Left Jaws Research Articles

EFFECT OF ASIATIC ACID ISOLATE ON DECREASING REACTIVE OXYGEN SPECIES (ROS) LEVELS IN MICE REVERSIBLE PULPITIS

Background: Pulpitis is a form of pulp inflammation that occurs due to the response of vascular connective tissue to a trauma or continuation of caries. During inflammation the release of Tumor Necrosis Factor Alpha (TNF-) will regulate excess ROS. Reactive Oxygen Species (ROS) can damage cellular lipids that cause oxidative stress, cell or tissue damage in mice caused by ROS to be seen with malondhydehyde biomarker (MDA) donors. Asiatic acid is a natural antioxidant that is able to neutralize free radicals by suppressing oxidative stress. This study aims to determine the effect of asiatic acid isolates on the reduction of ROS levels in reversible pulpitis mouse models. Method: This type of research is an experimental laboratory in vivo, conducted by making pulpitis on the right and left teeth of the right and left jaws of 24 male Wistar rats who were treated in the form of a control group, Asiatic Acid 0.5%, 1% and 2%, then examined using elisa sandwich method Result: The One way anova test showed that the highest mean rank was the control group and the lowest was the Asiatic Acid group of 1%. The p value < 0.05, there was a significant difference in the concentration of Asiatic Acid isolates against the significant reduction in ROS levels in reversible pulpitis between the four groups. Post Hoc LSD (Least Significant Difference test in between control groups and 1%, 0.5% and 1% group, and 1% and 2% groups obtained p < 0.05 which means there is a significant difference in reactive oxygen species (ROS) levels in reversible pulpitis between the two groups. Conclusion: Asiatic Acid was able to reduce the amount of Reactive Oxygen Species (ROS) as seen from the parameters of Malondialdehyde antibodies (MDA) in male wistar mice that developed reversible pulpitis

Evaluation the relationship between polymorphism of galactose mutarotase gene by creating jaw sound in patients with temporomandibular disorder (TMD)

Objective: One of the concerns of dentists is the referral of patients with temporomandibular prob- lems. Temporomandibular joint disorders (TMD) is a complex multifactorial clinical problem that involves masticatory muscles, temporomandibular joint and related structures. This complication is one of the three common chronic pains after headache and low back pain, which can manifest as pain in the temporoman- dibular region and limitation in joint movements, or even as clicking, crepitus, and popping sounds during temporomandibular joint movements. For the first time, the american association for oral pain (AAOP) proposed the role of genetic factors in the development of TMD. It is thought that a complex disorder such as TMD is multidimensional and can be subjected to environmental conditions as well as multiple gene polymorphisms. Identification of single nucleotide polymorphisms in the human genome can play an important role in clinical setting for diagnosis, prognosis and therapeutic interventions in various diseases including TMD. The aim of this study was to evaluate the relationship between polymorphism of galactose mutarotase gene by creating jaw sound in patients with temporomandibular disorder in a population with high similarity to the whole Iranian population and using the results in prevention and targeted treatment of affected patients.
 Study Design: 101 patients with TMD using DC/TMD criteria among those referred to Tehran University School of Dentistry and 103 healthy subjects for TMD that have age and gender matched were selected to control groupfrom those referring to the Oral and Maxillofacial Diseases and Oral and Maxillo- facial Pain departments. Blood samples were taken in 5cc and DNA extracted from the blood of both groups by applying the technique PCRARMS in terms of polymorphism rs4776783 in Galm gene were Compared.
 Results: 101 patients with TMD along with 103 healthy individuals without a history of TMD were evaluated to investigate rs4776783 polymorphism in GALM gene. The average age of the patients was 35.92, and 21 were men and 80 were women. According to the questionnaire, 61 people felt the sound in their jaw while moving. On the other hand, according to the TMD/DC criterion, the number of people who have crepitus in the right and left jaws is equal. The average age of the patients was 35.92, and 21 were men and 80 were women. According to the questionnaire, 61 people felt the sound in their jaw while moving. On the other hand, according to the TMD/DC criterion, the number of people who have crepitus in the right and left jaws is equal. The low prevalence of crepitation with p=0.734 has a significant relationship with the genotype of people.
 Conclusion: This study showed that there is a significant relationship between the rs4776783 poly- morphism in Galm gene and the occurrence of temporomandibular disorder (TMD), jaw sound and pain in many masticatory muscles such as lateral pterygoid and temporal. Therefore, it can be concluded that TMD has a genetic basis.

