Maxillary anterior segmental distraction osteogenesis to correct maxillary hypoplasia and dental crowding in cleft palate patients: a preliminary study.

BACKGROUND: The aim of this study was to present comprehensive skeletal, dental and facial aesthetic outcomes and long-term stability of maxillary anterior segmental distraction osteogenesis (MASDO) for the treatment of maxillary hypoplasia in CLP. MATERIALS AND METHODS: Six patients with maxillary hypoplasia treated with MASDO by a miniscrew assisted intraoral tooth-borne distractor were included. Cephalometric radiographs were obtained before distraction (T1), after the consolidation period (T2) and after orthodontic treatment or before orthognathic surgery (T3). Thirty-one cephalometric variables (12 skeletal, 9 dental, and 10 soft tissue variables) were used to evaluate changes in the dentofacial structures and the soft tissue profile. Friedman and Wilcoxon tests were applied to identify significant differences in hard and soft tissue changes during the T1-T2, T2-T3, and T1-T3 periods. RESULTS: All patients successfully underwent MASDO without serious complications. From T1 to T2, forward movements of ANS and A (FH ⊥ N-A, VRL-ANS and VRL-A) were significant (p < 0.05). Significant increases in SNA and ANB were noted. Significant upward movement of points ANS (CFH-ANS) and A (CFH-A) was observed (p < 0.05). After distraction, a significant decrease in overjet and an increase in overbite were obtained (p < 0.05). Anterior tipping of the upper incisors (U1/ANS-PNS and U1/SN) was observed (p < 0.05). The soft tissue points of Pn, Sn, Ss, and ls showed significant anterior movement (p < 0.05). In addition, a significant increase in the nasolabial angle was measured (p < 0.05). All of the above data showed no statistically significant changes between T2 and T3 (p > 0.05). CONCLUSION: MASDO using a miniscrew assisted tooth-borne distractor presented significant maxillary advancement and favorable long-term stability in treating CLP patients with maxillary hypoplasia.

Comparative study of three composite materials in bonding attachments for clear aligners.

OBJECTIVE: The aim of this study was to assess the operation time, shear bond strength, placement accuracy and wear resistance of 3 composite materials (Filtek Z350XT, Filtek Z350XT Flowable and SonicFill) that were used to make attachments for clear aligners. SETTINGS AND SAMPLE POPULATION: Laboratory of Stomatology of Shanghai Ninth People's Hospital affiliated to Shanghai Jiao Tong University School of Medicine. A total of 129 human mandibular premolars were collected, 69 of which were assigned to 3 groups (A1, B1 and C1). The remaining 60 teeth were divided into 3 groups (A2, B2 and C2). METHODS: Z350XT composite resin was used in groups A1 and A2 to bond the attachments. Z350XT Flowable composite resin was used in groups B1 and B2. SonicFill composite resin was used in groups C1 and C2. The operation time, shear bond strength, the placement accuracy and wear volume loss of 3 composite materials were evaluated. RESULTS: The operation time of Z350XT Flowable and SonicFill was shorter than Z350XT (P < .05). The shear bond strength of SonicFill was higher than Z350XT and Z350XT Flowable (P < .05). The SEM showed that the bonding interface of Z350XT and SonicFill was compact. The 3D deviation and volumetric change in the 3D designed attachments and the attachments after actual bonding of Z350XT Flowable were greater than that of Z350XT and SonicFill (P < .05). The wear volume loss of SonicFill and Z350XT was less than that of Z350XT Flowable (P < .05). CONCLUSION: SonicFill seems to represent a suitable material for producing attachments, which optimized the property combination.

Evaluation of the position and morphology of tongue and hyoid bone in skeletal Class II malocclusion based on cone beam computed tomography.

