Morphometric study of foramina transversaria in Jordanian population using cross-sectional computed tomography

Anatomical Science International - Foramina transversaria are bilateral landmarks of human cervical vertebrae. Morphometric analysis of foramina transversaria is valuable in both clinical and...     

Instant and quantitative epoxidation of styrene under ambient conditions over a nickel(ii)dibenzotetramethyltetraaza[14]annulene complex immobilized on amino-functionalized SBA-15

Nickel(ii)dibenzotetramethyltetraaza[14]annulene complex (Nitmtaa) was synthetized and immobilized on post amino-functionalized SBA-15 (N-SBA-15) to obtain a stable and reusable nanocatalyst named as Nitmtaa@N-SBA-15. Here (3-aminopropyl)triethoxysilane (APTES) was first grafted on the surface SBA-15, then Nitmtaa was added and coordinated on the silica surface via APTES amine groups. The structure and morphology, and thermal stability of the prepared nanocatalyst was investigated using SEM, HR-TEM, BET, FT-IR, powder XRD, and TGA. HR-TEM and XRD results revealed a high dispersion of Nitmtaa on the SBA-15 surface. The catalytic activity of this nanocatalyst was evaluated in the epoxidation of styrene, under ambient conditions, using meta-chloroperoxybenzoic acid (m-CPBA) as the oxygen donor. This nanocatalyst showed an immediate and quantitative epoxidation of styrene with high turn-over-frequency ∼31.58 s⁻¹. Moreover, the superior catalytic activity and high stability of Nitmtaa@N-SBA-15 could be maintained after four successive cycles. A possible reaction mechanism is also proposed.

Immediate and quantitative epoxidation of styrene under ambient conditions catalyzed by new nanocatalyst obtained by immobilizing nickel(ii)dibenzotetramethyltetraaza[14]annulene in amino-functionalized SBA-15.     

Effect of shoulder girdle strengthening on trunk alignment in patients with stroke

[Purpose] This study investigated the effect of shoulder girdle strengthening, particularly the scapular muscles, on poststroke trunk alignment. [Subjects and Methods] The study involved 30 patients with residual hemiparesis following cerebrovascular stroke. Patient assessment included measuring shoulder muscle peak torque, scapular muscles peak force, spinal lateral deviation angle, and motor functional performance. Patients were randomly allocated either to the control group or the study group and received an 18-session strengthening program including active resisted exercises for shoulder abductors and external rotators in addition to trunk control exercises. The study group received additional strengthening exercises for the scapular muscles. [Results] The two groups showed significant improvement in strength of all shoulder and scapular muscles, with higher improvement in the study group. Similarly, the lateral spinal deviation angles significantly improved in both groups, with significantly higher improvement in the study group. Transfer activity, sitting balance, upper limb functions, and hand movements significantly improved in the two groups, with higher improvement in the latter two functions in the study group. [Conclusion] Strengthening of shoulder girdle muscles, particularly scapular muscles, can significantly contribute to improving the postural alignment of the trunk in patients with poststroke hemiparesis.Key words: Stroke, Scapular muscles strengthening, Lateral trunk alignment     

A finite element study on stress distribution of two different attachment designs under implant supported overdenture

Objective

This study aimed to evaluate stress patterns generated within implant-supported mandibular overdentures retained by two different attachment types: ball and socket and locator attachments.

Materials and methods

Commercial CAD/CAM and finite element analysis software packages were utilized to construct two 3D finite element models for the two attachment types. Unilateral masticatory compressive loads of 50, 100, and 150 N were applied vertically to the overdentures, parallel to the longitudinal axes of the implants. Loads were directed toward the central fossa in the molar region of each overdenture, that linear static analysis was carried out to find the generated stresses and deformation on each part of the studied model.

Results

According to FEA results the ball attachment neck is highly stressed in comparison to the locator one. On the other hand mucosa and cortical bone received less stresses under ball and socket attachment.

Conclusions

Locator and ball and socket attachments induce equivalent stresses on bone surrounding implants. Locator attachment performance was superior to that of the ball and socket attachment in the implants, nylon caps, and overdenture. Locator attachments are highly recommended and can increase the interval between successive maintenance sessions.     

Repair of complete bilateral cleft lip with severely protruding premaxilla performing a premaxillary setback and vomerine ostectomy in one stage surgery

Background

The authors present a technique for selected cases of CBCL. The primary repair of the CBCL with a severely protruding premaxilla in one stage surgery is very difficult, essentially because a good muscular apposition is difficult, forcing synchronously to do a premaxillary setback to facilitate subsequent bilateral lip repair and, thus, achieving satisfactory results. We achieve this by a reductive ostectomy on the vomero-premaxillary suture.

Material and Methods

4 patients with CBCL and severely protruding premaxilla underwent premaxillary setback by vomerine ostectomy at the same time of lip repair in the past 24 months. The extent of premaxillary setback varied between 9 and 16 mm. The required amount of bone was removed anterior to the vomero-premaxillary suture. The authors did an additional simultaneous gingivoperiosteoplasty in all patients, achieving an enough stability of the premaxilla in its new position, to be able to close the alveolar gap bilaterally. The authors have examined the position of premaxilla and dental arch between 6 and 24 months. We did not do the primary nose correction, because this increased the risk of impairment of the already compromised vascularity of the philtrum and premaxilla.

Results

The follow-up period ranged between 6 and 24 months. None of the patients had any major complication. During follow-up, the premaxilla was minimally mobile. We achieved a good lip repair in all cases: adequate muscle repair, symmetry of the lip, prolabium and Cupid’s bow, as well as good scars.

Conclusions

To our knowledge, there are few reports of one stage surgery with vomerine ostectomy to repair CBCL with severely protruding premaxilla. Doing this vomerine ostectomy, we don’t know how it will affect the subsequent growth of the premaxila and restrict the natural maxillary growth. Applying this alternative treatment for children with CBCL and protruded premaxilla without any preoperative orthopedic, we can successfully perform, in a single-stage surgery, a good primary lip repair at our center. Further confirmations of this surgery with follow up and anthropometric studies of these patients during childhood and adolescence are required. Key words: Protruding premaxilla, bilateral cleft lip, vomerine ostectomy, one stage surgery, Millard II technique.