Morphological Changes in Total and Inferior Part of Maxillary Sinus After Le Fort I Osteotomy, as Determined by Cone-Beam Computed Tomography.

To investigate morphological changes of the total and inferior part of the maxillary sinus following Le Fort I osteotomy. 21 skeletal class II and 49 skeletal III patients who underwent orthognathic surgery were enrolled in this retrospective study. Cone-beam computed tomography taken before (T1) and 6 to 24 months after (T2) orthognathic surgery were imported into Mimics 20.0 software to analyze morphological changes of the total and inferior part of the maxillary sinus. Volume of the whole maxillary sinus was significantly reduced after surgery ( P ≤0.008), while the volume of the inferior part of the maxillary sinus was significantly greater than before surgery ( P ≤0.004). Maxillary sinus floor moved occlusally after Le Fort I osteotomy. Movement in the pitch direction of the posterior maxilla affected the state of the maxillary sinus mucosa after orthognathic surgery. Le Fort I osteotomy exerts a significant impact on the morphology of the total and inferior part of the maxillary sinus.

Dental Pulp Stem Cell-Derived Exosomes Alleviate Mice Knee Osteoarthritis by Inhibiting TRPV4-Mediated Osteoclast Activation.

Osteoarthritis (OA) is a degenerative disease that causes chronic pain and joint swelling and even disables millions of patients. However, current non-surgical treatment for OA can only relieve pain without obvious cartilage and subchondral bone repair. Mesenchymal stem cell (MSC)-secreted exosomes have promising therapeutic effects on knee OA, but the efficacy of MSC-exosome therapy is not well determined, and the mechanisms involved are still unclear. In this study, we isolated dental pulp stem cell (DPSC)-derived exosomes by ultracentrifugation and determined the therapeutic effects of a single intra-articular injection of DPSC-derived exosomes in a mice knee OA model. The results showed that the DPSC-derived exosomes effectively improved abnormal subchondral bone remodeling, inhibited the occurrence of bone sclerosis and osteophytes, and alleviated cartilage degradation and synovial inflammation in vivo. Moreover, transient receptor potential vanilloid 4 (TRPV4) was activated during the progression of OA. Enhanced TRPV4 activation facilitated osteoclast differentiation, and TRPV4 inhibition blocked this process in vitro. DPSC-derived exosomes repressed osteoclast activation in vivo by inhibiting TRPV4 activation. Our findings demonstrated that a topical, single injection of DPSC-derived exosomes is a potential strategy for knee OA treatment, and that the exosomes regulated osteoclast activation by TRPV4 inhibition, which may act as a promising target for clinical OA treatment.

Clinical feasibility evaluation of a digital workflow of prosthetically oriented onlay bone grafting for horizontal alveolar augmentation: a prospective pilot study.

BACKGROUND: Onlay bone grafting is considered highly reliable for reconstructing severe horizontal bone defects. A critical problem is how to achieve precise position of the bone block to control alveolar ridge dimensions. This research aims to establish a digital workflow for prosthetically oriented onlay bone grafting and evaluate its accuracy and efficiency. METHODS: This prospective pilot study investigated eight patients who required implant restoration in the esthetic area with horizontal alveolar bone defects. The workflow includes preoperative virtual planning, design and manufacture of patient-specific templates, bone grafting surgery, and implant insertion. Primary outcomes were graft accuracy, defined by root mean square estimate (RMSE) values between preoperatively designed and actual implanted outer contours of bone blocks. Secondary outcomes were bone graft and implant success rates. Besides, the surgeons used the visual analog scale (VAS) to rate the intuitiveness, ease of understanding, and helpfulness of the workflow. RESULTS: No bone grafts or implants failed in any of the eight patients, resulting in a 100% success rate. The RMSE values between the preoperative design and the implanted outer contour of bone blocks were 0.41 ± 0.15 mm. The digital approach showed advantages in intuitiveness (9.3 ± 0.5), understanding (9.0 ± 0.5), and helpfulness (8.4 ± 1.1) according to surgeons' VAS scores. CONCLUSIONS: A digital workflow provided encouraging results, in terms of accuracy and efficacy, for horizontal bone augmentation. TRIAL REGISTRATION: This study was registered in the National Clinical Trials Registry in 16/02/2023 under the identification number ChiCTR2300068361.

Evaluating the efficiency of three methods to clean and disinfect screw- and cement-retained prostheses.

