Effects of Dose and Injection Site on Gingival Smile Treatment with Botulinum Toxin Type A: A Prospective Study.

BACKGROUND: Botulinum toxin type A is an easy and efficacious treatment for gingival smile. However, the optimal dose and injection site are controversial. The authors compared the reduction in gingival exposure using two methods with different doses and injection sites. METHODS: In this prospective self-controlled study, healthy participants with gingival smile (anterior gingival exposure of >3 mm) underwent two treatment methods. First, participants received a single-point injection of 2 U of botulinum toxin type A per side (simplified method). After 8 months, the individualized method was performed with 2 to 5 U of botulinum toxin type A (total, 4 to 10 U), which was injected at one or two sites according to pretreatment severity. Data were collected at baseline and at 4, 12, and 32 weeks of follow-up. RESULTS: Fifty-five participants were enrolled. Anterior gingival exposure and bilateral posterior gingival exposure were significantly reduced 4 and 12 weeks after botulinum toxin type A injection ( P ≤ 0.05) with both methods. These parameters returned to baseline by 32 weeks ( P > 0.05). Posttreatment anterior gingival exposure at 4 weeks and 12 weeks with the individualized method was significantly lower compared with the simplified method (both P ≤ 0.05). Patient satisfaction with the individualized method was preferred compared with the simplified method ( P ≤ 0.05). Few adverse events were observed with both methods without statistical significance. CONCLUSION: It is necessary to increase the injection dose and tailor the injection site according to the pretreatment severity of anterior gingival smile.

The Relation between Morphology of Maxillary Sinus after Augmentation in Three Classification Methods and Residual Bone Height: A Retrospective Study.

Maxillary sinus augmentation is critical to oral implantology, particularly in some cases. The morphology of the sinus floor reflects the lifting effect to a certain extent; however, there has been limited research on the morphology after sinus augmentation. The present study aims to investigate the relationship between residual bone height (RBH) and the morphology of the sinus floor and determine whether a correlation exists between the different evaluation classifications. Maxillary sinus floor augmentation procedures were performed in 56 patients and 68 teeth using the sinus crest approach (SCA). Imaging results obtained after one year of sinus augmentation were analyzed and simultaneously classified along the coronal plane, the sagittal plane, and the biplane (coronal-sagittal). The higher the RBH, the closer the result tends to be to A, A', or type 1 (more satisfactory). There was a significant correlation between the three different evaluation classifications (p < 0.05). The morphology of perforation cases was involved in types C, D, C', and D'. A more satisfactory post-lifting morphology (tent type and flat type) is probably related to an optimal preoperative bone height, and an unsatisfactory post-lifting morphology is related to a low preoperative sinus floor height. The sagittal plane evaluation correlates with the coronal plane and biplane evaluation and is thus more recommended.

Individual Factors of Botulinum Type A in Treatment of Gummy Smile: A Prospective Study.

BACKGROUND: Botulinum type A (BTX-A) injection is a promising treatment for gummy smile (GS), although its effects are varied and inconsistent. OBJECTIVES: The aim of this study was to explore the effect of individual factors on BTX-A treatment for GS, and to establish treatment expectations. METHODS: In this prospective clinical study, a standardized technique comprising bilateral single-point injections of 2 U BTX-A (total, 4 U) was administered to all GS patients. Data were collected at baseline and after 4, 12, and 32 weeks of follow-up. Twenty-nine potential individual factors were analyzed by correlation and regression analysis to exclude confounding bias. RESULTS: Ninety-four patients completed the BTX-A treatment. After adjusting for potential confounding factors, the correlation and regression analysis confirmed the following formula: anterior gingival exposure (GE) at 4 weeks = 1.44 + (0.94 × baseline anterior GE) - (1.88 × sex) (where male = 1 and female = 2). The confidence interval (CI) of the prediction showed that for all female participants with baseline anterior GE <5.3 mm, the 95% CI of anterior GE was 0.3 to 3.0 mm after 4 weeks of treatment, and 3.0 to 8.9 mm with baseline anterior GE ≥6 mm. For male patients with baseline anterior GEs of 3 and ≥4.6 mm, the 95% CIs were 1.5 to 3.3 mm and 3.2 to 8.9 mm, respectively. CONCLUSIONS: The effect of average-dose BTX-A treatment for GS depended on GS severity and patient's sex, rather than GS etiology and other factors. Female participants with baseline anterior GE <5.3 mm were more likely to show complete improvement after 4 weeks of treatment. However, female participants with baseline anterior GE ≥6.0 mm or male participants were less likely to show complete improvement at 4 weeks.

