[Therapeutic effect of chlorhexidine combined with mechanical debridement on peri-implantitis and its influence on patients' SF-36 score].

PURPOSE: To study the effect of chlorhexidine combined with mechanical debridement on peri-implant inflammation and the influence on SF-36 score of patients. METHODS: One hundred patients with peri-implantitis admitted to Zhejiang Provincial People's Hospital from January 2015 to January 2019 were selected and randomly divided into control group and combined group with 50 cases in each group according to random number table method.Patients in both groups were treated with mechanical debridement, and patients in the combined group were gargled with chlorhexidine gargle apart from mechanical debridement. Plaque biofilm average activity and modified plaque index (mPLI), bleeding on probing (BOP), modified sulcus bleeding index (mSBI), probing the depth (PPD), clinical attachment level(AL) were measured before and after treatment. Sf-36 scale and VAS visual pain score were used to evaluate the quality of life and pain degree of patients, and the therapeutic effect and incidence of complications were assessed. The data were analyzed with SPSS 20.0 software package. RESULTS: There was no significant difference in average activity, mPLI, mSBI, AL, PPD, BOP, VAS and SF-36 scores between the two groups before treatment(P>0.05); after treatment, the average activity, mPLI, mSBI, AL, PPD, BOP and VAS scores of plaque biofilm in the combined group were significantly lower than those of the control group, and the total effective rate of SF-36 score was significantly higher than that of the control group. The total effective rate of the combined group was significantly higher than that of the control group(P<0.05). The incidence of complications in the combined group was significantly lower than that in the control group(P<0.05). CONCLUSIONS: Chlorhexidine combined with mechanical debridement is an effective treatment of peri-implantitis, which can effectively inhibit plaque biofilm activity and plaque formation, alleviate pain and improve the quality of life of patients.

[Analysis of factors affecting soft tissue infection after oral and maxillofacial debridement].

PURPOSE: To explore the factors affecting soft tissue infection after oral and maxillofacial debridement. METHODS: Fifty hundred patients with debridement were enrolled in this study from January 2013 to June 2016. The patients were divided into 2 groups according to soft tissue infection, 18 cases in infection group and 482 cases in non-infection group. Age, mean time to surgery, average length of stay, duration of antibiotics use, abbreviated injury scale (AIS), combined injuries, maxillofacial fractures, soft tissue injury, type of fracture, and history of diabetes were recorded and analyzed using SPSS 19.0 software package. RESULTS: The factors influencing soft tissue infection after oral and maxillofacial surgery were the aged, longer hospital stay, longer operation time, longer antibiotics use time, higher AIS score, Jaw bone injury and diabetes. CONCLUSIONS: The factors influencing soft tissue infection after oral and maxillofacial debridement are various. The aged, longer operation time, higher AIS score, jaw bone involvement lip and chin injury as well as diabetes might be the independent factors. Health care providers should give preventive measures to reduce the incidence of infection, according to specific factors.

[Effect of functional appliance on upper airway in adolescent patients with skeletal Class II malocclusion].

PURPOSE: To investigate the effect of functional appliance on upper airway in adolescent patients with skeletal Class II malocclusion based on cone-beam CT (CBCT). METHODS: Thirty adolescent patients (male:female=1:1) with skeletal Class II malocclusion and their 30 counterparts with skeletal Class I malocclusion were selected. Skeletal Class II malocclusion patients were treated with Activator for 12 months on average, meanwhile skeletal Class I malocclusion patients were treated with fixed appliance without extraction. Cone-beam CT (CBCT) films were taken before and 12 months after treatment. Films of skeletal Class II malocclusion patients were measured (items about skeletal and upper airway, and the outline of upper airway depicted with 3D reconstruction) and compared with the reference standards and the measurements of their counterpart patients with skeletal Class I malocclusion. Independent t test was performed in inter-group comparison and paired t test was performed in inner-group comparison using SAS 8.0 software package. RESULTS: Before treatment, patients with skeletal Class II malocclusion showed decreased SNB and APDI value, increased ANB, Wits, and OJ compared with standard value and value of skeletal Class I malocclusion patients. In addition, decreased MPW and PAS value, and downsized volume of upper airway and transverse diameter minimum were found in skeletal Class II malocclusion patients. After treatment with Activator, patients with skeletal Class II malocclusion showed increased MPW and PAS value, and enlarged volume of upper airway and transverse diameter minimum. All values of skeletal items of patients with skeletal Class II malocclusion showed trends to get close to the reference standards and the values of skeletal Class I malocclusion patients. There was no significant difference between different genders of the two groups. CONCLUSIONS: Patients with skeletal Class II malocclusion have constructed upper airways. Treatment with Activator can increase the MPW and PAS values and enlarge volume of upper airway and transverse diameter minimum. Functional appliance can ameliorate the narrowness of upper airway for skeletal Class II patients.

