Application of a Titanium Screw for the Hemorrhage from the Bone Channel during the Lateral Window Technique: A Technical Note.

Pulsatile and profuse hemorrhage occurred in the lateral window technique for implant placement. The surgery was performed in the dental clinic under local anesthesia. The posterior superior alveolar artery was suspected to be the main feeder. Ordinary methods for hemostasis, such as vasoconstrictor-soaked gauze compression, electrocautery hemostasis, absorbable hemostat packing, and bone wax application, were tried. However, strong pulsatile bleeding could not be controlled at all. Complete hemostasis was hardly expected. The idea came up when the titanium screws came into sight. The sterilized screw was always stocked for bone grafting. After visualizing the bleeding point clearly by suction, and the screw was inserted into the bone channel. The bleeding was completely stopped immediately. It may not be a novel method, but is certainly a reliable application of the screw, which is fundamentally the same as arterial catheter embolization.

A Novel Variation of the Lateral Window Approach for Sinus Floor Elevation in a Case of Bony Nodular Prominence.

Introduction: In sinus floor augmentation, bony nodular prominence at the floor of the maxillary sinus is an obstruction to lateral window approach. It is challenging to detach and elevate the sinus membrane without making any perforations around the nodular prominence, because the membrane is very thin. To overcome these difficulties, we developed a novel method. Method: The membrane was not detached from the surface of the nodular prominence except for at the basal point, but the nodular prominence was cut at the base. Nodular prominence and sinus membrane were elevated upward together. A resorbable collagen membrane was placed beneath it to provide mechanical support and cover any partial tear in the sinus membrane. Autogenous bone and/or bone substitute were packed in the vacant compartment depending on the condition. Conclusion: This method is very easy to be carried out without any difficulties and worries. It gives us great benefit on the sinus floor augmentation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12663-021-01572-7.

Comparison of Postoperative Stability Between BSSRO and Le Fort 1 Osteotomy with BSSRO in Skeletal Class III Malocclusion with Severe Open Bite.

INTRODUCTION: We aimed to investigate postoperative stability after orthognathic surgery in patients with skeletal class III malocclusion with severe open bite by comparison between bilateral sagittal splitting osteotomy (BSSRO) and BSSRO with Le Fort 1 osteotomy. MATERIALS AND METHODS: Seventeen patients with skeletal class III malocclusion with severe open bite who were needed more than 6 degree counterclockwise rotation of distal segment by only BSSRO in preoperative cephalometric prediction. The subjects were divided into group A, where 9 patients were treated by BSSRO, and group B, where 8 patients were treated by BSSRO with Le Fort 1 osteotomy. Patient's characteristics of age, gender, preoperative over jet (OJ) and over bite (OB) were not found to be significantly different between the two groups. Counterclockwise rotation of distal segment in preoperative cephalometric prediction by only BSSRO was not found to be significantly different between group A of 7.6 (6-10.6) degree and group B of 9 (6-13) degree. The amount of rotation was reduced to 5.4 (3-10) degree by bimaxillary surgery using BSSRO and Le Fort 1 osteotomy in group B. OJ and OB were measured as occlusal stability factor. Distance between ANS-to-PNS plane and the edge of upper incisor (NF-U1Ed), and distance between Menton and edge of lower incisor (Me-L1Ed) were measured as skeletal stability factor using cephalometric analysis. These lengths were measured at pre-surgery (T0), 2 weeks after surgery (T1) and 1 year after surgery (T2), and these differences between the two groups were statistically analyzed. RESULTS: OJ and OB kept a good relation at any experimental periods. The change of Me-L1Ed was significantly larger in group A (1.21 mm at T0-T1, 1.02 mm at T0-T2) than in group B (0.14 mm at T0-T1, 0.16 mm at T0-T2). The change of NF-U1Ed was not significantly different between group A (1.07 mm at T0-T1, 0.57 mm at T0-T2) and group B (0.51 mm at T0-T1, - 0.05 mm at T0-T2). CONCLUSION: In case with more than 6 degree counterclockwise rotation of distal segment, skeletal stability was better after bimaxillary surgery than only BSSRO; however, OJ and OB kept a good relation.