Evaluating the utility of various drought indices to monitor meteorological drought in Tropical Dry Forests.

Even though existing remote-sensing-based drought indices are widely used in many different types of ecosystems, their utility has not been widely assessed in tropical dry forests (TDFs). The aim of this study is to evaluate the performance of three remote-sensing-based drought indices, the Vegetation Condition Index (VCI), Temperature Condition Index (TCI), and Vegetation Health Index (VHI), for meteorological drought monitoring in TDFs using the moderate-resolution imaging spectroradiometer (MODIS) products. The correlation between the VCI, TCI, and VHI and multiple time scales of the Standardized Precipitation Index (SPI) (1, 3, 6, 9, 12, 15, 18, 21, 24 months) for each month (January to December) and each season (dry season, dry-to-wet season, wet season and wet-to-dry season) were conducted using the Pearson correlation analysis. We also correlated year-to-year changes of satellite-based drought indices with the changes of the in situ annual SPI (A_SPI) which provides annual information on the mean meteorological drought. The analysis reveals that the ability of these remote-sensing-based drought indices for meteorological drought monitoring varies with timing, and the TCI outperforms the VCI and VHI in terms of seasonal and annual scale. These remote-sensing indices performed well in monitoring meteorological drought in the dry season, poorly in the in the dry-to-wet season, and moderately in the wet season. The TCI performed best in monitoring meteorological drought in the wet-to-dry period, followed by VHI, whereas the VCI performed worst. All of these remote-sensing-based drought indices failed to detect drought in May during the green-up period and in September, October, and November when the water content in the root regions was abundant. Our results indicate that the evapotranspiration of TDFs is more sensitive than canopy greenness to detect meteorological drought. Results from this study increase the ability to provide real-time drought monitoring and early warnings of drought in TDFs.

[Measurement and analysis of the nasopalatine canal and its relative position by cone-beam computed tomography].

OBJECTIVE: To evaluate dimensions of the nasopalatine canal and the relationship between the canal and the central incisors, and the canal and the crest, by using cone-beam computed tomography (CBCT). METHODS: This study included 129 CBCTs, and the sagittal slices were used to measure the lower diameter (Sda), median diameter (Sdb), and higher diameter (Sdc), for calculating the average sagittal diameter (Sd); the coronal slices through canals were used to measure the lower diameter (Hda), median diameter (Hdb), and higher diameter (Hdc) for calculating the average horizontal diameter (Hd), length (H); the sagittal slices were used to measure the buccal bone thickness off the canal (Bt), and the distance to the crest off the lowest point (At), the horizontal slices were used to measure the distance between the canal and the central incisors (Id). These subjects were divided into two groups by gender; and divided into three groups by ages: (1) ≤ 30 years old, (2) 31-50 years old, and (3) ≥ 51 years old. SPSS 17.0 statistical software was used for statistical analysis. RESULTS: The overall Sd was (3.41 ±0.87) mm, the Hd was (5.16±0.93) mm, and the difference was statistically significant. The H was (14.29 ± 3.27) mm, the Bt was (7.49 ± 1.05) mm, the At was (8.25 ± 1.71) mm, and the Id was (2.71±0.89) mm. Of the male and female, the Sd were (3.64 ± 0.90) mm and (3.28 ± 0.82) mm, P=0.017; the Hd were (4.98 ± 0.89) mm and (5.27 ± 0.94) mm, P=0.081; the H were (15.47 ± .75) mm and (13.59 ± 3.32) mm, P=0.001; the Bt were (7.90 ± 0.96) mm and (7.25 ± 1.03) mm, P=0.001; the At were (7.41 ± 1.86) mm and (8.44 ± 1.90) mm, P=0.001; the Id were (2.71 ± 0.87) mm and (2.72 ± 0.91) mm, P=0.983. Among the groups, no statistically significant differences were detected of the Sd (P=0.325), of the Hd (P=0.636), of the H (P=0.292), and of the Bt (P=0.116); statistically significant differences were detected of the At (P=0.010), and of the Id (P<0.001). CONCLUSION: The nasopalatine canal anatomy is highly variable. Gender is related to the nasopalatine canal length, Bt width, and At distance. While age was related to At, and Id, but no effect on nasopalatine dimensions. The CBCT is a useful device for studying the nasopalatine canal in three dimensions, prior to dental implant placement.

