Endoscopic transcanal transtympanic myringoplasty vs. endoscopic transcanal tympanoplasty: 1-year follow-up study.

BACKGROUND: Endoscopic transcanal transtympanic myringoplasty (ETTM) is a relatively easier technique than endoscopic transcanal tympanoplasty (ETT) for repairing tympanic membrane perforations. No studies have compared the outcomes of these two procedures with tragal perichondrium after 1-year. Furthermore, there is no evidence-based stratification according to variations in perforation size in endoscopic ear surgery. Therefore, we compared the 1-year outcomes of ETTM and ETT stratified according to perforation size. METHODS: Patients who underwent ETT and ETTM to repair eardrum perforations with a tragal perichondrium graft were identified. Pure-tone audiometric tests and otoscopic examination were performed to assess hearing outcomes and perforation sizes both preoperatively and at least 1 year postoperatively. RESULTS: In total, 158 patients (159 ears) were included. ETT was performed on 83 ears, and ETTM was performed on 76 ears. The ETTM procedure time was 10-minutes shorter than that for ETT ( p < 0.001). Perforation size was significantly correlated with graft take-rate. For large perforations, the ETT success rate was significantly higher than that of ETTM (91.7% vs. 78.9%). Success rates for small-medium perforations were comparable for both methods ( p > 0.05). However, for medium perforations, the graft take-rate of ETT reached a plateau after 6 months, while that of ETTM gradually declined during the 12-month follow-up. Both groups had a comparable mean postoperative air-bone gap gain ( p = 0.666). CONCLUSION: ETTM is suitable for repairing small perforations, whereas ETT is preferred for large perforations. Both methods, and particularly ETTM, should be employed cautiously for medium perforations.

Effect of Structural Disorders on the Li Storage Capacity of Graphene Nanomaterials: A First-Principles Study.

We employed first-principles calculations to investigate the effect of structural disorders on the Li storage capacity of graphene nanomaterials. Our calculations first revealed that the Li storage capacity of a graphene monolayer does not necessarily increase with the size of a C vacancy created but is largely determined by the local geometry of the defect sites. Our electronic structure analysis further revealed that the enhanced Li storage capacity by the C vacancy defect is mainly attributed to the increased number of the unoccupied electronic density of states lying near the Fermi level, which can be substantially increased by raising the number of bond rotations within the vacancy sites. Furthermore, it was also found that the Li storage capacity of graphene can be effectively enhanced by increasing the degree of local ring disorders without the presence of any vacancy defect. The amorphous graphene structure was shown to possess a relatively higher Li storage capacity compared to pristine graphene, primarily owing to the presence of many nonhexagonal rings randomly distributed in the graphene lattice. These nonhexagonal rings can create many electron-deficient regions on the graphene surface to effectively accommodate more electrons from Li, thereby substantially enhancing the Li storage capacity of graphene nanomaterials.

Long-term results of palatal implantation for severe obstructive sleep apnea patients with prominent retropalatal collapse.

BACKGROUND: Most previous reports on palatal implantation for patients with severe obstructive sleep apnea have been anecdotal. Our objective in this study was to assess the long-term outcomes of palatal implantations from objective as well as subjective perspectives when applied to patients with severe obstructive sleep apnea and prominent retropalatal collapse. METHODS: This retrospective review was conducted in a single institution using subjective data (Epworth Sleepiness Scale and visual analog scales of snoring sounds and sleep quality) and objective data (respiratory disturbance index, minimum O2 saturation, sleep efficiency, and snoring index using a polysomnograph) before and after surgery. A total of ten patients were enrolled in this study. The median time between pre-operative sleep-related tests and the operation date was 1.0 months and the median time between operation date and post-operative sleep-related tests was 33.0 months. RESULTS: Significant improvements were observed in the visual analog scale scores of snoring (p = 0.004), visual analog scale scores of sleep quality (p = 0.005), and Epworth Sleepiness Scale (p = 0.012). Eight of the ten patients reported a reduction of at least 50% on the visual analog scale of snoring sounds, which was the criterion of subjective surgical success. We also observed significant improvements in the respiratory disturbance index (p = 0.009) and minimum O2 saturation (p = 0.033). Two of the ten patients presented a reduction in respiratory disturbance index of ≥50% and a subsequent respiratory disturbance index of <20, which were the criteria of objective surgical success. A percentage change in respiratory disturbance index was negatively associated with prominent retrolingual collapse and the length of the soft palate. CONCLUSION: Patients with severe obstructive sleep apnea and prominent retropalatal collapse may benefit from palatal implantation from a subjective perspective. Palatal implantation could be considered an alternate form of treatment for some cases of severe obstructive sleep apnea, due to the likelihood of improvement in clinical symptoms and the normalization of sleep quality.