BACKGROUND: The aim of the study was to analyze the morphology and position of the tongue and hyoid bone in skeletal Class II patients with different vertical growth patterns by cone beam computed tomography in comparison to skeletal Class I patients. METHODS: Ninety subjects with malocclusion were divided into skeletal Class II and Class I groups by ANB angles. Based on different vertical growth patterns, subjects in each group were divided into 3 subgroups: high-angle group (MP-FH ≥ 32.0°), average-angle group (22.0° ≤ MP-FH < 32°) and low-angle group (MP-FH < 22°). The position and morphology of the tongue and hyoid bone were evaluated in the cone beam computed tomography images. The independent Student's t-test was used to compare the position and morphology of the tongue and hyoid bone between skeletal Class I and Class II groups. One-way analysis of variance (ANOVA) was used to compare the measurement indexes of different vertical facial patterns in each group. RESULTS: Patients in skeletal Class II group had lower tongue posture, and the tongue body was smaller than that of those in the Class I group (P < 0.05). The position of the hyoid bone was lower in the skeletal Class II group than in Class I group (P < 0.05). The tongue length and H-Me in the skeletal Class I group with a low angle were significantly larger than those with an average angle and high angle (P < 0.05). There was no significant difference in the position or morphology of the tongue and hyoid bone in the skeletal Class II group with different vertical facial patterns (P > 0.05). CONCLUSION: Patients with skeletal Class II malocclusion have lower tongue posture, a smaller tongue body, and greater occurrence of posterior inferior hyoid bone position than skeletal Class I patients. The length of the mandibular body in skeletal Class I patients with a horizontal growth type is longer. The position and morphology of the tongue and hyoid bone were not greatly affected by vertical facial development in skeletal Class II patients.

Study on Tooth Movement After the Alveolar Bone Grafting in Patients With Unilateral Cleft Lip and Palate.

OBJECTIVES: The aim of the study was to explore the effectiveness of the cleft-adjacent teeth moved into the grafted alveolar bone in unilateral cleft lip and palate (UCLP) patients, and to evaluate the alveolar bone support of the teeth. METHODS: Twenty unilateral cleft lip and palate patients were recruited in this study. The average age was 12 years and 8 months. Periapical radiographs were taken for the cleft-adjacent teeth 3 months after bone grafting (T1) and after teeth moving into the grafted bone (T2), and for the contralateral teeth (T3) when teeth aligned. Alveolar bone support of the moved teeth and the contralateral teeth were measured using the ratio of bone support height to root length. Paired t test was performed for statistical analysis with SPSS17.0 software package. RESULTS: All the cleft-adjacent teeth were bodily moved into the grafted area. Average alveolar bone support ratio for the moved teeth was 86.48% (T1), 87.11% (T2), and 90.81% (T3) for the contralateral teeth. There was no statistically significant difference between T1 and T2 (P > 0.05). Although the contralateral teeth had the highest alveolar bone support ratio, significant differences were found between T3 and T2 (P < 0.05). CONCLUSIONS: Cleft-adjacent teeth could be bodily moved into the grafted bone from the iliac crest in UCLP patients. A successful level of alveolar bone support for the moved teeth was achieved. Moved-in teeth could be functionally loaded and may be benefit to the reduction of the resorption of grafted bone.

Myricetin Prevents Alveolar Bone Loss in an Experimental Ovariectomized Mouse Model of Periodontitis.