[Comparison of soft and hard tissue stability between immediate implant and delayed implant in maxillary anterior region after loading 2 years].

OBJECTIVE: To compare the peri-implant tissue stability between immediate implant and delayed implant in maxillary anterior region after loading 2 years. METHODS: In the study, 38 patients with single anterior tooth loss in the Second Clinical Division of Peking University School and Hospital of Stomatology from October 2010 to December 2011 were enrolled, and 43 implants were inserted. The gingival contour was induced using implant-supported temporary crowns prior to restoration till permanent prostheses delivered. The gingival papilla height, labial gingival margin level and peri-implant bone level were measured immediately after the permanent restoration and 2 years later. RESULTS: In the study, 16 patients were treated by immediate implant for 17 implants; 22 patients were treated by delayed implant for 26 implants. The implant stability quotient (ISQ) value of the 2 groups showed no significant difference before permanent restoration (P>0.05). In all the cases after loading 2 years, the average mesial gingival papilla height in the implant area of the immediate group and delayed group increased by (0.15 ± 0.42) mm and (0.06 ± 0.65) mm, respectively; the distal gingival papilla height increased by (0.06 ± 0.50) mm and (0.02 ± 0.57) mm respectively; while the labial gingival margin level shrinkages were (0.15 ± 0.23) mm and (0.15 ± 0.46) mm, respectively. The peri-implant bone losses in the mesial side were (0.67 ± 0.35) mm and (0.6 9 ± 0.49) mm, respectively, while in the distal side were (0.73 ± 0.31) mm and (0.75 ± 0.48) mm, respectively. All these indicators showed no significant difference between the 2 groups (P>0.05). CONCLUSION: Both the cases obtained optimizer results after loading 2 years, and the soft and hard tissues around the implant were very stable, which means that both the protocols can achieve reliable therapeutic effects. If we can handle the indications, immediate implant for anterior teeth shows similar efficacy with delayed implant in the short term. But immediate implant in terms of shortening the course of treatment is clearly superior to delayed implant.

Evaluation of the therapeutic efficiency of mandibular anterior implant-supported fixed bridges with cantilevers.

BACKGROUND: Dental implant technology has developed rapidly in recent years. However, the use of implant-supported fixed bridges with cantilevers has been controversial. The purpose of this study was to evaluate the clinical results of the mandibular anterior implant-supported fixed bridges with a cantilever. Method Thirty-three patients (15 males, 18 females; mean age, 42.6 years; range 20-54 years) with two missing anterior mandibular teeth had single implant-supported fixed bridges with a cantilever. Clinical examination was recorded and radiographs were taken. The mean duration of follow-up was 30 months (15-44 months). RESULTS: All implants survived. Loosening or fracture of the prosthesis was not observed. All patients were satisfied with the treatment. The mean bone resorption values after 12, 24, and 36 months of implant loading were 0.94, 1.18 and 1.35 mm respectively. The changes of gingival papilla height ranged from 0 to 0.5 mm. There was significant difference between 1-year and 2 or 3 years restoration groups regarding the average gingival height changes (P < 0.05). CONCLUSION: After careful and precise selection of patients, restoration with a single implant-supported fixed bridge with a cantilever can be recommended if two anterior mandibular teeth are missing.

[Evaluation of short-term clinical therapeutic efficiency of computer aided design and manufacturing titanium-ceramic-fixed partial dentures for implant-supported restoration in posterior region].