STATEMENT OF PROBLEM: Screw- and cement-retained prostheses (SCRPs) may be contaminated during fabrication in a dental laboratory, leading to mechanical and biological complications related to the implant treatment. Studies that explored methods to efficiently and conveniently clean and disinfect SCRPs are sparse. PURPOSE: The purpose of this clinical study was to compare the efficiency of 3 methods to remove contaminants and microorganisms present on the surface of an SCRP. MATERIAL AND METHODS: Forty-eight 1-unit SCRPs fabricated in a dental laboratory were randomly divided into 3 groups: wiping, soaking, or ultrasonic cleaning. The presence of contaminants was determined by scanning electron microscopy, and microbial cells were cultured before and after treatment. Bacterial colony-forming units (CFUs) on the surface of the SCRPs and contamination density at the implant-abutment interface and emergence profile area were assessed. Statistical tests including ANCOVA were used to compare the efficiency of different methods before and after treatment (α=.05). RESULTS: Significant differences in contamination density were noted during the treatment at the implant-abutment interface and at the emergence profile area in the 3 groups (P<.05), but no significant differences were observed in the number of CFUs (P>.05). There were significant differences among the 3 methods for cleaning efficiency both at the implant-abutment interface (P=.023) and the emergence profile area (P=.038). At the implant-abutment interface, the contamination density after treatment was lower in the ultrasonic cleaning group than that in the soaking group (P=.007), whereas at the emergence profile area, the contamination density after treatment was lower in the ultrasonic cleaning group than that in the wiping group (P=.019) and the soaking group (P=.048). CONCLUSIONS: All 3 treatment methods reduced contaminants on the SCRP surface, but ultrasonic cleaning yielded the most favorable results. However, none of the methods provided additional disinfection for SCRPs previously disinfected by ozone and UV in a dental laboratory.

Morphological analyses and a novel de novo DLX3 mutation associated with tricho-dento-osseous syndrome in a Chinese family.

Tricho-dento-osseous (TDO) syndrome, an autosomal-dominant disorder, affects the morphological appearance of the tooth enamel, hair, and bone. Previous studies have confirmed that mutations in the DLX3 gene are responsible for TDO. In this study, we describe a Chinese patient with the typical traits of TDO - kinky hair, enamel hypoplasia, skull and jaw bones thickening, and sclerosis. Unfortunately, as a result of excessive attrition, we were unable to assess taurodontism. Examination of the tooth ground section showed a thin layer of enamel with no rods on the patient's tooth and abnormalities in Tomes' granular layer and the dentinal tubules. Scanning electron microscopy and energy-dispersive X-ray spectroscopy of the tooth enamel showed significant differences between the patient and the control individuals. A hair sample from the patient observed under a laser-scanning microscope showed longitudinal grooves in the hair shaft. Dual-energy X-ray absorptiometry measurement showed that the bone mineral density values of the patient's bones was much higher than normal. Finally, genetic analysis revealed a novel de novo missense mutation c.533A>G (p.Q178R) in the conserved homeodomain of the DLX3 gene. This DLX3 mutation is the sixth causative mutation for TDO to be identified so far.

[Implanting the edentulous jaws with "All-on-4" immediate reconstruction: a preliminary clinical observation].

OBJECTIVE: To evaluate the treatment outcome of the "All-on-4" immediate loading protocol via survival rate of the implants,survival rate of the prosthesis,marginal bone, postoperative complications and patient satisfaction. METHODS: In our study, 40 patients with 49 edentulous jaws (31 mandibles and 18 maxillae) were enrolled. Each jaw was restored by the shortened dental arch prosthesis supported by only 4 implants according to the All-on-4 protocol (All-on-4, Nobel Biocare AB, Goteborg, Sweden). For all the patients enrolled in the study, the loading was applied within 12 hours of surgery. The provisional prosthesis could be replaced by the final restorations within 6 to 12 months. In the present study, the survival rate of the both implants and restorations were calculated and analyzed. The radiographic evaluation of marginal bone level changes was measured. The values of the marginal bone level changes of the angled and axial implants were analyzed by the statistic software. RESULTS: In the present study, totally 196 implants were inserted, of which 13 implants failed during the whole following up periods, with 11 implants of the maxillae and 2 of the mandibles. The survival rate of the prosthesis was 95.9% (47/49). The implant survival rate of the maxillae was 85.5% (65/76)while that for the mandibles was 98.3%(118/120). The implant survival rate of the angled implants was 91.8% (90/98), while that for the straight implants was 95.0% (93/98). No significant difference in marginal bone loss was found between angled and axial implants in the 12-month evaluation according to the Wilcoxon rank sum test (P>0.05). During the follow-up period,mechanical complications as fracture of the provisional prostheses, loose of the retain screw, or crack of the artificial teeth were found in 20 prostheses. CONCLUSION: The present preliminary data of the short term observation suggest that the "All-on-4" immediate loading protocol is a viable treatment modality for the edentulous jaws. However, long term clinical random controlled trials with large samples are still needed to confirm the validity of the technique.