A retrospective comparative study of endoscopic and microscopic Tympanoplasty.

BACKGROUND: This study compares endoscopic and microscopic tympanoplasty for the treatment of chronic otitis media (COM) without cholesteatoma. METHODS: This retrospective study included 153 ears (139 patients) treated surgically (endoscopic or microscopic tympanoplasty) for COM in the absence of cholesteatoma at our hospital between January 2008 and October 2015. The adoption of transcanal endoscopic ear surgery (TEES) or microscopic ear surgery (MES) was divided temporally (before and since 2014). Comparisons between these groups focused on the following: (I) surgical outcomes, including successful tympanic membrane healing and post-operative complications; (II) restoration of hearing; and (III) consumption of medical resources, including the duration of surgery and anesthesia. All patients had a follow-up period of at least 3 months after surgery. RESULTS: No statistically significant differences were observed between the two groups regarding surgical outcome or hearing restoration. TEES resulted in the successful healing of 96.2% of ear drums, whereas MES led to successful healing in 92% (p = 0.2826) of cases. The average hearing gains following surgery were 10.27 ± 6.4 and 12.43 ± 7.46 dB in TEES and MES, respectively. The consumption of medical resources in the TEES group was lower than that of the MES group (TEES versus MES) regarding the average operating time (87.8 ± 19.01 min (mins) versus 110.2 ± 17.0 (mins) (p <  0.0001)) and the mean duration of anesthesia ((for general anesthesia patients) (122.1 ± 21.25 mins versus 145.8 ± 16.88 mins) (p ≤  0.0001)). CONCLUSIONS: The results indicate that TEES can achieve surgical outcomes and hearing restoration comparable to those of MES. In addition, TEES appears to be associated with shorter surgical and anesthesia time, which makes it an ideal alternative for the management of COM without cholesteatoma. TRIAL REGISTRATION: This study was approved by the Institutional Review Board of the Cathay General Hospital. (CGHIRB No: CGH-P105012 ).

The anatomic applicability of transcanal endoscopic ear surgery in children.

OBJECTIVE: The feasibility of TEES in dealing with pediatric middle ear disease is still under investigation. The goal of this study was to compare anatomical dimensions of the EAC between children and adults, and to analyze the anatomic applicability of TEES in children. METHODS: Forty pediatric (18 years old and younger) and 20 adult patients who received TB-HRCT to evaluate middle ear conditions were enrolled from December 2010 to December 2015. Dimensions including the diameters of the EAC orifice, isthmus and tympanic membrane annulus, the length of EAC, the height of the middle ear, and the angle between tympanic membrane and EAC axis were determined according to the TB-HRCT data. RESULTS: The diameters of the EAC orifice and isthmus and length of EAC in the pediatric patients were slightly smaller than those in the adult patients. The anatomical dimensions of middle ear were similar in both groups. Simple regression analysis indicated that the diameters of the EAC orifice and isthmus and the length of the EAC were positively correlated with the age of the pediatric patients. In the pediatric patients, 67 ears (83.75%) had an EAC isthmus diameter larger than 4 mm and are sufficient with a 3-mm endoscope manipulation. CONCLUSION: TEES is applicable for most pediatric patients using an endoscope with a diameter of 3 mm or smaller. With an appropriate endoscope and instruments, TEES is a safe and effective alternative to treat pediatric middle ear disease.

Minimally traumatic stapes surgery for otosclerosis: Risk reduction of post-operative vertigo.

