Gemination aka twinning and fusion, are rare occurrences in posterior mandibular teeth, often requiring endodontic and surgical treatment for functional, orthodontic or cosmetic reasons. The diagnosis and design of a precise treatment plan in cases involving double teeth are in most cases challenging. The purpose of this case report is to describe a successful multidisciplinary treatment protocol for a double tooth. Upon completion of the endodontic, restorative and orthodontic treatments, the clinical and radiographic three-year follow-up revealed that the rest of the transected premolar showed evidence of healing of the supporting tissues and satisfactory cosmetic result.

This study was conducted to evaluate the association between aging and regenerative potential of spinal cord injury. Three groups of male Sprague–Dawley rats, including young (40 days), mature (5-6 months) and old (28-29 months) were spinally hemisected at the L1 level. The locomotor performance was assessed weekly for eight weeks after lesion using locomotors' rating scale developed by Basso, Bresnahan and Beattie (BBB). In the tracing study, retrograde labeled neuron was counted in the lateral vestibular nucleus for axonal regeneration. From 4-8 weeks, the functional recovery of the young and mature age rats was significantly increased in comparison to the old age group. At 8 weeks, young and mature animals achieved a plateau score of (mean±SD), 17±1.47 and 16.8±0.70 respectively, and the old rats reached an average score of 13.8±1.63 (P<0.05). The mean number of labeled neurons in the vestibular nucleus in the young group (mean±SD): 32.05±1.03 increase significantly compared to the older age group 5.01±1.31 (P<0.05). Current findings suggest that axonal repair and functional improvement decrease in aged animals after partial spinal cord injury. Thus, the aging process may affect the regenerative capacity of the injured central nervous system, and axonal regeneration is age dependent.

BACKGROUND: When the spinal cord is damaged, medical procedures are vital to prevent of improvement of the lesion. Because of poor regeneration ability of central nervous tissue, the most injuries are irreversible. One of encouraging interventions for treatment of spinal cord injury is Schwann cell transplantation. However, isolation of Schwann cell for clinical interventions is complicated approach with low cells yield and purity. Thus, easily accessed sources like Adipose mesenchymal stem cells have been taken notice. Therefore, this study was planned to assess the effect of adipose stromal cell-derived Schwann cell transplantation in functional recovery after lateral Hemisection in adult rats.METHODS After isolation, adipose stem cells were differentiated to Schwann cells. The differentiation was verified by immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Then, we loaded the cells into collagen scaffolds with parallel aligned canals and transplanted into rats with 3mm lesions at T9–T10 level. Motor and sensory improvement were evaluated by open field locomotor scale, narrow beam, and tail flick tests for 60 days. Subsequently, conventional histology and immunohistochemistry were performed.RESULTS: In vitro results revealed that mesenchymal stem cells after differentiation gained Schwann cells morphology and markers. Schwann cell-grafted group had significantly higher locomotor and sensory scores in comparison with the control and scaffold without cell groups. Histological observations showed differentiated cells have the ability to improve axonal regeneration and remyelination.CONCLUSION: Our study proved that adipose tissue-derived Schwann cells can change the rough environment of damaged spinal cord and support axon regeneration and enhance functional recovery, and possibly be helpful for people suffering from spinal cord injuries.

It has been shown that the immunophilin ligands have the special advantage in spinal cord repair.In this study, the effects of cyclosporine A (CsA) on functional recovery and histological outcome were evaluated following spinal cord injury in rats. After spinal cord Hemisection in thirty six adult female Sprague-Dawley rats (200- 250 g), treatment groups received CsA (2.5 mg/kgi.p.) at 15min and 24h after lesion (CsA 15min group and CsA 24h group) daily, for 8 weeks. Control and sham groups received normal saline and in sham operated animals the spinal cord was exposed in the same manner as treatment groups, but was not hemisected. Hindlimb motor function was assessed in 1, 3, 5 and 7 weeks after lesion, using locomotive rating scale developed by Basso, Bresnahan and Beattie (BBB). Motor neurons were counted within the lamina IX of ventral horn and lesion size was measured in 5 mm of spinal lumbar segment with the epicenter of the lesion site. The mean number of motor neurons and the mean BBB scale in 3, 5 and 7 weeks in CsA 15min groups significantly increased compared to the control group. Although, the lesion size reduced in rats with CsA treatment compared to the control group, no significant difference was observed. Thus, it can be concluded that CsA can improve locomotor function and histological outcome in the partial spinal cord injury.

