Clinical Implications and Risk Factors of Dilatation of Remnant Pancreatic Duct at 1 Year After Pancreatoduodenectomy: A Prospective, Japanese, Multicenter, Observational Cohort Study (DAIMONJI-Study).

BACKGROUND: To determine the precise frequency of main pancreatic duct (MPD) dilatation within the remnant pancreas at 1 year after pancreatoduodenectomy (PD) and its clinical implications, a prospective multicentre cohort study was performed in patients without MPD dilatation before PD (Registry number; UMIN000029662). METHODS: Between October 2017 and July 2020, patients with MPD diameter <3mm who were planned to undergo PD for periampullary lesions at 21 hospitals were enrolled. The primary endpoints were frequency of MPD dilatation at 1 year after PD, and the relationship between MPD dilatation and pancreatic endo- and exocrine function, nutritional status, and fatty liver. Secondary endpoints were risk factors for MPD dilatation at 1 year after PD and time-course change in MPD diameter. RESULTS: Of 200 registered patients, 161 patients were finally analyzed. Pancreatic fistula was the most frequent complication (n=76; 47.2%). MPD dilatation (MPD>3mm) at 1 year after PD was seen in 35 patients (21.7%). Pancreatic exocrine function, assessed by steatorrhea, was significantly impaired in patients with MPD dilatation. However, endocrine function, nutrition status and fatty liver development were comparable between the two groups. In multivariate analysis, the serum toral protein level≥7.3g/dl was an independent predictor for MPD dilatation at 1 year after PD (OR; 3.12, 95%CI; 1.31-7.15). A mean MPD diameter significantly increased at 6 months after PD and kept plateau thereafter. CONCLUSIONS: MPD dilatation at 1 year after PD was seen in 21.7% of patients and significantly associated with exocrine function impairment but not with endocrine function, nutrition status, or development of fatty liver.

Identification of patients at high risk for recurrence in carcinoma of the ampulla of Vater: Analysis in 460 patients.

Aim: Carcinoma of the ampulla of Vater (CAV) shows a favorable prognosis compared to that with the other periampullary tumors, while some cases have a poor prognosis. The aims of the present study are to clarify the clinicopathological factors associated with poor recurrence-free survival (RFS) in patients with CAV after curative resection and to validate the usefulness of adjuvant chemotherapy (AC). Patients: The study design is a multicenter retrospective cohort study. Patients with CAV who underwent pancreaticoduodenectomy between January 2008 and December 2020 at 26 hospitals were analyzed. The 30 clinicopathological factors were evaluated. A propensity score matching (PSM) was used to compare between patients with and without AC. Results: Finally, 460 patients were analyzed. Median duration of follow-up was 47.2 months. Twenty-one prognostic factors associated with poor RFS were identified by univariate analysis. In multivariate analysis, aged ≥71, tumor diameter ≥12 mm, pT2 or higher stage (pT≥2), portal vein invasion (PV+), venous invasion(V+), and node positive disease (pN+) were independent prognostic factors for poor RFS. Out of 80 patients who received AC, 63 patients were assigned to analysis for PSM. The results showed no beneficial effect of AC on RFS. The preoperative factors potentially predicting pT≥2, V+, and/or N+ were at least one of following; (1) CA19-9 > 37 IU/mL, (2) ulcerative or mixed type appearance, (3) except for well-differentiated tumor, or (4) except for intestinal subtype of histology. Conclusions: Aged ≥71, tumor diameter ≥12 mm, pT≥2, PV+, V+, and pN+ were independent prognostic factors for poor RFS in patients with CAV. An additional therapeutic strategy may be desirable in CAV patients at high risk for recurrence.

Intraneural fibrosis within ilioinguinal nerve in inguinal hernia patients with preoperative pain: it's the sign of irreversible nerve injury, isn't it?

