Investigating the accuracy of mandibulectomy and reconstructive surgery using 3D customized implants and surgical guides in a rabbit model.

BACKGROUND: This study aimed to analyze the accuracy of the output of three-dimensional (3D) customized surgical guides and titanium implants in a rabbit model, and of mandibulectomy, reconstructive surgery, and surgical outcome; additionally, the correlation between surgical accuracy and surgical outcomes, including the differences in surgical outcome according to surgical accuracy, was analyzed. RESULTS: The output of implants was accurately implemented within the error range (- 0.03-0.03 mm), and the surgical accuracy varied depending on the measured area (range - 0.4-1.1 mm). Regarding surgical outcomes, angle between the mandibular lower borders showed the most sensitive results and distance between the lingual cusps of the first molars represented the most accurate outcomes. A significant correlation was noted between surgical accuracy in the anteroposterior length of the upper borders pre- and postoperatively and the angle between the mandibular lower borders (regression coefficient = 0.491, p = 0.028). In the group wherein surgery was performed more accurately, the angle between the mandibular lower borders was reproduced more accurately (p = 0.021). A selective laser melting machine accurately printed the implants as designed. Considering the positive correlation among surgical accuracy in the mandibular upper borders, angle between the mandibular lower borders, and more accurately reproduced angle between the mandibular lower borders, the angle between the mandibular lower borders is considered a good indicator for evaluating the outcomes of reconstructive surgery. CONCLUSION: To reduce errors in surgical outcomes, it is necessary to devise a positioner for the surgical guide and design a 3D surgical guide to constantly maintain the direction of bone resection. A fixed area considering the concept of three-point fixation should be selected for stable positioning of the implant; in some cases, bilateral cortical bone fixation should be considered. The angle between the mandibular lower borders is a sensitive indicator for evaluating the outcomes of reconstructive surgery.

Surgery-first approach reduces the overall treatment time without damaging long-term stability in the skeletal class III correction: a preliminary study.

BACKGROUND: Compared to the conventional approach, including preoperative orthodontic preparation, the so-called surgery-first approach (SFA) seems to reduce the overall treatment time in the correction of skeletal class III dentofacial deformity. However, there have been controversies about postoperative skeletal stability with SFA. Therefore, we investigated the long-term stability and the overall treatment time after maxillomandibular surgery for skeletal class III correction with or without preoperative orthodontic preparation. METHODS: This retrospective study included eight patients who underwent maxillomandibular surgery for class III correction with the SFA (SFA group) and 20 patients who underwent the conventional approach (CA group). A comparative study of the change in the maxillary and mandibular position on preoperative (T1), 1-day (T2), 6-month (T3), and 2-year (T4) postoperative lateral cephalograms. We calculated the overall treatment time for each group. RESULTS: At the presurgical stage (T1), there was no bias in the skeletal features between the two groups. In the surgical change from T1 to T2, the mandible (point B) of the CA group was significantly moved superiorly. Short-term changes from T2 to T3 revealed that the mandible moved forward in both groups, whereas the maxillary position showed no significant changes. Long-term changes from T3 to T4 demonstrated that none of the measured parameters showed any significant differences. Finally, the average of overall treatment time was 15.1 months in the SFA group and 26.0 months in the CA group. CONCLUSIONS: These findings suggest that SFA in bimaxillary orthognathic surgery for skeletal class III correction leads to predictable long-term skeletal stability, similar to surgery with CA. Furthermore, SFA reduced the overall treatment time compared to CA.

Calcium pyrophosphate dihydrate deposition disease in the temporomandibular joint: diagnosis and treatment.

BACKGROUND: Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare disease in the temporomandibular joint (TMJ) space. It forms a calcified crystal mass and induces a limitation of joint movement. CASE PRESENTATION: The calcified mass in our case was occupied in the left TMJ area and extended to the infratemporal and middle cranial fossa. For a complete excision of this mass, we performed a vertical ramus osteotomy and resected the mass around the mandibular condyle. The calcified mass in the infratemporal fossa was carefully excised, and the segmented mandible was anatomically repositioned. Scanning electronic microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) microanalysis was performed to evaluate the calcified mass. The result of SEM/EDS showed that the crystal mass was completely composed of calcium pyrophosphate dihydrate. This result strongly suggested that the calcified mass was CPDD in the TMJ area. CONCLUSIONS: CPDD in the TMJ is a rare disease and is difficult to differentially diagnose from other neoplasms. A histological examination and quantitative microanalysis are required to confirm the diagnosis. In our patient, CPDD in the TMJ was successfully removed via the extracorporeal approach. SEM/EDS microanalysis was used for the differential diagnosis.

