Correlation Between Acquisition of Dental Implant Stability and Hounsfield Units at Dental Implant Placement.

Alveolar bone quality at the implantation site affects the initial stability of dental implant treatment. However, the relationship between bone quality and osseointegration has yet to be evaluated. Herein, we aimed to investigate the effect of bone quality on dental implant stability in osseointegration formation changes. Patients underwent computed tomography imaging before dental implantation at the posterior. Hounsfield units were measured at the platform, middle, and tip sites. Implant stability was measured using resonance frequency analysis immediately and at 3 months postoperatively, in which the difference in implant stability quotients (ISQ) was defined as the change between primary and secondary fixation. In multiple regression analysis, the dependent variable was the change between the immediate and secondary fixations. We included 81 implants that conformed to the criteria. Primary fixation yielded the following results: R2 = 0.117, F = 2.529, and P = .047. The difference between the maxilla and mandible of the implantation site (P = .02) and the platform-site Hounsfield units (P = .019) were identified as significant factors. The following results were obtained regarding the change between the immediate and secondary fixation: R2 = 0.714, F = 40.964, and P < .001. The difference between diameter (P = .008) and the immediate ISQ (P < .001) were identified as significant factors. Overall, the bone quality of the implantation site affected initial fixation; however, it had limited effect on secondary fixation. Our findings clarified the period where bone quality affects dental implant treatment and is expected to advance dental implant treatment.

Sphenoid Sinus Foreign Body After Le Fort I Osteotomy.

This report describes a rare case of a foreign body in the sphenoid sinus from the tip of an osteotome, which was lodged during the Le Fort I osteotomy. After surgery, a 2-mm-diameter round-shaped foreign body was seen as an opaque image in the right sphenoid sinus on computed tomography. The tip of the broken osteotome (Bauer) was confirmed after the intraoperative instruments were investigated. The foreign body was removed using an interventional endoscope and navigation computed tomography, and a good prognosis was obtained.

Change in CT Value at Mandibular Ramus After Mandibular Setback and Advancement Surgery With Bicortical Absorbable Plate Fixation.

PURPOSE: This study aimed to evaluate changes in computed tomography (CT) value of ramus bone after sagittal split ramus osteotomy (SSRO) in class II and class III patients using absorbable plates and screws. PATIENTS AND METHODS: In the retrospective study, the participants were female patients with jaw deformities who underwent bilateral SSRO with Le Fort I osteotomy. Maximum CT values (pixel values) of lateral and medial cortexes at anterior and posterior sites of the ramus were measured preoperatively and 1 year postoperatively by using horizontal planes at the mandibular foramen level (upper level) and 10 mm under the mandibular foramen level (lower level) parallel to Frankfurt horizontal plane. RESULTS: Fifty-seven patients and 114 sides (28 class II: 56 sides and 29 class III: 58 sides) were evaluated. Although CT values decreased at most sites of the ramus cortical bone after 1 year of surgery, they increased at the posterior-medial site at the upper level in class II ( P =0.0012) and the lower level in class III ( P =0.0346). CONCLUSION: This study suggested that bone quality at the mandibular ramus could change after 1 year of surgery, and there could be differences between mandibular advancement and setback surgery.

Efficacy of Nostril Supportive Splint Treatment for Nasal Septum Deformities after Le Fort I Osteotomy.

This retrospective study aimed to evaluate the efficacy of support splint treatment for deformities and deviations of the nasal septum after Le Fort I osteotomy (LFI). Patients were divided into two groups: the retainer group wore a nasal support splint immediately after LFI for 7 days, and the no retainer group did not wear a nasal support splint. Evaluation was performed by measuring the ratio of the difference between the left and right sides of the nasal cavity area (ratio of nasal cavity) and the angle of the nasal septum using three computed tomography frontal images (anterior, middle, and posterior) before and one year postoperatively. Sixty patients were included and divided into two groups, the retainer and no retainer group (n=30 each). Regarding the ratio of nasal cavity on middle images at one year postoperatively, the retainer and no retainer groups differed significantly (0.79±0.13 and 0.67±0.24, respectively; P =0.012). The angle of the nasal septum on anterior images at one year postoperatively was 164.8±11.7° in the retainer group and 156.9±13.5° in the no retainer group, showing a significant difference ( P =0.019). This study suggests that support splint treatment after LFI is effective in preventing post-LFI nasal septal deformation or deviation.