Comparison of Maximum Mouth Opening Following Mandibular Bilateral Sagittal Splitting Ramus osteotomies in Class III Females Using Two Different Osteosynthesis Methods.

BACKGROUND: Limitation of mouth opening is a common complaint following orthognathic surgery. OBJECTIVES: This investigation reports on the progress of maximum incisal opening following orthognathic surgery and compares the impact of two different osteosynthesis methods on mouth opening in female patients with Class III dentofacial deformities. METHODS: Forty cases of skeletal class III malocclusion were divided into twenty cases treated using the conventional single miniplate osteosynthesis method (P1) and twenty cases using the additional L-shaped miniplate osteosynthesis method (P2). No significant differences in pre-operative clinical status were detected between the P1 and P2 group, and all patients were managed with elastics in the post-operative period. Independent mouth opening exercises were initiated seven days after surgery, and inter-incisal distance was measured as maximum mouth opening (MMO) at 1 week, 2 weeks, and 1, 2, 3, 6 months. Statistical analysis was performed in order to analyse differences in MMO between the P1 and P2 groups (Prism 7 GraphPad software, San Diego, CA). Values of P < .05 were considered to be significant. RESULTS: MMO significantly increased from 2 weeks after surgery in both groups. The MMO of P2 was significantly larger than that of P1 in all experimental periods after surgery. MMO was statistically improved in P2 at 2 months after surgery, while MMO in P1 was significantly smaller than the pre-operative MMO, even at 6 months post-operative. A minimum MMO of 40 mm was achieved by all patients. CONCLUSION: L-shaped miniplate osteosynthesis was more useful for early limitation of mandibular opening improvement than conventional single miniplate osteosynthesis.

Factors related to patients' nutritional state after orthognathic surgery.

PURPOSE: The purpose of this study was to evaluate patients' nutritional state after orthognathic surgery. METHODS: The subjects were 40 female patients with dentofacial deformity aged 17-33 years who were undergoing bilateral sagittal splitting ramus osteotomy. Twenty patients were treated with intermaxillary fixation, and 20 patients were treated without intermaxillary fixation. Age and body mass index (kg/m2) were assessed as physical factors, operation time, blood loss, and amount of mandibular movement with or without intermaxillary fixation were assessed as operation stress factors, and the following laboratory data, total protein, serum albumin, total cholesterol, total lymphocytes, and cholinesterase were assessed as nutritional state factors at 1 and 2 weeks after surgery. Statistical analysis was performed for body weight loss and relationship between body weight loss and examination factors. RESULTS: Body weight significantly decreased 2.3% at 1 week and 3.9% at 2 weeks after surgery rather than preoperation. All laboratory data except total lymphocyte were decreased at 1 week after surgery and still remained significantly decreased at 2 weeks after surgery. There was a statistically significant relationship between body weight loss at 1 week after surgery and operation time. CONCLUSIONS: These results indicate that long operation time caused body weight loss in orthognathic surgery.

Simple Vestibuloplasty Using a Tube in Combination with Cortical Bone Screws Around Dental Implant.

INTRODUCTION: We developed a novel, reliable and easy method that retains stability of the repositioned flap and vestibular expansion. METHOD: The conventionally elevated mucosal flap is secured to the desired depth of the vestibule by the pressure created by the polyvinyl chloride 6Fr suction catheter which is fixed to the alveolar bone with cortical bone screws passing through the inner lumen of the tube. The keratinized free flap is placed on the periosteum conventionally, and horizontal mattress suturing is performed for immobilization, with the suture running through the inner lumen of the tube transversally. CONCLUSION: This simple method gives us great benefit on the vestibuloplasty.

The Mandible is Further Retruded Under General Anesthesia: The Latent Concept for a Favorable Outcome in Sagittal Split Ramus Osteotomy.