Silk Fibroin-Alginate-Hydroxyapatite Composite Particles in Bone Tissue Engineering Applications In Vivo.

The aim of this study was to evaluate the in vivo bone regeneration capability of alginate (AL), AL/hydroxyapatite (HA), and AL/HA/silk fibroin (SF) composites. Forty Sprague Dawley rats were used for the animal experiments. Central calvarial bone (diameter: 8.0 mm) defects were grafted with AL, AL/HA, or AL/HA/SF. New bone formation was evaluated by histomorphometric analysis. To demonstrate the immunocompatibility of each group, the level of tumor necrosis factor (TNF)-α expression was studied by immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) at eight weeks post implantation. Additionally, osteogenic markers, such as fibroblast growth factor (FGF)-23, osteoprotegerin (OPG), and Runt-related transcription factor (Runx2) were evaluated by qPCR or IHC at eight weeks post implantation. The AL/HA/SF group showed significantly higher new bone formation than did the control group (p = 0.044) and the AL group (p = 0.035) at four weeks post implantation. Additionally, the AL/HA/SF group showed lower relative TNF-α mRNA levels and higher FGF-23 mRNA levels than the other groups did at eight weeks post implantation. IHC results demonstrated that the AL/HA/SF group had lower TNF-α expression and higher OPG and Runx2 expression at eight weeks post implantation. Additionally, no evidence of the inflammatory reaction or giant cell formation was observed around the residual graft material. We concluded that the AL/HA/SF composite could be effective as a scaffold for bone tissue engineering.

Change of the airway space in mandibular prognathism after bimaxillary surgery involving maxillary posterior impaction.

BACKGROUND: The purpose of this retrospective study was to develop a two- and three-dimensional analysis of the airway using cone-beam computed tomography (CBCT) and to determine whether the airway space would be changed in mandibular prognathism after bimaxillary surgery involving maxillary posterior impaction. METHODS: Patients requiring orthognathic surgery from 2012 to 2014 were recruited for this study. CBCT scans were obtained at three points: preoperatively (T0), immediate postoperatively (T1), and after 6 months postoperatively (T2). The nasopharynx, oropharynx, and hypopharynx were measured on the CBCT scan for each patient in a repeatable manner. With the midsagittal plane, linear measurements in the middle of each were obtained. For the CBCT, volumetric measurements of each and total airway were obtained. RESULTS: A total of 22 consecutive patients (11 men and 11 women) were included in the present study. The total volume was significantly reduced (p < .001). However, the change of the diameter and volume of the nasopharynx was not statistically significant (p = .160, p = .137, respectively). In the oropharynx, the change of both the diameter and volume showed statistical significance between preoperatively and immediate postoperatively (p < .001, p = .001, respectively) and also preoperatively and after 6 months postoperatively (p = .001, p = .010, respectively). In the hypopharynx, the change of both the diameter and volume showed statistical significance between preoperatively and immediate postoperatively (p = .001, p < .001, respectively) and also preoperatively and after 6 months postoperatively (p = .001, p < .001, respectively). CONCLUSIONS: The bimaxillary surgery involving maxillary posterior impaction can reduce the volume of airway in the patients of mandibular prognathism. Although total airway volume was reduced significantly, the changes in the volume and diameter of the nasopharynx were not statistically significant. The maxillary posterior impaction affects on the nasopharyngeal airway minimally.

Long-term follow-up of early cleft maxillary distraction.

BACKGROUND: Most of cleft lip and palate patients have the esthetic and functional problems of midfacial deficiencies due to innate developmental tendency and scar tissues from repeated operations. In these cases, maxillary protraction is required for the harmonious facial esthetics and functional occlusion. CASE PRESENTATION: A 7-year old boy had been diagnosed as severe maxillary constriction due to unilateral complete cleft lip and palate. The author tried to correct the secondary deformity by early distraction osteogenesis with the aim of avoiding marked psychological impact from peers of elementary school. From 1999 to 2006, repeated treatments, which consisted of Le Fort I osteotomy and face mask distraction, and complementary maxillary protraction using miniplates were performed including orthodontics. But, final facial profile was not satisfactory, which needs compromising surgery. CONCLUSIONS: The result of this study suggests that if early distraction treatment is performed before facial skeletal growth is completed, an orthognathic surgery or additional distraction may be needed later. Maxillofacial plastic and reconstructive surgeons should notify this point when they plan early distraction treatment for cleft maxillary deformity.