Implant Survival and Complication Prevalence in Complete-Arch Implant-Supported Fixed Dental Prostheses: A Retrospective Study with a Mean Follow-up of 5 Years.

Purpose: To evaluate the implant survival and the prevalence of biologic and mechanical complications in edentulous patients restored with complete-arch implant-supported fixed dental prostheses (IFDPs). Materials and Methods: Patients restored with complete-arch screw-retained IFDPs between January 2012 and December 2019 with a minimum 2-year follow-up were included. Outcome measures were cumulative survival rate (CSR) for implants and prostheses, biologic complications, and mechanical complications. A generalized estimating equation model was used to estimate potential risk factors for mechanical complications. Patient satisfaction was investigated using a standardized questionnaire. Results: A total of 44 prostheses supported by 268 implants in 30 patients were included for a mean duration of 4.8 years (range: 2 to 9 years). Eighteen of the prostheses were zirconia-ceramic (group ZC), and 26 were titanium-ceramic (group TC). The CSR for the implants and IFDPs was 99.3% (95% CI: 98.2% to 100.3%) and 92.5% (95% CI: 84.2% to 100.8%), respectively. The most common biologic complication was peri-implant mucositis (4.5%), followed by peri-implantitis (3.0%). The most common mechanical complication was ceramic chipping (45.5%), followed by crown debonding (13.6%) and framework fracture (4.5%). There was no significant difference in the prevalence of complications between groups TC and ZC (P > .050). The presence of cantilever (OR = 5.54, P = .048) and maxillary arch (OR = 5.94, P = .041) were significantly associated with mechanical complications. Patient satisfaction scores were generally high, but some continued to be bothered by speech problems (13.6%). Conclusion: Complete-arch IFDPs presented reliable clinical outcomes for edentulous patients with a high implant survival rate and a high level of patient satisfaction. However, a high incidence of mechanical complications occurred in the long term.

Immediately or delayed sinus augmentation after pseudocyst removal: A randomized trial.

PURPOSE: To compare clinical and histological outcomes of sinus augmentation performed immediately or 3 months after pseudocyst removal through a prospective randomized controlled study. MATERIALS AND METHODS: In total, 33 sinus augmentation procedures were performed in 31 patients. Augmentation was performed either immediately after pseudocyst removal (one-stage intervention) or after 3 months (two-stage intervention). Six months postoperatively, bone specimens were harvested, and histomorphometric analysis was performed as primary outcome. Data were recorded and evaluated for implant survival rates, marginal bone resorption, complication rate, and patient-centered outcomes (visual analogue scale [VAS]). RESULTS: There were no baseline differences between groups or dropouts. Twelve biopsies obtained for histomorphometric analysis showed that delayed sinus augmentation, when compared to immediated led to a 1.1% increased mineralized bone ratio (95% confidence interval [CI]: -15.9 to 13.7). Graft leakage and acute sinusitis occurred in one patient in the one-stage group, none in the two-stage group. No pseudocyst recurrence was observed until the end of 1-year follow-up. Median VAS scores for overall acceptance were significantly increase of 1.4 (95% CI: 0.3-2.56) in immediate group. The degree of post-operative discomfort was not significantly different, although an increase of VAS (0.52, 95% CI: -0.32 to 1.37) was observed in delay group. CONCLUSIONS: Both procedures of sinus augmentation immediately and 3 months after pseudocyst removal could obtain comparable histological outcomes and had low complication rates. Patients who underwent the one-stage procedure had a short treatment course and high satisfaction rates, but this procedure is technically challenging to perform. This clinical trial was not registered prior to participant recruitment and randomization. The clinical trial registration number is ChiCTR2200063121. The hyperlink is as follows: https://www.chictr.org.cn/showproj.html?proj=172755.