Evaluation of accessory mental foramen and accessory infraorbital foramen with cone-beam computed tomography in Turkish population.

It was aimed to evaluate the frequency of accessory mental foramen (AMF) and accessory infraorbital foramen (AIOF) and analyse the correlation between these two foramina using cone-beam computed tomography (CBCT). The retrospective study reviewed the CBCT images of 1020 patients. The rates of AMF and AIOF were evaluated according to sex and age distributions. Correlations between the localizations of AMF and AIOF in the right and left jaws and the correlations between the occurrences of these foramina were evaluated. In the CBCT images of the 1020 patients, AMFs were detected in 48 patients, among which 14 were in the right half jaw, and 34 were in the left half jaw. AIOFs were detected in 143 patients, among which 65 were in the right half jaw, and 78 were in the left half jaw. Recognising and detecting AMF and AIOF with CBCT is important in terms of preventing complications that may occur in surgical procedures.

First Skeletal Fossil Record of the Red Seabream Pagrus major (Sparidae, Perciformes) from the Late Pleistocene of Subtropical West Pacific, Southern Taiwan.

Fish fossils are only occasionally found in Taiwan, and such fossils are rarely appropriately analyzed and described. Despite their sparse records, several Plio-Pleistocene localities rich in marine organisms have yielded well-preserved specimens, potentially providing insight into the rarely identified fish fauna in the tropical-subtropical West Pacific. We describe a sandstone nodule containing fish skeletons from the Late Pleistocene Szekou Formation in southern Taiwan. The specimen includes nearly complete left jaws, fragmentary right jaws, and part of the anterior body. The distinct dentition of the specimen suggests it to be a member of Sparidae family. Further morphological analysis based on dentition and a comparison with 153 recent specimens belonging to 14 sparid species in the area enabled us to assign the fossil to the species Pagrus major. We found that the characteristic sparid tooth patterns are useful in generic determination, at least in Taiwan. The occurrence of the specimen is the first evidence of P. major in the region. Finally, the specialized tooth pattern and the estimated size indicate that the fish was a middle-to-top predator that fed on small fish and invertebrates in a neritic lagoonal environment.

Comparison of second mesiobuccal canal prevalence of maxillary molar teeth by gender and age in a Turkish subpopulation: A cone-beam computed tomography study

Aim: The purpose of this study is to examine the distribution of second mesiobuccal (MB2) canal frequency according to age and gender in the maxillary molars of individuals in South-eastern Anatolia, Turkey, using cone-beam computed tomography (CBCT). It also seeks to inform dentists who perform root canal treatments about the prevalence of additional canals that affect the success of treatments. Methods: 300 patients who had already had CBCT images taken were grouped by gender and age. A total of 1,034 maxillary molar teeth were evaluated in the axial section. The chi-square test was used to evaluate the morphological differences between different age groups and genders. Results: The total frequency of MB2 canals was found to be 44.4% in 300 people (42.5% in women; 47.2% in men). In addition, the frequency of MB2 canals was 59.2% (n = 506) in maxillary first molars and 30.4% (n = 528) in maxillary second molars. On the basis of the right and left jaws, the incidence of MB2 canals was 44.2% in the right jaw and 44.9% in the left jaw. No statistically significant differences were found between gender and age. Conclusion: It is concluded that using CBCT will increase the detection of the presence of additional canals, increasing dentists’ success rates in performing root canal treatments. Furthermore, it has been observed that using new technologies and spending more time in the detection of MB2 canals will increase the success of root canal treatments in maxillary molar teeth. How to cite this article: Akay A, Öz H, Adıgüzel Ö, Erkan Akay S. Comparison of second mesiobuccal canal prevalence of maxillary molar teeth by gender and age in a Turkish subpopulation: A cone-beam computed tomography study. J Med Dent Invest 2021;2:e211062. https://doi.org/10.5577/jomdi.e211062 Linguistic revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English. Checked for plagiarism: Yes

Evaluation of Treatment Outcome in Gingival Hyperpigmentation with Scalpel Vis-a-Vis Laser