BACKGROUND: The author (Dr. Shiao) modified traditional stapes surgery (TSS) specifically for patients with otosclerosis. The proposed technique, referred to as minimally traumatic stapes surgery (MTSS), reduces the risk of subjective discomfort (i.e. vertigo and tinnitus) following surgery. This paper compares the effectiveness of MTSS with that of TSS. METHODS: The medical records of patients with otosclerosis after stapes surgery (TSS or MTSS) were analyzed. Outcome variables included post-operative vertigo, tinnitus, and hearing success. Multivariate logistic regression analysis was used to determine the correlation between surgical technique and outcome variables. RESULTS: TSS was performed in 23 otosclerosis ears and MTSS was performed in 33 otosclerosis ears. The risk of post-operative vertigo was significantly lower among patients that underwent MTSS (27%) than among those that underwent TSS (83%, p < 0.001). No differences in the incidence of tinnitus were observed between the two groups. Post-operative audiometric outcomes were also equivalent between the two groups. However, multivariate logistic regression analysis revealed a correlation between post-operative vertigo and surgical technique (p < 0.001). CONCLUSION: MTSS involves a lower risk of vertigo than does TSS. MTSS helps to prevent damage to the footplate, thereby reducing the risk of footplate floating. Therefore, MTSS provides a means to overcome some of the limitations associated with the narrow surgical field in Asian patients.

Increased risk of cholesteatoma among patients with allergic rhinitis: A nationwide investigation.

OBJECTIVES: No large population-based studies have reported on the risk of cholesteatoma developing after allergic rhinitis (AR). This study used a nationwide population-based claims database to investigate the hypothesis that AR may increase the risk of cholesteatoma. STUDY DESIGN: Retrospective cohort study. METHODS: Data from Taiwan's Longitudinal Health Insurance Database were analyzed to compile the following: 1) 15,953 patients newly diagnosed with AR between 1997 and 2000, and 2) a comparison cohort of 63,812 matched non-AR enrollees (with a ratio of 1 to 4). Each patient was followed for 10 years to identify cases in which cholesteatoma subsequently developed. The Kaplan-Meier method was used to determine the cholesteatoma-free survival rate, and the log-rank test was used to compare survival curves. Cox proportional hazard regressions were performed to compute adjusted hazard ratios (HRs). RESULTS: Among the 79,765 patients enrolled in this study, 45 (159,364 person-years) from the AR cohort and 88 (638,130 person-years) from the comparison cohort were diagnosed with cholesteatoma during the follow-up period (incidence rates 0.28 and 0.14 of 1,000 person-years, respectively). Patients with AR were more likely to develop cholesteatoma compared to those without AR (adjusted HR 1.57, 95% confidence interval = 1.05-2.34, P < 0.05). Patients with AR presented a significantly lower 10-year cholesteatoma-free survival rate than did those in the comparison group (log-rank, P < 0.001). CONCLUSION: This is the first study to demonstrate a link between AR and the development of cholesteatoma. We suggest that clinicians keep this association in mind and carefully investigate the possibility of development of cholesteatoma among patients with AR. LEVEL OF EVIDENCE: 3b. Laryngoscope, 128:547-553, 2018.

Association Between Middle Ear Cholesteatoma and Chronic Rhinosinusitis.

Importance: Chronic rhinosinusitis (CRS) can cause an obstruction of the tubal orifice and thereby compromise ventilation of the middle ear. The resulting negative pressure in the middle ear may, in turn, lead to the formation of an eardrum retraction pocket and subsequent acquired cholesteatoma. This study hypothesizes that CRS may increase the risk of cholesteatoma. Objective: To evaluate the risk of cholesteatoma in patients with CRS. Design, Setting, and Participants: This study used a nationwide, population-based claims database to test the hypothesis that CRS may increase the risk of cholesteatoma. The Longitudinal Health Insurance Database of Taiwan was used to compile data from (1) 12 670 patients with newly diagnosed CRS between January 1, 1997, and December 31, 2002, and (2) a comparison cohort of 63 350 matched individuals without CRS, resulting in a CRS vs control ratio of 1:5. Data analysis was performed from June 1 to October 27, 2015. Each patient was followed up for 8 years to identify those in whom cholesteatoma subsequently developed. The Kaplan-Meier method was used to determine the cholesteatoma-free survival rate, and the log-rank test was used to compare survival curves. Cox proportional hazards regression models were used to compute the 8-year hazard ratios (HRs). Main Outcomes and Measures: Diagnosis of cholesteatoma. Results: Among the 76 020 patients enrolled in this study, 35 220 (46.3%) were female; mean (SD) age was 27.57 (22.03) years. A total of 209 patients developed cholesteatoma, 66 (101 084 person-years) individuals from the CRS cohort and 143 (506 540 person-years) from the comparison cohort were diagnosed with cholesteatoma during the 8-year follow-up period. The incidence of cholesteatoma per 1000 person-years was more than twice as high among patients with CRS (0.65; 95% CI, 0.50-0.81 person-years) than among those without CRS (0.28; 95% CI, 0.24-0.33). The absolute difference in the incidence density between CRS and non-CRS group was 0.37 (95% CI, 0.21-0.53) per 1000 patient-years. After adjusting for potential confounders, patients with CRS had a 69% increased risk of cholesteatoma within 8 years, compared with those without CRS (HR, 1.69; 95% CI, 1.23-2.32). Patients with CRS presented a significantly lower 8-year cholesteatoma-free survival rate than did those in the comparison group. The absolute difference in the 8-year cholesteatoma-free survival rate between the CRS and non-CRS groups was 0.0029 (95% CI, 0.0016-0.0043). Conclusions and Relevance: This is the first large-scale study, to date, to demonstrate a prospective link between CRS and the subsequent development of cholesteatoma within a follow-up period of 8 years. The purpose of the study was to draw attention to the possibility of development of cholesteatoma among patients with CRS. Because that possibility exists, clinicians should keep this association in mind as well as the importance of a thorough head and neck examination.