[Influence of the placing depth of implants with platform switching on the marginal bone level in the posterior mandible: a clinical study].

OBJECTIVE: The purpose of this study was to evaluate the influence of the placing depth of the implants with platform switching (Ankylos) on the marginal bone remodeling, by means of radiological observation. METHODS: 111 Ankylos implants in the posterior mandible from 46 patients (20 male and 27 female) were enrolled in this study. Followed up by 58.1 months on average (from 36 to 85), 222 mesial and distal sites of these implants were evaluated by means of measuring the level of the marginal bone (LMB) on the panoramic radiograph. RESULTS: Among these 111 successfully functional loaded implants, there were no significant differences with the marginal bone absorption values, no matter the implants were placed below, at, or above the bone level (P>0.05). Concerning the stabilization of the marginal bone, when placed below the bone level, 67.7% of the implant sites had their LMBs stabilized at or above the implant platform, and 23.3% absorbed vertically, respectively 19.7% and 80.3% when placed at the bone level, with significant difference (P<0.001). CONCLUSION: Based on a long-term (over 3 years) observation, the implants placed below, as compared to at or above, the alveolar crest level, might have more chance to keep the marginal bone stabilized at or above the implant platform.

Influence of buccal emergence profile designs on peri-implant tissues: A randomized controlled trial.

BACKGROUND: The prosthetic emergence profile design might be an important factor in postsurgical mucosal recession etiology. Therefore, a restorative buccal emergence profile designed correctly might reduce gingival margin recession. PURPOSE: To compare the marginal gingival level and the width/height (W/H) ratio between two profile configurations of single implant-supported restorations at molar sites. MATERIALS AND METHODS: Twenty-one patients requiring a single mandibular molar tooth replacement with supracrestal mucosal thickness ≥2 mm were recruited and randomly assigned to a prosthesis buccal emergence profile design based on the buccal mucosal W/H ratio (Test Group) or maintained the original emergence profile of the healing abutment (Control Group). Assessments were made before delivery of the definitive restoration (T0), at prosthesis placement (T1), one (T2), and 12 (T3) months after loading. The gingival margin level change (△GM), initial emergence angle, buccal mucosal W/H ratio, marginal bone loss (MBL), implant failure, and complications were assessed. RESULTS: The gingival recession in the test group (0.13 ± 0.32 mm) was significantly lower than in the control group (0.63 ± 0.38 mm) at T3 (p = 0.006). The initial emergence angle in the test group (31.4 ± 7.22 degrees) was significantly lower than the control group (40.0 ± 7.60 degrees) (p = 0.025). The W/H ratio in the test group at T2 was significantly higher than at T0 but remained stable thereafter. The W/H ratio presented a continued rising trend in the control group. CONCLUSIONS: When the initial supracrestal soft tissue thickness was ≥2 mm, a restorative emergence profile based on the W/H ratio significantly reduced gingival margin recession. An emergence angle of 32.4 degrees showed better behavior in maintaining the gingival margin than 40 degrees. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR190002210.

Histologic and Clinical Evaluation of Ridge Augmentation of Extraction Sockets with Severe Bone Defects: A Clinical Prospective Study.

PURPOSE: To primarily evaluate the dimensional changes of bone and soft tissue following ridge augmentation in compromised molar regions. The secondary objective was to evaluate the histologic composition of augmented sites. MATERIALS AND METHODS: The study included 27 patients who underwent augmentation of extraction sites with grafts covered by a collagen membrane. CBCT was taken immediately after augmentation (T2) and after 8 months of healing, before implant placement (T3). The width and height of the extraction sites were recorded at extraction (T1) and reentry surgery (T4). A histomorphometric analysis was performed. Data were evaluated in terms of bone crest level, implant survival rates, and change in mucogingival junction. RESULTS: According to clinical measurement, horizontal and vertical bone gain was 10.15 ± 1.00 mm and 8.80 ± 1.86 mm, respectively. Radiographic measurement showed that the horizontal width changes were 1.46 ± 0.52 mm, 0.98 ± 1.29 mm, and 1.29 ± 0.82 mm, respectively, at 1, 3, and 5 mm apical to the crestal level. Vertical bone change was 2.34 ± 0.90 mm in the center of the socket. Histomorphometric analysis showed that percentages of mineralized bone, nonmineralized tissue, and bone substitute were 32.31% ± 13.25%, 25.36% ± 12.24%, and 42.34% ± 9.54%, respectively. The mucogingival junction shift was 0.6 ± 1.1 mm. Implant survival rates and crestal bone resorption were 100% and 0.78 ± 0.58 mm, respectively, after 1 year of loading. CONCLUSION: Ridge augmentation can be performed successfully to manage extraction sockets. Membrane coverage combined with primary wound closure could be conducive to new bone regeneration and peri-implant tissue health.

