[Oral treatment for obstructive sleep apnea syndrome].

Obstructive sleep apnea syndrome (OSAS) is a common clinical disease with high incidence and low treating proportion, difficult evaluation, and complicated nosogenesis. OSAS can cause systematic impairments. Various treatment methods were applied in clinical setting with the tendency of cross-disciplinary promotion. Oral treatment plays an exceedingly important role in OSAS research and therapy. This study reports the oral treatment involving OSAS therapy.

Analysis of the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair.

OBJECTIVE: The objective of this study was to analyze the correlative factors for velopharyngeal closure of patients with cleft palate after primary repair. STUDY DESIGN: Ninety-five nonsyndromic patients with cleft palate were enrolled. Two surgical techniques were applied in the patients: simple palatoplasty and combined palatoplasty with pharyngoplasty. All patients were assessed 6 months after the operation. The postoperative velopharyngeal closure (VPC) rate was compared by χ(2) test and the correlative factors were analyzed with logistic regression model. RESULTS: The postoperative VPC rate of young patients was higher than that of old patients, the group with incomplete cleft palate was higher than the group with complete cleft palate, and combined palatoplasty with pharyngoplasty was higher than simple palatoplasty. Operative age, cleft type, and surgical technique were the contributing factors for postoperative VPC rate. CONCLUSIONS: Operative age, cleft type, and surgical technique were significant factors influencing postoperative VPC rate of patients with cleft palate.

Study of relationship between clinical factors and velopharyngeal closure in cleft palate patients.

BACKGROUND: This study was carried out to analyze the relationship between clinical factors and velopharyngeal closure (VPC) in cleft palate patients. METHODS: Chi-square test was used to compare the postoperative velopharyngeal closure rate. Logistic regression model was used to analyze independent variables associated with velopharyngeal closure. RESULTS: Difference of postoperative VPC rate in different cleft types, operative ages and surgical techniques was significant (P=0.000). Results of logistic regression analysis suggested that when operative age was beyond deciduous dentition stage, or cleft palate type was complete, or just had undergone a simple palatoplasty without levator veli palatini retropositioning, patients would suffer a higher velopharyngeal insufficiency rate after primary palatal repair. CONCLUSIONS: Cleft type, operative age and surgical technique were the contributing factors influencing VPC rate after primary palatal repair of cleft palate patients.

Evaluation of the root and canal morphology of mandibular first permanent molars in a western Chinese population by cone-beam computed tomography.

INTRODUCTION: The purpose of this study was to evaluate the root and canal morphology of mandibular first permanent molars in a western Chinese population by using cone-beam computed tomography (CBCT). METHODS: In this study, 558 samples were examined by CBCT. Details of sex, tooth position, the number of roots and canals, and the canal configuration were recorded. The root canal configuration was categorized and compared according to Vertucci's criteria. RESULTS: Overall, 51.4% of the mandibular first permanent molars examined had four canals, and 25.8% had a separate distolingual root. In 48.1% of these, the fourth canal was in the separate distolingual root. In the two-rooted mandibular first permanent molars, 93.9% of the mesial root canals were of type IV, and 62.9% of the distal root canals were of type I. In the three-rooted samples, 94.4% of the mesial root canals were of type IV, and 98.6% of the distobuccal and 100% of the distolingual root canals were of type I. In addition, there was a higher incidence of three-rooted mandibular first permanent molars on the left side than on the right, but this relationship was not significantly correlated with sex. CONCLUSIONS: Mandibular first permanent molars commonly have four canals and a higher prevalence for a separated distolingual canal in a western Chinese population.

A cone-beam computed tomography study of maxillary first permanent molar root and canal morphology in a Chinese population.

