The result of instrumental analysis of the amount of motion in patients with different occlusive and skeletal classes according to the condylography

The temporomandibular joint is paired, a complex formation of an ellipsoid shape, which is formed by the articular head of the lower jaw, the mandibular fossa and the articular tubercle of the temporal bone, covered with fibrous cartilage. There are two types of movements in the temporomandibular joint: translation and rotation, which implement protrusion-retrusion, right and left mediotrusion, and opening-closing. Computerized axiography is used for assessment of the mandibular movements and the patient’s skeletal parameters. This type of examination allows you to adjust the articulator for an individual function and to study the qualitative and quantitative characteristics of the temporomandibular joint.

Sexual dimorphism and skull size and shape in the highly specialized snake species, Aipysurus eydouxii (Elapidae: Hydrophiinae)

Background Snakes exhibit sexual dimorphism in both head size and shape. Such differences are often attributed to different reproductive roles and feeding habits. We aim to investigate how sexual dimorphism is displayed in the highly specialised fish-egg-eating snake, Aipysurus eydouxii, by analysing two complementary features: body size and skull morphology. Methods We used data on body length, weight, and skull shape from 27 measurements of 116 males and females of A. eydouxii. We investigated both sexual dimorphism and allometric (multivariate and bi-variate) properties of skull growth in the analysed data set. Results We found that although there was female-biased sexual size dimorphism in body length, females were not heavier than males, contrary to what is commonly observed pattern among snakes. Moreover, females tend to possess relatively smaller heads than males. However, we only found very subtle differences in skull shape reflected in nasal width, mandibular fossa, quadrate crest and quadrate length. Discussion We suggest that the feeding specialisation in A. eydouxii does not allow for an increase in body thickness and the size of the head above a certain threshold. Our results may be interpreted as support for prey-size divergence as a factor driving skull dimorphism since such species in which the sexes do not differ in prey size also shows very subtle or no differences in skull morphology.

Possibilities of installation of lateral (disk) implants in cases of distal mandibular atrophy: results of own clinical experience

Summary. Distal mandibular aspects, especially in conditions of atrophy of the alveolar processes, are traditionally considered unfavorable for dental implantation, which is primarily due to unsatisfactory anatomical and topographic peculiarities (proximity of the inferior alveolar nerve, presence of the mandibular fossa) and require on the pre-implant preparation stage a row of additional surgical procedures aimed on increasing of bone volume or an employment of alternative implantation techniques. Aim – summarizing of own experience of placement of lateral (disc) implants in cases of severe distal mandibular atrophy. Materials and methods. 10 patients (men – 3, women– 7) with uni-, bilateral free-end defects or total mandibular adentia were examined and treated. 22 lateral (disc) implants BOI® (Ihde Dental AG, Switzerland) were installed in combination with 1-stage screwable compression implants KOS®, TPG® Uno (Ihde Dental AG, Switzerland) and loaded immediately within 3–4 days. Results. On the control clinical and roengenological inspections 6-9 mo post-op 20 (90.9 %) of 22 installed lateral (disc) were stable, painless at percussion, with absence of evident inflammation around them, demonstrating the signs of osteointegration. There was no one case of complications due to direct mechanical damage of mandibular canal walls by disc components of the implants. Conclusions. Placement of lateral (disc) implants in distal mandibular aspects creates a serious alternative to generally recognized techniques of pre-implant surgery, allows to provide a functional status of dento-maxillary system in shortest terms owing to realization of their immediate loading protocol. Key words: distal mandibular aspects, atrophy of the alveolar process, pre-prosthetic preparation, lateral (disc) implantation.

Comparative morphometry of the temporomandibular joint in brachycephalic and mesocephalic cats using multislice CT and cone beam CT

Objectives The purpose of this study was to analyse and compare morphometric measurements of the temporomandibular joint (TMJ) in two groups of cats with brachycephalic and mesocephalic craniofacial skull conformations using multislice CT and cone beam CT. Methods CT records of 20 cats without TMJ pathology were included in the study, and were divided into two groups according to those with mesocephalic or brachycephalic skull conformation. Width and depth of the mandibular fossa, width and height of the head of the mandible, and two different angles were measured in 40 TMJs. Results TMJ conformation differed between groups: 3/6 parameters were statistically different. Brachycephalic cats had a significantly narrower mandibular fossa, a shorter head of the mandible and a wider angle of congruence (angle 2). Conclusions and relevance The results provide morphometric measurements that can serve as a reference tool for the veterinary radiologist and surgeon when TMJ evaluation is necessary. Moreover, the study identified significant differences between the two craniofacial skull conformations.