PURPOSE: Preoperative pain is known as one of the most powerful risk factors for chronic postoperative inguinal pain (CPIP), while its pathogenesis has not been fully elucidated. The aim of the present study was to evaluate patients with preoperative pain from the pathological perspective and discuss the potential pathogenesis of CPIP in those patients. METHODS: This was a single-institutional retrospective study. The study population was inguinal hernia patients with preoperative pain who underwent open anterior hernia repair for primary inguinal hernia with pragmatic ilioinguinal neurectomy during surgery between March 2021 and March 2023. The primary and secondary outcomes were proportion of collagen deposition and mucus accumulation within ilioinguinal nerve in those patients, respectively, which were evaluated histologically using Image J software. RESULTS: Forty patients were evaluated. Median value of proportion of intraneural collagen deposition was 38.3% (27.7-95.9). These values were positively correlated with the duration of pain (r2=0.468, P<0.001). Median value of proportion of mucus accumulation in ilioinguinal nerve was 50.1% (0-82.0). These values had no correlation with any clinicopathological variables. CONCLUSIONS: In the present study population, all patients with preoperative pain had intraneural fibrosis within ilioinguinal nerve, and its degree had a positive correlation with the pain duration.

Uncertainties associated with direct thyroid measurements using an NaI(Tl) survey meter: the effect of anatomical differences among individuals.

Photon detectors utilised for direct thyroid measurements to determine the radioiodine content in the thyroid are normally calibrated using a phantom that mimics the human neck, including the thyroid. However, such measurements are necessarily subject to uncertainty because of the difference between the phantom and the real human subject and also the morphological differences among individuals. In this study, personal voxel phantoms were created from magnetic resonance images of the necks of 24 adult volunteers (15 males and 9 females), and numerical simulations using these phantoms were performed to examine the variation in a conversion factor (131I kBq in the thyroid per µSv h-1) for a conventional NaI(Tl) survey meter among the individuals and also to confirm the suitability of reference Japanese voxel phantoms as a calibration standard for such measurements. As a result, it was found that the conversion factor obtained from the reference Japanese male (female) phantom was 1.29 (1.18) times larger than the average conversion factor for the male (female) subjects, suggesting that the conversion factors of the reference Japanese adult male and female phantoms would generally overestimate the 131I thyroidal contents and that the thyroid volume would be one of the factors influencing the conversion factor. This study also revealed a wide difference in the thyroid volume among individuals, which would be of concern when performing specific dose assessments for heavily exposed persons.

Second Primary Metachronous Malignancies Occurring in Oral Cavity of Young Adult-A Case Report.

The incidence of oral cancer in Japan is increasing. Interestingly, the number of young patients with oral cancer is also rising. A 19-year-old man with no history of smoking or drinking alcohol presented with a 20×15-mm elastic, hard, protruding mass with a white surface on the right-hand margin of the tongue. A biopsy resulted in a diagnosis of a well-differentiated squamous cell carcinoma of the tongue, for which a partial resection was subsequently performed. During regular follow-up, the patient demonstrated no clinical or imaging abnormalities until 4 years and 9 months later, when erosion was observed at the right palatoglossal arch. A malignant tumor of the right palatoglossal arch was diagnosed based on cytology and imaging findings, and total resection of the lesion performed. Histopathological examination of the resected lesion revealed a moderately differentiated squamous cell carcinoma. Epithelial dysplasia on the right-hand margin of the tongue was diagnosed 4 years and 9 months after the second surgery and was subsequently resected. The patient's condition has been favorable for 7 years since the diagnosis of the second cancer, with no noted recurrence. This case emphasizes the importance of follow-up after initial treatment, as even young people, who are likely to have to endure long-lasting consequences from treatment, can develop metachronous cancer in the oral cavity.

A pathological perspective to painful inguinal hernia: Report of two cases.

INTRODUCTION: Preoperative inguinal pain (painful inguinal hernia) is a well-known factor associated with chronic postoperative inguinal pain (CPIP). However, it remains unclear what preventive measures should be taken in such patients. CASE PRESENTATION: We report two patients with painful inguinal hernia who underwent pragmatic ilioinguinal nerve neurectomy during open anterior repair. The nerve was compressed by bulky spermatic cord lipoma in case 1 and by the hernia sac presenting over a few decades in case 2. Hematoxylin and eosin staining of the resected nerves revealed mucoid degeneration. Toluidine blue staining of resin-embedded nerve sections demonstrated that fully-myelinated axons had significantly decreased in case 1 and almost disappeared in case 2, indicating the development of massive demyelination of the ilioinguinal nerve in both cases. DISCUSSION: In cases where the injured nerve is left in situ, CPIP may occur since demyelinating neuropathy sometimes becomes irreversible. CONCLUSION: Planned nerve resection via open anterior inguinal hernia repair may be an option to prevent CPIP in patients with painful inguinal hernia.