Context: Melanin pigmentation of the gingiva is a physiological process that occurs in all ethnicities. Many treatment modalities are available to treat gingival hyperpigmentation. These are based on the principle of complete removal of the epithelial layer along with a part of subepithelial connective tissue which is then permitted to heal by secondary intention. Aim: This study aims to compare the treatment outcome of laser and its effectiveness in the management of gingival hyperpigmentation over scalpel. Design: A split-mouth study. Methods: Twenty young patients, between the ages of 18–35 with no systemic comorbidities with concerns regarding of dark-colored gums were selected for the study. A split-mouth study involving treatment of melanin pigmentation using scalpel abrasion on one side (left side upper and lower jaws) and Diode laser (980 nm) on other side (right side upper and lower jaws) was carried out. Observations regarding time taken, amount of bleeding during procedure, postoperative pain, healing of wound, and recurrence were made. Statistical Analysis: Data were analyzed using SPSS version 21.0 for Microsoft Windows. Results: Pain and healing were comparable in both the groups, though intraoperative time consumed and bleeding was significantly lower for laser group. Recurrence also was significantly lower on the laser group. Conclusion: Diode lasers can give better results in the management of gingival pigmentation compared to conventional scalpel abrasion technique.

The comparison of roof visibility of the mandibular canal between cone-beam computed tomography scans and panoramic radiograph images as dependent on the cortical bone thickness of the mandible

BackgroundAccurate detection of the mandibular canal is a difficult process despite cutting-edge radiographic methods. The present study analyses whether mandibular canal roof visibility is comparable to panoramic radiography (PR) and cone-beam computed tomography (CBCT) and, further, examines whether the visibility in PR and CBCT is dependent on cortical bone thickness in the mandible.MethodsThis study was conducted on a group of 343 selected patients. It incorporated anonymised data on 343 patients in which a CBCT and PR were available. The first stage examines whether the mandibular canal roof visibility is comparable to PR and CBCT. In the second stage, measurements of cortical bone thickness showed buccal and lingual in the P2, M1, M2 and M3 teeth areas, both to the left and right of the mandible in CBCT images.Statistical analysis was supported by statistical software (IBM SPSS 25; Armonk, NY, USA).ResultsThe mean age of the patients was 58.8 years with an almost equal gender distribution. When performing a McNemar test on the P2, M1, M2 and M3 on both the left and right jaws, the difference between the two image modalities, with regard to the visibility of the canal roof, was found to be significant (McNemar test, p < 0.001).Statistically (U test, p≥0.05), it follows that the thickness of the cortical bone of the mandible exerts no influence on the visibility of the roof of canalis mandibulae in PR and CBCT images.ConclusionWe conclude that the visibility of the mandibular canal in PR and CBCT rays is not identical, and that the thickness of the cortical bone in the mandible does not represent a factor affecting the visibility of the roof of the mandibular canal.

Design of large-displacement asymmetric piezoelectric microgripper based on flexible mechanisms

The output displacement of the traditional symmetrical microgripper is large, but its micro-components or parts are easily damaged due to the uneven force exerted on the left and right jaws of the gripper. The output force of the traditional asymmetric microgripper is stable. However, its output displacement is small, typically half the output displacement of the symmetric microgripper. To solve these problems, in this study, we designed a large-displacement asymmetric microgripper. First, we calculated the relationship between the theoretical input and output variables based on their geometric relationship. Then, we analyzed the performance of the microgripper using finite element software. Lastly, we used a piezoelectric actuator as the input driver of the microgripper. The errors associated with the theoretical and simulated output displacements were 7.05% and 9.24%, respectively. At 150 V of driving voltage, the maximum output displacement was 224 µm, and the actual magnification was 11.2 times. Microparts can be gripped in parallel and stably, which confirms the validity of the design.

