Transcranial direct current stimulation (tDCS) has demonstrated clinical benefits such as analges... more Transcranial direct current stimulation (tDCS) has demonstrated clinical benefits such as analgesia, anti-inflammatory, and neuroprotective effects. However, the mechanisms of action of a single tDCS session are poorly characterized. The present study aimed to evaluate the effects of a single tDCS session on pain sensitivity, inflammatory parameters, and astrocyte activity in naive rats. In the first experiment, sixty-day-old male Wistar rats (n=95) were tested for mechanical pain threshold (von Frey test). Afterward, animals were submitted to a single bimodal tDCS (0.5mA, 20minutes) or sham-tDCS session. According to the group, animals were re-tested at different time intervals (30, 60, 120minutes, or 24hours) after the intervention, euthanized, and the cerebral cortex collected for biochemical analysis. A second experiment (n=16) was performed using a similar protocol to test the hypotheses that S100B levels in the cerebrospinal fluid (CSF) are altered by tDCS. Elisa assay quantified the levels of tumor necrosis factor-alfa (TNF-α), interleukin-10 (IL10), S100 calcium-binding protein B (S100B), and Glial fibrillary acidic protein (GFAP). Data were analyzed using ANOVA and independent t-test (P<0.05). Results showed that tDCS decreased pain sensitivity (30 and 60min), cerebral TNF-α and S100B levels (30min). CSF S100B levels increased 30minutes after intervention. There were no differences in IL10 and GFAP levels. TCDS showed analgesic, anti-inflammatory, and neuroprotective effects in naive animals. Therefore, this non-invasive and inexpensive therapy may potentially be a preemptive alternative to reduce pain, inflammation, and neurodegeneration in situations where patients will undergo medical procedures (e.g., surgery).
Introdução: A displasia fibrosa monostótica envolvendo a região maxilo-facial é mais frequente na... more Introdução: A displasia fibrosa monostótica envolvendo a região maxilo-facial é mais frequente na maxila, podendo ocorrer em outros ossos. Na maioria dos casos, a condição é assintomática e tem um crescimento lento, com evolução autolimitada, associada à maturação esquelética. O tratamento cirúrgico conservador é a conduta de eleição, sempre que possível. Objetivo e relato do caso: O artigo tem por objetivo apresentar o relato de um caso clínico de paciente jovem, com diagnóstico de displasia fibrosa monostótica zigomática-maxilar. O tratamento proposto foi a ressecção da lesão e reconstrução imediata do defeito com enxerto ósseo bovino liofilizado. O enxerto foi mantido com microplaca e parafusos de titânio. O paciente permaneceu em controle clínico e imaginológico sem evidências de recidiva no período pós-operatório de seis anos. Considerações finais: Na reconstrução imediata, o enxerto ósseo bovino liofilizado atuou como arcabouço osteocondutor e favoreceu a recuperação volumétri...
Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However,... more Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However, BIS has been associated with osteonecrosis and alterations in osteoclastogenesis and skeletal development. This study aimed to evaluate the effects of BIS (zoledronic acid - ZA and alendronate sodium - AS) on zones of the growth plate of rat femur. Animals (Wistar rats, n = 19) were divided into groups: 1) AS Group: animals received alendronate sodium orally (3 mg/kg per day); 2) ZA Group: ZA was administered intraperitoneally (0.2 mg/kg per week); and 3) Control Group (CG): a vehicle was administered. Animals were euthanized 21 days after the treatment, and femurs were collected for histological analysis. The images of all zones (resting, proliferative, hypertrophic, and calcified) were processed by the Qcapture® software providing a 40 and 400-fold increase. ZA decreased epiphyseal growth plate cell zones (ZA Group vs. CG) in most cases. Likewise, AS diminished the proliferative zone...
