Macrovibrissae and microvibrissae inversion and lateralization in elephants.

Effect of estrogen deficiency on regional variation of a viscoelastic tissue property of bone

To observe the effect of the apatite implant on the functioning jaw bone structure, we conducted an experiment. In the lower jaw bone (the sites corresponding to P3, P4 and M1) of adult dogs whose teeth were extracted several months ago, 3 or 4 pieces of 2-piece apatite implant each of the same size as the extracted one were placed on one side and the sites on the other side were left as they were extracted as controls. At about 4 months after the implants were placed, an occlusion having a normal vertical height was given to each implant and at 1 month and 10 months after occlusion began, specimens were taken for histological observation of the tissues surrounding the implants and around the control sites.Simultaneously, the sites on the implant-placed and control sides were compared and their the changes with time were also studied. As the result, the jaw bone with the sites left as they were after extraction tended to atrophy. But, the jaw bone on the functioning side showed various changes resulting from accommodating itself to the functional pressure applied to the implants. It was also observed that these changes were associated with the bone structure both in the implant-placed and opposite regions.

The Holocentridae are nocturnal fishes inhabiting shallow to deep water coral and rocky reefs in the tropical parts of the Indian, Pacific, and Atlantic oceans. They comprise two subfamilies, the squirrelfishes (Holocentrinae) and the soldierfishes (Myripristinae). Unlike the adults, holocentrid larvae are pelagic and are characterized by elaborate head spination, including a prominent rostrum and supraoccipital, preopercular, and opercular spines. The rostrum, formed by fused or separate nasal bones, can project far anterior to the mouth and is supported by a large, bulbous ethmoid cartilage. The spine-bearing bones, the lower jaw bones, and one pair of upper jaw bones (maxillae) are the first to ossify (at 1.2 mm NL). In several cleared-and-double-stained ontogenetic series of Holocentridae (1.2 mm NL–35.0 mm SL), we found that the other pair of upper jaw bones (premaxillae) exhibits a unique ontogenetic trajectory. The premaxillae develop late (between 5.9 mm and 6.6 mm), well after the other jaw bones and head spines are developed, and most of the remaining skeleton is ossified. Furthermore, the protuberant ethmoid cartilage precludes effective upper jaw protrusion until the larvae reach ca. 35 mm SL. In most marine fishes, all jaw bones ossify simultaneously very early in development along with the caudal fin and pectoral girdles, thus ensuring the ability to swim and feed immediately after hatching. We describe the jaw and rostrum development in holocentrids, compare it with that of tilefishes (Malacanthidae), the only other teleost in which the larvae have a rostrum comprising the nasal bones, and discuss the implications.

This paper is the third one of a series of articles (cf. VAN HASSELT, 1978, 1979a) on the morphology and the kinematics of the jaw apparatus of the labrid fishes Labrus berggylta Ascanius, Crenilabrus melops (L.), and Ctenolabrus rupestris (L.). These fishes show very rapid jaw movements during the catching of highly mobile prey (e.g., shrimps, small crabs). By the application of a deductive methodology, a kinematic qualitative jaw model was designed and developed to obtain a mechanism with very rapid, wide opening and rapid closing of the mouth brought about by a very small and relatively slow input movement, as well as closing of the protruded mouth. Premaxillary protrusion will be described in a separate paper. Once construction was begun with some assumptions or axioms, the development of the model progressed on the basis of simple kinematics and incorporation of topographical and biological demands and specifications. The main shape of the model became a symmetrical hollow pyramid-like configuration of essential structures arranged in the walls of the pyramid. These structures comprise a transverse axis of jaw rotation for each jaw at the jaw suspension, an articulating symphyseal line for transverse abduction and adduction, and a point for coupling between the upper and lower jaws. This is the basic model. Small adduction caused by the adducting suspensorium proves to be the most effective input movement for the rapid large jaw-rotations. In the labrids, the suspensorium-jaw apparatus shows adduction (VAN HASSELT, 1978). The location of these structures for the best working of the model appear to diverge somewhat from the positions in the basic model. In particular, the relatively stationary neurocranium and the ab-/adducting suspensorium demand different positions for the transverse axes. The model shows the upper-jaw axis and suspension in an area of minimal ab-/adductive movements, i.e., the area where the distal tips of the maxilla, the palatine, the nasal, and the lacrimal meet and are interconnected by a tangle of short ligaments. A safety mechanism is postulated to avoid any accidental rapid jaw action. In the model, the jaw axes appear to move slightly paramedially. A system with slightly approaching or separating jaw-axes causing rapid large jaw-rotations can be integrated into the basic-model system. A mechanical coupling between these two rapid systems reduces the need for muscles and nervous controls: the labrids have a ligament between the quadrate and the maxilla, and a movably connected suspensorium and palatine (in Ctenolabrus there is a narrow fusion) bearing the lower and upper jaw axes, respectively. The demands for the closing of a protruded mouth, with a maximal cavity inside a non-rotating protruded upper jaw, are incorporated into the basic-model system.