Double-layered reconstruction of the nasal floor in complete cleft deformity of the primary palate using superfluous lip tissue.

After cleft lip repair, many patients suffer from nasolabial fistulas, asymmetrical nasal floor, or an indistinct nostril sill, as well as intraoral wound dehiscence and subsequent scar contracture of surgical wounds leading to vestibular stenosis. For successful primary nasolabial repair of complete cleft deformity of the primary palate, cleft surgeons need special care in reconstructing the sound nasal floor. Especially when the cleft gap is wide or when any type of nasoalveolar molding therapy was not performed, three-dimensional reconstruction of the nasal floor is critical for a balanced nasal shape. In this study, the author describes an effective method for reconstructing a double-layered nasal floor using two mucosal flaps from both sides of the fissured upper lip. This is a report of six patients with unilateral or bilateral complete cleft of the primary palate with a detailed description of the surgical technique and a literature review.

Analysis of radiofrequency lesions in egg whites in vitro produced by application of the Tew electrode for different temperatures and times.

BACKGROUND: Understanding the size and shape of radiofrequency lesions is important to reduce side effects when applied to patients. OBJECTIVES: To investigate the radiofrequency lesions produced by the application of the Tew electrode for different temperatures and times. METHODS: The white from a fresh hen's egg was placed in a rectangular glass container and warmed to 37 °C. After immersion of the Tew electrode in the egg white, radiofrequency lesions were produced at 65 °C, 70 °C, 75 °C, 80 °C, 85 °C and 90 °C. For each temperature, photographs were taken at 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s, 110 s and 120 s. The size of the lesion was measured at each temperature and time. A mixed model was used to analyze the data. RESULTS: The size of the lesion increased with increasing temperature and time. There were statistically significant differences in the size of the internal radius between the 65 °C and 70 °C groups and the 70 °C and 75 °C groups, as well as in the 70 °C and 75 °C groups in the size of the external radius and the 60 °C to 80 °C groups in the size of the distal radius. The maximum lesion size was produced at 90 °C and 120 s, and was 1.06±0.16 mm in internal radius, 0.37±0.15 mm in external radius, 0.39±0.04 mm in distal radius. CONCLUSION: The Tew electrode produces lesions following the contour of the tip, and the internal radius is larger than the external and distal radius. The best combination of temperature and time for lesioning using the Tew electrode is 80 °C, for 60 s to 90 s.

Bimaxillary orthognathic surgery and condylectomy for mandibular condyle osteochondroma: a case report.

Osteochondroma is rarely reported in the maxillofacial region; however, it is prevalent in the mandibular condyle. This slowly growing tumor may lead to malocclusion and facial asymmetry. A 39-year-old woman complained of gradual development of anterior and posterior unilateral crossbite, which resulted in facial asymmetry. A radiological study disclosed a large tumor mass on the top of the left mandibular condyle. This bony tumor was surgically removed through condylectomy and the remaining condyle head was secured. Subsequently, bimaxillary orthognathic surgery was performed to correct facial asymmetry and malocclusion. Pathological diagnosis was osteochondroma; immunohistochemistry showed that the tumor exhibited a conspicuous expression of BMP-4 and BMP-2 but rarely expression of PCNA. There was no recurrence at least for 1 year after the operation. Patient's functional and esthetic rehabilitation was uneventful.

Powdered Wound Dressing Materials Made from wild Silkworm Antheraea pernyi Silk Fibroin on Full-skin Thickness Burn Wounds on Rats.

