Identification of dental implant systems from low-quality and distorted dental radiographs using AI trained on a large multi-center dataset.

Most artificial intelligence (AI) studies have attempted to identify dental implant systems (DISs) while excluding low-quality and distorted dental radiographs, limiting their actual clinical use. This study aimed to evaluate the effectiveness of an AI model, trained on a large and multi-center dataset, in identifying different types of DIS in low-quality and distorted dental radiographs. Based on the fine-tuned pre-trained ResNet-50 algorithm, 156,965 panoramic and periapical radiological images were used as training and validation datasets, and 530 low-quality and distorted images of four types (including those not perpendicular to the axis of the fixture, radiation overexposure, cut off the apex of the fixture, and containing foreign bodies) were used as test datasets. Moreover, the accuracy performance of low-quality and distorted DIS classification was compared using AI and five periodontists. Based on a test dataset, the performance evaluation of the AI model achieved accuracy, precision, recall, and F1 score metrics of 95.05%, 95.91%, 92.49%, and 94.17%, respectively. However, five periodontists performed the classification of nine types of DISs based on four different types of low-quality and distorted radiographs, achieving a mean overall accuracy of 37.2 ± 29.0%. Within the limitations of this study, AI demonstrated superior accuracy in identifying DIS from low-quality or distorted radiographs, outperforming dental professionals in classification tasks. However, for actual clinical application of AI, extensive standardization research on low-quality and distorted radiographic images is essential.

Auditory Brainstem Response Data Preprocessing Method for the Automatic Classification of Hearing Loss Patients.

Auditory brainstem response (ABR) is the response of the brain stem through the auditory nerve. The ABR test is a method of testing for loss of hearing through electrical signals. Basically, the test is conducted on patients such as the elderly, the disabled, and infants who have difficulty in communication. This test has the advantage of being able to determine the presence or absence of objective hearing loss by brain stem reactions only, without any communication. This paper proposes the image preprocessing process required to construct an efficient graph image data set for deep learning models using auditory brainstem response data. To improve the performance of the deep learning model, we standardized the ABR image data measured on various devices with different forms. In addition, we applied the VGG16 model, a CNN-based deep learning network model developed by a research team at the University of Oxford, using preprocessed ABR data to classify the presence or absence of hearing loss and analyzed the accuracy of the proposed method. This experimental test was performed using 10,000 preprocessed data, and the model was tested with various weights to verify classification learning. Based on the learning results, we believe it is possible to help set the criteria for preprocessing and the learning process in medical graph data, including ABR graph data.

Unique inverse association between allergic rhinitis and periodontitis: a nationwide population-based study.

The increase in fine dust levels in the atmosphere has been associated with a growth in the incidence of environmental diseases, including allergic rhinitis (AR). Nasal obstruction caused by AR can impact the conditions in the oral cavity. The aim of this study was to determine the association between AR and periodontitis in the Republic of Korea. This study was based on data from the Seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-1, 2016), which was conducted by the Korea Centers for Disease Control and Prevention. The study included 6129 adults older than 19 years. Sociodemographic information and medical variables including history of treatment of periodontitis (HTP) reflecting diagnosis of periodontitis and diagnosis of diseases such as AR were extracted from the data. HTP and AR were reported for 22.81 ± 0.84% (weighted percentage ± standard error) and 15.32 ± 0.63% of the studied population, respectively. A diagnosis of AR was reported for 11.07 ± 1.28% of those with HTP and for 17.55 ± 1.84% of those without HTP. From these, it was inferred that the prevalence of HTP was 1.536-fold higher in the non-AR group than in their counterparts with AR. Significant association was found between AR and HTP among those aged ≤ 64 years and the odds ratio (OR) of AR group for HTP was 0.62 (95% confidence interval:0.44-0.87; P = 0.0057). From this result, it can be inferred that patients diagnosed AR have lower risk of periodontitis.

Effect of photodynamic therapy according to differences in photosensitizers on Staphylococcus aureus biofilm on titanium.