Does a Severely Resorbed Subantral Ridge Decrease Long-Term Implant Survival Rate with Sinus Floor Augmentation?

PURPOSE: To identify the impact of residual bone height on 5-year implant survival and prosthetic complication rates in patients who underwent maxillary sinus grafting. MATERIALS AND METHODS: A total of 87 consecutive patients were treated with 104 lateral approach maxillary sinus floor augmentation procedures with 100% deproteinized bovine bone and received 169 implants. The analysis considered patient age, sex, time of implant placement, and residual bone height. Patients with < 3 mm residual bone height were assigned to the study group; otherwise, they were placed in the control group. RESULTS: The mean follow-up was 68.2 months (0 to 103 months). The mean residual bone height was 1.8 mm in the study group and 4.1 mm in the control group. The 5-year implant survival and prosthetic complication rates were, respectively, 97.4% and 8.0% in the study group and 100% and 12.5% in the control group. Residual bone height, sex, age, and time of implant placement were not significant factors for the 5-year implant survival or prosthetic complication rate. The lateral bone wall was significantly thinner in the study group. The grafted bone height reduction was significantly different at 6 months and 2 years postoperation in both groups, but there was no difference in the change in grafted bone height reduction over time between the two groups. CONCLUSION: A residual bone height < 3 mm did not impact the survival rates of implants placed in grafted maxillary sinuses or the prosthetic complication rate after 5 years of functional loading.

Cascaded convolutional networks for automatic cephalometric landmark detection.

Cephalometric analysis is a fundamental examination which is widely used in orthodontic diagnosis and treatment planning. Its key step is to detect the anatomical landmarks in lateral cephalograms, which is time-consuming in traditional manual way. To solve this problem, we propose a novel approach with a cascaded three-stage convolutional neural networks to predict cephalometric landmarks automatically. In the first stage, high-level features of the craniofacial structures are extracted to locate the lateral face area which helps to overcome the appearance variations. Next, we process the aligned face area to estimate the locations of all landmarks simultaneously. At the last stage, each landmark is refined through a dedicated network using high-resolution image data around the initial position to achieve more accurate result. We evaluate the proposed method on several anatomical landmark datasets and the experimental results show that our method achieved competitive performance compared with the other methods.

[Clinical study of the application of non-invasive porcelain veneer to improve the aesthetic effects in maxillary anterior area].

OBJECTIVE: To evaluate the clinical results of application of non-invasive porcelain veneer to reduce the black triangle of implant and adjacent teeth and to improve the aesthetic effect in the maxillary anterior area. METHODS: The study included 10 patients (Male: 4, Female: 6; average age: 41.5) accessioned during May 2007 to August 2009 in Peking University School of Stomatology. The provisional restorations were delivery on implant after 3-6 months healing period of the implant. The non-invasive porcelain veneers were used in the round tip adjacent teeth with gingival recession in the indicated patients. Main measured parameters on the model included horizontal distance and vertical distance. The Horizontal distance refers to the black triangle bottom which is from adjacent surface of the natural teeth to the implant restoration at the gingival level. The vertical distance is from mid-point of the triangle bottom to the contact point. Clinical observed items included bleeding index (BI), integrity of porcelain veneer and degree of satisfaction of the patients. RESULTS: A total of 14 adjacent natural teeth in 10 patients were cemented with porcelain veneer. No porcelain veneer was lost or fracture during follow-up period (range 6 to 27 months, mean of 10.4 months). Mean bleeding index 0-1. The horizontal distance was reduced from (3.1 + or - 0.8) mm before restoration to (1.1 + or - 0.5) mm after restoration. Vertical distance from (5.3 + or - 1.1) mm to (2.9 + or - 0.7) mm. All patients were satisfied with the clinical result. CONCLUSION: The data and the experience described in this study indicate that improvement of aesthetic effects by using no-invasive porcelain veneer techniques can be a predictable technique for patients with periodontal disease. Further study is needed to determine the long-term result of the technique.