Periodontitis is a common chronic inflammatory disease, which leads to alveolar bone resorption. Healthy and functional alveolar bone, which can support the teeth and enable their movement, is very important for orthodontic treatment. Myricetin inhibited osteoclastogenesis by suppressing the expression of some genes, signaling pathways, and cytokines. This study aimed to investigate the effects of myricetin on alveolar bone loss in an ovariectomized (OVX) mouse model of periodontitis as well as in vitro osteoclast formation and bone resorption. Twenty-four healthy eight-week-old C57BL/J6 female mice were assigned randomly to four groups: phosphate-buffered saline (PBS) control (sham) OVX + ligature + PBS (vehicle), and OVX + ligature + low or high (2 or 5 mg∙kg(-1)∙day(-1), respectively) doses of myricetin. Myricetin or PBS was injected intraperitoneally (i.p.) every other day for 30 days. The maxillae were collected and subjected to further examination, including micro-computed tomography (micro-CT), hematoxylin and eosin (H&E) staining, and tartrate-resistant acid phosphatase (TRAP) staining; a resorption pit assay was also performed in vitro to evaluate the effects of myricetin on receptor activator of nuclear factor κ-B ligand (RANKL)-induced osteoclastogenesis. Myricetin, at both high and low doses, prevented alveolar bone resorption and increased alveolar crest height in the mouse model and inhibited osteoclast formation and bone resorption in vitro. However, myricetin was more effective at high dose than at low dose. Our study demonstrated that myricetin had a positive effect on alveolar bone resorption in an OVX mouse model of periodontitis and, therefore, may be a potential agent for the treatment of periodontitis and osteoporosis.

A novel technique for presurgical nasoalveolar molding using computer-aided reverse engineering and rapid prototyping.

OBJECTIVE: To establish a new method of presurgical nasoalveolar molding (NAM) using computer-aided reverse engineering and rapid prototyping technique in infants with unilateral cleft lip and palate (UCLP). METHODS: Five infants (2 males and 3 females with mean age of 1.2 w) with complete UCLP were recruited. All patients were subjected to NAM before the cleft lip repair. The upper denture casts were recorded using a three-dimensional laser scanner within 2 weeks after birth in UCLP infants. A digital model was constructed and analyzed to simulate the NAM procedure with reverse engineering software. The digital geometrical data were exported to print the solid model with rapid prototyping system. The whole set of appliances was fabricated based on these solid models. RESULTS: Laser scanning and digital model construction simplified the NAM procedure and estimated the treatment objective. The appliances were fabricated based on the rapid prototyping technique, and for each patient, the complete set of appliances could be obtained at one time. By the end of presurgical NAM treatment, the cleft was narrowed, and the malformation of nasoalveolar segments was aligned normally. CONCLUSIONS: We have developed a novel technique of presurgical NAM based on a computer-aided design. The accurate digital denture model of UCLP infants could be obtained with laser scanning. The treatment design and appliance fabrication could be simplified with a computer-aided reverse engineering and rapid prototyping technique.

Cone-beam CT evaluation of temporomandibular joint in permanent dentition according to Angle's classification.

OBJECTIVES: To compare characteristics of temporomandibular joint (TMJ) and related structures according to Angle class I, II1, II2, and III. METHODS: 123 Chinese patients (13-36 years old, 60 males, and 63 females) were classified in four groups according to Angle's classification: skeletal class I (31 patients), skeletal class II division 1 (30 patients), skeletal class II division 2 (30 patients), and skeletal class III (32 patients). Left and right TMJs of each subject were evaluated independently with cone-beam computed tomography (CBCT). The position of condyle in the joint fossa was analyzed according to Pullinger. RESULTS: There were significant differences between class III subjects and class I, II1, II2 in the superior joint space (p < 0.05). Compared with class II1, II2, and III subjects, the height and diameter of condyle in class I was significantly larger (p < 0.05). The width of joint fossa was significantly larger in Angle class III than in Angle class I, II1, and II2, while the depth was significantly smaller. The condyle position in class III subjects was more anteriorly displaced compared with that in class I subjects. In class II2 patients, the condyle position was mainly concentric and posterior. CONCLUSIONS: There are significant differences in condylar morphology, joint space, joint fossa morphology, and condylar position between different Angle classifications.

Biomechanical analysis of rapid maxillary expansion in the UCLP patient.