PURPOSE: This study aimed to evaluate the antimicrobial effect of photodynamic therapy (PDT) against Staphylococcus aureus biofilm on a titanium surface and to compare the differences in the effect of PDT using toluidine blue O (TBO) and methylene blue (MB) as a photosensitizer. METHODS: The bacterial strain S. aureus ATCC 25,923 was used. Sandblasted and acid-etched (SLA) disks were divided into the following six groups: phosphate buffer saline (PBS), TBO, MB, PBS with laser (PBS + L), TBO with laser (TBO + L), and MB with laser (MB + L). The laser group samples were irradiated by a cold diode laser for 60 s. After treatment, the number of surviving bacteria was calculated by counting the colony-forming units (CFUs) and confocal laser scanning microscopy (CLSM) was applied to observe the bacteria on the disk surface. RESULTS: The TBO + L and MB + L groups showed significantly lower CFU/ml than the other groups (p < 0.01). The TBO + L group showed significantly lower CFU/ml than the MB + L group (p = 0.032). There was no significant difference between the PBS, TBO, MB, and PBS + L groups. Within the limitations of this in vitro study, PDT with TBO and MB can effectively reduce S. aureus biofilm on SLA titanium surfaces. TBO is more effective than MB as a photosensitizer. PDT with TBO may be applied to the treatment of peri­implant disease in the future.

Temporal changes of periodontal tissue pathology in a periodontitis animal model.

PURPOSE: This study aimed to characterize the early stages of periodontal disease and determine the optimal period for its evaluation in a mouse model. The association between the duration of ligation and its effect on the dentogingival area in mice was evaluated using micro-computed tomography (CT) and histological analysis. METHODS: Ninety mice were allocated to an untreated control group or a ligation group in which periodontitis was induced by a 6-0 silk ligation around the left second maxillary molar. Mice were sacrificed at 1, 2, 3, 4, 5, 8, 11, and 14 days after ligature placement. Alveolar bone destruction was evaluated using micro-CT. Histological analysis was performed to assess the immune-inflammatory processes in the periodontal tissue. RESULTS: No significant difference in alveolar bone loss was found compared to the control group until day 3 after ligature placement, and a gradual increase in alveolar bone loss was observed from 4 to 8 days following ligature placement. No significant between-group differences were observed after 8 days. The histological analysis demonstrated that the inflammatory response was evident from day 4. CONCLUSIONS: Our findings in a mouse model provide experimental evidence that ligature-induced periodontitis models offer a consistent progression of disease with marginal attachment down-growth, inflammatory infiltration, and alveolar bone loss.

Long-term effect of implant-abutment connection type on marginal bone loss and survival of dental implants.

PURPOSE: This study aimed to compare the long-term survival rate and peri-implant marginal bone loss between different types of dental implant-abutment connections. METHODS: Implants with external or internal abutment connections, which were fitted at Gangneung-Wonju National University Dental Hospital from November 2011 to December 2015 and followed up for >5 years, were retrospectively investigated. Cumulative survival rates were evaluated for >5 years, and peri-implant marginal bone loss was evaluated at 1- and 5-year follow-up examinations after functional loading. RESULTS: The 8-year cumulative survival rates were 93.3% and 90.7% in the external and internal connection types, respectively (P=0.353). The mean values of marginal bone loss were 1.23 mm (external) and 0.72 mm (internal) (P<0.001) after 1 year of loading, and 1.20 mm and 1.00 mm for external and internal abutment connections, respectively (P=0.137) after 5 years. Implant length (longer, P=0.018), smoking status (heavy, P=0.001), and prosthetic type (bridge, P=0.004) were associated with significantly greater marginal bone loss, and the use of screw-cement-retained prosthesis was significantly associated (P=0.027) with less marginal bone loss. CONCLUSIONS: There was no significant difference in the cumulative survival rate between implants with external and internal abutment connections. After 1 year of loading, marginal bone loss was greater around the implants with an external abutment connection. However, no significant difference between the external and internal connection groups was found after 5 years. Both types of abutment connections are viable treatment options for the reconstruction of partially edentulous ridges.

Susceptibility to Postoperative Changes in Music Appreciation in Elderly Cochlear Implant Recipients.

