Objectives: Biotype conversion around both natural teeth and implants with subepithelial connecti... more Objectives: Biotype conversion around both natural teeth and implants with subepithelial connective tissue graft (SCTG) has been advocated. The harvesting procedure should be carefully conducted to avoid violating the greater palatine neurovascular bundle (GPB). The GPB, which comprises the greater palatine artery, vein, and nerve, travels through the pterygopalatine fossa, passes through the pterygopalatine canal, and exits into the greater palatine foramen (GPF). This study assessed the accuracy of predicting the location of the GPF and measured the thickness of the palatal masticatory mucosa and the distance from the GPB in the posterior palatal area, using cone beam computerized tomography (CBCT). Methods: CBCT images of 21 patients (13 men and 8 women, 22~46y) were evaluated retrospectively. The inclusion criterion was complete dentition from the maxillary first premolar to the third molar (first premolar: P1, first molar: M1, second molar: M2, area between second molar and thi...
Objectives: Paralysis of the mental nerve is one of the principle surgical complications when pla... more Objectives: Paralysis of the mental nerve is one of the principle surgical complications when placing implants in the mental foramen region. Therefore, identifying the mental foramen is crucial for surgical procedures.Methods: This study was conducted using 3-dimentional (3D) computed tomographic (CT) analysis on both sexes. The mental foramen was present in 224 CT images of bilateral mandibles of Taiwanese patients. The criteria for including foramen in this study are as follows: (1) age and sex; (2) no missing mandibular teeth of the canine to first molar regions; (3) no pathologic findings between the teeth and the mandibular mental foramen; and (4) no participants with altered tooth positions from the original location, caused by orthognathic surgery and orthodontic treatment.Results: The findings indicated that the most common position for the mental foramen was in line with the longitudinal axis of the second premolar (54.9%), followed by a location between the second premolar...
Background: Many studies have shown that poor posture may lead to myofascial pain dysfunction syn... more Background: Many studies have shown that poor posture may lead to myofascial pain dysfunction syndrome (MPDS) of the trunk. Forward head posture is one of the most common forms of poor posture, and is related to neck pain. Hence, the aim of this study was to estimate the influence of body posture on MPDS of the temporomandibular joint (TMJ). Methods: Twenty-six otherwise healthy adults with MPDS of the TMJ were enrolled in this study. Clinical examination was performed at three time-points: prior to the treatment, at the 2-week follow-up, and at the 4-week follow-up. The subjects received a muscle relaxant drug and adjustment of body posture. Variables such as visual analogue scale (VAS) score, shoulder angle (SA), cervical spine angle-coronal (CSA-c), and cervical spine angle-sagittal (CSA-s) were evaluated at each stage. Generalized estimating equations (GEE) were used to control for non-independence among observations. Results: There were significant improvements in VAS score (p ...
We present a case of chemical injury in the oral cavity and esophageal tract resulting from the s... more We present a case of chemical injury in the oral cavity and esophageal tract resulting from the swallowing of alkaline detergent. Multiple ulcerations were detected on the lips as well as on the oral and esophageal mucosa. A grade II esophageal injury was also diagnosed by fiberoptic bronchoscopy. Scar formation and restriction of mouth opening were noted on day 14 post-injury. A simplified physiotherapy regimen was recommended involving a water hose and Vaseline lubricant, both materials that are easily obtainable, in order to prevent further restrictions regarding the range of motion of the mouth as a result of the chemical burn.
Objective: During the process of dental implantation, mistaken use of a surgical drill may cause ... more Objective: During the process of dental implantation, mistaken use of a surgical drill may cause damage to important anatomical structures. As a result, the use of computer-assisted systems to prevent damage has become commonplace among many dentists. Therefore, it is necessary to be aware of the accuracy of the surgical navigation system, and system accuracy is also an important reference for error range used by dentists in clinical practice. Materials and Methods: This study included the carrying out of an accuracy test on surgical navigation system and freehand drilling under an in vitro environment. Twelve dental implant plans were separately performed in two models; in addition, a surgical navigation system and freehand drilling were used in a simulated dental implant surgery. Furthermore, the accuracy of the planned and actual positions of the implants was assessed. Results: The entry lateral error of the surgical navigation system and freehand drilling was 0.73 ± 0.45 mm and ...