Rivaroxaban attenuates cardiac hypertrophy by inhibiting protease-activated receptor-2 signaling in renin-overexpressing hypertensive mice.

Rivaroxaban (Riv), a direct factor Xa (FXa) inhibitor, exerts anti-inflammatory effects in addition to anticoagulation. However, its role in cardiovascular remodeling is largely unknown. We tested the hypothesis that Riv attenuates the progression of cardiac hypertrophy and fibrosis induced by continuous activation of the renin-angiotensin system (RAS) in renin-overexpressing hypertensive transgenic (Ren-Tg) mice. We treated 12-week-old male Ren-Tg and wild-type (WT) mice with a diet containing Riv (12 mg/kg/day) or a regular diet for 4 weeks. After this, FXa in plasma significantly increased in Ren-Tg mice compared with WT mice, and Riv inhibited this increase. Left ventricular wall thickness (LVWT) and the area of cardiac fibrosis evaluated by Masson's trichrome staining were greater in Ren-Tg mice than in WT mice, and Riv decreased them. Cardiac expression levels of the protease-activated receptor (PAR)-2, tumor necrosis factor-α, transforming growth factor (TGF)-ß1, and collagen type 3 α1 (COL3A1) genes were all greater in Ren-Tg mice than in WT mice, and Riv attenuated these increases. To investigate the possible involvement of PAR-2, we treated Ren-Tg mice with a continuous subcutaneous infusion of 10 µg/kg/day of the PAR-2 antagonist FSLLRY for 4 weeks. FSLLRY significantly decreased LVWT and cardiac expression of PAR-2, TGF-ß1, and COL3A1. In isolated cardiac fibroblasts (CFs), Riv or FSLLRY pretreatment inhibited the FXa-induced increase in the phosphorylation of extracellular signal-regulated kinases. In addition, Riv or FSLLRY inhibited FXa-stimulated wound closure in CFs. Riv exerts a protective effect against cardiac hypertrophy and fibrosis development induced by continuous activation of the RAS, partly by inhibiting PAR-2.

Mesh shrinkage is the potential pathogenesis of chronic somatic pain following transabdominal preperitoneal repair: Report of two cases.

Although mesh-related pain, termed "somatic pain," is a well-known pain syndrome following Lichtenstein repair, few reports are available on somatic pain following transabdominal preperitoneal repair (TAPP) and its pathogenesis remains unclear. We report on two patients with refractory somatic chronic pain following TAPP. In the present two cases, both mesh fixation with rigid permanent metal tackers and mesh shrinkage resulting in contractile forces on the groin musculature could be considered as potential mechanisms in the etiology of chronic somatic pain following TAPP. The lessons learned from these two cases are: (a) mesh shrinkage resulting in contractile forces on the groin musculature could be considered as potential mechanisms in the etiology of chronic somatic pain following TAPP; (b) partial mesh removal would be an effective alternative to total mesh removal in those patients for remedial surgery.

Three-Dimensional Measurements of Pharyngeal Airway in Patients with Unilateral Cleft Lip and Palate.

The aim of this study was to investigate 3-dimensional (3D) airway volume in patients with unilateral cleft lip and palate (UCLP) using computed tomography (CT). The study population comprised 15 UCLP patients (UCLP group) scheduled to receive alveolar bone grafts and 15 with impacted teeth (control group). The clinical requirements for a CT scan were met in both groups. Measurements were recorded from 3D reconstructions of Digital Imaging and Communications in Medicine data obtained from the CT images. Airway volume, cross-sectional area, and linear and angular measurements were recorded. Airway volume and cross-sectional area showed no significant difference between the two groups. The narrowest section of the airway in the UCLP group was tighter than that in the control group, however (p=0.017). The results of this study suggest that this difference in the measurements of the narrowest section of the airway is involved in the particular maxillofacial morphology found in UCLP patients.

Utilization of desktop 3D printer-fabricated "Cost-Effective" 3D models in orthognathic surgery.