Computed Tomography Assessment of Maxillary Sinus and Inferior Nasal Airway After Le Fort I Osteotomy.

PURPOSE: This study aimed to evaluate and predict the factors that affect the postoperative maxillary sinus and inferior nasal cavity conditions after Le Fort I osteotomy. SUBJECTS AND METHODS: The rate of aerated (healthy) sinus area and the inferior nasal airway area were calculated by preoperative computed tomography measurements and at 1 week and 1 year postoperatively. Factors predicting the rate of aerated sinus area and the ratio of the inferior nasal cavity area after 1-week were examined using these variables. RESULTS: The subjects consisted of 112 patients (224 sides) who underwent Le Fort I osteotomy with sagittal split ramus osteotomy. The rate of aerated sinus area after 1 week was significantly correlated with sex, age, and amount of blood loss ( P < 0.0001). The rate of the inferior nasal cavity area after 1 week was significantly correlated with the anterior impaction amount of the maxilla and the preoperative rate of the inferior nasal airway area ( P= 0.0017). CONCLUSIONS: This study suggests that attention should be paid to females, older patients, and the amount of blood loss to prevent sinusitis, and larger maxillary impaction at the anterior site should be carefully planned to prevent severe nasal obstruction immediately after Le Fort I osteotomy.

Evaluation of Nasal Function and Upper Airway Morphology After Bi-Maxillary Surgery Using Rhinomanometry and Computed Tomography.

PURPOSE: This study was performed to evaluate changes in nasal airflow, nasal airway resistance, nasal cross-sectional area, pharyngeal horizontal area, nasopharyngeal and oropharyngeal volume following Le Fort I osteotomy (L1) impaction with sagittal split ramus osteotomy (SSRO) in classes II and III. MATERIALS AND METHODS: The subjects consisted of 35 patients (6 males and 29 females, 70 sides) 17 of which were diagnosed as class II and 18 as class III who underwent L1 and SSRO. Nasal airflow and resistance were measured using the rhinomanometry system (GM NR-6 EXECUTIVE) before and at 1 and 6 months after surgery. Nasal, cross-sectional area, and volume were measured using a 3-dimensional computed tomography respectively, before and 1-year after surgery. RESULTS: Although a significant decrease was found in nasal volume after surgery (P = 0.0042), there was no difference between before and after surgery in the nasal airway resistance in class II.A significant decrease in nasal volume was found after surgery (P = 0.0005) and there were no postoperative changes in both nasal airflow and resistance in class III. CONCLUSION: The study suggested that L1 impaction with SSRO did not worsen nasal function such as nasal airflow and nasal airway resistance, although nasal volume significantly decreased in both groups.

Effects of ultraviolet irradiation on beta-tricalcium phosphate as a bone graft substitute.

Surface modification of various materials using ultraviolet (UV) irradiation improves their wettability. The purpose of this study was to investigate the wettability of a ß-tricalcium phosphate (TCP) surface and the composition changes and bioactivity of ß-TCP after UV irradiation. We applied 172 nm UV treatment to a ß-TCP surface and measured the contact angle before and after UV irradiation. Energy-dispersive X-ray and Fourier transform infrared spectroscopy examinations were performed on the ß-TCP disk with or without UV treatment. In an adhesion test of bone marrow cells using ß-TCP disks with and without UV irradiation, cell attachment was measured 10, 30, 50, and 70 h after ß-TCP insertion. UV-irradiated ß-TCP osteogenesis and absorption of bone substitutes were evaluated using hematoxylin and eosin and tartrate-resistant acid phosphatase (TRAP) staining in a rabbit sinus model. The contact angle on the TCP surface decreased from 70° to 10° owing to UV irradiation. Conversely, UV irradiation did not change the composition of carbon, oxygen, and phosphorus. In the cell adhesion test, UV-irradiated ß-TCP significantly increased cell adhesion compared with UV-unirradiated ß-TCP after 10 to 30 h of culture. In the rabbit sinus model, TRAP staining showed that UV-irradiated ß-TCP significantly increased the number of TRAP-positive cells compared with unirradiated ß-TCP granules in the central part of ß-TCP. Our results indicate that the UV irradiation of ß-TCP improves its clinical utility for surgical bone augmentation in the oral and maxillofacial region.