OBJECTIVE Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect... more OBJECTIVE Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect on facial allodynia induced by chronic constriction of the infraorbital nerve (CCI-ION) and on the brainstem levels of TNF-α, NGF, IL-10, and serum LDH in rats. METHODS Rats were exposed to the CCI-ION model. Facial allodynia was assessed by von Frey filaments test at baseline, 3, 7, 10, and 14 days postsurgery and 24 hr and 7 days after the bimodal tDCS sessions for 20 min/day/8 days. RESULTS Chronic constriction of the infraorbital nerve induced a significant decrease in the mechanical threshold 14 days after surgery. This effect was reversed by tDCS treatment, with the mechanical threshold returning to basal levels at 24 hr after the end of the treatment and it persisted for 7 days after the end of the treatment. tDCS also decreased LDH serum levels compared to those in the control group. There was an interaction between pain and treatment with respect to brainstem levels of NGF, TNF-α, and IL-10. CONCLUSION Chronic constriction of the infraorbital nerve model was effective in establishing trigeminal neuropathic pain on 14 days after surgery, and tDCS reduced allodynia and LDH serum levels and promoted alterations in NGF, TNF-α, and IL-10 brainstem levels. Thus, we suggest that tDCS may be a potential therapy in the trigeminal pain treatment.
The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is... more The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is known that multifilament suture materials induce greater cellular reaction, most Dentists prefer to use cotton and silk. Rigidity and package memory are disadvantages of monofilament nonabsorbable suture materials. A new material, Polybutester (Novafil), has been used successfully in Medicine but its use is not common in Dentistry. Seventy male and female Wistar rats were used to study the clinical response of skin and abdominal wall muscle to the use of Novafil and nylon sutures. Under general anesthesia, standard wounds were created in the dorsum and abdomen of the animals and sutured with either Novafil or nylon. The animals were sacrificed immediately, 12, 24, and 72 hours and at 4, 5 and 7 days to evaluate the clinical aspect of both wounds. Polybutester presented some advantages such as strength, lack of package memory, elasticity and flexibility which made suturing quicker and ea...
Physiological and exogenous factors are able to adjust sensory processing by modulating activity ... more Physiological and exogenous factors are able to adjust sensory processing by modulating activity at different levels of the nervous system hierarchy. Accordingly, transcranial direct current stimulation (tDCS) may use top-down mechanisms to control the access for incoming information along the neuroaxis. To test the hypothesis that brain activation induced by tCDS is able to initiate top-down modulation and that chronic stress disrupts this effect, 60-day-old male Wistar rats (n = 78) were divided into control; control + tDCS; control + sham-tDCS; stress; stress + tDCS; and stress + sham-tDCS. Chronic stress was induced using a restraint stress model for 11 weeks, and then, the treatment was applied over 8 days. BDNF levels were used to assess neuronal activity at spinal cord, brainstem, and hippocampus. Mechanical pain threshold was assessed by von Frey test immediately and 24 h after the last tDCS-intervention. tDCS was able to decrease BDNF levels in the structures involved in the descending systems (spinal cord and brainstem) only in unstressed animals. The treatment was able to reverse the stress-induced allodynia and to increase the pain threshold in unstressed animals. Furthermore, there was an inverse relation between pain sensitivity and spinal cord BDNF levels. Accordingly, we propose the addition of descending systems in the current brain electrical modulation model.
Melatonin is a neuroendocrine hormone that presents a wide range of physiological functions inclu... more Melatonin is a neuroendocrine hormone that presents a wide range of physiological functions including regulating circadian rhythms and sleep, enhancing immune function, sleep improvement, and antioxidant effects. In addition, melatonin has received special attention in pain treatment since it is effective and presents few adverse effects. In this study, we evaluated the effect of acute dose of melatonin upon hyperalgesia induced by complete Freund's adjuvant in a chronic orofacial pain model in Sprague-Dawley rats. Nociceptive behavior was assessed by facial Von Frey and the hot plate tests at baseline and thereafter 30, 60, and 120 min, 24 h, and 7 days after melatonin treatment. We demonstrated that acute melatonin administration alters mechanical and thermal hyperalgesia induced by an orofacial pain model (TMD), highlighting that the melatonin effect upon mechanical hyperalgesia remained until 7 days after its administration. Besides, we observed specific tissue profiles of n...