With the rise in life expectancy and the consequent increase in the elderly population, the use of cochlear implants (CI) in elderly patients with hearing loss is also increasing. The aim of this study was to investigate whether music appreciation in elderly CI users differs from that of non-elderly users. Forty-nine adult CI recipients participated in the study, and the Korean version of the Music Background Questionnaire was utilized preoperatively and postoperatively to evaluate music appreciation. The changes between the preoperative and postoperative values were compared after categorizing the participants into a non-elderly group (<65 years; n = 31) and an elderly group (≥65 years; n = 18). When compared to the non-elderly group, the elderly individuals exhibited a significant decrease in music listening times, without a significant change in the genre of music listened to following CI surgery. Moreover, the elderly group demonstrated significant decreases in music appreciation scores in terms of music quality and music elements, perceiving music as less natural, less clear, and more complex. They also exhibited significant changes in scores with respect to perception of rhythm, melody, timbre, and lyrics. This susceptibility to postoperative changes in music appreciation among elderly CI users should be considered in surgical counseling and music training programs.

Does Metabolic Syndrome Affect the Incidence and Prognosis of Sudden Sensorineural Hearing Loss?

Earlier studies reported that the occurrence of sudden sensorineural hearing loss (SSNHL) is associated with chronic metabolic disorders such as hypertension, diabetes, and hyperlipidemia. Instead of focusing on the relationship between SSNHL and each metabolic disorder, this study aimed to identify the association with metabolic syndrome as a whole, including either prehypertension or prediabetes. As a case-control study, we reviewed 239 patients who experienced SSNHL, and compared them with the same number of healthy subjects (N = 478). Metabolic syndrome-related variables of SSNHL patients were compared to those of healthy control subjects. In addition, patients with SSNHL were classified into two subgroups: the first subgroup showed improvement in hearing ('response group'), and the second did not present significant improvement ('non-response group'). Metabolic syndrome was diagnosed according to the US National Heart, Lung, and Blood Institute's National Cholesterol Education Program Adult Treatment Panel III criteria. The risk for SSNHL was 4.3 times higher in patients with metabolic syndrome compared with patients without the syndrome (95% confidence interval, 1.98 to 9.33), even after adjusting for variables that showed significant between-group differences. The likelihood of being unresponsive to treatment was higher in those with metabolic syndrome (1.21 to 3.93; adjusted odds ratio = 2.18), and when the initial hearing loss pattern on a pure-tone audiometry was high tone or flat. Metabolic syndrome appears to be an independent risk factor for SSNHL and, simultaneously, a predictor of poor prognosis.

Deep learning improves implant classification by dental professionals: a multi-center evaluation of accuracy and efficiency.

PURPOSE: The aim of this study was to evaluate and compare the accuracy performance of dental professionals in the classification of different types of dental implant systems (DISs) using panoramic radiographic images with and without the assistance of a deep learning (DL) algorithm. METHODS: Using a self-reported questionnaire, the classification accuracy of dental professionals (including 5 board-certified periodontists, 8 periodontology residents, and 31 dentists not specialized in implantology working at 3 dental hospitals) with and without the assistance of an automated DL algorithm were determined and compared. The accuracy, sensitivity, specificity, confusion matrix, receiver operating characteristic (ROC) curves, and area under the ROC curves were calculated to evaluate the classification performance of the DL algorithm and dental professionals. RESULTS: Using the DL algorithm led to a statistically significant improvement in the average classification accuracy of DISs (mean accuracy: 78.88%) compared to that without the assistance of the DL algorithm (mean accuracy: 63.13%, P<0.05). In particular, when assisted by the DL algorithm, board-certified periodontists (mean accuracy: 88.56%) showed higher average accuracy than did the DL algorithm, and dentists not specialized in implantology (mean accuracy: 77.83%) showed the largest improvement, reaching an average accuracy similar to that of the algorithm (mean accuracy: 80.56%). CONCLUSIONS: The automated DL algorithm classified DISs with accuracy and performance comparable to those of board-certified periodontists, and it may be useful for dental professionals for the classification of various types of DISs encountered in clinical practice.

Antimicrobial photothermal therapy using diode laser with indocyanine green on Streptococcus gordonii biofilm attached to zirconia surface.

