dry skulls (43 out of 94 sides) examined. The spinal foramen connected with mental canal occurred at the midline of mandible in 6 cases (6 out of 47 cases) in dry skulls. In this small foramen, the inferior alveolar artery give some branches to the inside of mental region at the anterior mandible and which may be run pass through the lingual canal to the lingual foramen, where they emerge to enter the mylohyoid or anterior belly of digastric muscles. The observations of these are important considerations for surgical placement of dental implants in the region in the mandible.

Adult↗

Changes in mineral content, mineral deposition and vascular supply of the mandible after osteotomy.

Circulatory and skeletal damage in the form of a vertical osteotomy of the mandible, proximal to the entry of the inferior alveolar artery and mandibular perforantes, alone or in combination with unilateral or bilateral mucoperiosteal reflections were undertaken on young growing rats. Changes in mineral content and mineral deposition in the hard tissues of the mandibles were studied using microradiography and by labelling with tetracycline and lead acetate. Microangiography was performed to evaluate changes in the vascular supply. Resorption of the compact bone was seen in the central part of the compact bone, in the lower border of the mandible and in the incisal part of the alveolar bone. There was resorption of the cementum and dentin in the molar teeth. Remodelling processes were seen in the compact bone starting from vascular channels and on the surface of the bone trabeculae, ten days after osteotomy. Microangiography revealed that there is a collateral vascular system existing across the midline via the symphysis region, via submucosal tissue, via the mucoperiosteal pedicle to the inferior border of the mandible and via the network of small vessels in the periodontal membrane. It was concluded that the circulation to the peripheral parts of the mandible could in part be kept up by a retrograde flow in the collateral systems when the main circulation had ceased.

Angiography↗

[Bone statics of the face: the frontal-sphenoid-pterygoid bone pillars as biomechanic equivalents of the mandible].

In general biomechanics, trabecular osteo-architectonics is considered as a response to the mechanical strains present in the bone (compression or traction). The facial and cephalic skeleton is no exception to this law. The study of the bony architectionic provides the proof, since we have demonstrated in the fixed facial bone mass (at the limits of the facial skeleton and the skeleton of the base of the skull) the biomechanical equivalent of the mandible: the cranio-facial pterygo-spheno-frontal bony pillars. Paired, symmetrical and with a medio-frontal junction, they represent an embryological, anatomical and functional entity. Their ossification (mixed) may be compared to that of the mandible. They are made up of directional trabecular bone which may be analysed by stereology, electron microscope scanning and by strain gauges. Each pillar is made up of: - A part free of musculature corresponding to the supra-orbital frontal arch, which receives the four vertical pillars (naso-maxillary and maxillo-malo-frontal) of the superficial system of the face which transmit to the supra-orbital frontal arch the ascending mechanical strains of mastication registered in the spongy hard palate. The supra-orbital frontal arch is the biomechanical homologue in the fixed facial mass of the tooth bearing bony base of the mandible. - A spheno-pterygoid part, into which are inserted the alimentary muscles of the cephalic region (masticators, velar and superior pharyngeal). There is further functional homology between the ascending ramus of the mandible and the pterygoid greater wings and apophyses complex of the sphenoid. The 2 pterygo-spheno-frontal pillars also participate in the osseous statics of the orbit and the osseous statics of the temporo-mandibular joint. The basi-sphenoid plays a role of first importance in the general statics of the cephalic region. Thus the two pterygo-spheno-frontal pillars, biomechanical homologues of the mandible in the fixed facial mass, underline the functional interdependence of the osseous, dental and muscular systems of the cephalic region, a region which should be viewed as being in a stade of permanent dynamic equilibrium during growth and in the adult.

Biomechanical Phenomena↗

[Functional reconstruction of the masticatory organ after combined therapy in a 9-year-old boy with osteosarcoma of the mandible].

Resection of the considerable part of the arch of the mandible disturbs breathing, swallowing, speaking and alters the facial symmetry. One-staged reconstruction of the mandible is contraindicated in patients with malignant tumor and serious prognosis. The course of the combined treatment in 9-year-old boy with osteosarcoma of the mandible is presented (May 1987--resection of the anterior part of the body of the mandible and suprahyoid lymphadenectomy); the most severe postoperative functional disorders were treated immediately (tracheostomy, nasogastric tube for 3 weeks). The reconstruction of the mandible and restoration of the anatomical relationship in the masticatory organ were performed after 5 years. Because of the metastatic disease in the nuchal and cervical lymph nodes boy underwent chemotherapy (Jan 5th 1988-Feb 21st 1990) of the primary site of the tumor 7 months after surgery. The following cytostatic drugs were administered; BLM, CTX, ACT-D, ADM, CDDP. The functional rehabilitation, small correctional surgery and improvement in perception in the oral cavity facilitated the restoration of important functions of the masticatory organ (proved by the following studies: gustometric, manometric, logopedic, stereognostic, rentgenotelevision of the swallowing process). In addition, the self-perception and the boy's social status improved significantly after favourable change in patient's appearance.

