[Research for the influencing factors affecting the long-term survival time of implants: a retrospective cohort study].

PURPOSE: To investigate the timing of implant failure events and their relationship with the dental position and the factors affecting the survival time of implants. METHODS: A retrospective cohort study was conducted to analyze the patients who had implants removed due to implant failure in the Department of Dental Implantology of Hefei Stomatological Hospital from January 2019 to December 2021. The predictor variables were surgical age, gender, smoking habit, oral hygiene, glucose value, jaw and dental position, implant type, implant number, surgeon, implant placement timing, implant loading timing, and antibiotic use timing. The outcome measurement was the implant survival time and implant failure events. Chi-square test, Kaplan-Meier(Log-rank test), and Cox proportional hazards model were used to identify and stepwise determined potential risk factors for implant survival time with SPSS 21.0 software package. RESULTS: A total of 89 patients(95 implants) had to remove implants. The mean survival time of the failed implants was 31(95%CI :24.2-39.1) months. Implant number (P=0.038), implant loading timing (P=0.050), and tooth position (P=0.024) were significantly correlated with the implant survival time. The risk of failure with 2 implants was 2.709 (HR=3.709, 95%CI: 1.075-12.795) times higher than that with 1 implant, and the risk of failure with late implant loading was 0.551(HR=1.511, 95%CI: 0.999-2.406) times higher than that with early implant loading. The risk of anterior teeth implant failure was 1.384 times higher than that of molars(HR=2.384, 95%CI:1.327-4.283). For patients with implant failure, about 50% of the patients removed the failed implant within 1 year after surgery, and the rate of removal of the failed implant gradually slowed down in the following 2-10 years. Peri-implantitis most commonly occurred in molars(50%). Implant fracture lastly occurred at 55(95%CI: 42.2-67.9) months postoperatively（P=0.000）. CONCLUSIONS: The number of implants, implant loading timing, and dental position were considered as the influencing factors for the survival time of implants. Follow-up in the first year after implantation seems to be particularly important for timely detection of problems and timely intervention. The occurrence of implant failure events was related to dental position and time.

[A five-year experience for treating patients with chronic apical periodontitis with root canal treatment: a retrospective cohort study].

PURPOSE: To investigate the clinical outcomes, including survival and periapical healing rates and failure causes, of root canal treatment for patients with periapical lesion. METHODS: A retrospective cohort study was conducted which enrolled patients admitted for the evaluation and management of periapical lesion with root canal treatment. The primary predictor variables were difficulty assessment of root canal therapy (DARCT),which was divided into lower（DARCT =3-4）, medium (DARCT =5-7) and higher (DARCT =8-9) difficulty root canal, in terms of canal length, curvature and calcification. The primary outcome measurement was the incidence of periapical healing and survival rate. Potential confounders included patient demographics, canal number, root canal filling, and coronal restoration. SPSS 21.0 software package was used for data analysis. RESULTS: The 5-year survival rate was 81.4%(83/102) and healing rate was 77.1% (64/83). DARCT was significantly associated with the survival rate(P=0.017). Root fracture, deep pockets lesions and periodontal abscess were observed in DARCT with a value of 8-9(P=0.027), leading to tooth extraction. The teeth with multiple root canals were extracted due to recurrent or persistent periapical lesion (P=0.004). Chi-square test showed that root canal number (P=0.021), quality of root canal filling (P=0.006) as well as DARCT (P=0.000) were significantly correlated with the final healing rate. Multivariate logistic regression analysis showed that DARCT (P=0.000) and the quality of root canal filling (P=0.033) were associated with the final healing rate. CONCLUSIONS: DARCT and the quality of root canal filling play key roles in the clinical prognosis of periapical lesion, DARCT and number of root canal are more likely to be correlated with failure.

[The relationships between different surgical approaches for maxillary sinus augmentation and implant failure and complications: a retrospective cohort study].

PURPOSE: To investigate the 5-year survival and complication rates of implants placed in grafted sinuses with different surgical approaches and analyze the causes for failure. METHODS: This study retrospectively observed the prognosis of patients who underwent maxillary sinus augmentation by means of lateral window technique(LWT) or transalveolar osteotomy technique (TOT) and simultaneously installed implants performed, in Hefei Stomatological Hospital. The primary predictor variables were surgical approaches, including LWT and TOT. The primary outcome measurement was the 5-year implant survival rate, complication rates and failure causes. Potential confounders included diabetes, age at surgery, gender, smoking habit, oral hygiene, tooth position, length and diameter of implants and type of prosthesis. Chi-square test and logistic regression analysis were performed with SPSS 21.0 software package. RESULTS: Fifty-nine patients (31 males and 28 females), installed with 93 implants, with a mean age of (61.3±10.1) years old, were enrolled. Over (5±1.2) years of follow-up, five implants failed, with a total survival rate of 94.6%. In detail, there were 3 failed implants in the LWT group and 2 failed implants in the TOT group, for a survival rate of 85.7% and 97.2%, respectively. Chi-square test showed that smoking habit (P=0.010), oral hygiene(P=0.037) as well as operative approach(P=0.040) were significantly associated with the final survival rates, multivariate logistic regression analysis displayed that smoking habit (OR=0.030, 95%CI: 0.002-0.493, P=0.014) was still associated with the finial survival rates. Surgical approach(P=0.025) was markedly related to causes for the failed implants. Of which, three (100%) failed implants in the LWT group was due to poor osseointegration and implant mobility 3 months after sinus augmentation, and 2(100%) in the TOT group was because of persistent peri-implantitis and loss of the graft or alveolar bone 4 years after sinus augmentation. Smoking habit was also significantly relevant to complication rates(P=0.014), and the occurrence incidence of controllable peri-implantitis in patient having a smoking habit was relatively higher, accounting for 6.8%(6/88), compared with patients without smoking habit. Significant relationship between surgical approaches and implant complications was not observed(P=0.051). CONCLUSIONS: Different surgical approaches for maxillary sinus augmentation do not significantly correlate with implant survival rates and implant complications. However, surgical approach is markedly related to the causes of failed implants. Smoking will lead to a decreased implant survival rate and controllable peri-implantitis.