Evaluation of intravenous prophylaxis antibiotics for third molar extraction under general anesthesia.

Prophylactic antibiotic administration aims to maintain the postoperative wound environment. It is difficult to select appropriate prophylactic antibiotics to minimize the development of antibiotic resistant bacteria and the occurrence of complications. The purpose of this study was to compare the prophylactic effect of narrow spectrum antibiotics (cefazolin) with that of wide spectrum antibiotics (piperacillin) in preventing infection following third molar extraction. In addition, the effect of postoperative cefazolin administration was examined. This retrospective study included 350 patients who underwent third molar removal under general anesthesia. The patients were divided into three subgroups: preoperative cefazolin (N = 122), pre- and postoperative cefazolin (N = 101), and pre- and postoperative piperacillin (N = 127). The patients in the piperacillin group were administered the antibiotic preoperatively and postoperatively for 3 days. The patients in the preoperative cefazolin group were administered cefazolin preoperatively only. The patients in the pre- and postoperative cefazolin group were administered cefazolin preoperatively and postoperatively for 1 day. Surgical site infections (SSIs) were identified based on the Clavien-Dindo 30-day postoperative classification. There was a significant difference among the three groups of patients who had third molars classified as position C using the Pell and Gregory classification, according to the degree of impaction of the impacted third molar (P = 0.015). Our analysis showed that the number of SSI did not significantly differ between the three antibiotic treatment groups (P = 0.671). These results suggest that preoperative administration of cefazolin is as effective as postoperative administration of broad-spectrum antibiotics such as piperacillin.

Evaluation of Space-Maintaining Sinus Membrane Using the Absorbable Screws in Sinus Lifting Bone Augmentation.

PURPOSE: We investigated whether it was possible to perform a sinus lift maintaining absorbable screw material with biological activity. MATERIALS AND METHODS: Thirty rabbits were used. The screws used in this study were unsintered hydroxyapatite/poly-L-lactic acid (uHA/PLLA) (uHA/PLLA group) and titanium alloy (Ti group). Some uHA/PLLA screws were treated with ultraviolet light (UV-uHA/PLLA group). Each group consisted of 10 rabbits, and 2 screws were implanted for 1 rabbit. The screws were implanted into the frontal bone. Rabbits were euthanized at 3 days, 1, 2, 3, and 4 weeks postoperatively and prepared for histological examination, BMP-2 cell staining, and micro-computed tomography (micro-CT) assessment. RESULTS: At 1, 2, and 3 weeks, the UV uHA/PLLA group had significantly more bone contact and new bone ratio on histological assessment than the other 2 groups. At 1, 2, 3, and 4 weeks, micro-CT assessment revealed significant differences between the UV uHA/PLLA group and the other 2 groups. CONCLUSIONS: Sinus lift surgery using absorbable screw allowed bone formation. The UV-treated hydroxyapatite/poly-L-lactic acid (uHA/PLLA) was superior for sinus lift bone augmentation using a screw.

Assessment of temporomandibular joint disc position and skeletal stability after bimaxillary surgery.

PURPOSE: This study aimed to assess the correlation between temporomandibular joint (TMJ) disc position and skeletal stability and identify the cephalometric measurements associated with relapse after bimaxillary surgery. METHODS: The participants were 62 women with jaw deformities (124 joints) who underwent bimaxillary surgery. The TMJ disc position was classified into four types (anterior disc displacement (ADD), anterior, fully covered, and posterior) using magnetic resonance imaging, and cephalometric analysis was performed preoperatively and 1 week and 1 year postoperatively. The differences between pre- and 1-week postoperative values (T1) and 1-week and 1-year postoperative value (T2) were calculated for all cephalometric measurements. Moreover, the relationship between skeletal stability using cephalometric measurements, skeletal class, and TMJ disc position was analyzed. RESULTS: The participants included 28 patients in class II and 34 in class III. There was a significant difference in T2 in SNB between class II mandibular advancement cases and class III mandibular setback cases (P = 0.0001). In T2, in ramus inclination, there was a significant difference between the ADD and posterior types (P = 0.0371). Stepwise regression analysis revealed that T2 was significantly correlated with T1 for all measurements. However, the TMJ classification was not applied to all measurements. CONCLUSION: This study suggested that TMJ disc position, including ADD, could not affect skeletal stability, including the maxilla and distal segment after bimaxillary osteotomy, and short-term relapse could be related to the movement amount or angle change by surgery for all measurements.