Child↗

Detection of differentially expressed genes in the early developmental stage of the mouse mandible.

We previously examined the development of the mouse mandible, and demonstrated that odontogenesis occurs between embryonic day 10.5 (E10.5) and E12. Based on the histological findings, we performed cDNA subtraction between the E10.5 and E12 mandibles to detect any differentially expressed genes which might be involved in the initiation of odontogenesis. By sequencing, homology search and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), we thus found Pgk-1, Ccte, Hsp86, Nucleolin, Hsc73, Frg1, N-ras, Set alpha and Hsj2 from the E10.5 mandible, and E25, ATPase6, Mum2, Thymosin beta4 and L21 from the E12 mandible to be differentially expressed genes. These genes are functionally related to protein transport, signal transduction, transcription, translation and molecular chaperon activity. In situ hybridization analyses of Set alpha and E25 showed that Set alpha was detected in the tooth germ at E12 and E14.5, thus indicating a close relationship of this gene to odontogenesis. Meanwhile, the in situ signal of E25 was found in the muscular layer of the tongue, thus suggesting E25 to be related to the differentiation of muscular tissue. In conclusion, we found 15 differentially expressed genes in the course of the early developmental stage of the mouse mandible using a combination of the cDNA subtraction and semi-quantitative RT-PCR methods, while in addition, two genes were demonstrated to be related to the initiation and the development of both tooth germ and the tongue according to the in situ hybridization technique.

Animals↗

[The reconstruction of mandible and soft tissue defects with the osteocutaneous free fibula flap].

OBJECTIVE: To find a new material to reconstruct the defects involving mandible and the surrounding soft tissues with the donor site morbidity mild and transient. METHODS: Ten consecutive fibula free flaps were used to reconstruct composite defect of mandible and soft tissue. The average length of the fibular graft was 9.1 cm, and the average size of the cutaneous-flap was 4.5 cm x 6.2 cm. RESULTS: 99mTcO4- scan demonstrated that 9 flaps were survivial (9/10) 2 weeks postsurgery. The function and the contour of the mandible were excellent. The donor site morbidity was mild and transient. CONCLUSION: Fibula has a high density of cortical bone. There is enough bone available to reconstruct mandible defect. The osteocutaneous fibula flap is a new material to reconstruct the composite mandible and soft tissue defects.

Adult↗

Evaluation of location of mandibular and mental foramina in dry, young, adult human male, dentulous mandibles.

The present study was undertaken to determine the precise location of the mental and mandibular foramina and the surrounding anatomic landmarks. Measurements were made on both right and left sides of each of 34 dried young Turkish adult (30-40 years old) human male mandibles. The mandibles were moderately robust and were from dentulous subjects. The results obtained in the study showed that the distance of the mandibular foramen to the angle of the anterior ramus were 16.9 mm on the right and 16.78 mm on the left. The distance to the posterior side of the ramus was 14.09 mm on the right, and 14.37 mm on the left. The narrowest anteroposterior diameters were 32.8 mm on the right and 32.05 mm on the left. The mandibular foramen is 0.5 mm posterior to the centre of the ramus on the right and 0.75 mm on the left. The distance of the lowest point of mandibular notch to the foramen was 22.37 mm on the right and 22.17 mm on the left. The distance from the mandibular foramen to the inferior border of the ramus in the mid position of the ramus was 30.97 mm on the right and 29.75 mm on the left. The average angle of the mandible (gonial angle) was 120.17 degrees on both sides. The distance of the mental foramen to the inferior border of the mandible was 14.61 mm and 14.29 mm on the right and left, respectively. Its distance to the superior border was 13.62 mm on the right and 14.62 mm on the left. The horizontal dimensions of the mental foramen was 2.93 mm on the right, 3.14 mm on the left and its vertical dimension was 2.38 mm on the right and 2.64 mm on the left. The mental foramen was located below the root of the second premolar in 21 bones (61.76%) on the right and 17 bones (50%) on the left while in the remaining mandibles, the foramen was present between the roots of the first and second premolars in 13 bones (38.2%) on the right and in 17 (50%) on the left. The average angle of the mental foramen was 96.82 degrees.

Adult↗

Reconstruction of mandible with fibular flap and dental implant distractor: a new approach.