This study was designed to investigate the biomechanical effects of rapid maxillary expansion (RME) in the patient with unilateral cleft lip and palate (UCLP). A finite element model of a patient's craniofacial complex with UCLP was created using data from spiral computed tomographic (CT) scanning. A transversal displacement with a magnitude of 5mm was applied on the maxillary premolar and first permanent molar crown of the model simulating the clinical situation. The stress and deformation within the craniofacial complex were then calculated and analyzed during 0.25- and 5-mm expansions. The corresponding orthodontic forces on each loaded tooth were also calculated. Obtained results revealed the biomechanical performance of the craniofacial complex with UCLP undergoing RME, including the distribution pattern of the stress and displacement, the transmission and dissipation of the orthodontic force, the stress level and the magnitude of the orthodontic force. All these findings could help us better comprehend the biomechanical mechanism of RME in the UCLP patient and provided theoretic data for optimizing surgical assisted RME in clinic.

[Comparison of skeletal structure of temporomandibular joint through cone-beam CT between Angle Classâ , â ¡1, â ¡2, â ¢ malocclusion patients with permanent dentition].

PURPOSE: To compare characteristics of temporomandibular joint and related structures according to gender and Angle Ⅰ, Ⅱ1, Ⅱ2 and Ⅲ class. METHODS: Cone-beam CT (CBCT) was performed in 123 patients with malocclusion, and three-dimensional reconstruction was performed with Mimics 19.0 software. The anterior, upper, and posterior spaces of temporomandibular joint, width and depth of acetabulum, height and horizontal angle of condyle, radius of condyle, and anteroposterior and long-axis diameter of condyle were analysed on sagittal plane. The position of condyle in the joint fossa was analyzed using Pullinger methods. SPSS 22.0 software package was used for statistical analysis. RESULTS: Significant differences were found in the long axis and radius of the condyles between Class Ⅰ and Ⅲ, Class Ⅰ and Ⅱ1, respectively (P<0.05). The widest acetabulum was observed in Class Ⅲ, followed by Class Ⅰ, Ⅱ1, and Ⅱ2. Moreover, the deepest acetabulum was found in Class Ⅱ2, followed by Class Ⅱ1, Ⅰ, and Ⅲ. No significant differences were detected in the left and right condyle-related structures among different temporomandibular articulation. In addition, the anterior articular space was significantly larger in Class Ⅰ patients, compared with Class Ⅱ2 patients. CONCLUSIONS: There are significant differences in condylar morphology, joint space, joint fossa morphology and condylar position between different Angle classifications.

The effects of a newly designed twin-slot bracket on severely malpositioned teeth--a typodont experimental study.

The aims of this study were to design a twin-slot bracket featuring two horizontal slots and to examine its efficiency in tooth displacement. Based on the structure of a traditional edgewise bracket, an additional slot was added to a twin-slot bracket and the prototype products were fabricated for the typodont experiments. The orthodontic correction of malpositioned canines was conducted on a typodont to examine the efficiency of the twin-slot bracket in tooth displacement compared with a single-slot edgewise bracket. Three modalities of tooth movement requiring a heavy force moment, namely, axial rotation, mesiodistal tipping, and bodily translation, were conducted. The canine positions before and after simulation were measured and the changes identified. Statistical analysis was undertaken using a t-test to determine the significance of the differences in canine repositioning between the two bracket types. The results showed that in the twin-slot bracket group, the treatment changes in the canine position by derotation and uprighting were 40 +/- 3 and 25 +/- 2 degrees, respectively, compared with 20 +/- 5 and 10 +/- 2 degrees in the edgewise group (P < 0.01). When retracted into an extraction space with an initial 10 degrees of mesial tip, the mesiodistal angulation of the canines in the twin-slot bracket group remained unchanged while in the edgewise group the canines became distally tipped by 5 +/- 2 degrees (P < 0.01). The twin-slot bracket significantly increased the bracket width without reducing the interbracket span and therefore can generate increased force moments within the bracket, leading to an improved manipulation in tooth repositioning.

[A study on effects of unilateral maxillary canine impaction on the dento-maxillofacial three-dimensional structure].