A comparative first-principles study of the structural and electronic properties of the liquid Li-Si and Li-Ge alloys.

We have performed a comparative first-principles study on the structural and electronic properties of the liquid Li1-xSix and Li1-xGex alloys over a range of composition from x = 0.09 to 0.50. Our calculations showed that Si and Ge atoms can exhibit very distinct local bonding characteristics as they were alloyed with the Li atoms in the liquid state, where Si atoms tended to form a variety of covalent bonding configurations while Ge atoms predominantly appeared as the isolated anions in the liquid alloys. These differences in bonding characteristics were reflected in their electronic density of states, in which the liquid Li1-xGex alloys have a lower degree of s-p hybridization with narrower distributions of the 3s and 3p states than the liquid Li1-xSix alloys. Our calculations also showed that the optical conductivities of these two liquid alloys can undergo a transition from the Drude-like metallic nature to the semiconductor-like character as the Si/Ge content increases from 0.09 to 0.22. However, as the Si/Ge content further increases to 0.50, the liquid Li1-xGex alloys may transit to exhibit the Drude-like metallic nature, while the liquid Li1-xSix alloys can still hold the semiconductor-like character. Moreover, our calculations revealed that the dc conductivities of these liquid alloys are predominantly determined by the number of total electronic states at the Fermi level. As the liquid Li1-xSix alloys are within the composition range between 0.20 and 0.50, the increment of the states at the Fermi level with increasing the Si content is nearly identical to the amount of the Li states decreased, leading to an almost unchanged number of total electronic states at the Fermi level. However, since Ge atoms do not favor forming covalent bonding in the liquid alloys to keep the Fermi level at a minimum of the density of states, the liquid Li1-xGex alloys would have more electronic states at the Fermi level and thereby higher dc conductivities than the liquid Li1-xSix alloys within the same composition range.

Risk of sudden sensorineural hearing loss in stroke patients: A 5-year nationwide investigation of 44,460 patients.

Poststroke sudden sensorineural hearing loss (SSNHL) can hinder communication between patients and healthcare professionals, thereby restricting participation in rehabilitation programs and limiting improvements in physical performance. However, the relationship between stroke and SSNHL remains unclear. This study employed a nationwide population-based dataset to investigate the relationship between stroke and SSNHL.The Taiwan Longitudinal Health Insurance Database was used to compile data from 11,115 stroke patients and a comparison cohort of 33,345 matched nonstroke enrollees. Each patient was followed for 5 years to identify new-onset SSNHL. Stratified Cox proportional-hazard regression analysis was used to examine the association of stroke with subsequent SSNHL.Among the 44,460 patients, 66 patients (55,378 person-years) from the stroke cohort and 105 patients (166,586 person-years) from the comparison cohort were diagnosed with SSNHL. The incidence of SSNHL was approximately twice as high among stroke patients than among nonstroke patients (1.19 and 0.63/1000 person-years, respectively). Stroke patients had a 71% increased risk of SSNHL, compared with nonstroke patients (adjusted hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.24-2.36). We also observed a remarkable increase in risk of SSNHL in stroke patients within 1-year of follow-up (adjusted HR 5.65, 95% CI 3.07-10.41) or under steroid therapy during hospitalization (adjusted HR 5.14, 95% CI 2.08-12.75).Patients with stroke had a higher risk of subsequent SSNHL compared with patients without stroke. In particular, stroke patients within 1-year follow-up and those undergoing steroid therapy during hospitalization should be treated with the utmost caution, considering that the risk of SSNHL increases by more than 5-fold.