Influence of crown-to-implant ratio and different prosthetic designs on the clinical conditions of short implants in posterior regions: A 4-year retrospective clinical and radiographic study.

BACKGROUND: Short implants (intra-bony length ≤ 8 mm) are generally considered as an alternative to bone augmentation in challenging situations; however, clinical evidence from large-scale studies with long follow-up regarding the application of short implants remains deficient. PURPOSE: The present study aimed to assess the mid-term clinical outcomes of short implants supporting fixed prostheses in the posterior region, and to investigate the effects of the crown-to-implant ratio (C/I), and other patient-, implant-, prosthesis-relevant factors on the clinical conditions around short implants. MATERIALS AND METHODS: 180 Thommen short implants in 130 partially edentulous patients were enrolled in the study after 3 to 7 (mean 4.2) years of follow-up. Potential risk factors (patient sex and age, implant diameter and location, splinted vs single-tooth restorations, retention mode, anatomical and clinical C/I ratios) were evaluated according to the following outcomes: Implant survival, marginal bone loss (MBL), and mechanical and biological complications. RESULTS: In total, four implants in four patients failed as a result of peri-implantitis. The cumulative survival rate was 97.8% for implant-based analysis. The peri-implant MBL around 180 short implants was 0.90 ± 0.78 mm. The mean clinical C/I ratio was 1.16 ± 0.36. Correlation analysis revealed that the influence of the clinical C/I ratio and patient age were significant for MBL (P < .05), whereas other potential risk factors showed no significant association with the outcome. Among 180 short implants, 24 cases (13.3%) had biological complications and 32 cases (17.8%) had mechanical complications, respectively. Peri-implant MBL and complication rates around splinted and non-splinted implants were not statistically different. CONCLUSION: Within the limitations of this study, short implants supporting fixed prostheses in the posterior region achieved predictable clinical outcomes over a 3 to 7 year period. Within the range of 0.47 to 3.01, the higher the C/I ratio, the less the peri-implant MBL.

Histological and clinical outcomes of lateral sinus floor elevation with simultaneous removal of a maxillary sinus pseudocyst.

BACKGROUND: Maxillary sinus pathologies are a potential risk for failure of implant and bone augmentation. Management of lateral sinus floor elevation in the presence of a pseudocyst remains controversial, and reports on histological outcomes of endo-sinus bone augmentation with maxillary cysts are scarce. PURPOSE: To present a modified surgical technique for removal of maxillary pseudocyst with simultaneous sinus floor elevation, and to evaluate clinical and histological outcomes of the bone grafting. MATERIALS AND METHODS: Patients with a radiographic dome-shaped opacity in the posterior maxillary sinus were included to receive lateral sinus floor elevation with simultaneous pseudocyst removal. Bone core specimens harvested from the lateral aspect of the augmentation sites were histomorphometrically analyzed. Data were recorded and evaluated in terms of survival rates and complications. RESULTS: A total of 15 patients were included who underwent 17 maxillary sinus augmentation surgeries. Implant survival rate was 97.0%. Bone biopsy specimens were obtained at 6 months after surgery. Histomorphometric analysis revealed that mean percentages of mineralized bone, bone substitute, and nonmineralized tissue were 24.9% ± 18.1%, 14.4% ± 12.5%, and 60.1% ± 12.44%, respectively. No recurrence of the pseudocyst was detected on radiographic examination. CONCLUSIONS: The described technique could be successfully applied in clinical practice to perform sinus augmentation in the presence of pseudocysts.

[Clinical study of free palatal connective tissue grafts for enhancement of periimplant soft tissue topography in maxillary esthetic area].

OBJECTIVE: To evaluate the results and clinical characteristics of free palatal connective tissue graft in closing of immediate implant wound and reconstructing of labial soft tissue topography. METHODS: A total of 285 cases underwent free palatal connective tissue graft transplantation in the implant treatment from June 1997 to June 2006 were included in this study. All cases were followed up for at least one year (1 to 8 years). RESULTS: 4 grafts in 3 cases had necrosis. The other 295 grafts survived well. Following Jemt classification of papilla, 127 cases reached II degree, and 18 cases reached III degree one year after prostheses. 87 cases had no concave defect of labial soft tissue. CONCLUSION: It is effective and predictable to preserve and reconstruct periimplant soft tissue topography with palatal free connective tissue grafts in maxillary esthetic area.