PURPOSE: To investigate the three-dimensional structure characteristics of unilateral impacted teeth by cone-beam CT (CBCT), and to evaluate the risk factors for upper impacted teeth, so as to provide evidence for early clinical intervention in orthodontics. METHODS: Thirty patients with unilateral maxillary canine impaction were included. Their CBCT images were measured by three-dimensional reconstruction of Romexis software. The differences of the three-dimensional structure characteristics between two sides were measured and compared with SPSS17.0 software package. Paired t test and regression analysis of related data were performed. RESULTS: Significant difference in inclination of both canine and lateral incisor was found between impacted side and normal eruption side, with canine mesially inclined and lateral incisor distally inclined (P<0.001). Volumes of the canines were significantly bigger and those of the lateral incisor were significantly smaller on the impacted side compared with the normal eruption side (P<0.05). The occurrence of impacted canine increased with the increase of the volume of the canine and decrease of the volume of the lateral incisor. Significant difference in arch length and arch width in canine and premolar area was found between impacted side and normal eruption side (P<0.001). There was no significant difference in width in molar area between both sides(P>0.05). There was no significant difference in arch length in canine, premolar and molar region (P>0.05). CONCLUSIONS: Maxillary impacted canines can lead to three-dimensional abnormalities of the ipsilateral teeth and alveolar bone, the severity of maxillary impacted canine is closely related to surrounding dental structural abnormalities, suggesting that maxillary impacted canines can be predicted, early diagnosed, and early effectively intervened as well.

[Features and influence of impacted maxillary permanent canine on surrounding structures].

Impacted maxillary permanent canine is the tooth that most commonly fails to erupt after the third molars. It can probably affect the dental arch alignment and form, occlusal function and facial profile as well. In this review, the epidemiology, etiology and influence on surrounding tissue of the impacted maxillary permanent canine were analyzed based on related literatures with the hope of providing references for clinical practice.

[Torque control evaluated by lateral cephalometric radiography and cone-beam CT after retraction of the upper anterior teeth].

PURPOSE: To investigate the relationship between torque control and movement type of the teeth and to investigate the correlation between reconstruction of the alveolar bone and retraction of the upper anterior teeth. METHODS: Cephalograms of pre-treatment and post-treatment of 111 cases and cone-beam computed tomography of pre-retraction and post-retraction of 7 cases were collected. The inclination degree of the upper anterior teeth, the horizontal and vertical displacement of edge and apex,and the thickness of the alveolar bone at the apex level were measured. Student's t test and Pearson χ2 test were performed for statistical analysis with SAS 8.02 software package. RESULTS: Cases who received torque control during the period of retraction displayed less change of inclination degree of the upper anterior teeth, less lingual displacement of the edge, more lingual displacement of the apex. The total thickness of the alveolar bone at the apex level and the length of the teeth significantly decreased after retraction(P<0.05). The amount of the alveolar bone rebuilt after retraction was less than that of the tooth movement, and there was no significant difference between teenagers and adults. CONCLUSIONS: During retraction of the upper anterior teeth, cases who received torque control showed less inclination degree change of the upper anterior teeth, less lingual displacement of the edge, more lingual displacement of the apex. More bodily movement and partially controlled tipping movement as well as higher incident rate of severe root resorption would also arise. There was correlation between reconstruction of the alveolar bone and the tooth movement. Since the amount of adaptive reconstruction of the lingual alveolar bone was limited, and there was no difference between teenagers and adults, excessive lingual displacement would surpass its adaption ability, and gave rise to alveolar bone and tooth damage.

Bond strength of metal brackets bonded to a silica-based ceramic with light-cured adhesive : Influence of various surface treatment methods.