Depression and cholesteatoma: Preliminary findings from a nationwide population-based retrospective cohort study.

OBJECTIVE: To estimate the risk of developing depressive disorder (DD) following diagnosis with cholesteatoma. METHODS: In the study, we analyzed data from the Longitudinal Health Insurance Database of Taiwan. A total of 599 patients newly diagnosed with cholesteatoma between 1997 and 2007 were included with a comparison cohort of 2995 matched non-cholesteatoma enrollees. Each patient was followed for 3 years to identify the subsequent development of DD. Cox proportional hazard regression analysis was performed to compute adjusted 3-year hazard ratios. RESULTS: The incidence of DD per thousand person-years was approximately twice as high among patients with cholesteatoma (11.32) as among those without cholesteatoma (5.85). After adjusting for potential confounders, patients with cholesteatoma were 1.99 times (95% CI=1.18-3.34, P=0.010) more likely to suffer from DD within 3 years compared to those without cholesteatoma. CONCLUSIONS: This is the first study to demonstrate a link between cholesteatoma and subsequent DD within a three-year followup. We suggest that clinicians keep this critical but neglected issue in mind and carefully investigate the possibility of subsequent psychological problems among cholesteatoma patients.

First-principles study of the structural and dynamic properties of the liquid and amorphous Li-Si alloys.

We have performed density functional theory calculations and ab initio molecular dynamics to investigate the structures and dynamic properties of the liquid and amorphous LixSi alloys over a range of composition from x = 1.0 - 4.8. Our results show that Si atoms can form a variety of covalently bonded polyanions with diverse local bonding structures in the liquid alloys. Like in c-LiSi, Si atoms can form a continuous bond network in liquid Li1.0Si at 1050 K, while it gradually disintegrates into many smaller Si polyanions as the Li content increases in the alloys. The average sizes of Si polyanions in these liquid alloys were found to be relatively larger than those in their crystalline counterparts, which can even persist in the highly lithiated Li4.81Si alloy at 1500 K. Our results also show that amorphous LixSi alloys have similar local bonding structures but a largely increased short-range order as compared to their liquid counterparts. The differences between the average coordination number of each atomic pair in amorphous solids and that in the liquids are less than 1.1. Furthermore, our calculations reveal that Li and Si atoms can exhibit very distinct dynamic behaviors in the liquids and their diffusivities appear to be largely dependent on the chemical composition of the alloys. The diffusivity of Li was found to increase with the Li content in the alloys primarily because of the reduced interactions between Li and Si atoms, while the Si diffusivity also increases due to the gradual disintegration of the strongly interconnected Si bond network. The diffusivity of Li in amorphous LixSi was predicted to lie in the range between 10(-7) and 10(-9) cm(2)/s at 300 K, which is more than 20-fold larger than that of Si over the composition range considered. Our calculations further show that the diffusivities of both Li and Si can increase by two orders of magnitude as x increases from 1.0 to 3.57 in amorphous LixSi, indicating a more profound dependence on the alloy composition than those in the liquid state.

Multidimensional staging system for pediatric acquired cholesteatoma: A 30-year verification data.

OBJECTIVE: This article presents a points-based prognostic prediction model for pediatric acquired cholesteatoma, incorporating the multidimensional factors that contribute to surgical failure. METHODS: This study included 132 ears with acquired cholesteatoma from 128 children (≤18 years) identified between 1982 and 2012. Each case was scored for the extent of the cholesteatoma, history of grommet insertion, age of the patient, ossicular destruction, and otorrhea. The patients were classified as stage I, II, or III. We compared differences between stages regarding the cumulative rates of recidivism and linear trends in these rates. RESULTS: Among stage I cases, the rate of cumulative recidivism was 0%; however, among stage 2 cases, this increased with time, eventually leveling off at 15.7% after 18 years of follow-up. The same was observed among stage III cases, which leveled off at 34.1% after 17 years of follow-up. In the second half of the cohort and the entire cohort, differences in the cumulative recidivism curves reached statistical significance, as did the linear trends (all p<0.05). CONCLUSIONS: Our findings demonstrate the efficacy of the proposed multidimensional staging system in linking the severity of cholesteatoma to outcomes, thereby enabling the stratification of patients according to prognosis in order to identify children at risk of recidivism.