Background: Spinal cord has a limited capacity to repair; therefore, medical interventions are necessary for treatment of injuries. Transplantation of Schwann cells has shown a great promising result for spinal cord injury (SCI). However, harvesting Schwann cell has been limited due to donor morbidity and limited expansion capacity.Furthermore, accessible sources such as bone marrow stem cells have drawn attentions to themselves. Therefore, this study was designed to evaluate the effect of bone marrow-derived Schwann cell on functional recovery in adult rats after injury.Methods: Mesenchymal stem cells were cultured from adult rats’ bone marrow and induced into Schwann cells in vitro. Differentiation was confirmed by immunocytochemistry and RT-PCR. Next, Schwann cells were seeded into collagen scaffolds and engrafted in 3 mm lateral Hemisection defects. For 8 weeks, motor and sensory improvements were assessed by open field locomotor scale, narrow beam, and tail flick tests. Afterwards, lesioned spinal cord was evaluated by conventional histology and immunohistochemistry.Results: In vitro observations showed that differentiated cells had Schwann cell morphology and markers. In this study, we had four groups (n=10 each): laminectomy, control, scaffold and scaffold+Schwann cells. Locomotor and sensory scores of cell grafted group were significantly better than control and scaffold groups. In histology, axonal regeneration and remyelination were better than control and scaffold groups.Conclusion: This study demonstrates that bone marrow-derived Schwann cells can be considered as a cell source for Schwann cells in SCI treatment.

Objective(s): Glial cell line-derived neurotrophic factor (GDNF) can effectively promote axonal regeneration， limit axonal retraction， and produce a statistically significant improvement in motor recovery after spinal cord injury (SCI). However, the role in primate animals with SCI is not fully cognized. Materials and Methods: 18 healthy juvenile rhesuses were divided randomly into six groups, observed during the periods of 24 hr, 7 days, 14 days, 1 month, 2 months, and 3 months after T11 hemisecting. The GDNF localization, changes in the injured region, and the remote associate cortex were detected by immunohistochemical staining. Results: Immunohistochemical staining showed that GDNF was located in the cytoplasm and the neurite of the neurons. Following SCI, the number of GDNF positive neurons in the ventral horn and the caudal part near the lesion area were apparently reduced at detected time points (P<0. 05). Moreover, the number in the rostral part of the ventral horn in 7 day, 14 day, and 1 month groups were fewer than those in the caudal part. Importantly, in the contralateral cortex motor area, the positive neurons decreased sharply after hemi-SCI, while gradually increased and went back to normal in 3 months after hemi-SCI. Conclusion: To sum up, GDNF disruption in neurons occurred after SCI especially in cortex motor area. Intrinsic GDNF in the spinal cord, plays an essential role in neuroplasticity. Thereafter extrinsic GDNF supplementing may be a useful strategy to promote recovery after SCI.

Background and Importance: Brown-Sequard Syndrome (BSS) is a rare neurological condition resulting from a Hemisection injury to or unilateral compression on the spinal cord. The common causes of BSS that are amenable to be treated surgically can be divided into traumatic and nontraumatic injuries. Traumatic injuries are often reported as the main cause of BSS. However, nontraumatic injuries of the spinal cord are more seen in recent years. This study aims to classify and update surgically treatable causes of BSS. Case Presentation: Retrospective data of 17 patients operated for BSS between 2008 and 2020 were included. The long-term outcomes of these patients were evaluated. In addition, a comprehensive search in PubMed, Scopus, and CINAHL was conducted for the retrieval of all relevant studies. Results: Magnetic Resonance Image (MRI) of our patients revealed Cervical Disc Herniation (CDH), spinal canal stenosis with cervical spondylosis, epidural hematoma, and ossification of the posterior longitudinal ligament. The postoperative outcomes of our cases ranged from partial to complete recovery. While the patients with acute epidural hemorrhage achieved complete recovery after surgery, neurological deficits in the other patients, especially those with severe cervical spinal canal stenosis, persisted despite adequate surgical decompression. The systematic literature review revealed that CDH is the most common non-traumatic surgically treatable cause of BSS, followed by spinal cord herniation and spinal epidural hematoma. Conclusion: Non-traumatic injuries of the spinal cord accompanied by narrowed cervical spinal canal pathologies are prominent surgically treatable causes of BSS. Contrary to the definition made 100 years ago, BSS can occur spontaneously due to underlying pathologies rather than major traumatic injuries.