OBJECTIVE: The purpose of this work was to evaluate the effects of several surface treatment methods on the shear bond strengths of metal brackets bonded to a silica-based ceramic with a light-cured adhesive. MATERIALS AND METHODS: Silica-based ceramic (IPS Classic(®)) with glazed surfaces was cut into discs that were used as substrates. A total of 80 specimens were randomly divided into four groups according to the method used: 9.6 % hydrofluoric acid (group 1), 9.6 % hydrofluoric acid (HF) + silane coupling agent (group 2), sandblasting (aluminum trioxide, 50 µm) + silane (group 3), and tribochemical silica coating (CoJet™ sand, 30 µm) + silane (group 4). Brackets were bonded to the treated specimens with a light-cure adhesive (Transbond XT, 3 M Unitek). Shear bond strength was tested after bracket bonding, and the Adhesive Remnant Index (ARI) scores were quantified after debonding. RESULTS: Group 4 showed the highest bond strength (12.3 ± 1.0 MPa), which was not significantly different from that of group 3 (11.6 ± 1.2 MPa, P > 0.05); however, the bond strength of group 4 was substantially higher than that of group 2 (9.4 ± 1.1 MPa, P < 0.05). The shear bond strength of group 1 (3.1 ± 0.6 MPa, P< 0.05) was significantly lower than that of the other groups. CONCLUSION: Shear bond strengths exceeded the optimal range of ideal bond strength for clinical practice, except for the isolated HF group. HF acid etching followed by silane was the best suited method for bonding on IPS Classic(®). Failure modes in the sandblasting and silica-coating groups revealed signs of damaged ceramic surfaces.

[Three-dimensional finite element analysis of the biomechanical effects of multiloop edgewise archwire (MEAW)].

This study is designed to theoretically evaluate the treatment effects of MEAW with tip back bends on the mandible dentition when used as a finishing archwire without elastic and with long class III elastics respectively, and to compare them with those of stainless-steel wire and shape-memory wire. The finite element analysis (FEA) method was adopted and the findings were as follows: (1) In the case of no elastics, the MEAW rotates the second premolar, the first molar and the second molar distally while rotating other teeth mesially, and depresses anterior teeth. However, the stainless-steel wire and the shape-memory wire rotate molars distally while rotating other teeth mesially. Furthermore, they extrude anterior teeth and depress posterior teeth. (2) The MEAW with tip back bends and long class III elastics inclines and rotates posterior teeth more distally than the MEAW with only tip back bends does. In the case of tip back bends and long class III elastics loaded together, the shape-memory wire inclines teeth in greater strength as compared with the stainless-steel wire. (3) The stress level of tooth root is the lowest with MEAW, the highest with stainless-steel wire, and is middle with the shape-memory wire. From these results, it is suggested that: (1) The MEAW therapy technique is effective for leveling the curve of Spee and regulating tooth respectively. (2) The MEAW therapy technique can transfer therapy force efficiently. (3) The MEAW is considered to be suitable for treating openbite malocclusion to make the posterior teeth upright because it effectively rotates teeth distally through the force of posterior bends and long class III elastics. (4) The loaded force on the teeth is more soft and permanent in the MEAW than in the stainless-steel wire and the shape-memory wire.

Rapid maxillary expansion in alveolar cleft repaired with a tissue-engineered bone in a canine model.

This study aims to investigate the effects of orthodontic expansion on graft area of a tissue-engineered bone (TEB) BMSCs/ß-TCP, and to find an alternative strategy for the therapy of alveolar cleft. A unilateral alveolar cleft canine model was established and then treated with BMSCs/ß-TCP under rapid maxillary expansion (RME). Sequential fluorescent labeling, radiography and helical computed tomography were used to evaluate new bone formation and mineralization in the graft area. Hematoxylin-eosin staining and Van Gieson׳s picro fuchsin staining were performed for histological and histomorphometric observation. ALP activity, mineralization and the expression of osteogenic differentiation related genes of BMSCs that grew on the ß-TCP scaffold were promoted by their cultivation in osteogenic medium. Based on fact, TEB was constructed. After 8 weeks of treatment with BMSCs/ß-TCP followed by RME, new bone formation and mineralization of the dogs were markedly accelerated, and bone resorption was significantly reduced, compared with the untreated dogs, or those only treated with autogenous iliac bone. The treatment with both TEB and RME evidently made the bone trabecula more abundant and the area of bone formation larger. What is more, there were no significant differences between BMSCs/ß-TCP group and the group treated with autogenous bone and RME. This study further revealed that TEB was not only a feasible clinical approach for patients with alveolar cleft, but also a potential substituent of autogenous bone, and its combination with RME might be an alternative strategy for the therapy of alveolar cleft.