INTRODUCTION: In orthognathic surgery, we often experience that model mounting by the occlusal bite record taken at centric relation under the conscious condition in the sitting position does not always correctly replicate the actual maxilla-mandibular relationship under general anesthesia. Mandible often moves backward further in the latter condition. The present study was carried out to investigate the degree of extra retrusion of the mandible under general anesthesia and to determine the characteristics in each of the three original skeletal class patterns in a Japanese population. PATIENTS AND METHODS: Fifty patients with jaw deformities (14 males and 36 females) were enrolled in this prospective study, their ages ranging from 16 to 49 years. The occlusal bite record at the incisor region obtained from a mounted articulator was compared with the records from the oral cavity of the patient under general anesthesia before surgery. RESULTS: Retrusion in the supine position under general anesthesia was observed in all skeletal classes, and it was significantly greater in skeletal Class II, compared to skeletal Class I and Class III. CONCLUSION: This study clearly revealed the difference among three different skeletal classes, and the mandible in the skeletal Class II moved backward significantly compared to other classes.

Suramin, screened from an approved drug library, inhibits HuR functions and attenuates malignant phenotype of oral cancer cells.

AU-rich elements (ARE) exist in the 3'-untranslated regions of the mRNA transcribed from cell growth-related genes such as proto-oncogenes, cyclin-related genes, and growth factors. HuR binds and stabilizes ARE-mRNA. HuR is expressed abundantly in cancer cells and related malignant phenotypes. HuR knockdown attenuates the malignant phenotype of oral cancer cells. In this study, we screened 1570 compounds in the approved drug library by differential scanning fluorimetry (DSF) to discover a HuR-targeted compound. Firstly, 55 compounds were selected by DSF. Then, 8 compounds that showed a shift in the melting temperature value in a concentration-dependent manner were selected by DSF. Of them, suramin, an anti-trypanosomal drug, binds to HuR, exhibiting fast-on and fast-off kinetic behavior on surface plasmon resonance (SPR). We confirmed that suramin significantly decreased mRNA and protein expression of cyclin A2 and cyclin B1. The cyclin A2 and cyclin B1 mRNAs were destabilized by suramin. Furthermore, the motile and invasive activities of a tongue carcinoma cell line treated with suramin were markedly lower than those of control cells. The above findings suggest that suramin binds to HuR and inhibits its function. We also showed that the anticancer effects of suramin were caused by the inhibition of HuR function, indicating its potential as a novel therapeutic agent in the treatment of oral cancer. Our results suggest that suramin, via its different mechanism, may effectively suppress progressive oral cancer that cannot be controlled using other anticancer agents.

Length-Marked Osteotome for Secure Le Fort I Osteotomy.

INTRODUCTION: To avoid injury of the descending palatine artery during Le Fort I osteotomy, I believe that it is important to measure the right distance between the piriform rim and the most anterior point of the descending palatine canal on the CT images and to insert the chisel to the correct distance. To achieve this maneuver easily, a novel chisel with depth markings is developed. MATERIAL AND METHODS: The osteotome is based on a general thin osteotome of 6 mm width. Laser-striped markings are made for easy identification of 25, 27, 30, 33, 35, 37, and 40 mm from the top, with unique color-coded stripe. It enables easy bone-cut without anxiety in a short time. It is also a useful instrument for bone-cut where the length and depth are critical. CONCLUSION: This length-marked osteotome is a reliable instrument for secure osteotomy without injuries.

Changes in ventilation mechanics during expiratory rib cage compression in healthy males.

[Purpose] The purpose of this study was to clarify the differences in ventilation mechanics between quiet breathing and expiratory rib cage compression, and between expiratory rib cage compression on the upper rib cage and on the lower rib cage. [Subjects and Methods] Subjects comprised 6 healthy males. Expiratory rib cage compression was performed manually by compressing the upper and lower rib cages. Changes in the lung volume, flow rate, and esophageal and gastric pressure were examined. [Results] The end expiratory lung volume was significantly lower during expiratory rib cage compression than at rest, but the end inspiratory lung volume was not significantly different. When compared with the esophageal and gastric pressures on the upper and lower rib cages at rest, the gastric pressures were significantly higher at end expiration. Lung resistance was significantly higher during expiratory rib cage compression than at rest. [Conclusion] Although expiratory rib cage compression promoted expiration and increased tidal volume, the lung volume did not increase beyond end inspiratory levels at rest. Lung resistance may increase during expiratory rib cage compression due to a decrease in lung volume. The mechanism by which expiration is promoted differed between the upper and lower rib cages.