Morphological changes in temporomandibular joint dysfunction and effectiveness of different treatment methods

Objectives: Temporomandibular joint dysfunction (TMD) results in changes in anatomical structures. The aim of this study was to examine the morphological changes using magnetic resonance imaging (MRI) and evaluate the effectiveness of different treatment methods in patients with TMD. Methods: 34 TMD patients (18–62 years of age) were randomly divided into two treatment groups. Group A (n=18) was subjected to dry needling (DN) and mobilization for 10 sessions, Group B (n=16) was instructed to use occlusal splint with home exercises for one month. The control group included MRIs of 17 healthy adults that were randomly selected from the archives of Radiology Department of Mustafa Kemal University. The length and width of the masseter, lateral and medial pterygoid muscles and the depth of the mandibular fossa were measured and mandibular condyle types were recorded. Range of motion of each temporomandibular joint was evaluated in pre- and post-treatment periods to test the effectiveness of the treatment methods. Results: The size of the masticatory muscles in TMD group was significantly smaller than the control group (p<0.05). The depth of the mandibular fossa was significantly shallower in the TMD group (p<0.05). The most commonly encountered condylar shape was convex in the TMD group (63.6%), but flat (58.8%) in the control group. No statistically significant relationship was observed between condyle type and fossa depth (p>0.05). However, the fossa depth showed a significant correlation with muscle size (p<0.05) and this correlation decreased with dysfunction. Dry needling and mobilization significantly decreased pain and increased mandibular movements (p<0.05); however, there was no significant change for Group B. Conclusion: The anatomical structures associated with the temporomandibular joint seems to be affected in patients with TMD. We suggest that the limited movement of the temporomandibular joint may cause atrophy of the masticatory muscles, affecting the range of motion of the joint. Dry needling and mobilization techniques might be a more effective alternative than occlusal splint in the treatment of TMD.

Computed tomography-assisted morphological assessment of the components of the temporomandibular joint – a pilot study

Introduction. Temporomandibular joint (TMJ) disorders are a common diagnostic problem. No universal radiological parameter of the analysis was introduced. Aim. Comparison of values of selected radiological parameters between asymptomatic patients and those with the TMJ arthropathy. Material and methods. Retrospective analysis of CT scans of patients of the Department of Dental and Maxillofacial Radiology and the Department of Cranio-Maxillofacial Surgery, Oral Surgery and Implantology, Medical University of Warsaw. Patients were divided into two groups: 1. without TMJ disorders, 2. with TMJ dysfunction symptoms. Following parameters of heads of mandible were analyzed bilaterally: shape, anteroposterior and lateromedial dimensions, the distance between lateral points of both heads (HL-HR), distance between a head and the mandibular fossa. The angle between the horizontal axis of the head of mandible and the line drawn by posterior points of heads of mandible was measured. Results. The most common type of the head of mandible in group 1 (40 patients; 13 women, 27 men) was convex (14 patients), in group 2 (16 patients; 14 women, 2 men) – plane (8 patients). Significant differences between groups were obtained for: GL-GP (group 1 – 120.35 mm, group 2 – 115.4 mm), dimensions of heads of mandible: lateromedial – 19.7 mm, 18.14 mm, anteroposterior – 8.03 mm, 7.04 mm for group 1 and 2, respectively. Conclusions. Computed tomography allowed for an accurate analysis of the TMJ components. Measurements of structures discussed in this work should be a part of the diagnosis of patients with TMJ dysfunction.

CT-like MRI using the zero-TE technique for osseous changes of the TMJ

Objective: This study was conducted to assess the clinical usability of the zero-echo time (ZTE) technique of MRI for evaluating bone changes of the temporomandibular joint (TMJ) in comparison with CBCT. Methods: Twenty patients with TMJ disorder who underwent both CBCT and MRI were randomly selected. CBCT images were obtained with an Alphard 3030 device (Asahi Roentgen Ind., Co. Ltd, Kyoto, Japan). MRIs were obtained using a 3.0 T scanner (Pioneer; GE Healthcare, Waukesha, WI, USA) and a 21-channel head coil. An isotropic three-dimensional proton-density-weighted ZTE sequence was acquired. Two radiologists evaluated 40 joints of 20 patients for the presence of the following osseous changes: flattening, erosion, osteophyte and sclerosis of the condyle; and flattening, erosion and sclerosis of the articular fossa. CBCT and ZTE-MRI assessments were performed at a 2-month interval. The prevalence-adjusted and bias-adjusted κ statistic was used to analyse interexaminer and intraexaminer agreement and the agreement between ZTE-MRI and CBCT. Results: Intraexaminer and interexaminer agreement analyses of ZTE-MRI showed high reproducibility (κ>0.80), which was comparable to that of CBCT. Flattening, osteophyte and sclerosis of the condyle and all types of bone changes in the mandibular fossa showed nearly perfect agreement between CBCT and ZTE-MRI (κ = 0.80–0.90). Erosion of the condyle showed substantial agreement between both sets of images (κ = 0.65–0.70). Conclusions: It is suggested that ZTE-MRI provides clinically reliable images for bone assessment in TMJ disorder. MRI may become a beneficial diagnostic tool for patients with both TMJ disc and bone pathology, with advantages involving medical costs and radiation dose.