[Inter-relationship between mandibular rotation center and maxillary Le Fort I impaction osteotomies].

PURPOSE: The purpose of the present investigation was to locate the instantaneous rotation center of the mandible during maxillary surgical impaction, and explore the relationship between automatic rotation center of the mandible and maxillary elevation amount, the length of the mandible and mandibular plane angle. METHODS: Twenty-five patients who underwent maxillary Le Fort I impaction without concomitant major mandibular ramus split osteotomies were included. The preoperative and postoperative lateral cephalograms were used to evaluate the surgical changes and locate the mandibular autorotation center with Reuleaux method. The automatic rotation center of the mandible was compared to the maxillary elevation amount, the length of the mandible and mandibular plane angle with Pearson correlation and linear regression analysis. The data was analyzed by SPSS 13.0 software package. RESULTS: The mandibular automatic rotation center was located in average 15.64 mm below and 0.82 mm behind the center of the condylar head in these 25 patients. The correlation analysis demonstrated a positive correlation between maxillary elevation amount, the length of the mandible and the position of the rotation center of the mandible. Similar positive correlation was presented between the mandibular plane angle and the vertical position of the rotation center of the mandible. CONCLUSIONS: The rotation center in 25 cases were located outside the condylar head. The maxillary elevation amount, the length of the mandible and the mandibular plane angle was positively correlated to the position of the rotation center of the mandible.

[Establishment of a dog model of orthodontic tooth moving into newly distracted bone].

PURPOSE: This study was to establish an animal model of tooth moving into newly distracted bone after mandibular distraction osteogenesis in Beagle dog. METHODS: Eight Beagle dogs were selected in this study four dogs (experiment group) underwent 10 mm of bilateral mandibular distraction osteogenesis. After 0-week consolidation periods, the bilateral third premolars were moved distally into the regenerated bone with 150g orthodontic force for 8 weeks. Four dogs(control group) were extracted the fourth premolar. Twelve weeks later, the bilateral third premolars were moved distally with 150g orthodontic force for 8 weeks. The force was checked and activated weekly. The characters about the third premolar movement style, movement rate and alveolar bone remodeling were investigated by the following methods: measuring the distance of tooth movement, radiographic examination and histological examination. RESULTS: The experimental procedure was well tolerated in all animals and 10 mm distraction length was successfully achieved. A dog model for tooth moving into newly distracted bone was established successfully. The rate of movement in the experimental group was faster when the teeth were moved into newly distracted bone after 0-week consolidation periods than that in the control group. We observed significant root resorption extending into the cementum with 150g orthodontic force in the group after 0-week consolidation periods. CONCLUSION: Beagle dog is a satisfactory animal on the experimental study for tooth moving into newly distracted bone. Supported by Shanghai Leading Academic Discipline Project (S30206).

[Research on periodontal changes on the compression side during rapid tooth movement into newly distracted bone].