Effects of posture on chest-wall configuration and motion during tidal breathing in normal men.

[Purpose] The purpose of this study was to clarify the impact of postural changes during tidal breathing on the configuration and motion of chest-wall in order to further breathing motion evaluation. [Subjects and Methods] Chest-wall configuration and motion in the supine, right lateral, and sitting positions were measured using optoelectronic plethysmography in 15 healthy adult men. [Results] The anteroposterior diameters of the chest wall were significantly lower in the supine position for the pulmonary and abdominal rib cages, whereas the mediolateral diameters in the lateral position were lowest for the abdominal rib cage. Regarding chest-wall motion, both craniocaudal and anteroposterior motions of the anterior surface of the pulmonary and abdominal rib cages were significantly greater in the sitting position. Regarding motion of the left lateral abdominal rib cage, lateral motion was greatest in the lateral position. [Conclusion] Chest-wall configuration and motion changed according to posture in healthy men, particularly in the pulmonary and abdominal rib cages.

Post-operative Stability After Bimaxillary Surgery in Patients with Facial Asymmetry: Comparison of Differences Among Different Original Skeletal Class Patterns.

PURPOSE: When improving jaw deformity by two-jaw surgery, we are of the opinion from our clinical experience that a certain degree of undercorrection is occasionally beneficial from the perspective of stability. Functional deterioration is not always seen with undercorrection. We conducted this retrospective study to assess post-operative stability in patients with facial asymmetry, with the aim of both clarifying differences between the original three skeletal class patterns, and confirming the efficacy of surgery performed on the basis of our concept. PATIENTS AND METHODS: All patients received optimal orthognathic treatment before and after surgery. Surgery was performed by our concept that undercorrection is not always bad. Nineteen patients were enrolled, and separated into three skeletal classes according to the ANB angle, because of the difference of the treatment modalities between them. Evaluations were performed by cephalometric measurements taken at least two-year post-operatively. Transverse occlusal cant, chin deviation, point A, point B, overjet and overbite were assessed. RESULTS: In all patients, transverse occlusal cant improved to <4°, which has been reported as the threshold for visual recognition of facial symmetry. Chin deviation was also improved to the degree at which soft tissue can sufficiently mask the asymmetry. The changes remained stable throughout follow-up and satisfaction was obtained from all patients. CONCLUSIONS: Irrespective of original skeletal class patterns, post-operative stability of patients with facial asymmetry was achieved. Undercorrection is thus by no means problematic from the clinical perspective of stability and our concept of approach appears valid.

Evaluation of a three-stage method for improving mandibular retrognathia with labially inclined incisors using genioplasty, segmental osteotomy, and two-jaw surgery.

We have sometimes encountered difficulty in improving labially inclined teeth, particularly in patients with mandibular retrognathia, because the symphysis menti is often thin and insufficient space is available to permit sagittal rotation of the teeth without root exposure from the alveolar bone. We have previously described a three-stage method to overcome this problem, involving genioplasty for improving the retruded chin, and to construct the infrastructure for subsequent subapical segmental alveolar osteotomy, subapical segmental alveolar osteotomy itself, and, finally, two-jaw surgery. Bone augmentation with thin cortical bone at the gap created on the upper surface of the advanced genial segment was also addressed in the previous report. In the present study, to confirm the benefits of the three-stage method using objective data, cephalometric evaluation was performed in each step. In all cases, pogonion (Pog) was moved forward substantially. Net linear forward movement of Pog and net changes in SN-Pog were from 12 mm to 20 mm and from 4.8° to 7.0°, respectively. Angle of mandibular incisors and interincisal angle also improved to desirable levels. Although this method requires three separate surgeries, the approach safely improves the clinical situation and accentuates treatment efficacy.

Measurements of chest wall volume variation during tidal breathing in the supine and lateral positions in healthy subjects.