BACKGROUND: In daily practice, three-dimensional patient-specific jawbone models (3D models) are a useful tool in surgical planning and simulation, resident training, patient education, and communication between the physicians in charge. The progressive improvements of the hardware and software have made it easy to obtain 3D models. Recently, in the field of oral and maxillofacial surgery, there are many reports on the benefits of 3D models. We introduced a desktop 3D printer in our department, and after a prolonged struggle, we successfully constructed an environment for the "in-house" fabrication of the previously outsourced 3D models that were initially outsourced. Through various efforts, it is now possible to supply inexpensive 3D models stably, and thus ensure safety and precision in surgeries. We report the cases in which inexpensive 3D models were used for orthodontic surgical simulation and discuss the surgical outcomes. REVIEW: We explained the specific CT scanning considerations for 3D printing, 3D printing failures, and how to deal with them. We also used 3D models fabricated in our system to determine the contribution to the surgery. Based on the surgical outcomes of the two operators, we compared the operating time and the amount of bleeding for 25 patients who underwent surgery using a 3D model in preoperative simulations and 20 patients without using a 3D model. There was a statistically significant difference in the operating time between the two groups. CONCLUSIONS: In this article, we present, with surgical examples, our in-house practice of 3D simulation at low costs, the reality of 3D model fabrication, problems to be resolved, and some future prospects.

Blockade of PAR-1 Signaling Attenuates Cardiac Hypertrophy and Fibrosis in Renin-Overexpressing Hypertensive Mice.

Background Although PAR-1 (protease-activated receptor-1) exerts important functions in the pathophysiology of the cardiovascular system, the role of PAR-1 signaling in heart failure development remains largely unknown. We tested the hypothesis that PAR-1 signaling inhibition has protective effects on the progression of cardiac remodeling induced by chronic renin-angiotensin system activation using renin-overexpressing hypertensive (Ren-Tg) mice. Methods and Results We treated 12- to 16-week-old male wild-type (WT) mice and Ren-Tg mice with continuous subcutaneous infusion of the PAR-1 antagonist SCH79797 or vehicle for 4 weeks. The thicknesses of interventricular septum and the left ventricular posterior wall were greater in Ren-Tg mice than in WT mice, and SCH79797 treatment significantly decreased these thicknesses in Ren-Tg mice. The cardiac fibrosis area and monocyte/macrophage deposition were greater in Ren-Tg mice than in WT mice, and both conditions were attenuated by SCH79797 treatment. Cardiac mRNA expression levels of PAR-1, TNF-α (tumor necrosis factor-α), TGF-ß1 (transforming growth factor-ß1), and COL3A1 (collagen type 3 α1 chain) and the ratio of ß-myosin heavy chain (ß-MHC) to α-MHC were all greater in Ren-Tg mice than in WT mice; SCH79797 treatment attenuated these increases in Ren-Tg mice. Prothrombin fragment 1+2 concentration and factor Xa in plasma were greater in Ren-Tg mice than in WT mice, and both conditions were unaffected by SCH79797 treatment. In isolated cardiac fibroblasts, both thrombin and factor Xa enhanced ERK1/2 (extracellular signal-regulated kinase 1/2) phosphorylation, and SCH79797 pretreatment abolished this enhancement. Furthermore, gene expression of PAR-1, TGF-ß1, and COL3A1 were enhanced by factor Xa, and all were inhibited by SCH79797. Conclusions The results indicate that PAR-1 signaling is involved in cardiac remodeling induced by renin-angiotensin system activation, which may provide a novel therapeutic target for heart failure.

Investigation of Surgical Site Infections and Bacteria Detected Following Neck Dissection in Patients with Oral Cancer.

During dissection for oral cancer, there is a high probability of bacteria indigenous to the oral cavity migrating to the surgical field in the neck due to the opening of new pathways of communication with the oral cavity. The risk of postoperative surgical site infection (SSI) in such patients is high due to malnutrition arising from perioperative eating disorders and dysphagia. Neck infections after neck dissection in oral cancer patients were investigated to elucidate the development of SSIs and their relationship with the results of bacterial culture.A total of 86 patients with oral squamous cell carcinoma who underwent neck dissection between January 2012 and December 2016 were enrolled. Ten factors were selected for investigation: (1) sex; (2) age; (3) primary site; (4) type of dissection; (5) whether or not there was a new pathway of communication between the oral cavity and the neck; (6) operative time; (7) blood loss; (8) number of drainage days; (9) amount of drainage at the time of drain removal; and (10) whether or not there was an SSI. Bacteria isolated from the catheter tip on drain removal were also investigated. Significant differences were observed between patients with and without SSIs (p-0.010) according to the presence of a new pathway of communication between the oral cavity and the neck (p-0.004); operative time (p-0.007); number of drainage days (p-0.029); or the amount of drainage at the time of drain removal. The present results indicate that selecting antibiotics appropriate to each patient and administering perioperative oral care are important in preventing SSIs.