[The relationship between the movement type during retracting the anterior teeth and the external apical root resorption and its evaluation methods].

External apical root resorption was a common phenomenon associated with orthodontic treatment. The reported incidence ranged from 0% to 100%. It was caused by several factors, which could be mainly divided into biological and mechanical aspects. Biological factors included genetic susceptibility, systemic diseases, gender and medication intake. Mechanical factors consisted of the magnitude of orthodontic force, force type and duration, types of tooth movement, as well as excessive tooth movement. This review discussed the relationship between the movement type during retracting the anterior teeth and the external apical root resorption and its evaluation methods.

Shear bond strength of an experimental composite bracket.

OBJECTIVE: The in vitro shear bond strength of MZ100 brackets (an experimental composite bracket developed by the Dental Biomaterial Laboratory at Boston University) and the effect of different treatment methods on these brackets were evaluated. MATERIALS AND METHODS: As the bonding substrates, 80 Vitablocs® Mark II (Vident, Brea, CA, USA) were chosen. Three treatment methods were employed on 60 MZ100 bracket bases (20 brackets per treatment): silane coupling agent (Porcelain Primer; Ormco, Orange, CA, USA), sandblasting (Basic Professional Model Sandblaster; Renfert GmbH, Germany), and non-treatment. Two different orthodontic adhesives were also used: Blugloo™ (Ormco, Orange, CA, USA) and Enlight™ (Ormco, Orange, CA, USA). Twenty metal brackets were used as controls. Shear bond strength tests were performed after sample preparation and bracket bonding. RESULTS: The mean shear bond strength of non-treated MZ100 brackets bonded with Enlight™ had the lowest value (7.9 MPa), while that of sandblasted MZ100 brackets bonded with Blugloo™ showed the highest value (17.9 MPa). The mean shear bond strength of non-treated MZ100 brackets was significantly lower than that of the other groups (p<0.05). The mean shear bond strength of sandblasted MZ100 brackets bonded with Blugloo™ was significantly higher than that of those bonded with Enlight™ (p<0.05). With the exception of the silane-Blugloo™ group, the treated MZ100 brackets demonstrated shear bond strengths that did not significantly differ from metal brackets. CONCLUSION: The use of sandblasting and silane coupling agent significantly increases the shear bond strength of the MZ100 brackets to values resembling those of metal brackets.

[Review of the impact of orthodontic treatments on soft tissue profile].

There are some people who have demands on the soft tissue profile among the patients who search for even teeth.On the other hand,when drawing up a plan,orthodontists will consider the soft tissue analysis.This review is focused on the assessment way of soft tissue profile,impact of orthodontic treatments such as functional appliances, extraction treatment, etc on the profile.

[Presurgical alveolar molding using computer aided design in infants with unilateral complete cleft lip and palate].

PURPOSE: To establish a new method of presurgical alveolar molding using computer aided design(CAD) in infants with complete unilateral cleft lip and palate (UCLP). METHODS: Ten infants with complete UCLP were recruited. A maxillary impression was taken at the first examination after birth. The study model was scanned by a non-contact three-dimensional laser scanner and a digital model was constructed and analyzed to simulate the alveolar molding procedure with reverse engineering software (RapidForm 2006). The digital geometrical data were exported to produce a scale model using rapid prototyping technology. The whole set of appliances was fabricated based on these solid models. RESULTS: The digital model could be viewed and measured from any direction by the software. By the end of the NAM treatment before surgical lip repair, the cleft was narrowed and the malformation of alveolar segments was aligned normally, significantly improving nasal symmetry and nostril shape. CONCLUSIONS: Presurgical NAM using CAD could simplify the treatment procedure and estimate the treatment objective, which enabled precise control of the force and direction of the alveolar segments movement.