Evaluation the Success Rate, Survival Rate, and Tissue Health Indices around XiVE® Dental Implants Placed in Patients in a Dental Office in Isfahan

Background and aims. Despite the very good results, implant treatment has also been associated with some failures. The aim of this study was to evaluate the success rate, survival rate, and tissue health indices around XiVE® dental implants placed in patients in a dental office in Isfahan. Materials and methods. In this cross-sectional study, 129 XiVE® dental implants were selected. A form was prepared by two periodontists for the collection of demographic information and assessment of soft- and hard-tissue health at the implant sites. Data were analyzed by t-test and the Wilcoxon test with SPSS20 statistical software; p = 0.05 was considered statistically significant. Results. Of the 129 implants, 57.3% were in males and 42.7% in females; of the total, 47.3% were maxillary, 52.7% mandibular, and 17.8% were single- and 82.2% multi-unit. Periodontal indices, except probing depth, were significantly lower around maxillary implants (p &lt; 0.05). There was no statistically significant difference between the left and right jaws in terms of periodontal index (p &gt; 0.05). In all cases, the periodontal indices of dental implants were lower than those of the teeth and showed 100% success and survival rates. Conclusion. The results of this study showed 100% success and 2-year survival rates with XiVE® implants with healthy tissues surrounding the implants.

Comparison of digital panoramic radiography versus cone beam computerized tomography for measuring alveolar bone

BackgroundCone beam computerized tomography (CBCT) has been widely used in dental implanting. However, the local hospitals usually don’t have access to CBCT due to the cost and medical investment, especially in West of China. The doctors in local hospitals have to make reasonable dental planting using orthopantomography (OPG) to reduce risks. Therefore, it is clinically meaningful to determine the magnification rate of OPG to obtain correct diagnosis. This study investigated the magnification rate of OPG in measuring different maxillofacial loci compared with CBCT.MethodsEighty-six patients demanding dental implanting were scanned by CBCT and OPG. The vertical distance between the alveolar ridge crest of the maxillary first molar and the sinus bottom of the upper jaw, the distance between the alveolar ridge crest of the mandibular first molars and the top of nerviduct in the mandibular alveolar, and the distance between the alveolar ridge crest of the maxillary central incisors and the bottoms of the nasal cavities were measured. The horizontal distance in those loci were also measured. The distances derived from CBCT were used as reference. The distances between the two methods were compared using paired t-test. The magnification rates at these positions were calculated. The relationship between the data acquired from the two methods was analyzed Pearson correlation.ResultsThe correlation coefficients (R) between the paired samples obtained from OPG and CBCT were highly related (P < 0.05) with R values varying from 0.840 and 0.959 in vertical distances and R values varying from 0.703 and 0.904 in horizontal distances. Compared with data obtained from CBCT, the mean vertical magnification rates were 11.38% and 12.95% vertically and 8.55% and 9.43% horizontally for the first molars in the right and left maxilla respectively; 7.26% and 6.35% vertically and 5.33% and 4.96% horizontally for the first molars in the right and left mandible respectively; and 5.55% and 4.84% vertically and 6.53% and 7.47% horizontally for the central incisors in the upper right and left jaws respectively.ConclusionThe magnification rates of OPG at these teeth are different. The distances measured by OPG were highly correlated with that measured by CBCT.

Functional morphology of durophagy in black carp, Mylopharyngodon piceus.

The black carp, Mylopharyngodon piceus (Osteichthyes: Cyprinidae), crushes its snail and other molluscan prey with robust pharyngeal jaws and strong bite forces. Using gross morphology, histological sectioning, and X-ray reconstruction of moving morphology (XROMM), we investigated structural, behavioral, and mechanical aspects of pharyngeal jaw function in black carp. Strut-like trabeculae in their pharyngeal jaws support large, molariform teeth. The teeth occlude with a hypertrophied basioccipital process that is also reinforced with stout trabeculae. A keratinous chewing pad is firmly connected to the basioccipital process by a series of small bony projections from the base of the pedestal. The pharyngeal jaws have no bony articulations with the skull, and their position is controlled by five paired muscles and one unpaired median muscle. Black carp can crush large molluscs, so we used XROMM to compare pharyngeal jaw postures as fish crushed ceramic tubes of increasing sizes. We found that black carp increase pharyngeal jaw gape primarily by ventral translation of the jaws, with ventral rotation and lateral flaring of the jaws also increasing the space available to accommodate large prey items. A stout, robust ligament connects left and right jaws together firmly, but allows some rotation of the jaws relative to each other. Contrasting with the pharyngeal jaw mechanism of durophagous perciforms with fused left and right lower pharyngeal jaws, we hypothesize that this ligamentous connection may serve to decouple tensile and compressive forces, with the tensile forces borne by the ligament and the compressive forces transferred to the prey.