PURPOSE: The purpose of this study was to evaluate the antimicrobial effects of photothermal therapy using indocyanine green (ICG) and an 810-nm infrared diode laser on Streptococcus gordonii biofilm attached to zirconia surfaces in vitro. METHODS: A biofilm was formed using the static method on zirconia disks placed in a 24-well plate. The biofilms were subdivided into the following six treatment groups: control, commercial photodynamic therapy (PDT), chlorhexidine gluconate (CHX), laser only (L, 810-nm infrared diode), ICG, and laser with ICG (PTT). After treatment, each disk was agitated and the solution with detached bacteria was spread directly on a blood agar plate. Cells were cultured under anaerobic conditions and colony-forming units were counted. Confocal laser-scanning microscopy was used to assess the survival according to the height of the biofilm. RESULTS: The PTT, PDT, and CHX groups showed a significant reduction in S. gordonii viability (p<0.05), while the L and ICG groups showed no significant difference compared to the control group (p = 0.32, p = 0.97; respectively). In confocal laser-scanning microscopy images, the PTT, PDT, and CHX groups presented most of the dead bacteria in both the upper and lower levels of biofilm. CONCLUSION: Within the limitations of this in vitro study, PTT with ICG was effective in significantly reducing the viability of S. gordonii bacteria on zirconia. Further studies are needed to establish a standardized PTT protocol to treat peri­implant diseases.

Posterior Tympanotomy Versus Subtotal Petrosectomy: A Comparison of Complications in Cochlear Implantation.

OBJECTIVE: To compare the postoperative complications between posterior tympanotomy cochlear implantation (PTCI) and subtotal petrosectomy cochlear implantation (SPCI). STUDY DESIGN: A retrospective cohort study. SETTING: Two tertiary referral centers. PATIENTS: Two hundred ninety-eight patients who underwent PTCI and 33 who underwent SPCI. INTERVENTIONS: Cochlear implantation using either posterior tympanotomy or subtotal petrosectomy. MAIN OUTCOME MEASURES: Postoperative complications between the two groups were compared after categorization into minor complications (requiring conservative management) and major complications (requiring surgical revision or hospitalization treatment). RESULTS: Dizziness was the most common complication in both groups. The major complication rate in the SPCI group was significantly higher than in the PTCI group (12.1% [4 of 33] versus 1.3% [4 of 298], p = 0.004), while the minor complication rate was similar between the two groups. Among the major complications, device migration was significantly more common when SPCI was performed (9.1% [3 of 33] versus 0.3% [1 of 298], p = 0.003). CONCLUSIONS: Major complication rate of SPCI was higher than that of PTCI; particularly, device migration was more commonly observed after SPCI than PTCI. Therefore, special attention should be paid to device placement and fixation during SPCI.

A Performance Comparison between Automated Deep Learning and Dental Professionals in Classification of Dental Implant Systems from Dental Imaging: A Multi-Center Study.

In this study, the efficacy of the automated deep convolutional neural network (DCNN) was evaluated for the classification of dental implant systems (DISs) and the accuracy of the performance was compared against that of dental professionals using dental radiographic images collected from three dental hospitals. A total of 11,980 panoramic and periapical radiographic images with six different types of DISs were divided into training (n = 9584) and testing (n = 2396) datasets. To compare the accuracy of the trained automated DCNN with dental professionals (including six board-certified periodontists, eight periodontology residents, and 11 residents not specialized in periodontology), 180 images were randomly selected from the test dataset. The accuracy of the automated DCNN based on the AUC, Youden index, sensitivity, and specificity, were 0.954, 0.808, 0.955, and 0.853, respectively. The automated DCNN outperformed most of the participating dental professionals, including board-certified periodontists, periodontal residents, and residents not specialized in periodontology. The automated DCNN was highly effective in classifying similar shapes of different types of DISs based on dental radiographic images. Further studies are necessary to determine the efficacy and feasibility of applying an automated DCNN in clinical practice.

Correlation analysis of gingival recession after orthodontic treatment in the anterior region: an evaluation of soft and hard tissues.