OBJECTIVE: To evaluate the clinical results of computer aided design and computer aided manufacturing (CAD/CAM) titanium-ceramic-fixed partial dentures for implant-supported restoration in posterior region. METHODS: In the study, 90 patients (47 males, 43 females, and the mean age of 48.7 years ranging from 30-62 years) with posterior tooth missing underwent implant-supported porcelain fuse mental prostheses with CAD/CAM titanium-base. A total of 135 prostheses (159 prosthetic units) were fabricated, and 152 implants were placed. The evaluators examined the integrity of restoration, gingival health, color match and marginal adaptation. The mean follow-up time was 51.9 months (24-80 months). RESULTS: No implant was lost during the loading time. All the patients were satisfied at the end of their treatment. The chipping rate of porcelain fuse mental prostheses with CAD/CAM titanium-base was 13.2%(21/159 prosthetic units), No fracture of titanium-base was observed, and 7.4% (10/135) prostheses were found loosening. The authors rated 97.8% (132/135) prosthesis as good or better in regard to color match, 100% (152/152) implants had excellent marginal adaptation. CONCLUSION: The implant-supported titanium-based porcelain fuse mental prostheses with CAD/CAM show good marginal integrity and shade stability, with a clinically acceptable chipping rate, and these restorations can achieve success in the case of posterior tooth missing. Further study is needed to determine the long-term results.

Reconstruction of accessory nerve defects with sternocleidomastoid muscle-great auricular nerve flap.

We introduced a new method for reconstruction of accessory nerve defects by using the sternocleidomastoid muscle (SCM)-great auricular nerve flap. Thirty-four patients receiving traditional radical neck dissection were divided into two groups: the accessory nerve not-reconstructed group (Group A, N = 19) and the accessory nerve reconstructed group (Group B, n = 15). The surgical procedure of the reconstruction is described in detail. Postoperative shoulder functions were compared between the two groups. We found that Group B experienced much better shoulder function recovery than Group A. Both groups had good wound healing. It is concluded that reconstruction of accessory nerve defects with SCM-great auricular nerve flap is simple, effective and complication-free and worthwhile.

[Preliminary proposal of the severity score system for maxillofacial injuries].

OBJECTIVE: A new injury severity score system was proposed in this study to evaluate maxillofacial injuries. METHODS: Based on AIS-90, all clinical samples were given diagnosis. Their month opening limitation, malocclusion and facial deformity were recorded as indices in scoring system. Severity injury scores for different groups and types were statistically. analyzed. RESULTS: It was demonstrated that there was a significant difference in scores between injuries of soft tissue and bone tissue and between different fracture groups. CONCLUSIONS: The proposed scoring was system useful to predict the cost of medical care and the days of in-patient, reliable, sensitive and specific in evaluation the maxillofacial injury severity.

[Reconstruction of accessory nerve defects with sternocleidomastoid muscle-great auricular nerve flap].

OBJECTIVE: To describe a new method of accessory nerve defect reconstruction with sternocleidomastoid muscle-great auricular flap. METHODS: Thirty-four cases receiving traditional radical neck dissection were divided into two groups: single neck dissection group (n = 19) and accessory nerve reconstruction group (n = 15). Surgical procedure of the reconstruction was described in detail. Postoperative shoulder functions were compared between the two groups. RESULTS: Accessory nerve reconstruction group experienced much better shoulder function recovery than that in single neck dissection group. CONCLUSIONS: Reconstruction of accessory nerve defects with sternocleidomastoid muscle-great auricular nerve flap is simple, effective and complication-free.

[Surgical anatomy and preservation of the accessory nerve in radical functional neck dissection].

OBJECTIVE: The surgical anatomy and preservation of the accessory nerve in radical functional neck dissection were studied. METHODS: Thirty-three cN(0) patients with oral cancers were entered into the study. Radical functional neck dissection were performed and the relations between the accessory nerve and its surrounding structures were recorded. RESULTS: The accessory nerve going through or beneath the sternocleidomastoid muscle occurred in 82% (27/33) and 18% (6/33) of the patients respectively. Communicating branches between the accessory and the cervical nerves were found in 85% (28/33). There was 2 to 3 cm of the accessory nerve paralleled to the anterior border of the trapezius muscle before it entered the muscle in 70% (23/33). The dissection of the nerve needed 20 to 30 minutes. Twenty-seven percent of the patients had pathologically proved lymph node metastases. CONCLUSIONS: Looking for accessory nerve under the upper portion of the sternocleidomastoid muscle and above the middle point of the muscle posterior border is simple and safe. The point of the great auricular nerve going out the muscle is an important indicator for finding the accessory nerve.