Background: The evaluation of periapical radiographic evidence of these foramina might be helpful... more Background: The evaluation of periapical radiographic evidence of these foramina might be helpful to avoid hemorrhaging of the highly vascularized regions of the floor of the mouth. Accuracy and reliability of the dental radiography in depicting the interalveolar medial foramina on 28 dry mandibles was tested in this study. Materials and Methods: The 28 mandibles were radiographically examined for the presence of median and lateral foramina that were interalveolar. The foramina diameters and the distance of the foramen to the cementoenamel junction, and to the alveolar bone crest, were measured. Two radiographic images of the symphysis areas were obtained, with and without the insertion of metal wires into the foramina. On the radiographic films, the presence of the foramina was identified and marked by two periodontists. The accuracy, sensitivity, specificity, interobserver reliability and the agreement of the readings between the diagnostic films and the films with wire insertions were analyzed. Results: Two to four foramina were observed on the lingual surfaces in the symphysis areas in 27 dry skulls. Among the 52 median foramina, 22 and 21 foramina were identified by observers 1 and 2, respectively. The accuracy, sensitivity, and specificity for the identification of the foramina were 41.1%, 42.3%, and 25.0%, respectively, for observer 1, and 37.5%, 40.4%, and 0.0%, respectively, for observer 2. The interobserver reliability was 0.57 (Kappa value). The readings for the diagnostic films and those for the films with wire insertions showed no agreement, regardless of the observer. Conclusions: Dental radiography revealed the presence of interalveolar foramina in 28 skulls; nonetheless, this result should be interpreted cautiously, as the accuracy was <50%.
Background: The dimension of maxillary sinus is dynamic and might complicate the dental practice.... more Background: The dimension of maxillary sinus is dynamic and might complicate the dental practice. Therefore, the purpose of this study is to analyze maxillary sinus dimension with respect to different ages, genders, tooth sites, and relationships between root of posterior maxillary teeth (RPMT) and adjacent maxillary sinus floor, using cross-sectional images from cone-beam computed tomography (CBCT). Methods: The 320 qualified cross-sectional posterior maxillary images of CBCT from 50 patients retrieved from the database were used to analyze the maxillary sinus area. Five types of relationship between RPMT and adjacent maxillary sinus floor were classified accordingly. The associated factors, such as age, genders, and tooth sites, were also examined. The one-way analysis of variance with Tukey's post hoc test was performed to compare the maxillary sinus cross-sectional area in different classifications of RPMT relative to adjacent maxillary sinus floor. Results: There were significant differences of mean maxillary sinus area between different genders (P < 0.001) and age groups (P = 0.01). The mean sinus area measured from cross-sectional images was greater in Type 3 classification of RPMT relative to maxillary sinus, compared to Type 2, Type 1, and Type 0 (P < 0.001). Conclusions: The RPMT relative to adjacent sinus floor may be associated with area of maxillary sinus. The maxillary sinus with greater area in cross-sectional images of CBCT would be closer to the RPMT and might complicate the dental practice.
The International Journal of Oral & Maxillofacial Implants, 2018
Computer-aided surgery under navigation system guidance is widely applied in dental implant proce... more Computer-aided surgery under navigation system guidance is widely applied in dental implant procedures. However, the accuracy of drilling with such navigation systems has not been comparatively evaluated alongside those of laboratory guide-based and freehand drilling. Therefore, this study aimed to compare the accuracies of these three drilling systems. Materials and Methods: A navigation system, a laboratory guide, and freehand drilling were used to drill 150 holes on 30 cast models. Two master modelsone each for the maxilla and mandible-were prepared with the idea of placing five implants per cast. After drilling five holes on each cast, postoperative cone beam computed tomography images were acquired to measure the magnitude of errors. Results: The navigation system and laboratory guide were more accurate than freehand placement with respect to total errors at the entry and apex, lateral error at the apex, and angular error. The navigation system was more accurate than the laboratory guide with respect to angular error. Laboratory guide-based drilling was more accurate than freehand drilling in terms of lateral error at entry. Conclusion: In comparison with the laboratory guide and freehand placement, the navigation system exhibited lower angular and axial errors. Despite its higher accuracy, the navigation system requires the operator to pay greater attention.
The International journal of periodontics & restorative dentistry
This study evaluated use of a solid-state laser to avoid the flap technique and suturing. An Er:Y... more This study evaluated use of a solid-state laser to avoid the flap technique and suturing. An Er:YAG laser was used in 26 consecutive patients referred for osseous crown lengthening in 32 posterior teeth. The distance from the planned restoration margin to the alveolar crest (B) satisfied a 3-mm dentogingival complex. No tissue necrosis and no significant change in the distance from the gingival margin to B or probing depth were detected at 3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for definitive restoration.
Background: Chronic periodontitis and gingivitis are associated with various diseases; however, t... more Background: Chronic periodontitis and gingivitis are associated with various diseases; however, their impact on dementia is yet to be elucidated. This study is aimed at investigating the association between chronic periodontitis and gingivitis, and the risk of developing dementia. Methods: A total of 2,207 patients, with newly diagnosed chronic periodontitis and gingivitis between January 1, 2000 and December 31, 2000, were selected from the National Health Insurance Research Database of Taiwan, along with 6,621 controls matched for sex and age. After adjusting for confounding factors, Cox proportional hazards analysis was used to compare the risk of developing dementia during the 10-year follow-up period. Results: Of the study subjects, 25 (1.13%) developed dementia compared to 61 (0.92%) in the control group. Cox proportional hazards regression analysis revealed that the study subjects were more likely to develop dementia (hazard ratio (HR) 2.085, 95% CI 1.552-4.156, p < 0.001)...