PURPOSE: This study evaluated powdered burn wound dressing materials from wild silkworm fibroin in an animal model. METHODS: Fifteen rats were used in this experiment. Full-thickness 2×2 cm burn wounds were created on the back of rats under anesthesia. In the two experimental groups, the wounds were treated with two different dressing materials made from silkworm fibroin. In the Control Group, natural healing without any dressing material was set as control. The wound surface area was measured at five days, seven days and 14 days. Wound healing was evaluated by histologic analysis. RESULTS: By gross observation, there were no infections or severe inflammations through 14 days post-injury. The differences among groups were statistically significant at seven days and 14 days, postoperatively (P <0.037 and 0.001, respectively). By post hoc test, the defect size was significantly smaller in experimental Group 1 compared with the Control Group and experimental Group 2 at seven days postoperatively (P =0.022 and 0.029, respectively). The difference between Group 1 and Group 2 was statistically significant at 14 days postoperatively (P <0.001). Group 1 and control also differed significantly (P =0.002). Group 1 showed a smaller residual scar than the Control Group and Group 2 at 14 days post-injury. Histologic analysis showed more re-epithelization in Groups 1 and 2 than in the Control Groups. CONCLUSION: Burn wound healing was accelerated with silk fibroin spun by wild silkworm Antheraea pernyi. There was no atypical inflammation with silk dressing materials. In conclusion, silk dressing materials can be used for treatment of burn wound.

Effectiveness of Woven Silk Dressing Materials on Full-skin Thickness Burn Wounds in Rat Model.

PURPOSE: This study evaluated woven silk textile for burn wound dressing materials in an animal model. METHODS: Ten rats were used in this experiment. Full-thickness 2×2 cm burn wounds were created on the back of the rats under anesthesia. In the experimental group, the wounds were treated with three different dressing materials from woven silk textile. In the control group, natural healing without any dressing material was set as control. The wound surface area was measured at five days, seven days, and 14 days. Wound healing was evaluated by histologic analysis. RESULTS: There were no statistically significant differences among groups at five days post injury. The mean defect size at seven days was largest in Group 3 (462.87 mm(2)), and smallest in Group 1 (410.89 mm(2)), not a significant difference (P =0.341). The mean defect size at 14 days was smallest at the Group 3 (308.28 mm(2)) and largest in the control group (388.18 mm(2)), not a significant difference (P =0.190). The denuded area was smaller in Group 1 (84.57 mm(2)) and Group 2 (82.50 mm(2)) compared with the control group (195.93 mm(2)), not statistically significant differences (P =0.066, 0.062). The difference between Group 3 and control was also not statistically significant (P =0.136). In histologic analysis, the experimental groups re-epithelialized more than control groups. No evidence was found of severe inflammation. CONCLUSION: The healing of burn wounds was faster with silk weave textile more than the control group. There was no atypical inflammation with silk dressing materials. In conclusion, silk dressing materials could be used to treat burn wounds.

Defatting Vestibuloplasty for Functional and Esthetic Reconstruction of Tongue.

The radial forearm free flap (RFFF) is a thin and pliable tissue with many advantages for tongue reconstruction. However, tongues reconstructed with RFFF occasionally need revision surgery because inadequate defect measurement at primary surgery can lead to bulkiness and limited movement of reconstructed tongue. In this case, the patient underwent partial glossectomy and RFFF reconstruction for treatment of tongue cancer five years prior. We could not make a lower denture for the patient, because the alveolo-lingual sulcus of tongue was almost lost. So we performed vestibuloplasty with a modified Kazanjian method on the lingual vestibule of the mandibular right posterior area, and defatting surgery to debulk the flap. After surgery, we observed that the color and texture of the revised tongue changed to become similar with adjacent tissue. The patient obtained a more functional and esthetic outcome. Accordingly, we present a case report with a review of relevant literature.

Tapia's syndrome following cervical laminoplasty -A case report-.

Tapia's syndrome is the palsy of the 10th and 12th cranial nerves, resulting in ipsilateral paralysis of the vocal cord and tongue. It is a rare complication which is related to the anesthetic airway management and positioning of the patient's head during the surgery. We describe a patient with a postoperative unilateral Tapia's syndrome, after general anesthesia, with uncomplicated endotracheal intubation. The patient's symptoms improved gradually for three months.

Neuroprotective effects of stanniocalcin 2 following kainic acid-induced hippocampal degeneration in ICR mice.