Acid reflux and head and neck cancer risk: A nationwide registry over 13 years.

OBJECTIVE: Gastro-esophageal reflux disease (GERD) is a highly prevalent disorder; however, important questions remain regarding the link between GERD and extra-esophageal cancers. This nationwide cohort study investigated the risk of developing head and neck cancers (HNCs) among patients with GERD. METHODS: Newly diagnosed GERD patients aged ≥20 years without antecedent cancer were included. Case data were obtained from the National Health Insurance Research Database covering period from 1998 to 2010. We compared the standardized incidence ratios (SIRs) of cancer among GERD patients with those of the general population. RESULTS: A total of 98 cancers were identified among the 39,845 GERD patients in the study, representing 128,361 person-years. The SIR for all cases of cancer was 1.59 (95% CI 1.29-1.93). GERD patients exhibited significantly higher SIRs for oropharyngeal (SIR 3.58, 95% CI 1.85-6.25) and hypopharyngeal (SIR 3.96, 95% CI 2.35-6.26) cancers. Male patients had a significantly higher risk of HNCs (SIR 1.70, 95% CI 1.36-2.10), particularly oropharyngeal (SIR 4.01, 95% CI 2.00-7.17) and hypopharyngeal (SIR 3.91, 95% CI 2.28-6.26) cancers. Following adjustment for age and co-morbidities, the hazard ratio was 9.06 (95% CI 4.70-17.44) for males compared to females. CONCLUSION: There may be a potential association between GERD and risk of HNCs, which however merits further studies to confirm the causal relationship. Our observations indicate a need for careful extra-esophageal examination of patients with acid reflux. Our findings also underline the importance of raising awareness among clinicians regarding the possibility of concurrent HNCs in GERD patients with refractory laryngo-pharyngeal symptoms.

Updates and knowledge gaps in cholesteatoma research.

The existence of acquired cholesteatoma has been recognized for more than three centuries; however, the nature of the disorder has yet to be determined. Without timely detection and intervention, cholesteatomas can become dangerously large and invade intratemporal structures, resulting in numerous intra- and extracranial complications. Due to its aggressive growth, invasive nature, and the potentially fatal consequences of intracranial complications, acquired cholesteatoma remains a cause of morbidity and death for those who lack access to advanced medical care. Currently, no viable nonsurgical therapies are available. Developing an effective management strategy for this disorder will require a comprehensive understanding of past progress and recent advances. This paper presents a brief review of background issues related to acquired middle ear cholesteatoma and deals with practical considerations regarding the history and etymology of the disorder. We also consider issues related to the classification, epidemiology, histopathology, clinical presentation, and complications of acquired cholesteatoma and examine current diagnosis and management strategies in detail.

Investigation of prognostic factors for post-traumatic olfactory dysfunction.

BACKGROUND: Post-traumatic olfactory dysfunction is common but has a poor prognosis. The purpose of this study was to analyze the effect of clinical features on improvements in post-traumatic olfactory dysfunction. METHODS: From 2007 to 2013, patients with post-traumatic olfactory dysfunction were enrolled. Olfactory function was assessed using the Sniffin' Sticks test at the first and final visits. Olfactory improvement was defined as a change in olfactory state to an improved level. Variables with a potential effect on improvements in olfactory dysfunction, including age, sex, time from trauma to first visit, initial olfactory function, observation time, and olfactory bulb integrity, were entered into logistic regression analysis. RESULTS: In total, 107 patients were included, with a mean age of 40 years. The mean follow-up period was 9.4 months. Eighteen patients (16.8%) had improvements with regard to olfactory function. No clinical factors were found to influence olfactory recovery in univariate and multivariate analyses (all p > 0.05). In addition, there were no differences in clinical features between the patients with and without olfactory recovery (all p > 0.05). CONCLUSION: No significantly favorable prognostic factors for post-traumatic olfactory recovery were identified, reflecting, to some extent, the poor prognosis of post-traumatic olfactory damage. The results of this study provide useful information that clinical physicians can use when counseling patients with post-traumatic olfactory disorder regarding the prognosis, observation choice, and possible treatment strategy.