With regard to oral cavity, it is known that jaw bone morphology greatly changes with tooth loss. Therefore, it is necessary to consider the muscles attached to the jaw bone and the surrounding vessels and nerves, in connection with the jaw bone morphology after tooth loss. As an example, the height of the mandibular bone decreases to the position of the mylohyoid line after tooth loss. By this marked morphological change in the alveolar area, the lingual nerve and the lingual artery branches running in the sublingual area on the mandibular inner surface becomes located in the area almost the same as the alveolar crest.

Residents' journal review

Intra-osseous lipoma is extremely rare in the jaw bones. Characteristic histopathological finding consists of the presence of only mature adipose cells. The majority of jawbone intra-osseous lipomas are found in adults, and of uncertain origin and etiology but are usually associated with molar teeth. We present here a case of a fifteen-year-old boy who experienced a painless, gradual swelling of the right side mandibular angle for 3 years. We also discuss and compare this case with the other intra-osseous lipoma cases.

<strong>Resumen</strong> Los huesos maxilares no son ajenos a las patologías que se pueden presentar en el sistema esquelético. Algunas de esas condiciones y patologías son singulares por sus características clínicas, su distribución y prevalencia. Los torus palatinos, los torus mandibulares (TM) y las exostosis de los maxilares son un claro ejemplo de ellos. Hasta la presente existen ideas especulativas acerca de su etiopatogenia, de los factores asociados, de su incidencia y prevalencia, de su necesidad de tratamiento, lo que puede crear confusión entre los clínicos tanto en diagnóstico como en el manejo.El torus como tumor óseo benigno puede localizarse en el maxilar a nivel del paladar, o en la mandíbula a nivel de las tablas internas; o puede aparecer en cualquier parte del esqueleto. El TM es una exostosis o crecimiento óseo en la superficie lingual de la mandíbula. Este crecimiento ocurre generalmente cerca de la línea milohioidea, opuesto a los premolares, pero se puede extender del canino al primer molar. La mucosa que los recubre tiende a ser fina y no tolera por lo general las fuerzas de las prótesis que se colocan encima de ellos. La incidencia del torus de la mandíbula es baja en el 6% a 12.5% entre caucásicos y en los habitantes de la llanura africana. De manera contraria, algunos autores reportan una prevalencia mucho más elevada en la Costa Atlántica Colombiana.Se presenta el caso de un paciente con torus mandibulares bilaterales, con muchos años de crecimiento, hasta que por situaciones tanto fonéticas como de ulceraciones repetitivas decidió someterse al acto quirúrgico de forma bilateral. Se presentan algunas consideraciones para el manejo de esta. (Duazary 2008; 111-114) <strong>Abstract</strong> The jawbone is not a strange to the pathologies that can occur in the skeletal system. Some of these terms and conditions are unique for their clinical features, distribution and prevalence. The torus palate, jawbone torus (TM in spanish) and exostosis of the jaw are a precise example of them. For this reason there are speculative ideas about its pathogenesis, associated factors, incidence and prevalence and their need for treatment, which can create confusion among dental clinics for diagnosis and management. The torus as a benign bone tumor can occur in the jaw at the palate, jaw or in the level of internal tables; can appear anywhere in the skeleton. The TM is an exostosis or bone growth on the lingual surface of the jaw. This growth usually occurs near the milohyoided line, opposed the premolars, but it can extend from the canine to the first molar. The mucous membrane that covers tends to be thin and in general does not tolerate the forces of the prosthesis that are placed above them. The incidence of the torus of the jaw is low at 6% to 12.5% among Caucasians and people of African plain. So contrary, some authors report a much higher prevalence in the Colombian Atlantic coast. In this article is presented a case of male patient with bilateral mandibular torus, with many years of growth, even in situations that both phonetic and ulcerations repetitive decided to undergo surgery on a bilateral way. It is showed some considerations for handling this pathologic condition. <strong>Key Words:</strong> jawbone torus; exostosis; resective surgery. <p class="Pa4">11-114).