This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including ... more This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including disc or non-disc-related disorders, and joint hypermobility syndrome (JHS) retrospectively and to analyze the factors by estimating the magnitude of the association between the two conditions using a nationwide population-based dataset. A total of 975,788 eligible patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; de-identified data were obtained from a representative database composed of one million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population since 2004 to 2008. All associated factors, such as gender, age, facial trauma, and psychosis, which correlated with TMDs and JHS were examined. Multiple logistic regression modeling adjusted for confounding variables to determine the odds ratio of variables that made an important contribution to TMDs and JHS. For all TMDs patients, only 1.47 % patients had disc-related disorders. For all JHS patients, only 3.85 % patients are diagnosed with concomitant TMDs. Statistically significant association was observed between joint hypermobility and TMDs. Furthermore, the prevalence of JHS patients shows significant difference within TMD subgroups, in which 9.52 % of JHS patients have disc disorders and 90.48 % of JHS patients do not. All associated factors, such as gender, age, JHS, facial trauma, and psychosis, had a significant impact on the TMDs. Interestingly, patients with TMJ articular disc disorders are 6.7 times more likely to be diagnosed with JHS compared to patients without disc-related disorders. Our results confirm that there is a significant positive association between TMDs and JHS, highlighting that patients with disc-related TMDs are more likely to experience JHS than patients with TMDs without disc disorders. Individuals with TMD associated with JHS should be carefully evaluated by inter-disciplinary specialists as these factors may eventually have impact on the prognosis of TMDs and JHS.
Background and Objective: Previous systematic reviews have reported that the use of a coronally a... more Background and Objective: Previous systematic reviews have reported that the use of a coronally advanced flap (CAF) combined with a connective tissue graft (CTG) or enamel matrix derivative (EMD) is more likely to achieve complete root coverage (CRC) than other modalities. However, the details of periodontal parameters and comparisons among a variety of combinations of CAF with CTG and/or EMD are left to be investigated. This study aimed to analyze the differences in periodontal parameters between these treatment modalities. Material and Methods: A literature search was performed using the Cochrane library and MEDLINE (PubMed) for studies focused on the treatment of gingival recession (Miller Class I, II and III) with CAF alone or combined with CTG, EMD or both up to December 2011. Randomized controlled clinical trials with a follow-up duration ≥ 6 mo were included. The outcome analysis included changes in periodontal probing depth (PPD), clinical attachment level, recession depth (RED) and keratinized tissue width (KTW). Results: Thirteen randomized controlled clinical trials, including 529 Miller Class I-III defects from 321 patients were included. For an increase in KTW, CAF + CTG significantly improved more than CAF alone. CAF + EMD also gained more KTW than CAF alone. EMD reduced PPD, however, a significant difference was not found. Furthermore, the effects on changes of RED and clinical attachment level were not identified in the study. Conclusion: When combined with CAF, CTG contributed more in the increase of KTW, while EMD seemed helpful for wound healing by its potential in PPD reduction. However, further research is needed to clarify the effects on changes in RED and clinical attachment level.
Background: This study analyzes the prognostic factors affecting the survival rate of root-resect... more Background: This study analyzes the prognostic factors affecting the survival rate of root-resected molars by using a representative population-based dataset. Materials and Methods: A total of 635,216 eligible patients were enrolled from a representative cohort composed of one million of Taiwan's population. The tooth-related factors influencing the survival rates of root-resected teeth were examined on 516 molars, in 492 patients. Cox regression was performed to statistically analyze the factors. Results: The overall survival rate for the root-resected molars was 91.7%. Of the analyzed factors with respect to root-resection procedures, whether or not concomitant flap surgery was performed in the medical institutions, the dental arch and tooth location demonstrated a considerable influence on the treatment and decision-making. The main reasons and results of root-resected molars receiving root-resection therapy in hospitals were the periodontal-compromised conditions, whereas, the root-resected molars that received root-resection therapy in private practice clinics were caused by caries/endodontic reasons. After adjusting for other factors, in the outcome of root-resected molars, a higher risk of extraction occurrence was seen in hospitals than in private practice clinics (hazard ratio = 2.03; 95% CI = 1.04 to 3.98; P = 0.039). Conclusions: Of the analyzed prognostic factors, medical institutions significantly affect the treatment decision and survival of root-resected molars. Therefore, a comprehensive evaluation, risk assessment, and treatment plan should be executed before the root-resection procedure is performed.