Effect of milk and yogurt on streptococcus sobrinus counts and caries score in rats.

An anti-cariogenic diet containing probiotics can be effective in caries prevention. This animal study compared the effects of milk and yogurt on Streptococcus sobrinus counts and caries score. A total of 36 male rats were infected with S. sobrinus (27,607) and divided into three groups. Group A and B received 200 mL of milk and 100 g of yogurt per day, respectively, and a control group received 2.5 mL of NCP number 2 diet twice daily for 21 days. After killing the animals, their lower left jaws were removed and sonicated to quantify the colonies of S. sobrinus. Dental caries was scored using Keyes technique. Data were analyzed using ANOVA and Kruskal-Wallis, Mann-Whitney and Wilcoxon-Signed Rank tests. Statistical significance was set at P < 0.05. The mean (±standard error of the mean) of S. sobrinus colonies in the milk, yogurt and control groups were determined at 119666.67 (±20733), 46416.666 (±12846) and 163,250 (±33493), respectively. Microbial counts decreased in the yogurt group compared with the milk and control groups (P = 0.004 and P = 0.000; respectively). There were significant differences between caries scores of smooth surfaces in the milk and yogurt groups compared with the control group (P = 0.000 and P = 0.000, respectively). Both milk and yogurt significantly reduced caries score of fissured surfaces compared with controls (P = 0.004 and P = 0.000, respectively). Considering the limitations of this study, yogurt administration reduces S. sobrinus counts. In addition, yogurt and milk regimens reduce the caries scores of smooth and fissured surfaces.

The structure and function of a muscle articulation-type jaw joint of a polychaete worm.

The arrangement of the musculature and the fibers of the extracellular matrix (ECM) in the flexible jaw joint of the sandworm Alitta virens (Annelida, Polychaeta) was studied using dissection and histology. The jaws are capable of a wide range of motions principally related to defense and feeding. The left and right jaws are embedded in and moved by a compact pharyngeal bulb of muscle and ECM that also forms the mouth and esophagus. Eight pharyngeal bulbs were removed and dissected to document gross anatomical features or preserved and embedded in plastic for sectioning in multiple planes. The sections were stained with toluidine blue and basic fuchsin to differentiate muscle and ECM. The sections were then digitized and used to develop a three-dimensional computer illustration. We hypothesize that the muscle and fibers in the ECM are arranged as a muscular hydrostat to support the movement of the jaws. Four specimens were recorded using a digital video camera and a tank with an angled mirror to record lateral and ventral views of jaw movements during locomotion and biting associated with burrow guarding and feeding. Frame by frame kinematic analysis of this video showed that the jaws move symmetrically in a roughly horizontal plane. Although the angle between the jaws increases and then decreases after maximum gape has been reached, the jaws also translate relative to each other such that the axis of rotation is not fixed. Together, these functional morphological and behavioral data identify the jaw mechanism as a flexible joint known as a muscle articulation. As muscle articulations have been previously described only in the beaks of cephalopods and flatworms, this study implies that this type of joint is more common and important than previously recognized.

Dental Bio-metrics as Human Personal Identifier using Pixel Neighborhood Segmentation Techniques

ntal Biometrics has emerged as vital bio-metric information of human being on account of its stability and invariant nature and of course uniqueness. The presented work shows the dental unique feature set that may be used for claiming of the human personal identity using dental radiograph (x-ray graph).. The complete jaw is divided into four parts: left and right upper jaws, left and right lower jaws. Unique feature set includes number of teeth in each portion, maximum and minimum size in each portion, area and perimeter of each tooth in each portion and information regarding missing teeth in any of the portion. Later on, a database of features along with person under scanner profile is maintained for retrieval purposes.