PURPOSE: The aim of this study was to investigate and identify the main causes of periodontal tissue change associated with labial gingival recession by examining the anterior region of patients who underwent orthodontic treatment. METHODS: In total, 45 patients who had undergone orthodontic treatment from January 2010 to December 2015 were included. Before and after the orthodontic treatment, sectioned images from 3-dimensional digital model scanning and cone-beam computed tomography images in the same region were superimposed to measure periodontal parameters. The initial labial gingival thickness (IGT) and the initial labial alveolar bone thickness (IBT) were measured at 4 mm below the cementoenamel junction (CEJ), and the change of the labial gingival margin was defined as the change of the distance from the CEJ to the gingival margin. Additionally, the jaw, tooth position, tooth inclination, tooth rotation, and history of orthognathic surgery were investigated to determine the various factors that could have affected anterior periodontal tissue changes. RESULTS: The mean IGT and IBT were 0.77±0.29 mm and 0.77±0.32 mm, respectively. The mean gingival recession was 0.14±0.57 mm. Tooth inclination had a significant association with gingival recession, and as tooth inclination increased labially, gingival recession increased by approximately 0.2 mm per 1°. CONCLUSIONS: In conclusion, the IGT, IBT, tooth position, tooth rotation, and history of orthognathic surgery did not affect labial gingival recession. However, tooth inclination showed a significant association with labial gingival recession of the anterior teeth after orthodontic treatment.

Surgical outcomes of simultaneous cochlear implantation with subtotal petrosectomy.

OBJECTIVE: To evaluate the surgical outcomes of simultaneous cochlear implantation (CI) with subtotal petrosectomy (SP). METHODS: Medical records of thirty-one patients (31 ears) who underwent simultaneous CI with SP in two tertiary referral centers for management of profound hearing loss secondary to chronic suppurative otitis media, cholesteatoma, previous open cavity, temporal bone fracture, and temporal bone irradiation were retrospectively analyzed. Pre and postoperative speech performances and related complications requiring surgical correction were evaluated. RESULTS: Significant improvement in postoperative speech performance was observed in all 31 patients compared to preoperative result. Of the 31 patients, complications occurred in three patients (9.6%). One patient exhibited the breakdown of blind sac closure of the external auditory canal and two others exhibited the migration of the receiver-stimulator cochlear implant. The migrations occurred despite tie-down fixation of the device to the skull. The migrated devices were repositioned using revision surgery. CONCLUSIONS: Simultaneous CI with SP is an effective and safe surgical method with relatively low complication incidence. However, particular attention should be paid to prevent certain complications. The receiver-stimulator may be predisposed to migrate to abnormal position because it can be placed with lack of tight subperiosteal support at a more superior or posterior location of the skull where the skull curvature changes abruptly than can conventional CI using limited mastoidectomy and posterior tympanotomy approach.

Soft tissue expander for vertically atrophied alveolar ridges: Prospective, multicenter, randomized controlled trial.

OBJECTIVES: Conventional guided bone regeneration (GBR) limits the amount of bone graft due to limited soft tissue expansion. We hypothesize that the use of tissue expander will successfully augment soft tissue prior to bone graft, allowing for sufficient amount of grafting which will lead to a more stable and effective vertical bone graft. The authors aimed to evaluate effectiveness of the novel self-inflating tissue expander for vertical augmentation in terms of soft tissue expansion, clinical outcomes, and related complications. MATERIAL AND METHODS: A prospective, multicenter, randomized controlled trial was performed on patients requiring vertical augmentation. For experimental group patients, the tissue expander was subperiosteally implanted and followed by a tunneling bone graft without full flap reflection. Control patients underwent conventional vertical GBR. Primary objectives were to evaluate the dimensional changes of soft tissue and radiographic vertical bone gain and retention. As a secondary outcome, clinical complications and thickness changes of expanded overlying tissue were assessed and analyzed. RESULTS: Twenty-three patients in each group were included. During a 4-week expansion, two of the experimental group showed over-expansion and one showed mucosal perforation associated with previous severe scars. The other patients showed uneventful expansion and mean tissue augmentation was 6.88 ± 1.64 mm vertically. Ultrasonographic measurements of overlying gingiva revealed no thinning after tissue expansion (p > .05). Significantly higher vertical bone gain was shown in the experimental group (5.12 ± 1.25 mm) compared with that in the control patients (4.22 ± 1.15 mm; p < .05). After a 6-month retention period, the mean vertical bone measurement of the controls had decreased to 1.90 mm (55.0% reduction), which was a significantly greater decrease than that in the experimental group (mean 3.55 mm, 30.7% reduction; p < .05). CONCLUSION: Our results demonstrated the effectiveness of tissue expanders followed by tunneling bone graft for vertical augmentation; however, studies comparing the two techniques without tissue expanders are needed to elucidate the net effect of tissue expansion.