Osteonecrosis of the jaw (ONJ) is a potential side effect of bisphosphonate therapy. This Taiwane... more Osteonecrosis of the jaw (ONJ) is a potential side effect of bisphosphonate therapy. This Taiwanese national-scale cohort study aimed to investigate its incidence and risk of development by using a qualified control group with different demographic factors (age/gender), dental (tooth extraction/periodontal therapy) and medical (jaw radiotherapy) treatments, delivery routes (oral/intravenous), and diseases (diabetes/osteoporosis/cancer). Data (n=958,136) from January 1, 2006 through December 31, 2008 were sourced from the Longitudinal Health Insurance Database 2005 of Taiwan. Cases of BRONJ were identified by three criteria modified from the definition proposed by the American Association of Oral and Maxillofacial Surgeons. The Cox proportional-hazards regression model and Kaplan-Meier estimates were used to analyse the results. The incidence densities of ONJ in the unexposed and bisphosphonate-exposed cohorts were estimated as 4.4 and 73.5 per 100,000 person-years, respectively (relative risk=16.8; 95% CI=6.0-37.5; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Multivariate analysis revealed strong associations of delivery route, tooth extraction, and oral cancer with ONJ (hazard ratios=51.4 for oral bisphosphonates, 153.3 for intravenous bisphosphonates, 5.3 for tooth extraction, and 278.1 for oral cancer). These results not only demonstrate the incidence and relative risk of bisphosphonate-related ONJ in Taiwan but also indicate that tooth extraction and oral cancer may have a major impact on its development. Physicians should be aware of individual patient risk factors before prescribing bisphosphonates. Bisphosphonate treatment is justified in the amelioration of life-threatening conditions in patients in whom ONJ would only affect quality of life.
Treatment of furcation-involved molars presents a clinical challenge. This study retrospectively ... more Treatment of furcation-involved molars presents a clinical challenge. This study retrospectively investigates the demographic parameters affecting treatment decisions and outcomes of root-resected molars using a nationwide population-based dataset. De-identified data from 471 eligible patients were obtained from a representative cohort composed of 1 million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population. Demographic factors that influence treatment decisions and outcomes of root-resected teeth were examined. Cox regression was performed to statistically analyze the factors. The overall survival rate for root-resected molars was 91.1%. The survival times of the extracted and surviving teeth were 303.0 ± 274.6 and 551.8 ± 327.2 days, respectively (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The analyzed patient-related factors, such as living district, urbanization level, medical institution, and monthly income, have remarkable influence on treatment decisions; however, there is no statistically significant difference in survival rate between root-resected molars receiving flap surgery and those that do not (P = 0.504). After adjusting for other factors, patients aged &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;74 years have 3.33 times (hazard ratio = 3.33; 95% CI = 1.04 to 10.66; P = 0.043) higher rates of molar extraction than younger counterparts. The overall survival rate of root-resected molars was satisfactory. Patients with advanced age (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;74 years) had a higher risk of extraction occurrence on resected molars. Patient-related factors may influence the treatment decision of whether molars receive flap surgery. These findings suggest that demographic factors should be carefully evaluated before and after performing root-resection procedures because these factors may eventually impact the outcome of root-resected molars.
This study evaluated use of a solid-state laser to avoid the ap technique
and suturing. An Er:YA... more This study evaluated use of a solid-state laser to avoid the ap technique and suturing. An Er:YAG laser was used in 26 consecutive patients referred for osseous crown lengthening in 32 posterior teeth. The distance from the planned restoration margin to the alveolar crest (B) satis ed a 3-mm dentogingival complex. No tissue necrosis and no signi cant change in the distance from the gingival margin to B or probing depth were detected at 3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for de nitive restoration.
This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including ... more This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including disc or non-disc-related disorders, and joint hypermobility syndrome (JHS) retrospectively and to analyze the factors by estimating the magnitude of the association between the two conditions using a nationwide population-based dataset. A total of 975,788 eligible patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; de-identified data were obtained from a representative database composed of one million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population since 2004 to 2008. All associated factors, such as gender, age, facial trauma, and psychosis, which correlated with TMDs and JHS were examined. Multiple logistic regression modeling adjusted for confounding variables to determine the odds ratio of variables that made an important contribution to TMDs and JHS. For all TMDs patients, only 1.47 % patients had disc-related disorders. For all JHS patients, only 3.85 % patients are diagnosed with concomitant TMDs. Statistically significant association was observed between joint hypermobility and TMDs. Furthermore, the prevalence of JHS patients shows significant difference within TMD subgroups, in which 9.52 % of JHS patients have disc disorders and 90.48 % of JHS patients do not. All associated factors, such as gender, age, JHS, facial trauma, and psychosis, had a significant impact on the TMDs. Interestingly, patients with TMJ articular disc disorders are 6.7 times more likely to be diagnosed with JHS compared to patients without disc-related disorders. Our results confirm that there is a significant positive association between TMDs and JHS, highlighting that patients with disc-related TMDs are more likely to experience JHS than patients with TMDs without disc disorders. Individuals with TMD associated with JHS should be carefully evaluated by inter-disciplinary specialists as these factors may eventually have impact on the prognosis of TMDs and JHS.