Is the remnant pancreas still working over a year after surgery in patients undergoing pancreaticoduodenectomy with reconstruction by pancreaticogastrostomy?

BACKGROUND: Pancreaticogastrostomy (PG) has been widely used as an alternative to pancreatojejunostomy (PJ) in patients undergoing pancreaticoduodenectomy (PD), but its long-term exocrine function remains unclear. The present study aimed to measure the secretion of pancreatic α-amylase (p-AMY) into the gastric cavity in patients who underwent PG reconstruction after PD over 1 year after surgery and to evaluate the relationship between gastric p-AMY level and clinically available indirect tests. METHODS: Clinical records of 39 patients who underwent PG reconstruction after PD were reviewed. Pancreatic exocrine function was evaluated over 1 year after surgery using the following methods: 1) Measurement of p-AMY level in gastric fluids (gastric p-AMY level) during routine gastrointestinal endoscopy, 2) Qualitative faecal fat determination by Sudan III staining on faeces and 3) Pancreatic function diagnostic (PFD) test using oral administration of N-benzoyl-l-tyrosyl-p-aminobenzoic acid. RESULTS: Gastric p-AMY level was detectable in 31 of 39 patients (79%), and 12 patients (30.8%) had steatorrhea over a year after surgery. Patients with steatorrhea had significantly lower gastric p-AMY level, larger diameter of remnant main pancreatic duct (MPD) and larger pancreatic duct to parenchymal thickness ratio than those without steatorrhea (84 IU/L vs 7979 IU/L, respectively; P < 0.001, 5.3 mm vs 3.2 mm, respectively; P = 0.001, and 0.38 vs 0.23, respectively; P = 0.007). Receiver operating characteristic analysis showed that the cut-off value of the diameter of the remnant MPD to predict steatorrhea was 3.5 mm (sensitivity, 92.3%; specificity, 70.4%). PFD test was not associated with any clinical data. CONCLUSIONS: Pancreatic enzyme was detected in 79% of patients having PG reconstruction. Diameter of remnant MPD >3.5 mm and pancreatic parenchymal atrophy may be surrogate markers of postoperative exocrine insufficiency following PD.

Surgical Orthodontic Treatment Involving Mandibular Premolar Extraction in Patient with Mandibular Retrusion Associated with Temporomandibular Joint Osteoarthritis.

Here, we report retention following surgical orthodontic treatment in a patient with vertical maxillary excess associated with temporomandibular joint osteoarthritis (TMJOA) and marked mandibular retrusion. The patient was a man aged 20 years 10 months who presented with the chief complaint of maxillary protrusion. The facial profile was of the convex type due to marked mandibular retrusion. In addition, the patient had a gummy smile. Intraoral findings revealed a Class II molar relation, +11 mm overjet, and 0 mm overbite. Mandibular dentition arch length discrepancy showed crowding of -2 mm, and the maxillary dentition showed a spaced arch of +5 mm. Panoramic radiographs confirmed flattening of the condylar head and proliferation of the bone margin. Cephalometric analysis of the skeletal pattern revealed that, horizontally, the maxilla was anterior and the mandible posterior; vertically, a dolichofacial pattern was noted. The anterior maxillary tooth axis was standard, but the anterior mandibular tooth axis showed labial inclination. Based on these findings, skeletal maxillary protrusion associated with TMJOA was diagnosed. Surgical orthodontic treatment comprised bilateral mandibular first premolar extraction with two-jaw surgery and genioplasty. Orthodontic treatment was performed with a multibracket system using a 0.22-slot pre-adjusted edgewise appliance. At 2 years and 11 months after initiation of treatment, the maxilla was transposed 6 mm upwards by orthognathic surgery and the mandible 17 mm anteriorly and 5 mm upwards by counterclockwise rotation. At 3 years and 10 months, the Pogonion was moved 6 mm anteriorly by genioplasty. At 4 years, orthodontic treatment was concluded on confirming satisfactory occlusion and improvement in facial features. At 2 years after completion of treatment, occlusion and the maxillofacial morphology remain stable, with almost no relapse. In addition, no temporomandibular joint disorder symptoms have occurred. Careful comprehensive follow-up observation will be continued.