Cochlear Implantation in Patients with Chronic Suppurative Otitis Media: Surgical Outcomes and a Management Algorithm.

BACKGROUND: Chronic suppurative otitis media (CSOM) was considered as a contraindication of cochlear implantation (CI) in the past. Recently, various surgical options have been adopted for CI in CSOM patients with showing a low complication rate. OBJECTIVES: To evaluate surgical outcomes of CI in patients with CSOM and to propose a management algorithm for those patients. METHODS: Thirty-six consecutive patients with CSOM who underwent single stage or staged CI were enrolled. Speech performance, including Categories of Auditory Performance (CAP) test and sentence score, and complications were retrospectively analyzed. RESULTS: The average follow-up was 3.1 years (range 0.5-9.2 years). Postoperative median CAP and sentence scores were 6 and 78%, respectively. Three (8.3%) of the 36 patients had postoperative complications. One experienced breakdown of the ear canal closure. Recurrence of the pars tensa retraction was observed in another patient with adhesive otitis media who underwent CI and cartilage tympanoplasty as a single stage operation. Electrode extrusion occurred in another patient who underwent staged CI with maintenance of a previous open cavity. Subtotal petrosectomy and cavity obliteration were used to manage the latter 2 complications. All implant patients with good mastoid pneumatization exhibited no complications. There were no significant differences in postoperative speech performance and complication rates between single stage CI and staged CI. Based on these current findings, a management algorithm was proposed according to type of CSOM, presence of open cavity, and mastoid pneumatization. CONCLUSIONS: Patients with CSOM show good postoperative speech performance after CI. Proper surgical options according to type of CSOM, presence of open cavity, and mastoid pneumatization may help in reducing complications.

Evaluation of prognosis related to compliance with supportive periodontal treatment in patients with chronic periodontitis: a clinical retrospective study.

PURPOSE: The purpose of this study was to evaluate the prognostic effect of patient compliance with supportive periodontal treatment (PC-SPT). Chronic periodontitis patients were classified based on their compliance level, and factors affecting PC-SPT and the prognosis of PC-SPT were investigated. METHODS: This study selected 206 patients who started SPT after receiving periodontal treatment between 2010 and 2012. Patients who continued SPT through February 2016 were included. The patients were classified according to whether they exhibited complete compliance (100% of visits), excellent compliance (≥70% of visits), incomplete compliance (<70% of visits), or non-compliance (only 2 visits). Patient characteristics that could affect PC-SPT, such as age, sex, distance of the clinic from their residence, implantation, and periodontal treatment, were investigated. The number of newly decayed and extracted teeth, alveolar bone level changes around the teeth and implants, and implant removal were examined to evaluate the prognosis of PC-SPT. RESULTS: Sex and the presence of an implant significantly affected PC-SPT. Additionally, the number of newly decayed and extracted teeth and changes in alveolar bone levels around the teeth and implants were significant prognostic factors related to PC-SPT. CONCLUSIONS: PC-SPT in chronic periodontitis patients will help maintain periodontal health and prevent further periodontal disease.

Characteristics of Local Delivery Agents for Treating Peri-Implantitis on Dental Implant Surfaces: A Preclinical Study.