Maxillary bone healing and CT value after Le Fort I osteotomy using absorbable plate system: A retrospective study.

This study aimed to evaluate maxillary bone healing and computed tomography (CT) values after Le Fort I osteotomy with sagittal split ramus osteotomy in patients with class II and III malocclusion. Four absorbable plates and screws were used to fix the maxillary segments in all patients. For 112 sides (58 patients), the bone defect areas at the anterior and posterior sites between the maxillary segments were measured using 3-dimensional CT views reconstructed over a constant CT value at 1 week and 1 year postoperatively. Subsequently, CT values at the upper, middle, and lower sites around the osteotomy line in the medial, middle, and lateral regions were measured. The bone defect area after 1 year increased at the anterior site in class III and at both the anterior and posterior sites in class II (P < 0.05). This study suggests that the increase in bone defect area was affected by lower CT values at the middle site of the middle and lateral regions in class II, and that bony defects between fragments in the maxilla could partially remain in both classes II and III within 1 year after Le Fort I osteotomy.

Comparison between unsintered hydroxyapatite/poly-L-lactic acid mesh and titanium mesh in bone regeneration of rabbit mandible.

PURPOSE: The purpose of this study was to compare the bone regenerative capability of using unsintered hydroxyapatite/poly-L-lactic acid (uHA/PLLA) mesh and titanium mesh. MATERIALS AND METHODS: Adult male white rabbits (n = 24) were divided into 2 groups. After incising along the mandible, 3 × 5 mm bone defects were made in both sides and covered by an uHA/PLLA mesh (n = 12) or a titanium mesh (n = 12) on the right side but no mesh on the left side (n = 12). The rabbits were sacrificed at 1, 2, and 4 weeks postoperatively, and formalin-fixed specimens were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immunohistochemical analysis, the specimens were treated with BMP-2. RESULTS: The titanium group and uHA/PLLA group were significantly larger than the control group regarding the bone area ratio postoperatively at 2 and 4 weeks. However, there were no significant differences between the uHA/PLLA group and titanium group regarding the BMP-2. CONCLUSIONS: This study suggested that the uHA/PLLA mesh could increase new bone formation more than the absence of a mesh in bone defects. However, there was no significant difference between uHA/PLLA mesh and the titanium mesh in bone augmentation.

Relationship between condylar surface CT value in coronal plane and condylar morphology in jaw deformity patients.

OBJECTIVES: This study aimed to examine the relationship between condylar surface computed tomography (CT) values in the coronal plane and condylar morphology in patients with jaw deformities classes II and III before and after orthognathic surgery. MATERIALS AND METHODS: The maximum CT values (pixel values) at three points on the condylar surface, height, and joint space were measured on the coronal plane. The condylar width, thickness, and angle were measured on the horizontal plane preoperatively and at 1 year postoperatively. RESULTS: A total of 112 temporomandibular joints of 56 female patients were divided into two groups according to skeletal class (56 joints each in class II and class III). The maximum CT values of class II were higher than those of class III at the medial, central, and lateral sites on the condylar surface, preoperatively and at 1 year postoperatively (P < 0.05). CT values of the condylar surface were significantly negatively correlated with the condylar heights at the center and lateral sites preoperatively and at 1 year postoperatively (P < 0.05). CONCLUSIONS: Condylar surface CT values in the coronal plane are associated with condylar morphology, including condylar height.

Evaluation of tongue pressure and lip closing force in bimaxillary orthognathic surgery: A retrospective study.