Efficacy of the split-thickness labial flap method for soft tissue management in anterior ridge horizontal augmentation procedures: A clinical prospective study in the anterior maxilla.

OBJECTIVE: To introduce a novel method of split-thickness labial flap in maxillary anterior ridge horizontal augmentation and to evaluate its efficacy and morbidity. MATERIALS AND METHODS: 230 patients were selected to receive either particulate or onlay grafting. A split-thickness labial flap was applied to cover the grafted area and close the wound. The incidence of postsurgical complications and the level of patient discomfort were evaluated. A visual analog scale was used to quantify the amount of pain and swelling in the patients. RESULTS: In all 375 surgical sites, passive primary closure was achieved with the split-thickness labial flap method. Membrane exposure after surgery was seen in 6 cases in the onlay group and in 4 in the particulate group. No long-lasting pain (>1 week), paresthesia, or signs of infection occurred during the follow-up period of 6 months. The mean pain and swelling scores in the particulate graft group (2.75 ± 3.01 and 2.02 ± 2.51, respectively) were lower than the scores in the onlay graft group (3.18 ± 2.79 and 3.85 ± 2.25, respectively). CONCLUSIONS: The flap advancement technique presented in this study facilitates clinically passive primary closure. This technique can be used successfully in both particulate and onlay horizontal graft procedures.

Onlay grafting with bovine bone mineral block for horizontal reconstruction of severely atrophic alveolar ridges in anterior maxillae: A 6-year prospective study.

PURPOSE: The aim of this prospective study was to evaluate the efficacy and long-term outcomes of onlay grafting with bovine bone mineral block for reconstruction of horizontal alveolar ridge defects in anterior maxillae. MATERIALS AND METHODS: Fourteen patients requiring rehabilitation of edentulous anterior maxillae were enrolled to receive onlay grafting in two layers. A cortical block harvested from the lateral aspect of the mandibular ramus was split to acquire approximately 1-mm-thick bone laminae. The cortical bone plate and block graft were compressed and fixed to the recipient sites. After 6 months, the width of the augmentation was recorded, and implants were inserted. Provisional and definitive prostheses were delivered 3 and a further 6 months later. Implant success and associated complications were assessed. RESULTS: The horizontal bone gain was 8.73 ± 0.82, with a resorption rate of 7.03%. Severe bone resorption was noticed 6 months and 2 years after loading. Fistula occurred with the nonintegrated bovine block on the labial sides of the augmented sites 6 years after loading. CONCLUSION: Onlay grafting with bovine bone mineral block in the anterior maxilla may yield optimal horizontal gain with low resorption rates, under the condition of at least 6 months' healing time, mixation with autogenous particulate bone, and application of a membrane to cover the graft site.

New classification of maxillary sinus contours and its relation to sinus floor elevation surgery.

BACKGROUND: It is complicated to select an appropriate sinus floor elevation and the procedure for sinus floor elevation lacks of consensus. Sinus contour plays an important role in choosing a surgery approach. But there are still no published articles revealing the influence of sinus contours to sinus floor elevation surgery. PURPOSE: We propose a new classification depending on sinus contours from cone-beam computed tomography (CBCT), analyze clinical characters of different types, and investigate the relationship between sinus contours and sinus floor elevation. MATERIALS AND METHODS: We divide sinus into five categories: narrow tapered, tapering, ovoid, square, and irregular. For the first four types, subtypes are classified into three categories: without recess, with buccal-sinus-recess (BSR), and with palate-nasal-recess (PNR). For irregular type, subtypes are classified into three categories: tooth protruding into sinus floor, irregular floor, and septa/exostosis on sinus floor. Then the distribution features of sinuses of 698 patients are described. Sinus widths are measured at second premolar, first and second molar on both sides, and are compared among different types and subtypes. RESULTS: Narrow tapered sinus occupies 88% at second premolar sites, while tapered sinus occupies almost 50% at first and second molar sites. At second premolar and first molar sites, 62% are without recess types. While 92% are without recess types at second molar. Sinuses with BSR present in only three of 3765 sites. There is an increasing trend of sinus width from narrow tapered to irregular type. Sinus width of the group with recesses is significantly higher than the one without recess. At the end, we provide corresponding treatment recommendations for each sinus types and subtypes. CONCLUSION: This is the first classification system that gives treatment recommendations for sinus floor elevation surgery based on sinus contours. The classification system is consistent, easy to visualize, and practicable.