British Journal of Oral and Maxillofacial Surgery, 2016
Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma... more Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma, or overloading of the joint. We have therefore systematically evaluated the histological progression of experimental osteoarthritis induced by a high concentration of monosodium iodoacetate into the rabbit TMJ. These findings may contribute to the establishment of a protocol to investigate the benefits of treatment of osteoarthritis of the TMJ. We used 21 male New Zealand rabbits; the 15 in the test group were given an intra-articular injection of monosodium iodoacetate 10mg/ml into the right TMJ and were killed after 60 (n=5), 80 (n=5), and 100 days (n=5). The six in the control group were given an injection of saline into the right TMJ. The assessment system for osteoarthritis based on six grades was used for the histological analysis of severity. The model was effective in producing histological changes in the cartilage consistent with those found in osteoarthritis at all time points. The within-group analysis indicated that the disease did not progress after 60 days. The successful induction of osteoarthritis in this way, its stabilisation after 60 days, and the appropriate size of the animal suggest that this experimental model is ideal for future studies of the effectiveness of treatment in osteoarthritis of the TMJ.
The authors report on the effects of low-level laser therapy (LLLT) in the treatment of maxillofa... more The authors report on the effects of low-level laser therapy (LLLT) in the treatment of maxillofacial disorders. Further to our previous studies, this paper reports the results of the use of LLLT on the treatment of several disorders of the oral and maxillofacial region. This paper presents LLLT as an effective method of treating such disorders. Two hundred and five female and 36 male patients ages between 7 and 81 years old (average 38.9 years old), suffering from disorders of the maxillofacial region, were treated with 632.8, 670, and 830 nm diode lasers at the Laser Center of the Universidade Federal de Pernambuco, Recife, Brazil (UFPE). The disorders included temporomandibular joint (TMJ) pain, trigeminal neuralgia, muscular pain, aphatae, inflammation, and tooth hypersensitivity postoperatively and in small hemangiomas. Most treatment consisted of a series of 12 applications (twice a week) and in 15 cases a second series was applied. Patients were treated with an average dose of 1.8 J/cm2. One hundred fifty four out of 241 patients were asymptomatic at the end of the treatment, 50 improved considerably, and 37 were symptomatic. These results confirm that LLLT is an effective tool and is beneficial for the treatment of many disorders of the maxillofacial region.
Transcranial direct current stimulation (tDCS) has demonstrated clinical benefits such as analges... more Transcranial direct current stimulation (tDCS) has demonstrated clinical benefits such as analgesia, anti-inflammatory, and neuroprotective effects. However, the mechanisms of action of a single tDCS session are poorly characterized. The present study aimed to evaluate the effects of a single tDCS session on pain sensitivity, inflammatory parameters, and astrocyte activity in naive rats. In the first experiment, sixty-day-old male Wistar rats (n=95) were tested for mechanical pain threshold (von Frey test). Afterward, animals were submitted to a single bimodal tDCS (0.5mA, 20minutes) or sham-tDCS session. According to the group, animals were re-tested at different time intervals (30, 60, 120minutes, or 24hours) after the intervention, euthanized, and the cerebral cortex collected for biochemical analysis. A second experiment (n=16) was performed using a similar protocol to test the hypotheses that S100B levels in the cerebrospinal fluid (CSF) are altered by tDCS. Elisa assay quantified the levels of tumor necrosis factor-alfa (TNF-α), interleukin-10 (IL10), S100 calcium-binding protein B (S100B), and Glial fibrillary acidic protein (GFAP). Data were analyzed using ANOVA and independent t-test (P<0.05). Results showed that tDCS decreased pain sensitivity (30 and 60min), cerebral TNF-α and S100B levels (30min). CSF S100B levels increased 30minutes after intervention. There were no differences in IL10 and GFAP levels. TCDS showed analgesic, anti-inflammatory, and neuroprotective effects in naive animals. Therefore, this non-invasive and inexpensive therapy may potentially be a preemptive alternative to reduce pain, inflammation, and neurodegeneration in situations where patients will undergo medical procedures (e.g., surgery).