PURPOSE: To investigate periodontal remodeling mechanism on the compression side during early tooth movement into newly distracted bone. METHODS: Ten male Beagle dogs were selected. Distraction osteogenesis was performed on randomized side as experimental group, while the fourth premolars were extracted on the other side as control group. Then the third premolars were distalized with 30g orthodontic force instantly after the cessation of distraction or extraction. The distance of the tooth movement was measured with a sliding caliper every week. Each distance was measured 3 times and the mean value was recorded. The measurement data were analysed with paired t test by SPSS 18.0 software package. Beagle dogs were killed in the first, second, fourth week after tooth movement. Slices were obtained for HE staining and TRAP staining to observe the periodontal tissue on the compression side. RESULTS: The average moving velocity of the teeth in the distracted bone was (1.055±0.054)mm per week, which was significantly faster than that in the control group(P<0.05).There was no apparent lag period in the experimental group. In addition, there was no hyalinization observed on the compression side of the periodontal tissue in the experimental group, while the amount and area of distribution of the TRAP-positive cells on the compression side was significantly larger and strongly expressed. CONCLUSIONS: The moving velocity of the teeth in the newly distracted bone was significantly faster, and no apparent lag period, which may be related to no hyalinization and more early-appeared, vigorous and wide-distributed osteoclasts on the compression side of the periodontal tissue.

[Cephalometric analysis of implant anchorage-assisted retraction of anterior teeth].

PURPOSE: The purpose of this study is to compare the different effects of alveolar bone remolding due to retraction of anterior teeth by two types of anchorage mini-screw implant or regular maximum anchorage. METHODS: The sample comprised 26 orthodontic patients with upper dental alveolar bone protrusion and mild crowding. The treatment plan was to remove the four first bicuspids. 14 patients,3 males,11 females, aged 20-54 years old (mean: 25 years) were treated with implant anchorage to retract the maxillary anterior teeth. 12 patients, 1 male,11 females, aged 18-30 years old (mean: 21 years) were treated with regular maximum anchorage to retract maxillary anterior teeth. Lateral cephalograms of all patients were evaluated at two stages: pretreatment, post-treatment.The changes of the long axis of the anterior teeth and dental alveolar were measured.SPSS11.0 software package was used for statistical analysis. RESULTS: The cephalometric findings showed that the anterior teeth were retracted with implant anchorage significantly more than the maximum anchorage, there was no significant difference in the dental alveolar bone remolding between two groups. The first molars moved anteriorly slightly (less than 1mm) with implant anchorage, but significantly (3.08 mm) with regular maximum anchorage. CONCLUSIONS: The maxillary anterior teeth are significantly retraced with the implant anchorage; the molars move mesially significantly less in the implant group than the maximum group. There are no significant differences in dental alveolar bone remolding between both groups. Support by Shanghai Leading Academic Discipline Project (Grant No.Y0203) and Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No. 05B224).

[Clinical evaluation of implant anchorage for molar intrusion: report of the short-term results].

PURPOSE: The purpose of this study is to evaluate the efficiency and security of self-drilling mini-screw implant anchorage for molar intrusion, to achieve the right position of the mini-screw implant. METHODS: Ten patients with overerupted maxillary molars were selected, aging from 25 to 53 years old, the average age was 33 years old. There were 2 men and 8 women. All the overerupted molars were intruded in gingival direction with mini-screw implants anchorage. RESULTS: The mean intrusive movement of the overerupted maxillary molars was 3 mm, the mean treatment time were 3.5 months.All of the missing teeth were treated by prosthetic treatment. No obvious root resorption, pulp necrosis and tooth loosen were found. CONCLUSIONS: Significant true intrusion of maxillary molars could be obtained by mini-screw implant as bony anchorage.Supported by Shanghai Leading Academic Discipline Project (Grant No.Y0203) and Research Fund of Science and Technology Committee of Shanghai Municipality (Grant No.05B224).

[Research advances on distraction osteogenesis combined with rapid orthodontic movement].

The principle of distraction osteogenesis can be applied to the correction of facial skeletal deformities.The orthodontists pay more attention to the tooth moving into the new generated bone to relieve the crowding.This paper reviewed the clinical application and histological feature of the distraction osteogenesis,the opportunity and the force magnitude of tooth movement into the new generated bone.