Objectives: Biotype conversion around both natural teeth and implants with subepithelial connecti... more Objectives: Biotype conversion around both natural teeth and implants with subepithelial connective tissue graft (SCTG) has been advocated. The harvesting procedure should be carefully conducted to avoid violating the greater palatine neurovascular bundle (GPB). The GPB, which comprises the greater palatine artery, vein, and nerve, travels through the pterygopalatine fossa, passes through the pterygopalatine canal, and exits into the greater palatine foramen (GPF). This study assessed the accuracy of predicting the location of the GPF and measured the thickness of the palatal masticatory mucosa and the distance from the GPB in the posterior palatal area, using cone beam computerized tomography (CBCT). Methods: CBCT images of 21 patients (13 men and 8 women, 22~46y) were evaluated retrospectively. The inclusion criterion was complete dentition from the maxillary first premolar to the third molar (first premolar: P1, first molar: M1, second molar: M2, area between second molar and thi...
Objectives: Paralysis of the mental nerve is one of the principle surgical complications when pla... more Objectives: Paralysis of the mental nerve is one of the principle surgical complications when placing implants in the mental foramen region. Therefore, identifying the mental foramen is crucial for surgical procedures.Methods: This study was conducted using 3-dimentional (3D) computed tomographic (CT) analysis on both sexes. The mental foramen was present in 224 CT images of bilateral mandibles of Taiwanese patients. The criteria for including foramen in this study are as follows: (1) age and sex; (2) no missing mandibular teeth of the canine to first molar regions; (3) no pathologic findings between the teeth and the mandibular mental foramen; and (4) no participants with altered tooth positions from the original location, caused by orthognathic surgery and orthodontic treatment.Results: The findings indicated that the most common position for the mental foramen was in line with the longitudinal axis of the second premolar (54.9%), followed by a location between the second premolar...
Background: Many studies have shown that poor posture may lead to myofascial pain dysfunction syn... more Background: Many studies have shown that poor posture may lead to myofascial pain dysfunction syndrome (MPDS) of the trunk. Forward head posture is one of the most common forms of poor posture, and is related to neck pain. Hence, the aim of this study was to estimate the influence of body posture on MPDS of the temporomandibular joint (TMJ). Methods: Twenty-six otherwise healthy adults with MPDS of the TMJ were enrolled in this study. Clinical examination was performed at three time-points: prior to the treatment, at the 2-week follow-up, and at the 4-week follow-up. The subjects received a muscle relaxant drug and adjustment of body posture. Variables such as visual analogue scale (VAS) score, shoulder angle (SA), cervical spine angle-coronal (CSA-c), and cervical spine angle-sagittal (CSA-s) were evaluated at each stage. Generalized estimating equations (GEE) were used to control for non-independence among observations. Results: There were significant improvements in VAS score (p ...
We present a case of chemical injury in the oral cavity and esophageal tract resulting from the s... more We present a case of chemical injury in the oral cavity and esophageal tract resulting from the swallowing of alkaline detergent. Multiple ulcerations were detected on the lips as well as on the oral and esophageal mucosa. A grade II esophageal injury was also diagnosed by fiberoptic bronchoscopy. Scar formation and restriction of mouth opening were noted on day 14 post-injury. A simplified physiotherapy regimen was recommended involving a water hose and Vaseline lubricant, both materials that are easily obtainable, in order to prevent further restrictions regarding the range of motion of the mouth as a result of the chemical burn.
Objective: During the process of dental implantation, mistaken use of a surgical drill may cause ... more Objective: During the process of dental implantation, mistaken use of a surgical drill may cause damage to important anatomical structures. As a result, the use of computer-assisted systems to prevent damage has become commonplace among many dentists. Therefore, it is necessary to be aware of the accuracy of the surgical navigation system, and system accuracy is also an important reference for error range used by dentists in clinical practice. Materials and Methods: This study included the carrying out of an accuracy test on surgical navigation system and freehand drilling under an in vitro environment. Twelve dental implant plans were separately performed in two models; in addition, a surgical navigation system and freehand drilling were used in a simulated dental implant surgery. Furthermore, the accuracy of the planned and actual positions of the implants was assessed. Results: The entry lateral error of the surgical navigation system and freehand drilling was 0.73 ± 0.45 mm and ...
Background: The evaluation of periapical radiographic evidence of these foramina might be helpful... more Background: The evaluation of periapical radiographic evidence of these foramina might be helpful to avoid hemorrhaging of the highly vascularized regions of the floor of the mouth. Accuracy and reliability of the dental radiography in depicting the interalveolar medial foramina on 28 dry mandibles was tested in this study. Materials and Methods: The 28 mandibles were radiographically examined for the presence of median and lateral foramina that were interalveolar. The foramina diameters and the distance of the foramen to the cementoenamel junction, and to the alveolar bone crest, were measured. Two radiographic images of the symphysis areas were obtained, with and without the insertion of metal wires into the foramina. On the radiographic films, the presence of the foramina was identified and marked by two periodontists. The accuracy, sensitivity, specificity, interobserver reliability and the agreement of the readings between the diagnostic films and the films with wire insertions were analyzed. Results: Two to four foramina were observed on the lingual surfaces in the symphysis areas in 27 dry skulls. Among the 52 median foramina, 22 and 21 foramina were identified by observers 1 and 2, respectively. The accuracy, sensitivity, and specificity for the identification of the foramina were 41.1%, 42.3%, and 25.0%, respectively, for observer 1, and 37.5%, 40.4%, and 0.0%, respectively, for observer 2. The interobserver reliability was 0.57 (Kappa value). The readings for the diagnostic films and those for the films with wire insertions showed no agreement, regardless of the observer. Conclusions: Dental radiography revealed the presence of interalveolar foramina in 28 skulls; nonetheless, this result should be interpreted cautiously, as the accuracy was <50%.