OBJECTIVE: To study the application of dental implant distractor (DID) in mandibular functional reconstruction. METHODS: We designed a new device named DID, which includes the permanent dental implant and the temporary distractor in itself. It is specially designed for fibula wider distraction in mandible reconstruction. Twenty-five sets of DID devices were put into 8 patients (6 men and 2 women) during operation. Two patients suffered from ameloblastoma of the mandible, 2 from odontogenic cyst of the mandible, 1 from fibrous dysplasia, and the other 3 from malignant tumor of the mandible. The age of 8 patients ranged from 19 to 67 (mean 46.8) years. RESULTS: During postoperative 2 - 15 months follow up, 7 patients were found to be successful. The clinical examination and X-ray film showed the normal shape of the mandible and the osteointegration of the implants were solid enough to withstand the denture force. Others had the DID removed because of inflammation. Two of the patients successfully worn the fixed dental prosthesis. The outcomes was satisfying. CONCLUSION: The DID device specially designed for mandibular reconstruction with fibular flap can help to simplify convenient procedures to a single surgery.

Adult↗

[Observation of blood supplies system to mandible in transparent specimen].

OBJECTIVE: To search for a direct observation method in blood supply system of mandible. METHODS: Six specimens of mandible were made transparent specimens after the vascular system was perfused with Chinese ink from the common carotid artery, and the blood supply system of mandible were observed and analyzed. RESULTS: The distribution of mandibular arteries was distinctly demonstrated in transparent specimens. The normal mandible receives its blood supply from the inferior alveolar artery and the periosteal vessel meshwork. CONCLUSION: The transparent specimen is an effective observation method in blood supply system of mandible.

Female↗

[Stress distribution of mandible under different loading and biting condition].

OBJECTIVE: To study the stress distribution of intact mandible, especially that of the mandibular angle under different muscle loading and biting condition. METHODS: Develop a more accurate, more objective mandibular model, measure the different stress patterns on the outer surface of the mandible by strain gauges due to different biting sites (INC and ICP) and different loading methods (masseter, temporalis and four pairs of muscles). RESULTS: It was found that the strain in the zone of mandibular angle is more markedly under masseter loading; that the strain in the zone of anterior mandibular ramus is more markedly under temporalis loading; and that the stress in the zone of mentum becomes a tension because of the medial pterygoid under the load of four pairs of muscles. During anterior teeth biting, the stress of mandible angle is larger than that of the bilateral molar biting. When an occlusal load is on the ipsilateral molars, there is a reversal result of the stress direction in the upper line of the mandibular angle. CONCLUSION: Different muscular loading and biting condition can change the stress distribution of the mandible. It is important to develop a functional model of human mandible to study its complex biomechanics behavior.

Adult↗

Spontaneous bone regeneration after mandible resection in a case of ameloblastoma--a case report.

INTRODUCTION: A case of spontaneous bone regeneration after mandible resection is reported. CASE REPORT: A 6-year-old boy suffered from ameloblastoma in his right mandible. Six months after haemimandibulectomy, a bone regeneration forming a new form of mandible is seen. HISTOPATHOLOGY: Lamellar mature bone was observed. Resection of the large portion of the mandible as the choice of treatment as the tumor was grown extensively. Spontaneous bone regeneration after a mandible resection. CONCLUSION: Unexpected spontaneous bone regeneration may be explained by the fact that periosteum, as the source of osteogenic cells, might be responsible for this process.

Ameloblastoma↗

[Application of CTA and CAD\CAM techniques in mandible reconstruction with free fibula flap].

OBJECTIVE: To explore the application of computed tomographic angiography (CTA) and computer aided design\manufacture (CAD\CAM) techniques in mandible reconstruction with free fibula flap. METHODS: 7 cases of complex mandible defect were reconstructed with free fibula flap. Patients' lower extremity vasculature was evaluated by preoperative CTA examination; mandible tumor resection and reconstruction were simulated by CAD technique, the surgical template was manufactured with CAM technique preoperatively; and fibula flap was shaped according to surgical template during mandible reconstruction operation. RESULTS: Preoperative CTA examination performed without complication, the desired anatomy was adequately demonstrated in all patients. All of flaps survived, patients' facial contour are symmetry approximately. CONCLUSIONS: CTA and CAD\CAM techniques have important value for complex mandible reconstruction in selection of donor site, planning of operation and shaping of fibula flap.

Adolescent↗

Effects on the rat mandible of a chincup-type appliance and of partial or complete immobilization.

Sixty 20-day-old male rats were divided into 4 groups: controls (group 1), partly immobilized mandible with a chincup-type appliance (group 2) and completely immobilized mandible without (group 3) or with (group 4) a chincup-type appliance. After 4 weeks the rats were killed and 3 parameters were measured: number of 3H-thymidine labelled cells in the condylar cartilage. "Stutzmann's angle" and length of the mandible. The growth rate of the condylar cartilage and the lengthening of the mandible were both smaller than in the controls. The chincup treatment was much more efficient when the mandible was completely immobilized than when it was only partly immobilized.