The purpose of this study was to quantitatively compare changes in tongue pressure and lip closing force among skeletal Class II and Class III patients, who had undergone orthognathic surgery, and a control group. Maximum tongue pressure and lip closing forces were measured preoperatively and at 6 and 12 months postoperatively. Time-course changes were analyzed and compared among the groups. The control group involved 40 skeletal Class I occlusion volunteers (20 male and 20 female), the Class II group involved 20 female patients, and the skeletal Class III group involved 40 patients, who were subdivided by sex into two groups comprising 20 males and 20 females, respectively. Time-course changes in tongue pressure were not significantly different between and within groups. However, postoperative lip closing forces became gradually higher in the Class III group female and male subjects compared with the control group, although this was not observed in the Class II group. There were significant correlations between tongue pressure and lip closing force before and after surgery (p = 0.001), and these correlations increased over time. Although there was no significant increase in maximum tongue pressure after orthognathic surgery, there was an associated increase in perioral muscle strength. This suggests that an increase in perioral muscle strength may contribute more to the stability of postoperative jaw morphology.

Bone healing and stability after advancement genioplasty using a pre-bent absorbable plate and screws.

This study aimed to compare the bone healing and stability of the chin with a pre-bent absorbable plate and a manually bent absorbable plate after advancement genioplasty. Patients with class II malocclusion who underwent genioplasty with bimaxillary surgery were included. After genioplasty, two absorbable bicortical screws were fixed on both sides. Then, a pre-bent absorbable plate and screws were used in the center area to fix the segment in advancement genioplasty (PB group). A manually bent absorbable plate was used for the remaining patients (MB group). Computed tomography (CT) was performed before surgery and 1 week and 1 year after surgery. Changes in the pogonion (Pog) and menton (Me) points, soft tissue points, and the ratio of bone squares under the plate were evaluated using lateral cephalometric images reconstructed with 3-dimensional CT data. 32 patients were included in the study. There were no significant differences in the cephalometric measurements in the time interval from 1 week to 1 year. However, the bone square ratio in the PB group showed a significant increase after 1 year (P = 0.0021). Within the limitations of the study it seems that the use of a pre-bent absorbable plate is effective in promoting bone healing after advancement genioplasty.

Meningitis with septic shock resulting from odontogenic infection misdiagnosed as closed-lock in temporomandibular disorder: A case report and literature review.

RATIONALE: Infections that spread to the pterygomandibular muscle can be misdiagnosed as temporomandibular disorder (TMD) because of the resulting difficulty in opening the mouth. Importantly, infection of the pterygomandibular space can extend to the skull base in the early stages, and a delay in therapeutic intervention can lead to severe complications. PATIENT CONCERNS: A 77-year-old Japanese man with trismus after pulpectomy was referred to our department. This case report describes a rare instance of meningitis with septic shock caused by an odontogenic infection, initially misdiagnosed as TMD due to similar symptoms, leading to life-threatening complications. DIAGNOSIS: The patient was diagnosed with sepsis and meningitis resulting from cellulitis in the pterygomandibular space caused by iatrogenic infection after pulpectomy of the right upper second molar. INTERVENTIONS: After emergency hospitalization, the patient developed septic shock and required blood purification. Subsequently, abscess drainage and extraction of the causative tooth were performed. However, the patient developed hydrocephalus secondary to meningitis and underwent ventriculoperitoneal shunting to alleviate the condition. OUTCOMES: The infection was controlled and the patient level of consciousness improved following treatment for hydrocephalus. The patient was transferred to a hospital for rehabilitation on the 106th day of hospitalization. LESSONS: Infections of the pterygomandibular space may be misdiagnosed as TMD, owing to the main symptoms of restricted mouth opening and pain on mouth opening. A prompt and appropriate diagnosis is crucial because these infections can lead to life-threatening complications. A detailed interview, along with additional blood tests and computed tomography (CT) scans, can aid in making an accurate diagnosis.

Nodular fasciitis arising from the buccal region after segmentectomy with rapid growth mimicking postirradiation myxofibrosarcoma: A case report.