Background: The dimension of maxillary sinus is dynamic and might complicate the dental practice.... more Background: The dimension of maxillary sinus is dynamic and might complicate the dental practice. Therefore, the purpose of this study is to analyze maxillary sinus dimension with respect to different ages, genders, tooth sites, and relationships between root of posterior maxillary teeth (RPMT) and adjacent maxillary sinus floor, using cross-sectional images from cone-beam computed tomography (CBCT). Methods: The 320 qualified cross-sectional posterior maxillary images of CBCT from 50 patients retrieved from the database were used to analyze the maxillary sinus area. Five types of relationship between RPMT and adjacent maxillary sinus floor were classified accordingly. The associated factors, such as age, genders, and tooth sites, were also examined. The one-way analysis of variance with Tukey's post hoc test was performed to compare the maxillary sinus cross-sectional area in different classifications of RPMT relative to adjacent maxillary sinus floor. Results: There were significant differences of mean maxillary sinus area between different genders (P < 0.001) and age groups (P = 0.01). The mean sinus area measured from cross-sectional images was greater in Type 3 classification of RPMT relative to maxillary sinus, compared to Type 2, Type 1, and Type 0 (P < 0.001). Conclusions: The RPMT relative to adjacent sinus floor may be associated with area of maxillary sinus. The maxillary sinus with greater area in cross-sectional images of CBCT would be closer to the RPMT and might complicate the dental practice.
The International Journal of Oral & Maxillofacial Implants, 2018
Computer-aided surgery under navigation system guidance is widely applied in dental implant proce... more Computer-aided surgery under navigation system guidance is widely applied in dental implant procedures. However, the accuracy of drilling with such navigation systems has not been comparatively evaluated alongside those of laboratory guide-based and freehand drilling. Therefore, this study aimed to compare the accuracies of these three drilling systems. Materials and Methods: A navigation system, a laboratory guide, and freehand drilling were used to drill 150 holes on 30 cast models. Two master modelsone each for the maxilla and mandible-were prepared with the idea of placing five implants per cast. After drilling five holes on each cast, postoperative cone beam computed tomography images were acquired to measure the magnitude of errors. Results: The navigation system and laboratory guide were more accurate than freehand placement with respect to total errors at the entry and apex, lateral error at the apex, and angular error. The navigation system was more accurate than the laboratory guide with respect to angular error. Laboratory guide-based drilling was more accurate than freehand drilling in terms of lateral error at entry. Conclusion: In comparison with the laboratory guide and freehand placement, the navigation system exhibited lower angular and axial errors. Despite its higher accuracy, the navigation system requires the operator to pay greater attention.
The International journal of periodontics & restorative dentistry
This study evaluated use of a solid-state laser to avoid the flap technique and suturing. An Er:Y... more This study evaluated use of a solid-state laser to avoid the flap technique and suturing. An Er:YAG laser was used in 26 consecutive patients referred for osseous crown lengthening in 32 posterior teeth. The distance from the planned restoration margin to the alveolar crest (B) satisfied a 3-mm dentogingival complex. No tissue necrosis and no significant change in the distance from the gingival margin to B or probing depth were detected at 3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for definitive restoration.
Background: Chronic periodontitis and gingivitis are associated with various diseases; however, t... more Background: Chronic periodontitis and gingivitis are associated with various diseases; however, their impact on dementia is yet to be elucidated. This study is aimed at investigating the association between chronic periodontitis and gingivitis, and the risk of developing dementia. Methods: A total of 2,207 patients, with newly diagnosed chronic periodontitis and gingivitis between January 1, 2000 and December 31, 2000, were selected from the National Health Insurance Research Database of Taiwan, along with 6,621 controls matched for sex and age. After adjusting for confounding factors, Cox proportional hazards analysis was used to compare the risk of developing dementia during the 10-year follow-up period. Results: Of the study subjects, 25 (1.13%) developed dementia compared to 61 (0.92%) in the control group. Cox proportional hazards regression analysis revealed that the study subjects were more likely to develop dementia (hazard ratio (HR) 2.085, 95% CI 1.552-4.156, p < 0.001)...