Animals↗

Study on vibrations of the mandible.

In order to elucidate the phenomenon of vibrations of the mandible, a simplified plaster model was prepared and the fundamental vibrations were investigated. Studies using either dried human skulls or in situ mandible yielded similar results. The results obtained were as follows: 1. The vibrations generated by tapping a simplified mandible model were similar to those of the transverse type of a bar and tuning fork. 2. Both vibration models belonged to the transverse type bar vibrations. 3. Similar results were obtained by tapping the teeth of the mandible in situ. 4. The presence of fractures and cysts in the mandible might induce changes in vibrations.

Dental Stress Analysis↗

Effects of the muscular dysgenesis gene on developmental stability in the mouse mandible.

Muscular dysgenesis (mdg) is an autosomal recessive gene in mice affecting primarily the skeletal musculature. mdg/mdg mice exhibit developmental arrest of myogenesis and degenerative changes in all skeletal muscles. In addition, there are pronounced abnormalities in skeletal traits, including the shape of the skull and mandible. Herein, we examine the phenotypic consequences of a single mdg allele in the heterozygous condition (+/mdg) on the size, shape, and developmental stability in 14 osteometric traits from the mouse mandible. Developmental stability in the mandible is measured by fluctuating asymmetry in bilateral traits. There are no statistically significant differences in the size or shape of the mandible between +/+ and +/mdg mice. However, compared to +/+ mice, +/mdg individuals exhibit less developmental stability for several mandible traits. The more unstable traits include height at the mandibular notch, height at the incisive process, condyloid width, height and area of the coronoid process, and size of the tooth-bearing region. All of these latter traits are closely associated with areas of muscle attachment and/or the muscular dysgenesis phenotype, suggesting that the presence of a single mdg allele is sufficient to alter developmental pathways. Traits not showing significantly increased instability in +/mdg mice bear no clear relationship to either muscle attachment areas or to the mdg/mdg phenotype.

Abnormalities, Multiple↗

The ontogeny of morphological differences in the mandible in two inbred strains of mice.

We have analyzed the postnatal ontogeny of the mandible of two inbred strains of mice (C3HeB and C57/BL) with conventional statistical analysis of area traits and with Euclidian Distance Matrix Analysis (EDMA). The relative contribution of the distal tooth-bearing part of the mandible to the area of the whole mandible decreases over time. The most prominent differences in shape between mice of 10 days and 25 days postnatal age are found in the lower posterior part of the mandible. Between angular and condylar process intramembranous ossification proceeds at a high rate and gradually fills the space between these two processes. The position of the proximal end of the molar tooth-row is relocated ventrally during this period. Morphological differences between C3H and C57 are most pronounced at 15 days postnatal age. Regions that discriminate best between the two strains change during development. While differences in the coronoid process separate the two groups clearly at 10 and 25 days postnatal age, no significant differences in the coronoid process are found at 20 days postnatal age. Similarly, masseter area shows significant differences at 15 and 25 days postnatal age, while C57 and C3H mice are equivalent for this trait at the other times. The same qualitative results are obtained by Euclidian Distance Matrix Analysis (EDMA): regions of major differences between strains are not consistent among ages. These results suggest that the ontogeny of morphological differences between closely related taxa is quite an erratic process; development of morphometric differences does not proceed smoothly and continuously. This unpredictable pattern of development of morphometric differences is expected if development of the mandible is tightly integrated by epigenetic and regulatory processes.

Age Factors↗

The arrangement of the trabecular bone in the vestibular surface of the human fetus mandible. I. A scanning electron microscopy study (1).

The characteristics of trabecular bone in human fetuses at three to six months intra-uterine life were studied in the vestibular surface of the mental and body portions of the mandible. Rounded trabeculae disposed vertically were observed in the alveolar region of the mental portion until 3 months of age. Bundles of collagen fibers were present longitudinally in the alveolar region of the mandibular body: laminar and longitudinal trabeculae lying parallel to the mandible base were seen in the basilar region. In 4 to 6-month old fetuses rounded trabeculae were observed in the alveolar region of the mental portion; in the medium region, the trabeculae were oblique while in the basilar region they were longitudinal and parallel to mandible base. In the alveolar region of the mandibular body, trabeculae with a rounded aspect were seen: in the medium region, they were straight, oblique and longitudinal to the mandible ramus: in the basilar region, the trabeculae were longitudinal and parallel to mandible base. The alveolar foramina exhibit differing diameters and shapes in the mental and body portions: thick bundles of collagen fibers and osteocyte lacunae of varying diameters were present in the bone surface.

Embryonic and Fetal Development↗