Proper Choice of Donor Site Veins for Patients Undergoing Free Radial Forearm Flap Reconstruction for the Defects of Head and Neck.

PURPOSE: The purpose of this study was to analyze the reliability of the deep venous drainage system of the free radial forearm flap. MATERIALS AND METHODS: The authors implemented a retrospective cohort study and enrolled patients admitted for the evaluation and management of head and neck tumors with radial forearm flap reconstruction. The primary predictor variables were the donor site veins, including the deep, dual, and superficial venous drainage systems. The primary outcome measurement was the incidence of venous compromise. Potential confounders included patient demographics, history of chemotherapy with or without radiotherapy, defect sites, and the recipient artery and vein. The χ2 test and logistic regression analysis were used for statistical analysis. RESULTS: The final study population consisted of 520 patients (mean age, 54 years) who underwent head and neck soft tissue reconstruction using the free radial forearm flap. Patients with the deep system (odds ratio [OR] = 0.251; 95% confidence interval [CI], 0.108-0.581) or dual system (OR = 0.197; 95% CI, 0.064-0.605) had a markedly lower risk of venous compromise than those with the superficial system. The overall incidence of inadequate outflow was 2.5% (5 of 204) when the deep system was used alone and 8.9% (19 of 212) when the superficial system was used alone (P = .004). CONCLUSIONS: Patients with the deep venous drainage system had a statistically lower risk of venous compromise. This study recommends using the deep system as a drainage vein for the free radial forearm flap.

Mattress cerclage combined with electrochemical therapy and pingyangmycin injection after embolization for management of arteriovenous malformation on oral and maxillofacial region.

BACKGROUND: The purpose of the article was to assess the clinical results of mattress cerclage combined with electrochemical therapy and pingyangmycin injection after embolization in treating arteriovenous malformations (AVMs). METHODS: During the period from January 2008 to December 2012, a total of 26 patients with AVMs were treated through mattress cerclage combined with electrochemical therapy and pingyangmycin injection after embolization and were retrospectively examined. The size of the lesions ranged from 2.5 cm × 3 cm to 8 cm × 10 cm. The follow-up time varied from 8 months to 24 months. The clinical outcome was evaluated using a 4-grade scale. RESULTS: All the lesions decreased in size after the treatment. The clinical follow-up showed excellent response in 20 of the 26 patients, whereas the remaining 6 patients also had satisfactory response. The most common complication was swelling, followed by pain and fever, without serious adverse effects being encountered. CONCLUSIONS: Mattress cerclage combined with electrochemical therapy and pingyangmycin injection after embolization was a reliable method for AVMs.

Reconstruction for facial nerve defects of zygomatic or marginal mandibular branches using upper buccal or cervical branches.

BACKGROUND: Many reconstructive methods for facial nerve defects have been described previously, such as the greater auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. Herein, we want to instruct a new technique of repairing facial nerve defects of zygomatic or marginal mandibular branches using upper buccal or cervical branches when we have to face segment defects of facial nerve with wide gaps between facial nerve stumps. METHODS: The distal part of the upper buccal or cervical branches with peripheral tissue was removed to repair the defects of zygomatic or marginal mandibular branches. Clinical and electromyographic examinations were employed to investigate the clinical efficacy of this method. RESULTS: Killed branches of facial nerve included 11 marginal mandibular branches and 16 zygomatic branches in 26 patients. The length of facial nerve defects ranged from 0.9 cm to 2.3 cm with a mean gap of 1.87 cm (SD, 0.89). Seventeen patients finally showed a superb facial function (grade I), 6 patients an excellent outcome (grade II), and 3 patients a good result (grade III). A fair or poor result (grade IV or V) was not observed. CONCLUSIONS: The essence of this method is equivalent to direct facial-facial nerve anastomosis which seems to be able to avoid synkinesis between the upper and lower face. We believe that this method is adaptable to the length of facial nerve defects less than 2 cm.

Appraisal of efficacy and safety of intralesional injection of high concentration of bleomycin A5 for treatment of huge macrocystic lymphatic malformations in cervical region.