This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including ... more This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including disc or non-disc-related disorders, and joint hypermobility syndrome (JHS) retrospectively and to analyze the factors by estimating the magnitude of the association between the two conditions using a nationwide population-based dataset. A total of 975,788 eligible patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; de-identified data were obtained from a representative database composed of one million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population since 2004 to 2008. All associated factors, such as gender, age, facial trauma, and psychosis, which correlated with TMDs and JHS were examined. Multiple logistic regression modeling adjusted for confounding variables to determine the odds ratio of variables that made an important contribution to TMDs and JHS. For all TMDs patients, only 1.47 % patients had disc-related disorders. For all JHS patients, only 3.85 % patients are diagnosed with concomitant TMDs. Statistically significant association was observed between joint hypermobility and TMDs. Furthermore, the prevalence of JHS patients shows significant difference within TMD subgroups, in which 9.52 % of JHS patients have disc disorders and 90.48 % of JHS patients do not. All associated factors, such as gender, age, JHS, facial trauma, and psychosis, had a significant impact on the TMDs. Interestingly, patients with TMJ articular disc disorders are 6.7 times more likely to be diagnosed with JHS compared to patients without disc-related disorders. Our results confirm that there is a significant positive association between TMDs and JHS, highlighting that patients with disc-related TMDs are more likely to experience JHS than patients with TMDs without disc disorders. Individuals with TMD associated with JHS should be carefully evaluated by inter-disciplinary specialists as these factors may eventually have impact on the prognosis of TMDs and JHS.
Background and Objective: Previous systematic reviews have reported that the use of a coronally a... more Background and Objective: Previous systematic reviews have reported that the use of a coronally advanced flap (CAF) combined with a connective tissue graft (CTG) or enamel matrix derivative (EMD) is more likely to achieve complete root coverage (CRC) than other modalities. However, the details of periodontal parameters and comparisons among a variety of combinations of CAF with CTG and/or EMD are left to be investigated. This study aimed to analyze the differences in periodontal parameters between these treatment modalities. Material and Methods: A literature search was performed using the Cochrane library and MEDLINE (PubMed) for studies focused on the treatment of gingival recession (Miller Class I, II and III) with CAF alone or combined with CTG, EMD or both up to December 2011. Randomized controlled clinical trials with a follow-up duration ≥ 6 mo were included. The outcome analysis included changes in periodontal probing depth (PPD), clinical attachment level, recession depth (RED) and keratinized tissue width (KTW). Results: Thirteen randomized controlled clinical trials, including 529 Miller Class I-III defects from 321 patients were included. For an increase in KTW, CAF + CTG significantly improved more than CAF alone. CAF + EMD also gained more KTW than CAF alone. EMD reduced PPD, however, a significant difference was not found. Furthermore, the effects on changes of RED and clinical attachment level were not identified in the study. Conclusion: When combined with CAF, CTG contributed more in the increase of KTW, while EMD seemed helpful for wound healing by its potential in PPD reduction. However, further research is needed to clarify the effects on changes in RED and clinical attachment level.
Background: This study analyzes the prognostic factors affecting the survival rate of root-resect... more Background: This study analyzes the prognostic factors affecting the survival rate of root-resected molars by using a representative population-based dataset. Materials and Methods: A total of 635,216 eligible patients were enrolled from a representative cohort composed of one million of Taiwan's population. The tooth-related factors influencing the survival rates of root-resected teeth were examined on 516 molars, in 492 patients. Cox regression was performed to statistically analyze the factors. Results: The overall survival rate for the root-resected molars was 91.7%. Of the analyzed factors with respect to root-resection procedures, whether or not concomitant flap surgery was performed in the medical institutions, the dental arch and tooth location demonstrated a considerable influence on the treatment and decision-making. The main reasons and results of root-resected molars receiving root-resection therapy in hospitals were the periodontal-compromised conditions, whereas, the root-resected molars that received root-resection therapy in private practice clinics were caused by caries/endodontic reasons. After adjusting for other factors, in the outcome of root-resected molars, a higher risk of extraction occurrence was seen in hospitals than in private practice clinics (hazard ratio = 2.03; 95% CI = 1.04 to 3.98; P = 0.039). Conclusions: Of the analyzed prognostic factors, medical institutions significantly affect the treatment decision and survival of root-resected molars. Therefore, a comprehensive evaluation, risk assessment, and treatment plan should be executed before the root-resection procedure is performed.
Osteonecrosis of the jaw (ONJ) is a potential side effect of bisphosphonate therapy. This Taiwane... more Osteonecrosis of the jaw (ONJ) is a potential side effect of bisphosphonate therapy. This Taiwanese national-scale cohort study aimed to investigate its incidence and risk of development by using a qualified control group with different demographic factors (age/gender), dental (tooth extraction/periodontal therapy) and medical (jaw radiotherapy) treatments, delivery routes (oral/intravenous), and diseases (diabetes/osteoporosis/cancer). Data (n=958,136) from January 1, 2006 through December 31, 2008 were sourced from the Longitudinal Health Insurance Database 2005 of Taiwan. Cases of BRONJ were identified by three criteria modified from the definition proposed by the American Association of Oral and Maxillofacial Surgeons. The Cox proportional-hazards regression model and Kaplan-Meier estimates were used to analyse the results. The incidence densities of ONJ in the unexposed and bisphosphonate-exposed cohorts were estimated as 4.4 and 73.5 per 100,000 person-years, respectively (relative risk=16.8; 95% CI=6.0-37.5; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Multivariate analysis revealed strong associations of delivery route, tooth extraction, and oral cancer with ONJ (hazard ratios=51.4 for oral bisphosphonates, 153.3 for intravenous bisphosphonates, 5.3 for tooth extraction, and 278.1 for oral cancer). These results not only demonstrate the incidence and relative risk of bisphosphonate-related ONJ in Taiwan but also indicate that tooth extraction and oral cancer may have a major impact on its development. Physicians should be aware of individual patient risk factors before prescribing bisphosphonates. Bisphosphonate treatment is justified in the amelioration of life-threatening conditions in patients in whom ONJ would only affect quality of life.