To evaluate the predictive accuracy of the SurgiCase CMF software in surgical simulation and prediction for mandibular asymmetry with 3-dimensional simulation and measurement. CBCT data of 27 patients with mandibular asymmetry were observed in CMF, and postoperative soft tissue physiognomy were predicted by simulating sagittal ramus osteotomy with or without genioplasty. The measurement parameters representing the symmetry of soft tissue were selected and the horizontal, coronal and sagittal planes were established. The results were analyzed by SPSS 19. 0. The overlap compared color grading charts were observed. Angles between cheilions and the horizonta plane (Ch-Ch-FH) in the simulation and postoperative soft tissues are (2. 35 ± 1. 81)° and (1. 44 ± 1. 13)°. The angles constructed among subnasale, upper lip and lower lip (Sn-UL-LL) are (4. 02 ± 3. 05)° and (2. 59 ± 1. 64)°, showing statistically different (P < 0. 01, P < 0. 05), which means that predictive accuracy of the lip canting and lip vertical deviation is relatively low. Distance between gonioi and sagittal plane (Go'-MS), distance between gonion and pogonion (Go'-Pog') and angle betweer subnasale to menton and the horizontal plane (Sn-Me'-MS) are not statistically different, which mean! high predictive accuracy of mandibular angle and chin. By observing the overlap compared color gradin-) charts, the predictive accuracy is not good in the cheek, especially in the deviate side. The predictive accuracy of CMF system for patients with mandibular asymmetry is relatively high, but it is not good in the lip and cheek. The software improvement is still necessary.

Surgical removal of bone tumour from the jaws to prepare the jaws to receive full dental compensation: Case report

Objectives: The purpose of this study was to develop a novel resorbable α-calcium sulfate hemihydrate/amorphous calcium phosphate (α-CSH/ACP) bone graft substitute specifically for alveolar ridge augmentation that could mimic the natural regeneration rate of human jaw bone by resorbing and substituted by bone within three to six months. A canine model was used to investigate the in vivo biocompatibility, biodegradation and osteoconductivity of the novel bone substitute. Materials and Methods: An innovative single process was used to produce synthetic bone graft substitute (SBGS) of α-CSH/ACP. Setting test for various hydrated α-CSH/ACP compositions was conducted by the Vicat needle to determine formulation good for granular particles preparation. In vitro dissolution was conducted by immersing of specimens (granules of, α-CSH/ACP 60/40, 70/30, 80/20 and CS/β-TCP 60/40, 70/30, 80/20, pellets of TMU CS and Osteoset®) in phosphate buffered solution (PBS) and incubated in a shaking bath operated at 30 rpm and 37oC. Bone defects of φ 5mm x 8 mm depth were created bilaterally in mandibles of beagle dogs and implanted with α-CSH/ACP (60/40), CS/β-TCP (60/40) as well as (40/60), CS, Osteoset®(CS) and one defect was left empty as a control. After three weeks and six weeks, specimens were harvested with trephine burs and prepared with H.E staining for histological and histomorphometrical analysis under microscope and Image J computer software. Unpaired and one tailed student t test, ANOVA and pos hoc tukey’s test were used for statistical interpretation of data. P value < 0.05 was stated as significance. Results: The results displayed high purity manufactured α-CSH and ACP. Setting time of α-CSH/ACP composites was shortened as the ACP content increasing. All materials displayed early rapid dissolution in PBS due to calcium sulfate followed by remarkable slow dissolution as a result of poor crystalline hydroxyapatite formation. Composites of α-CSH/ACP and CS/β-TCP resorbed slower than TMU CS alone. Resorption rate of composites α-CSH/ACP and CS/β-TCP reduced as the amount of ACP or β-TCP increasing. TMU CS and Osteoset pellets demonstrated similar resorption rates, while composites of α-CSH/ACP dissolute faster than CS/β-TCP composites. Histological examination after three weeks revealed no obvious presence of inflammation or immune rejection for all implanted SBGS. After six weeks, woven bone were replaced by lamellae bone and empty defects showed presence of big empty spaces. After three weeks, bone regeneration were α-CSH/ACP 21.1 ±9.5%, CS/β-TCP (60/40) 23.0 ±9.9, Osteoset (CS) 29.0 ±16.0, CS/β-TCP (40/60) 33.1 ±12.0% and empty control 13.6 ±9.5%. At six weeks, ratio of new bone formation for α-CSH/ACP, CS/β-TCP (60/40), CS/β-TCP (40/60), Osteoset®(100%CS),CS, and empty control were 62.2 ±6.8%, 48.9 ±8.1%, 52.7 ±6.7%, 53.3 ±4.6%, 42.4 ±8.8%, and 40.1 ±7.2%, respectively. All SBGS except CS exhibited more new bone formation than the control. Osteoset®(CS) and CS/β-TCP 40/60 regenerated more bone than TMU CS, while α-CSH/ACP yielded more new bone than all the other SBGS, p value < 0.05. Extrapolation graph approximated this novel composite of α-CSH/ACP to be resorbed and substituted by new bone within three to four months in human jaw bone. Conclusion: All experimented SBGS were resorbable, biocompatible and osteoconductive. Based on the extrapolation of ratio of new bone formation with time, the α-CSH/ACP (60/40) composite could be resorbed and substituted by bone within three to six months implying the resorption rate closely mimics the natural bone regeneration rate. Novel composite of α-CSH/ACP could shorten the healing and implant treatment period, therefore it could be an ideal SBGS for dental implants in the future.