AIM: This study evaluated root and canal morphology of permanent maxillary first molars in a Chinese population using cone-beam computed tomography scanning. METHODOLOGY: The sample included 775 cone-beam computed tomography images of maxillary first molars; 627 of the subjects had unilateral qualifying molars and 74 had bilateral qualifying molars. The following observations were made: (1) frequency of root and canal numbers, (2) frequency of additional canals in the mesiobuccal root by sex, age, and tooth position, and (3) unilateral and bilateral occurrence of additional canals in the mesiobuccal root. RESULTS: Fused roots were present in 2.71% of unilateral qualifying molars. Multiple canals were present in the following frequencies: two canals in 0.31%, three canals in 47.21%, four canals in 50.40%, five canals in 1.75%, and six canals in 0.31% of teeth. Additional canals were detected in 52.24% of mesiobuccal roots, 1.12% of distobuccal roots, and 1.76% of palatal roots. Patients aged 20 to 30 years showed a higher prevalence of additional mesiobuccal root canals. This prevalence did not differ with sex and tooth position. Most (71.11%) of the additional mesiobuccal root canals in subjects with bilateral qualifying molars were symmetric. CONCLUSION: Cone-beam computed tomography scanning is an effective method for studying external and internal dental morphology. The root and canal configurations of maxillary first molars in this Chinese population were consistent with previously reported data. More attention should be given to the detection of additional canals in patients between 20 and 30 years of age. These data may facilitate successful endodontic treatment.

[Investigation of the optimized surgical procedure for the cleft palate patients over six years old].

OBJECTIVE: To establish the optimized surgical procedure in our approach to treat the velopharyngeal insufficiency and improve the articulations of the patients with cleft palate over six years old. METHODS: Thirty-seven subjects over six years (including six years) old underwent the palatoplasty and sphincter pharyngoplasty simultaneously. We assessed the outcome of the surgery by perceptual speech assessment, nasopharyngoscopy and lateral cephalogram 10 to 15 months postoperatively. RESULTS: Twenty-two subjects got complete velopharyngeal closure. The velopharyngeal closure ratio of 15 subjects were over 85% according to the findings of the nasopharyngoscopy. Lateral cephalograms reveal that all the subjects could get their velars raised and well contacted with the posterior pharyngeal wall in dynamic condition. Perceptual speech assessment: The rate of hypernasality and nasal emission decreased significantly, and the consonant articulation increased. CONCLUSION: Our surgical procedure in this study corrected the velopharyngeal insufficiency and improved the articulation of the patients over six years old significantly.

[Usage status of periapical films undertaking in root canal treatment].

OBJECTIVE: To determine the current radiographic practices of root canal treatment (RCT) undertaken by endodontists, general dentist practitioners (GDPs) and interns, and to analyze the relationship between the usage of periapical films and the quality of RCT. METHODS: The patients who had received RCT treatment in West China College of Stomatology were investigated at random and were divided into three groups: Endodontists treating group, GDPs treating group and interns treating group according treating physician. The usage status of periapical film were investigated by the well designed questionnaires. The obturation quality of postoperative films were evaluated. Chi-square analysis was used to compare usage rates of periapical films of three groups. Mann-Whitney test was used to determine the relationship between the usage of periapical films and the quality of RCT. RESULTS: 571 teeth of 412 patients were investigated. In endodontists treating group, GDPs treating group and interns treating group, the usage rates of preoperative films were 95.3%, 89.5% and 92.1% respectively. The usage rates of working length films were 5.2%, 1.1% and 5.8% respectively. The usage of master point films was 94.8%, 72.1% and 97.4% respectively. The usage of postoperative films was 97.9%, 76.3% and 95.3% respectively. There were statistically significant differences among the working length films, master point films and postoperative films of three groups (P<0.05). The periapical films of adequate quality RCT and inadequate quality RCT were 3.14+/-0.639 and 2.84+/-0.736 respectively. There was statistically significant difference between periapical films of adequate quality RCT and inadequate quality RCT (P<0.05). CONCLUSION: Radiographic practices of endodontists and interns are more standardized than GDPs. Quality RCT is related to radiographic practices. Standard radiographic practices would be benefit to RCT.

[Effect of root canal curvature on canal length measurement on digital image of human lower mandibular permanent incisor].

OBJECTIVE: To investigate the effect of canal curvature on measured precision in canal length of human lower mandibular permanent incisors imaged by direct digital radiograph. METHODS: With Trophy digital X-ray system, 299 Chinese lower mandibular permanent incisors were selected to take the direct digital X-ray photography in both facial to lingual (L-T) and proximal directions (M-D). Two operators familiar with endodontic knowledge estimated the canal length by means of on-screen DDR with 2-and 3-click measurements. RESULTS: The true canal length of Chinese lower mandibular permanent incisors was (19. 54 +/- 1.62) mm. The tooth root canal length on digital image was overestimated with 3-click measurement (P < 0.05), and the canal length with 2-click measurement was almost similar to the true canal length from the facial-lingual direction X-ray photography (P > 0.05). The less than 1 mm difference between the estimated canal and the true canal length was above 95%. The canal length was underestimated with 2-click measurement as the curvature severity increased. CONCLUSION: Direct digital radiography system is applicable to estimate the canal length in clinic as the accuracy is very good. The curved canal length should be estimated with 3-click measurement.