PURPOSE: To study the feasibility and the laterality of measurements of chest wall volume variation during tidal breathing in the lateral position in healthy subjects. METHODS: Eighteen normal subjects were studied. Chest wall volume changes were measured by optoelectronic plethysmography in the supine and right and left lateral positions during quiet breathing. The accuracy of measuring lung volume was also examined using hot wire spirometry in 10 of the subjects. RESULTS: The measurement errors between lung volume changes and chest wall volume changes were not significantly different in all positions. There was no significant difference between right and left compartmental volume changes in the supine position. However, chest wall volume changes were lower on the dependent side in the lateral position than on the non-dependent side because of the decrease in abdominal rib cage and abdomen volume changes. CONCLUSION: Chest wall volume measurements during quiet breathing in the lateral position have high measuring accuracy and show laterality.

Relationship between spontaneous expiratory flow-volume curve pattern and air-flow obstruction in elderly COPD patients.

BACKGROUND: Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. METHODS: In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV(1) 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. RESULTS: Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV(1)% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). CONCLUSIONS: Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.

Dental pulp can be a good candidate for nerve grafting in a xeno-graft model.

Dental pulp is discarded after extirpation of dental pulp and after tooth extraction. However, it contains nerve tissue abundantly and could be used more effectively. This study was designed to examine whether a dental pulp could be a candidate of donor for nerve grafting in xenografting model. The dental pulp was obtained from a human vital extracted tooth for orthodontic treatment, and treated with freezing and thawing method for reducing antigenicity. The treated sample was inserted into chitosan mesh tube for easy suturing, and then the complex was implanted into transected sciatic nerve in Sprague-Dawley (SD) rats (dental pulp group). As controls, chitosan tubes with and without sciatic nerve harvested from another SD rats were implanted (isograft group and tube group, respectively). As early as 4 weeks after grafting, regenerating axons accompanied by host Schwann cells were found to grout out through basal laminae by electron microscopy. The intact structure of basal laminae at this period suggested that they were derived from the original structure of donor graft. Twelve weeks after grafting, sporadic axonal regeneration was confirmed by light microscopy in the dental pulp group. Thirty-two weeks after implantation, aggregation of axons was observed in this group and matched that in isograft group. The average diameter of axons in dental pulp group was comparable to that in isograft group, whereas number of minifascicles and axon proportion were smaller. It was suggested that some delay occurred in dental pulp group because of the phagocytosis and absorption of tissue debris components remained after the freezing and thawing treatment. These findings clearly demonstrate that even dental pulp can act as conduits for regenerating axons.

In vitro biomechanical evaluation of the effect of an additional L-shaped plate on straight or box plate fixation in sagittal split ramus osteotomy using a bioabsorbable plate system.

PURPOSE: Relapse caused by clockwise (opening) rotation of the distal segment (dentate segment) in the sagittal plane is one of the postoperative complications sometimes seen after sagittal split ramus osteotomy. The force involved in this movement is primarily exerted by the masticatory and suprahyoid muscles. For postoperative stability, we have used two plates on each side: a straight plate placed over the vertical osteotomy line at the buccal surface of the first molar and an L-shaped plate placed at the distal or lateral part of the last molar over the osteotomy line, just crossing over the upper-lateral edge of the buccal shelf, to prevent the tail of the distal segment from moving upward. Although postoperative stability was clinically fine, experimental evaluations have not previously been performed. To clarify the effects of the L-shaped plate, we performed an experimental study using a bioabsorbable plate system. METHODS: A custom-fabricated jig was made to simulate rotational movement of the segments. Two segments made from polyoxymethylene resin were fixed with a four-hole straight or four-hole box poly-L-lactate bioabsorbable plate. An L-shaped plated was then added for rigidity, and mechanical testing was performed. RESULTS: The yield load exerted by the four-hole straight plate alone was 152.4 ± 11.0 N. This increased significantly to 273.8 ± 43.7 N with addition of an L-shaped plate (P < 0.05). CONCLUSION: Addition of an L-shaped plate significant improves the rigidity of four-hole straight plate fixation in a bioabsorbable plate system.