Convergence in morphology and masticatory function between the pharyngeal jaws of grass carp,Ctenopharyngodon idella, and oral jaws of amniote herbivores

The cellulose-rich walls that protect plant cells are difficult to digest, and therefore mechanical food processing is a key aspect of herbivory across vertebrates. Cell walls are typically broken down by translation of flattened teeth in the occlusal plane (i.e. grinding) as part of a complex, rhythmic chewing stroke. The grass carp, Ctenopharyngodon idella, is a voracious, invasive herbivorous fish that relies solely on its pharyngeal teeth, located in the back of the throat, for mechanical processing of plant material. Here, we describe the musculoskeletal anatomy of the pharyngeal jaws of grass carp and use XROMM to quantify chewing kinematics and muscle strain. The pharyngeal jaws are suspended in a sling of 11 muscles and maintain no bony articulation with any other skeletal elements in the head. The jaws bear long, serrated teeth that are worn during use into flattened tooth cusps. Our kinematic data show that this wear is the result of the teeth being elevated into occlusion against the basioccipital process and keratinous chewing pad, not tooth-on-tooth occlusion. Pharyngeal jaw elevation results from large strains in the jaw elevator muscle, the levator arcus branchialis V, to drive a pulley-like mechanism that rotates the jaws about a pivot point at the symphysis between the left and right pharyngeal jaws. These complex, rhythmic jaw rotations translate the teeth laterally across the chewing surface throughout the occlusion phase. The grass carp chewing system is strikingly similar in gross morphology and masticatory function to herbivorous chewing strategies in other vertebrates.

Antibacterial efficacy of prophylactic ozone treatment on patients with fixed orthodontic appliances

Objective. This study investigated the efficacy of ozone on microflora of patients with fixed orthodontic appliances. Materials and methods. Ten subjects undergoing fixed appliance therapy were enrolled in the study. Before any application, two elastic ligatures were removed with the aid of a sterile probe from the premolar brackets on the upper right and lower left jaws for baseline bacteriological counts. Then ozone gas was applied for 180 s by running the device on prophylaxis mode with included mouth tray according to the manufacturer's recommendations on all brackets. After the ozone application, two other elastic ligatures were removed from the opposite sides of the mouth of the patients. One week after the application two more elastic samples, which were not changed in the previous session, were collected from the upper right and lower left premolar brackets. The elastic ligatures were immersed in transfer solutions and cultured to determine the Streptococcus mutans and Lactobacillus acidophilus. Statistical analysis of the data was obtained by paired Student's t-tests. Results. The ozone treatment reduced the S. mutans and L. acidophilus immediately after the application and these reductions were found to be statistically significant (p = 0.038 and p = 0.020). Both the S. mutans and L. acidophilus values increased by the 1-week period and the S. mutans values were significantly higher than the baseline values (p = 0.01). Conclusion. It can be concluded that the ozone treatment may have an instantaneous lethal effect on S. mutans and L. acidophilus; however, within the limitations of this study, a long-term preventive effect could not be observed.

Vision-based measurement of microassembly forces

This work describes a vision-based force sensing method for measuring microforces acting upon the jaws of passive, compliant microgrippers, used to construct 3D microstructures. The importance of jaw force measurement during microassembly is to confirm that the microgripper–micropart makes a successful grasp and to protect the microparts and microgripper from excessive forces which may lead to damage during the assembly process. Finite-element analysis of the microgripper is performed to determine the relation between the displacement and the resultant forces of its jaw. The resulting nearly linear force–displacement relationship is fitted to a first-degree equation. A mathematical model of the microgripper system validated this force–displacement relation. The proposed vision-based gripper force measurement techniques determine the deflections of the microgripper jaws during the microassembly process. The deflections in the gripper jaws are measured during the microassembly processes through computation of the relative displacements of the right and left microgripper jaws with respect to the microgripper base. Two approaches are proposed. The first approach uses pattern identification to measure these relative displacements. Two-dimensional pattern identification is performed using normalized cross-correlation to estimate the degree to which the image and pattern are correlated. The second approach uses object recognition and image processing methods, such as zero-crossing Laplacian of Gaussian edge detection and region filling. Experiments performed confirm the success of both approaches in measuring the microgripper jaw deflections and therefore the assembly forces.

Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog

To study dimensional alterations of the alveolar ridge that occurred following implant placement in fresh extraction sockets. Five beagle dogs were included in the study. In both quadrants of the mandible, incisions were made in the crevice region of the third and fourth pre-molars. Buccal and minute lingual full-thickness flaps were elevated. The mesial root of the four pre-molars root was filled and the teeth were hemi-sected. Following flap elevation in (3)P(3) and (4)P(4) regions, the distal roots were removed. In the right jaw quadrants, implants with a sand blasted and acid etched (SLA) surface were placed in the fresh extraction sockets, while in the left jaws the corresponding sockets were left for spontaneous healing. The mesial roots were retained as surgical control teeth. After 3 months, the animals were examined clinically, sacrificed and tissue blocks containing the implant sites, the adjacent tooth sites (mesial root) and the edentulous socket sites were dissected, prepared for ground sectioning and examined in the microscope. At implant sites, the level of bone-to-implant contact (BC) was located 2.6+/-0.4 mm (buccal aspect) and 0.2+/-0.5 mm (lingual aspect) apical of the SLA level. At the edentulous sites, the mean vertical distance (V) between the marginal termination of the buccal and lingual bone walls was 2.2+/-0.9 mm. At the surgically treated tooth sites, the mean amount of attachment loss was 0.5+/-0.5 mm (buccal) and 0.2+/-0.3 mm (lingual). Marked dimensional alterations had occurred in the edentulous ridge after 3 months of healing following the extraction of the distal root of mandibular pre-molars. The placement of an implant in the fresh extraction site obviously failed to prevent the re-modelling that occurred in the walls of the socket. The resulting height of the buccal and lingual walls at 3 months was similar at implants and edentulous sites and vertical bone loss was more pronounced at the buccal than at the lingual aspect of the ridge. It is suggested that the resorption of the socket walls that occurs following tooth removal must be considered in conjunction with implant placement in fresh extraction sockets.

Differences in Dental and Bone Maturation in Regions With or Without Hemihypertrophy in Two Patients with Russell-Silver Syndrome

Hemihypertrophy (hemihyperplasia) is defined as asymmetric body overgrowth of one or more body parts. Hemihypertrophy can be isolated or be part of well-defined syndromes, such as Russell-Silver syndrome (RSS). RSS is characterized by severe intrauterine growth retardation, postnatal short stature, asymmetry of the face, body, and limbs, short and incurved fifth fingers, broad forehead, pointed small triangular shaped face, girdle nose, normal psychomotor development, variations in the pattern of sexual development, and dental and oral abnormalities. The aim of this study was to determine whether or not there was any difference in the maturity of bone in left and right hand-wrist radiographs and dental development in the right and left jaws of two patients with RSS. In addition, the clinical features of the syndrome are discussed.

Structures and movements of the buccal and pharyngeal jaws in relation to feeding in Diplodus sargus

The present paper studies the possibly different feeding strategies of Diplodus sargus to crustaceans, molluscs, worms, and small fish. The buccal jaws are built strongly and bound together by numerous ligaments. The dentition is heterodont: incisors in front and molars in the middle and hind parts. The principal originality of the musculature of this species is the forward insertion of the adductores mandibulae. These are very thick and insert on both the upper and lower jaws, so that contraction of any individual muscle acts on the buccal pieces as a whole, which thus constitute a remarkable crushing device. The pharyngeal jaws are frail as in primitive perciforms: the lower ones are well separated, being bound only anteriorly, while the upper ones consist of the second and third pharyngobranchials and a posterior toothed plate. When feeding on crabs, Diplodus sargus always sucks in the prey and seizes it with the buccal jaws. Mouth opening is accompanied by extensive protrusion of the mouth, with or without neurocranial elevation. Mouth sucking and seizing movements vary little. Once seized, the prey is usually moved to the molars and crushed. The crushing movements may be fast and ample or slow. In the latter case, deformation of the prey is observable. Crushing usually results in the crab being broken into pieces. The pharyngeal jaws grip one part of the prey and shift it to the oesophagus, then seize the second part. Diplodus sargus adapts its feeding behaviour to the type of prey. A snail, for instance, is crushed by the buccal or pharyngeal teeth, the pieces of shell are ejected, and the soft parts conveyed with difficulty to the oesophagus by the pharyngeal jaws. A fish on the other hand, is sucked tail first into the mouth cavity and quickly shifted to the digestive tract by the pharyngeal bones. Behaviour toward different prey differs by the presence or absence of parts of the sequence of feeding movements (for example crushing) or by the fact that certain movements or parts of the sequence are repeated. The variability of any movement in the sequence is the same whatever the sort of prey. Crushing occurs between the buccal incisors and molars and was observed twice between the pharyngeal teeth. Usually, it seems, the latter are involved in transport only. In transport, the left and right pharyngeal jaws may perform different functions: their movements, unlike the symmetrical movements of the buccal jaws, sometimes differ.