The objective of this study was to investigate the therapeutic effects and safety of intralesional injection of high concentration of bleomycin A5 for huge (more than 5 cm in diameter) macrocystic lymphatic malformations (LMs) in the cervical region. Thirty-two patients with huge macrocystic LMs were treated with percutaneous injection of bleomycin A5 in our department between 2006 and 2011. Among them, 13 patients had unilateral submandibular lesions, and 19 patients had lesions in anterior cervical regions. The age of patients ranged from 10 months to 29 years (mean age, 11.4 y). The concentration of the drug was as high as 2.7 mg/mL (8 mg/3 mL) with an addition of dexamethasone. The mean sessions of injection were 1.6 (1-3 sessions). Repeated injection interval was 4 to 6 weeks. The follow-up period was 6 months to 4 years after the last treatment, and the mean follow-up time was 18 months. The results were evaluated based on clinical examination and Doppler ultrasonography scan. The clinical follow-up showed excellent response in 28 of the 32 patients, whereas 4 of the 32 patients also had a satisfactory response. No serious complications were encountered. Intralesional injection of high concentration of bleomycin A5 was an effective and safe treatment of huge macrocystic LMs in the cervical region and can obtain satisfactory results esthetically and functionally without surgery.

Treatment of postburn anteriorly located neck contractures with local flaps.

OBJECTIVE: The objective of this study was to summarize our experience of using local flaps for the reconstruction of neck defects after cervical contractures release, particularly of using the extended deltopectoral flaps whose distal margin was beyond the anterior axillary line even reaching dorsalis for reconstruction of anterior neck scar contractures in a single-stage procedure. METHODS: From 1987 to 2008, neck scar contractures were reconstructed using various local flaps in 68 patients with postburn anteriorly located neck contractures. The local flaps used consisted of 36 deltopectoral flaps, 6 extended deltopectoral flaps, 4 free scapular flaps, 8 neck-shoulder flaps, and 14 Z-plasties. The distal end of extended deltopectoral flaps was transferred as microvascular-free flap provided by the posterior circumflex humeral artery, but the proximal end as pedicle flap supplied by the anterior perforating branches of internal mammary artery. Other flaps were elevated conventionally as described previously in the articles. RESULTS: Of 68 patients, there were 59 cases (86.8%) whose release of the contractures was excellent. For 51 patients, the whole process of treatment was finished only in a single-stage procedure. We used extended deltopectoral flap, which was developed from our own anatomic studies and from previous reports in the literature, in 6 patients. This new flap extends the volume of the original deltopectoral flap, from 22 to 32 cm in length and 10 to 22 cm in width (at the apex). Postoperatively, all flaps survived completely. Patients were satisfied with their results. The follow-up period ranged 1 to 10 years; no obvious recontractures have been noted. There were no severe donor-site complications. CONCLUSIONS: The local flap with matching texture, color, elasticity, and pliability is still the best choice for reconstruction of postburn anteriorly located neck contractures. The extended deltopectoral flap has been used successfully to yield satisfactory outcomes for the scar contractures in the anterior neck and should be conserved as a selective method for reconstructive surgeons.

Reconstruction for defects of the lower lip after tumor ablation.

BACKGROUND: The lip carcinoma, which frequently affects the lower lip, is one of the most common cancers of the head and neck region composing 25% to 30% of all oral cancers. The accepted method of therapy for lip cancer is surgical excision and reconstruction. The repair should satisfy 2 fundamental requirements: to achieve appropriate aesthetic quality and to conserve labial function. Currently, a wide range of reconstructive procedures have been developed. OBJECTIVE: The objective of the study was to summarize the clinical experience of reconstruction for lower lip defects to facilitate the selection of a proper reconstructive strategy for different conditions in clinical practice. METHODS: We performed a retrospective analysis of 43 patients who had undergone a standardized reconstructive approach based on the literature published and our own experience over the past 4 years. RESULTS: Over an average period of 7.5 months' follow-up, recurrences or major complications did not happen, and most patients were satisfied with their functional and aesthetical outcome. Focusing on the location and the width of the defects of lower lip, a table has been exhibited to orient the surgeons to select a suitable reconstructive procedure for each patient. CONCLUSIONS: Successful reconstruction of all defects can be attained, if as many surgical procedures as possible have been mastered, and a more proper means used.

Effect of electrochemical treatment on high-flow vascular malformations in the maxillofacial region.

We explored the effect of electrochemical therapy for the treatment of high-flow venous malformations in the maxillofacial region in 32 patients. We used a method of anaesthesia that was suitable to the site and size of the lesion, and then inserted platinum needles into the lesion in a sterile environment. We protected the normal skin by inserting the cannulas into plastic sheaths, and connected the needles to an electrochemical machine. The common voltage, electric current, and amount of electricity were 6-8 V, 80-100 mA, and 10-20 C/cm(2), respectively. During a follow up period of two months to three years, 18 (56%) patients had a complete response, and 14 a partial response (44%). Electrochemical treatment is a simple, relatively atraumatic method of dealing with high-flow venous malformations that leaves no scars.