Introdução: A displasia fibrosa monostótica envolvendo a região maxilo-facial é mais frequente na... more Introdução: A displasia fibrosa monostótica envolvendo a região maxilo-facial é mais frequente na maxila, podendo ocorrer em outros ossos. Na maioria dos casos, a condição é assintomática e tem um crescimento lento, com evolução autolimitada, associada à maturação esquelética. O tratamento cirúrgico conservador é a conduta de eleição, sempre que possível. Objetivo e relato do caso: O artigo tem por objetivo apresentar o relato de um caso clínico de paciente jovem, com diagnóstico de displasia fibrosa monostótica zigomática-maxilar. O tratamento proposto foi a ressecção da lesão e reconstrução imediata do defeito com enxerto ósseo bovino liofilizado. O enxerto foi mantido com microplaca e parafusos de titânio. O paciente permaneceu em controle clínico e imaginológico sem evidências de recidiva no período pós-operatório de seis anos. Considerações finais: Na reconstrução imediata, o enxerto ósseo bovino liofilizado atuou como arcabouço osteocondutor e favoreceu a recuperação volumétri...
Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However,... more Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However, BIS has been associated with osteonecrosis and alterations in osteoclastogenesis and skeletal development. This study aimed to evaluate the effects of BIS (zoledronic acid - ZA and alendronate sodium - AS) on zones of the growth plate of rat femur. Animals (Wistar rats, n = 19) were divided into groups: 1) AS Group: animals received alendronate sodium orally (3 mg/kg per day); 2) ZA Group: ZA was administered intraperitoneally (0.2 mg/kg per week); and 3) Control Group (CG): a vehicle was administered. Animals were euthanized 21 days after the treatment, and femurs were collected for histological analysis. The images of all zones (resting, proliferative, hypertrophic, and calcified) were processed by the Qcapture® software providing a 40 and 400-fold increase. ZA decreased epiphyseal growth plate cell zones (ZA Group vs. CG) in most cases. Likewise, AS diminished the proliferative zone...
OBJECTIVE Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect... more OBJECTIVE Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect on facial allodynia induced by chronic constriction of the infraorbital nerve (CCI-ION) and on the brainstem levels of TNF-α, NGF, IL-10, and serum LDH in rats. METHODS Rats were exposed to the CCI-ION model. Facial allodynia was assessed by von Frey filaments test at baseline, 3, 7, 10, and 14 days postsurgery and 24 hr and 7 days after the bimodal tDCS sessions for 20 min/day/8 days. RESULTS Chronic constriction of the infraorbital nerve induced a significant decrease in the mechanical threshold 14 days after surgery. This effect was reversed by tDCS treatment, with the mechanical threshold returning to basal levels at 24 hr after the end of the treatment and it persisted for 7 days after the end of the treatment. tDCS also decreased LDH serum levels compared to those in the control group. There was an interaction between pain and treatment with respect to brainstem levels of NGF, TNF-α, and IL-10. CONCLUSION Chronic constriction of the infraorbital nerve model was effective in establishing trigeminal neuropathic pain on 14 days after surgery, and tDCS reduced allodynia and LDH serum levels and promoted alterations in NGF, TNF-α, and IL-10 brainstem levels. Thus, we suggest that tDCS may be a potential therapy in the trigeminal pain treatment.
The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is... more The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is known that multifilament suture materials induce greater cellular reaction, most Dentists prefer to use cotton and silk. Rigidity and package memory are disadvantages of monofilament nonabsorbable suture materials. A new material, Polybutester (Novafil), has been used successfully in Medicine but its use is not common in Dentistry. Seventy male and female Wistar rats were used to study the clinical response of skin and abdominal wall muscle to the use of Novafil and nylon sutures. Under general anesthesia, standard wounds were created in the dorsum and abdomen of the animals and sutured with either Novafil or nylon. The animals were sacrificed immediately, 12, 24, and 72 hours and at 4, 5 and 7 days to evaluate the clinical aspect of both wounds. Polybutester presented some advantages such as strength, lack of package memory, elasticity and flexibility which made suturing quicker and ea...