Local delivery agents (LDAs) are widely used in peri-implantitis treatments. The aim of this study was to identify LDAs remaining on the dental implant surfaces and to analyze the components of these residues after applying various cleaning methods. Implants were prepared with a sand-blasted, large-grit, acid-etched surface. Four kinds of LDAs were applied on the implant surfaces: chlorhexidine gel (group 2), tetracycline solution (group 3), and 2 kinds of minocycline hydrochloride agents (groups 4 and 5). Group 1 received normal saline as a control. Two cleaning methods were applied for different durations as follows: (1) running distilled water for 10 seconds (subgroup A), 5 minutes (subgroup B), and 15 minutes (subgroup C); and (2) water spray of a dental-unit chair for 10 seconds (subgroup D) and 5 minutes (subgroup E). Scanning electron microscopy and energy-dispersive x-ray spectroscopy were used to analyze the surface morphology and residue components for all implants. The amount of LDA removed from the implant surfaces in groups 1, 2, 3, and 5 increased with the cleaning duration and pressure. However, Minocline remained coated on the implant surfaces in group 4 under all cleaning conditions. Minocline could not be cleaned off well by water due to its hydrophobicity. Therefore, directly using this agent on implant surfaces with peri-implantitis should be carefully considered. The presence of LDA residues without drug efficacies on implant surfaces might interfere with reosseointegration and act as a reservoir of microorganisms.

Validity assessment of quantitative light-induced fluorescence-digital (QLF-D) for the dental plaque scoring system: a cross-sectional study.

BACKGROUND: The aim of this study was to analyze the correlation between the dental plaque indices measured using quantitative light-induced fluorescence-digital (QLF-D) and conventional clinical indices that assess gingival status. METHODS: From among the patients who visited Ewha Womans University Mokdong Hospital, 33 adults in their 20s who had relatively even teeth were selected for full-mouth QLF-D imaging. The images were used to analyze the QLF-D score and the QLF-D ΔR score. As clinical indices, the gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), and patient hygiene performance (PHP) index were measured. The correlations between the QLF-D score and QLF-D ΔR score and each clinical index were analyzed. Analyses were performed comparing the indices of maxillary and mandibular teeth, the teeth on right and left sides of the mouth, anterior and posterior teeth, and buccal and lingual surfaces of each tooth. Pearson's correlation analysis was conducted (p < 0.05). RESULTS: The mean full-mouth QLF-D score was highly correlated with the GI, BOP, PPD, PHP index (p < 0.01). The mean full-mouth QLF-D score showed the highest correlation with GI (r = 0.749) and the lowest correlation with PPD (r = 0.683). The correlations between the QLF-D score were higher in the mandible than in the maxilla and in the anterior teeth than in the posterior teeth, while no significant differences were seen between the buccal and lingual surfaces of tooth. CONCLUSIONS: This study concluded that the correlations between the plaque indices measured for each tooth surface area using QLF-D and the clinical indices assessed were significantly high, and it allowed objective determination of the gingival status. Therefore, the plaque index measured using QLF-D may be used as an alternative to supplement the shortcomings of conventional clinical indices for educating patients about plaque control and continued patient oral care.

Significance of 1 kHz Pure-tone Threshold in Acute Low-frequency Sensorineural Hearing Loss.

OBJECTIVES: To analyze risk factors for acute low-frequency hearing loss (ALFHL), and compare treatment outcomes in the presence or absence of such risk factors. STUDY DESIGN: A case series featuring retrospective chart review. SETTING: An academic university hospital. PATIENTS: We included 170 ALFHL patients without vertigo. All of the patients received one of four treatments: low-dose steroid (LD-steroid), high-dose steroid (HD-steroid), LD-steroid and diuretics (LD-combination therapy), and ITDI (intratympanic dexamethasone injection) and diuretics (ITDI-combination therapy). To identify risk factors, we reviewed the clinical features of patients such as age, sex, chief complaint, accompanying symptoms, diabetes, hypertension, time from disease onset, the extent of hearing loss, treatment methods, and 1 kHz involvement. INTERVENTIONS: ALFHL was diagnosed based on the average hearing loss >30 dB at 250 and 500 Hz. RESULTS: The overall rates of hearing recovery were 70-80% in the four treatment groups. In terms of the prognosis of ALFHL patients, we found that a longer time from disease onset and 1 kHz involvement were independent risk factors for poor prognosis. In addition, we compared treatment outcomes of four treatment methods in the presence or absence of risk factors. In ALFHL patients with risk factors, we found statistically significant differences (p = 0.042) among treatment methods; effectiveness ranged in the order if ITDI-combination therapy, LD-combination therapy, HD-steroid, and LD-steroid. CONCLUSIONS: Risk factors for poor hearing recovery in ALFHL included longer symptom duration and 1 kHz involvement. In ALFHL with such risk factors, combination therapy was more effective than oral steroid therapy.