Treatment of furcation-involved molars presents a clinical challenge. This study retrospectively ... more Treatment of furcation-involved molars presents a clinical challenge. This study retrospectively investigates the demographic parameters affecting treatment decisions and outcomes of root-resected molars using a nationwide population-based dataset. De-identified data from 471 eligible patients were obtained from a representative cohort composed of 1 million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population. Demographic factors that influence treatment decisions and outcomes of root-resected teeth were examined. Cox regression was performed to statistically analyze the factors. The overall survival rate for root-resected molars was 91.1%. The survival times of the extracted and surviving teeth were 303.0 ± 274.6 and 551.8 ± 327.2 days, respectively (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). The analyzed patient-related factors, such as living district, urbanization level, medical institution, and monthly income, have remarkable influence on treatment decisions; however, there is no statistically significant difference in survival rate between root-resected molars receiving flap surgery and those that do not (P = 0.504). After adjusting for other factors, patients aged &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;74 years have 3.33 times (hazard ratio = 3.33; 95% CI = 1.04 to 10.66; P = 0.043) higher rates of molar extraction than younger counterparts. The overall survival rate of root-resected molars was satisfactory. Patients with advanced age (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;74 years) had a higher risk of extraction occurrence on resected molars. Patient-related factors may influence the treatment decision of whether molars receive flap surgery. These findings suggest that demographic factors should be carefully evaluated before and after performing root-resection procedures because these factors may eventually impact the outcome of root-resected molars.
This study evaluated use of a solid-state laser to avoid the ap technique
and suturing. An Er:YA... more This study evaluated use of a solid-state laser to avoid the ap technique and suturing. An Er:YAG laser was used in 26 consecutive patients referred for osseous crown lengthening in 32 posterior teeth. The distance from the planned restoration margin to the alveolar crest (B) satis ed a 3-mm dentogingival complex. No tissue necrosis and no signi cant change in the distance from the gingival margin to B or probing depth were detected at 3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for de nitive restoration.
This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including ... more This study aims to investigate the risk factors of temporomandibular disorders (TMDs), including disc or non-disc-related disorders, and joint hypermobility syndrome (JHS) retrospectively and to analyze the factors by estimating the magnitude of the association between the two conditions using a nationwide population-based dataset. A total of 975,788 eligible patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; de-identified data were obtained from a representative database composed of one million of Taiwan&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s population since 2004 to 2008. All associated factors, such as gender, age, facial trauma, and psychosis, which correlated with TMDs and JHS were examined. Multiple logistic regression modeling adjusted for confounding variables to determine the odds ratio of variables that made an important contribution to TMDs and JHS. For all TMDs patients, only 1.47 % patients had disc-related disorders. For all JHS patients, only 3.85 % patients are diagnosed with concomitant TMDs. Statistically significant association was observed between joint hypermobility and TMDs. Furthermore, the prevalence of JHS patients shows significant difference within TMD subgroups, in which 9.52 % of JHS patients have disc disorders and 90.48 % of JHS patients do not. All associated factors, such as gender, age, JHS, facial trauma, and psychosis, had a significant impact on the TMDs. Interestingly, patients with TMJ articular disc disorders are 6.7 times more likely to be diagnosed with JHS compared to patients without disc-related disorders. Our results confirm that there is a significant positive association between TMDs and JHS, highlighting that patients with disc-related TMDs are more likely to experience JHS than patients with TMDs without disc disorders. Individuals with TMD associated with JHS should be carefully evaluated by inter-disciplinary specialists as these factors may eventually have impact on the prognosis of TMDs and JHS.
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and suturing. An Er:YAG laser was used in 26 consecutive patients referred
for osseous crown lengthening in 32 posterior teeth. The distance from
the planned restoration margin to the alveolar crest (B) satis ed a 3-mm dentogingival complex. No tissue necrosis and no signi cant change in the distance from the gingival margin to B or probing depth were detected at
3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for de nitive restoration.
and suturing. An Er:YAG laser was used in 26 consecutive patients referred
for osseous crown lengthening in 32 posterior teeth. The distance from
the planned restoration margin to the alveolar crest (B) satis ed a 3-mm dentogingival complex. No tissue necrosis and no signi cant change in the distance from the gingival margin to B or probing depth were detected at
3 and 6 months. Minimally invasive Er:YAG laser surgery decreases the time needed to establish the gingival margin necessary for de nitive restoration.