The aim of this study was to describe hard and soft tissue changes after mandibular advancement surgery and to investigate the possible differences between Class II facial patterns. Lateral cephalograms of 109 patients who underwent combined orthodontic treatment and bilateral sagittal split osteotomy (BSSO) were studied. Radiographs were taken within 6 weeks before surgery (T0) and at least 6 months postoperatively (T1). Patients were classified into 3 groups according to the preoperative mandibular plane angle. Hard- and soft-tissue changes were analysed with an x-y cranial base coordinate system. Measurements were evaluated statistically. Soft and hard tissues of the chin moved forward and downward. The position of the upper lip remained unchanged, while the lower lip moved forward and upward and decreased in thickness. The soft tissue points of the chin follow their corresponding skeletal points almost completely, while the change of the lower lip was only 76 per cent of the movement of the underlying hard tissue. The increase of SNB was more evident in the low-angle group, as well as improvement of the facial convexity. Stomium superius moved more forward in the low- and medium-angle cases. Ratios of hard and soft tissue changes showed no differences for different facial patterns. Limitations derived from the retrospective study design. Only short-term changes could be addressed. The distinction between surgical changes and changes due to skeletal relapse is difficult to assess. Also, the difficulty to reproduce a relaxed lip position during imaging may influence our results. Class II characteristics improved after mandibular advancement. Soft tissues of the chin follow their skeletal structures almost in a 1:1 relationship, while movement of the lower lip was less predictable. The facial pattern of Class II patients should be considered in treatment planning.

Glandular odontogenic cyst: a case report.

Oropharyngeal adenoid cystic carcinoma invading the mandibular bone through the mandibular foramen.

Arteriovenous hemangioma is apparently caused by some abnormality occurring in the course of development of arteries and veins. It is manifested as an arteriovenous fistula or an arteriovenous aneurysm. Acquired arteriovenous hemangioma is caused by trauma or incomplete excision of a hemangioma. In the oral region, arteriovenous hemangioma usually arises in the jaw bone, and reports of cases arising in soft tissue are rare.Recently, we treated an arteriovenous hemangioma that had developed in the lower lip and extended to the right buccal region of a 30-year-old woman. Purpura of the mental region had been present since birth. The lesion was excised when the patient was 5 years old, and she subsequently had received surgical therapy four times. Accordingly, angiography showed no characteristic findings of arteriovenous hemangioma, and the lesion was surgically removed. Histologically, the walls of the arteries and veins consisted of well-developed layers of muscle, and the vascular lumen was dilated. Based on these findings, arteriovenous hemangioma was diagnosed.