Stanniocalcin 2 (STC2), the paralog of STC1, has been shown to act as a novel target of the mammalian unfolded protein response. We investigated the potential neuroprotective actions of STC2 against kainic acid toxicity in the hippocampus of ICR mice. STC2-treated mice experienced less neuronal cell loss in the CA3 area of the hippocampus. Also, microglial activation and heme oxygenase 1 expression were attenuated in the hippocampus of STC2-treated mice. To confirm whether STC2 regulates microglial activation directly, nitric oxide levels were measured in BV2 cells cultured with and without 10nM STC2. STC2 decreased the level of nitric oxide induced by lipopolysaccharide (LPS) treatment significantly. Also, STC2 pretreatment significantly decreased TNF-α and IL-1ß expression induced by LPS treatment. These observations demonstrated that STC2 exerts neuroprotective actions against excitotoxic insults through the inhibition of microglial activation.

Maternal social separation of adolescent rats induces hyperactivity and anxiolytic behavior.

Exposure to early stressful adverse life events such as maternal and social separation plays an essential role in the development of the nervous system. Adolescent Sprague-Dawley rats that were separated on postnatal day 14 from their dam and litters (maternal social separation, MSS) showed hyperactivity and anxiolytic behavior in the open field test, elevated plus-maze test, and forced-swim test. Biologically, the number of astrocytes was significantly increased in the prefrontal cortex of MSS adolescent rats. The hyperactive and anxiolytic phenotype and biological alteration produced by this MSS protocol may provide a useful animal model for investigating the neurobiology of psychiatric disorders of childhood-onset diseases, such as attention deficient hyperactive disorder.

Temporomandibular joint ankylosis caused by chondroid hyperplasia from the callus of condylar neck fracture.

A patient who complained of difficulty in opening his mouth after condylar neck fracture 1 year ago presented typical features of temporomandibular joint ankylosis in clinical and radiologic examinations. To demonstrate a possible pathogenesis of temporomandibular joint ankylosis after condylar neck fracture, the fractured condylar portion removed was examined by histologic and immunohistochemical stainings. Interpositional gap arthroplasty was performed by removing the inferomesially displaced fractured condyle, and reconstruction with subcutaneous dermis to the previous vertical height was performed immediately. The fractured condylar portion was almost intact with slight erosion of the condylar cartilage. In the hematoxylin and eosin and Masson trichrome stainings, an extensive chondroid hyperplasia with abundant hyaline cartilage was shown in the removed condylar portion. There were also hyperplastic features of the synovial membrane, which were abnormally distributed throughout the chondroid tissues. In the immunohistochemical stainings of proliferating cell nuclear antigen (PCNA) and bone morphogenetic protein (BMP)-2 and BMP-4, the chondroid tissues were conspicuously hyperplastic and strongly positive for BMP-4 but sparse for BMP-2. From these results, we think that the hyperplastic chondroid tissue was derived from the callus of the primary fractured site of the condylar neck and propose that the chondroid tissue could proliferate continuously because of synovial tissue support from around the temporomandibular joint, resulting in temporomandibular joint ankylosis. This pathogenesis is quite different from those of other diaphyseal fracture of long bones.

Melatonin Induces Akt Phosphorylation through Melatonin Receptor- and PI3K-Dependent Pathways in Primary Astrocytes.

Melatonin has been reported to protect neurons from a variety of neurotoxicity. However, the underlying mechanism by which melatonin exerts its neuroprotective property has not yet been clearly understood. We previously demonstrated that melatonin protected kainic acid-induced neuronal cell death in mouse hippocampus, accompanied by sustained activation of Akt, a critical mediator of neuronal survival. To further elucidate the neuroprotective action of melatonin, we examined in the present study the causal mechanism how Akt signaling pathway is regulated by melatonin in a rat primary astrocyte culture model. Melatonin resulted in increased astrocytic Akt phosphorylation, which was significantly decreased with wortmannin, a specific inhibitor of PI3K, suggesting that activation of Akt by melatonin is mediated through the PI3K-Akt signaling pathway. Furthermore, increased Akt activation was also significantly decreased with luzindole, a non-selective melatonin receptor antagonist. As downstream signaling pathway of Akt activation, increased levels of CREB phoshorylation and GDNF expression were observed, which were also attenuated with wortmannin and luzindole. These results strongly suggest that melatonin exerts its neuroprotective property in astrocytes through the activation of plasma membrane receptors and then PI3K-Akt signaling pathway.