RATIONALE: Nodular fasciitis (NF) can be misdiagnosed as a sarcoma because of its rapid growth and pathological features, such as nuclear atypia and mitoses. PATIENT CONCERNS: We present a rare case of a 72-year-old Japanese man who developed NF with suspected postirradiation myxofibrosarcoma (MFS) after segmentectomy for left-sided osteoradionecrosis (ORN) of the mandible. DIAGNOSIS: A mass appeared in the intraoral postoperative wound 1 year after left-sided mandibular segmentectomy and showed rapid growth, reaching a size of 50 mm within 2 months. Incisional biopsy revealed strongly Ki-67-positive spindle-shaped cells with large irregular nuclei and a diagnosis of postirradiation MFS. INTERVENTIONS: The patient was diagnosed with oropharyngeal cancer (T4aN2bM0) and underwent surgical resection of primary oropharyngeal squamous cell carcinoma with selective neck dissection and reconstruction with a rectus abdominis musculocutaneous flap at the age of 57 years, followed by postoperative 66 Gy of radiotherapy combined with cisplatin administration. No recurrent or metastatic lesions of oropharyngeal squamous cell carcinoma have been detected for > 10 years. However, the ORN of the jaw worsened, and the patient underwent sequestrectomy 3 times on the right side of the mandible, followed by a left-sided segmentectomy at the age of 72 years. One year after segmentectomy, a 10-mm mass with soft-to-firm consistency appeared in the buccal mucosa of the wound and grew rapidly. An incisional biopsy revealed MFS. Complete resection under general anesthesia was immediately performed. OUTCOMES: The histopathological diagnosis of the excised specimen was NF without any malignant findings. Two years after surgery, there was no evidence of recurrence or metastasis. LESSONS: NF grows rapidly and has pathological features similar to sarcoma, making differential diagnosis difficult at the time of incisional biopsy. Further studies should be conducted to determine the clinical and pathological features of this tumor.

Automatic discrimination of Yamamoto-Kohama classification by machine learning approach for invasive pattern of oral squamous cell carcinoma using digital microscopic images: a retrospective study.

OBJECTIVE: The Yamamoto-Kohama criteria are clinically useful for determining the mode of tumor invasion, especially in Japan. However, this evaluation method is based on subjective visual findings and has led to significant differences in determinations between evaluators and facilities. In this retrospective study, we aimed to develop an automatic method of determining the mode of invasion based on the processing of digital medical images. STUDY DESIGN: Using 101 digitized photographic images of anonymized stained specimen slides, we created a classifier that allowed clinicians to introduce feature values and subjected the cases to machine learning using a random forest approach. We then compared the Yamamoto-Kohama grades (1, 2, 3, 4C, 4D) determined by a human oral and maxillofacial surgeon with those determined using the machine learning approach. RESULTS: The input of multiple test images into the newly created classifier yielded an overall F-measure value of 87% (grade 1, 93%; grade 2, 67%; grade 3, 89%; grade 4C, 83%; grade 4D, 94%). These results suggest that the output of the classifier was very similar to the judgments of the clinician. CONCLUSIONS: This system may be valuable for diagnostic support to provide an accurate determination of the mode of invasion.

Retraction notice to "Effect of low-intensity pulsed ultrasound on injured temporomandibular joints with or without articular disc removal in a rabbit model "[Journal of Dental Sciences Volume 16, Issue 1, January 2021, Pages 287-295].

[This retracts the article DOI: 10.1016/j.jds.2020.04.002.].

Loss of intercellular bridges in the depth of invasion measurement area is a novel negative prognostic factor for oral squamous cell carcinoma: A retrospective study.

OBJECTIVE: This study aimed to evaluate intercellular bridges in the depth of invasion (DOI) measurement area as prognostic factors in oral squamous cell carcinoma (OSCC). STUDY DESIGN: The mode of invasion was determined based on the Yamamoto-Kohama classification system by observing the hematoxylin-eosin-stained whole-slide images of specimens obtained from 78 patients with OSCC, and the clinicopathologic features were characterized. The presence of intercellular bridges was analyzed in 46 patients with Yamamoto-Kohama classification grade ≥3 whose DOI was measured by dividing the measurement area into 3 parts: the surface, center, and front of the tumor. RESULTS: Univariate analyses identified lymph node metastasis, loss of intercellular bridges in the DOI measurement area, DOI of ≥4500 µm, and pattern of invasion 4C-4D as negative prognostic factors. Multivariate analyses revealed that lymph node metastasis and the loss of intercellular bridges in the entire area were independent factors, with hazard ratios of 9.34 (95% confidence interval, 2.09-42.03; P = .003) and 3.64 (95% confidence interval, 1.10-11.99; P = .045), respectively. CONCLUSIONS: Loss of intercellular bridges in the DOI measurement area is a negative prognostic factor for OSCC and may be useful in selecting treatment.