[Comparative research of craniofacial structural characteristics of syndromic and non-syndromic patients with cleft palate].

OBJECTIVE: To compare craniofacial structural characteristic of syndromic and non-syndromic patients with cleft palate and to probe into the reason of their maxillary hypoplasia and to lay a foundation for better treatment protocol for syndromic patients with cleft palate. METHODS: The sample consisted of 8 individuals with Treacher Collin syndrome, 9 patients with Pierre Robin syndrome, and 40 patients with non-syndromic cleft palate which met certain criterions. Lateral cephalometric radiographs were obtained from each study subject. A total of 18 variables, comprising 9 angular, 7 linear, and 2 ratio measurements, were studied. SPSS 12.0 software was used to describe the statistics data, consisting of means, SD, and t test. RESULTS: The tendency for smaller value in SNB and larger value in ANB indicate a severer anteroposterior mandibular hypoplasia in the syndromic type cleft. There was no difference between syndromic and non-syndromic cleft palate patients with regards to maxillary anteroposterior development. No significant difference on the development in cranial base area was found either. CONCLUSION: This interplay of cranio-facial bones is very important in the development of this complex, which will not only affect the growth but also the defect development. In this study, the patients with the two syndromes showed the similar growth potential of maxilla with the non-syndromic cleft patients.

[Root canal curvature in chinese mandibular permanent incisors].

OBJECTIVE: To investigate the root canal curvature in Chinese mandibular permanent incisors. METHODS: Two hundred and ninety nine Chinese mandibular permanent incisors were included in this study. The root canals were inserted with stainless steel 15# K files, and then taken radiography from the facial and proximal view by X-ray paralleling technique. Canal curvatures were evaluated by measuring the angle, the radius of the curvatures, and the length of the curved part of the canal. Based on the curved angle and the shape of curved canals, the root canals were classified. RESULTS: The curved angle, radius, and the curved canal length was 5.28 degrees +/- 5.52 degrees, 16.19 mm +/- 12.38 mm, 4.10 mm+/-2.01 mm, respectively in the facial view; 9.99 degrees +/- 5.84 degrees, 18.86 mm +/- 9.71 mm, 3.27 mm +/- 2.39 mm, respectively in the proximal view. The prevalence of straight, light, moderate, and serve curved root canals in mandibular permanent incisors was 15.7%, 66.9%, 16.7%, and 0.7%, respectively (P<0.05) based on the curved angle. The prevalence of straight, L shape, and S shape curved root canals was 7.7%, 50.5%, and 41.8%, respectively (P < 0.05). CONCLUSION: Most of the root canals in mandibular permanent incisors are curve.

[Difficulty assessment of root canal therapy in Chinese permanent maxillary anterior teeth].

PURPOSE: To assess the difficulty of root canal therapy in Chinese permanent maxillary anterior teeth by radiographic methods in vitro. METHODS: 80 maxillary anterior teeth including 27 maxillary central incisors, 22 maxillary lateral incisors and 31 maxillary canines were collected and X-rayed in 3 individual directions: labiopalatal projection, mesiodistal projection and the maximal angle shot. Three anatomic risk factors: root curvature, calcification and working length of root canal therapy were assessed by difficulty assessment standards and criterions. Kruskal-Wallis test was used to analyze the data. RESULTS: The results showed that the root canal therapy of 2 and 3 were significantly more difficult than 1, P < 0.05; while there was no significant difference between 2 and 3, P > 0.05. In 1, the results of difficulty assessment of root canal therapy were significantly different among 3 individual X-rays which were projected from 3 different directions (P < 0.05). The difficulty caused by root curvature was significantly greater than calcification and working length in labiopalatal X-ray in 1 (P < 0.05) and 2 (P < 0.01), while there was no significant difference among these 3 risk factors in 3 in labiopalatal projection (P > 0.05). CONCLUSIONS: The results suggest that the labiopalatal X-rays can be safely regarded as the reliable projection shot for difficulty assessment before endodontic procedures. Root curvature was by far the most important risk factor that affected the difficulty of root canal therapy in 1 and 2 while root curvature, calcification and working length played the same roles in root canal therapy of 3.