Novel Electrocardiographic Criteria for the Diagnosis of Left Ventricular Hypertrophy in the Japanese General Population.

Although there are several diagnostic criteria for left ventricular hypertrophy (LVH), their sensitivity remains low. A recent study reported that the sum of the amplitude of the deepest S wave in any lead (SD) and the S wave in lead V4 (SV4) (SD + SV4) improved sensitivity compared with commonly used criteria. To test whether this new formula improves sensitivity in the Japanese general population, we analyzed 12-lead electrocardiograms for Japanese residents participating in the Iwaki Health Promotion Project (n = 866). Left ventricular mass was calculated by echocardiography, indicating that 156 (18%) of the study population had LVH. In receiver operating characteristic analyses, the sum of the R wave in limb lead Ι (RLΙ) and the S wave in V4 (SV4) (RLΙ + SV4) showed a higher area under the curve (AUC = 0.76) than the Sokolow-Lyon voltage criteria (0.61) and the SD + SV4 criteria (0.63), and almost the same AUC as the Cornell voltage criteria (0.74) and the Cornell product criteria (0.76). The validation study also showed similar results. The cutoff values of RLΙ + SV4 criteria were ≥1.6 mV in men and ≥1.4 mV in women with a sensitivity of 39% and a specificity of 89%, whereas the sensitivity and specificity calculated based on SD + SV4 criteria were 21% and 94%, respectively. Thus, the diagnostic criterion of RLΙ + SV4 seems to be more useful than the previous criteria for diagnosing LVH in the Japanese general population.

Rivaroxaban, a Direct Factor Xa Inhibitor, Ameliorates Hypertensive Renal Damage Through Inhibition of the Inflammatory Response Mediated by Protease-Activated Receptor Pathway.

Background An enhanced renin-angiotensin system causes hypertensive renal damage. Factor Xa not only functions in the coagulation cascade but also activates intracellular signaling through protease-activated receptors ( PAR ). We investigated the effects of rivaroxaban, a factor Xa inhibitor, on hypertensive renal damage in hypertensive mice overexpressing renin (Ren-TG). Methods and Results The 12- to 16-week-old Ren-TG and wild-type mice were orally administered with or without 6 or 12 mg/kg of rivaroxaban for 1 or 4 months. Plasma factor Xa was significantly increased in the Ren-TG compared with the wild-type mice and was reduced by 12 mg/kg of rivaroxaban ( P<0.05). Urinary albumin excretion (UAE) was higher in the nontreated 8-month-old Ren-TG than in the wild-type mice (69.6±29 versus 20.1±8.2 µg/day; P<0.01). Treatment with 12 mg/kg of rivaroxaban for 4 months decreased the UAE to 38.1±13.2 µg/day ( P<0.01). Moreover, rivaroxaban treatment attenuated histologic changes of glomerular hypertrophy, mesangial matrix expansion, effacement of the podocyte foot process, and thickened glomerular basement membrane in the Ren-TG. The renal expression of PAR -2 was increased in the Ren-TG, but was inhibited with rivaroxaban treatment. In vitro study using the human podocytes showed that the expressions of PAR -2 and inflammatory genes and nuclear factor--κB activation were induced by angiotensin II stimulation, but were inhibited by rivaroxaban. PAR -2 knockdown by small interfering RNA also attenuated the PAR -2-related inflammatory gene expressions. Conclusions These findings indicate that rivaroxaban exerts protective effects against angiotensin II-induced renal damage, partly through inhibition of the PAR -2 signaling-mediated inflammatory response.

Prognostic factors for maxillary sinus mucosal thickening following Le Fort I osteotomy: a retrospective analysis.

BACKGROUND: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. METHODS: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. RESULTS: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. CONCLUSIONS: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.