Physiological and exogenous factors are able to adjust sensory processing by modulating activity ... more Physiological and exogenous factors are able to adjust sensory processing by modulating activity at different levels of the nervous system hierarchy. Accordingly, transcranial direct current stimulation (tDCS) may use top-down mechanisms to control the access for incoming information along the neuroaxis. To test the hypothesis that brain activation induced by tCDS is able to initiate top-down modulation and that chronic stress disrupts this effect, 60-day-old male Wistar rats (n = 78) were divided into control; control + tDCS; control + sham-tDCS; stress; stress + tDCS; and stress + sham-tDCS. Chronic stress was induced using a restraint stress model for 11 weeks, and then, the treatment was applied over 8 days. BDNF levels were used to assess neuronal activity at spinal cord, brainstem, and hippocampus. Mechanical pain threshold was assessed by von Frey test immediately and 24 h after the last tDCS-intervention. tDCS was able to decrease BDNF levels in the structures involved in the descending systems (spinal cord and brainstem) only in unstressed animals. The treatment was able to reverse the stress-induced allodynia and to increase the pain threshold in unstressed animals. Furthermore, there was an inverse relation between pain sensitivity and spinal cord BDNF levels. Accordingly, we propose the addition of descending systems in the current brain electrical modulation model.
Melatonin is a neuroendocrine hormone that presents a wide range of physiological functions inclu... more Melatonin is a neuroendocrine hormone that presents a wide range of physiological functions including regulating circadian rhythms and sleep, enhancing immune function, sleep improvement, and antioxidant effects. In addition, melatonin has received special attention in pain treatment since it is effective and presents few adverse effects. In this study, we evaluated the effect of acute dose of melatonin upon hyperalgesia induced by complete Freund's adjuvant in a chronic orofacial pain model in Sprague-Dawley rats. Nociceptive behavior was assessed by facial Von Frey and the hot plate tests at baseline and thereafter 30, 60, and 120 min, 24 h, and 7 days after melatonin treatment. We demonstrated that acute melatonin administration alters mechanical and thermal hyperalgesia induced by an orofacial pain model (TMD), highlighting that the melatonin effect upon mechanical hyperalgesia remained until 7 days after its administration. Besides, we observed specific tissue profiles of n...
British Journal of Oral and Maxillofacial Surgery, 2016
Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma... more Osteoarthritis can be induced in the temporomandibular joint (TMJ) by primary or secondary trauma, or overloading of the joint. We have therefore systematically evaluated the histological progression of experimental osteoarthritis induced by a high concentration of monosodium iodoacetate into the rabbit TMJ. These findings may contribute to the establishment of a protocol to investigate the benefits of treatment of osteoarthritis of the TMJ. We used 21 male New Zealand rabbits; the 15 in the test group were given an intra-articular injection of monosodium iodoacetate 10mg/ml into the right TMJ and were killed after 60 (n=5), 80 (n=5), and 100 days (n=5). The six in the control group were given an injection of saline into the right TMJ. The assessment system for osteoarthritis based on six grades was used for the histological analysis of severity. The model was effective in producing histological changes in the cartilage consistent with those found in osteoarthritis at all time points. The within-group analysis indicated that the disease did not progress after 60 days. The successful induction of osteoarthritis in this way, its stabilisation after 60 days, and the appropriate size of the animal suggest that this experimental model is ideal for future studies of the effectiveness of treatment in osteoarthritis of the TMJ.
The authors report on the effects of low-level laser therapy (LLLT) in the treatment of maxillofa... more The authors report on the effects of low-level laser therapy (LLLT) in the treatment of maxillofacial disorders. Further to our previous studies, this paper reports the results of the use of LLLT on the treatment of several disorders of the oral and maxillofacial region. This paper presents LLLT as an effective method of treating such disorders. Two hundred and five female and 36 male patients ages between 7 and 81 years old (average 38.9 years old), suffering from disorders of the maxillofacial region, were treated with 632.8, 670, and 830 nm diode lasers at the Laser Center of the Universidade Federal de Pernambuco, Recife, Brazil (UFPE). The disorders included temporomandibular joint (TMJ) pain, trigeminal neuralgia, muscular pain, aphatae, inflammation, and tooth hypersensitivity postoperatively and in small hemangiomas. Most treatment consisted of a series of 12 applications (twice a week) and in 15 cases a second series was applied. Patients were treated with an average dose of 1.8 J/cm2. One hundred fifty four out of 241 patients were asymptomatic at the end of the treatment, 50 improved considerably, and 37 were symptomatic. These results confirm that LLLT is an effective tool and is beneficial for the treatment of many disorders of the maxillofacial region.
Uploads