Treacher Collins syndrome: Orthodontic treatment with mandibular distraction osteogenesis and orthognathic surgery.

Interdisciplinary treatment for patients with Treacher Collins syndrome is challenging because of the rarity of the condition and the wide variety of phenotypic expression. A 23-year-old male was diagnosed with Treacher Collins syndrome with a history of severe obstructive sleep apnea. He presented with a Pruzansky-Kaban classification grade I mandible, skeletal type II pattern with a hyperdivergent mandibular plane, severe convex profile, and Class II malocclusion with a missing mandibular incisor. Improvement of facial esthetics was achieved by a combination of orthodontics, mandibular distraction osteogenesis, and 2-jaw maxillomandibular advancement surgery. Presurgical orthodontic treatment involved permanent tooth extraction to relieve severe crowding, and Class III mechanics were employed to increase overjet. Correction of mandibular hypoplasia by increasing ramal height and the mandibular length was done by intraoral mandibular distraction osteogenesis. Counterclockwise rotation of the mandibular plane angle and a Class III occlusion with negative overjet were achieved after mandibular distraction osteogenesis. A postdistraction posterior open bite was maintained with a biteplane during the consolidation period. Subsequently, 2-jaw orthognathic surgery was performed. LeFort I osteotomy was done for maxillary advancement to correct an anterior crossbite, eliminate canting, and reestablish occlusal contact at the mandibular occlusal plane. Bilateral sagittal split ramus osteotomy was done to correct the residual mandibular deviation. A genioplasty was also performed to improve chin projection. Postoperatively, the oropharyngeal airway was enlarged. The patient's facial profile and obstructive sleep apnea problem were improved as a result of advancement and counterclockwise rotation of the maxillomandibular complex.

Effectiveness of miniscrew assisted rapid palatal expansion using cone beam computed tomography: A systematic review and meta-analysis.

Objective: This study aims to examine the effectiveness of miniscrew assisted rapid palatal expansion (MARPE) treatment in late adolescents and adult patients using cone-beam computed tomography (CBCT). Methods: Literature search was conducted in five electronic databases (PubMed, Embase, Scopus, Web of Science, and Cochrane Library) based on the PICOS keyword design focusing on MARPE. Out of the 18 CBCT screened outcomes, only nine parameters were sufficient for the quantitative meta-analysis. The parameters were classified into three main groups: 1) skeletal changes, 2) alveolar change, and 3) dental changes. Heterogeneity test, estimation of pooled means, publication bias, sensitivity analysis and risk of bias assessment were also performed. Results: Upon database searching, only 14 full-text articles were qualified from the 364 obtained results. Heterogeneity test indicated the use of the random-effects model. The pooled mean estimate were as follows: 1) Skeletal expansion: zygomatic width, 2.39 mm; nasal width, 2.68 mm; jugular width, 3.12 mm; and midpalatal suture at the posterior nasal spine and anterior nasal spine, 3.34 mm and 4.56 mm, respectively; 2) Alveolar molar width expansion, 4.80 mm; and 3) Dental expansion: inter-canine width, 3.96 mm; inter-premolar width, 4.99 mm and inter-molar width, 5.99 mm. The percentage of expansion demonstrated a skeletal expansion (PNS) of 55.76%, alveolar molar width expansion of 24.37% and dental expansion of 19.87%. Conclusions: In the coronal view, the skeletal and dental expansion created by MARPE was of the pyramidal pattern. MARPE could successfully expand the constricted maxilla in late adolescents and adult patients.

Primary bilateral cleft lip-nose repair: the Tawanchai Cleft Center's integrated and functional reconstruction.

BACKGROUND: The repair of a bilateral cleft is more difficult than a unilateral repair because of numerous anatomical challenges, such as difficulty of repairing the skin and muscle overlying the protruded premaxilla and bilateral nasal reconstruction with shortening of the columella. An optimum outcome is achieved when all of the deformities of the primary cleft palate, the problems of scar and secondary deformities have been addressed. OBJECTIVES: To propose an integrated and functional reconstruction of the primary bilateral cleft lip-nose repair and to present the preliminary outcomes of this technique and its advantages. MATERIAL AND METHOD: An integrated, functional reconstruction process includes: 1) analysis of the bilateral cleft deformities; 2) interdisciplinary management and use of Tawanchai Center's protocol for cleft lip and palate care; 3) pre-surgical orthopedic treatments; and, 4) integrated primary cleft lip-nose repair and post-operative management. This approach to repair includes: 1) design of a prolabial flap and a modified, rotation advancement technique for skin surgery; 2) functional muscle reconstruction; 3) correction of nasal deformities and columella lengthening; 4) reconstruction of the vermillion; and, 5) final skin closure. RESULTS: Between 2002 and 2010, this technique was performed and evaluated on 42 patients who received primary bilateral cleft lip-nose repair, including 31complete, 6 incomplete and 5 right complete and left incomplete, 27 males and 15 females. Six parameters (scar, Cupid's bow symmetry, vermillion border symmetry, philtrum anatomic fidelity, muscle function and nasal symmetry) were used for evaluating the results, based on 4 scales (0-3) by 2 plastic surgeons. Among the mean scores better rating scales were achieved in philtrum anatomic fidelity (0.69) and Cupid' bow symmetry (0.76) while the mean of the less satisfactory rating scale was found in scar (1.13) and nasal asymmetry (0.96). These preliminary outcomes showed satisfactory results. Secondary reconstruction is less difficult and may be performed at the age of 4-6 years if indicated. DISCUSSION AND CONCLUSION: The authors introduced the Tawanchai Center's integrated concepts and functional reconstruction technique for bilateral cleft lip-nose repair. The technique offers the advantages of an integrated assessment for all of the deformities of the primary cleft palate, the design of an integrated technique together with proper peri-operative care, presurgical orthodontic treatment, and a well-coordinated, holistic, interdisciplinary management. A satisfactory preliminary outcome was demonstrated but more improvement of the outcome can be achieved by: 1) continuing assessment of this group of patients until they reach maturity; 2) refining techniques; 3) improving interdisciplinary care; and, 4) setting benchmarks for the outcome.

The effect of different surface preparation techniques on the survival probabilities of orthodontic brackets bonded to nanofill composite resin.

OBJECTIVE: To analyze the survival probabilities of different surface preparation techniques for bonding brackets to nanofill composite resin. DESIGN: In vitro, laboratory study. SETTING: Mahidol University, Bangkok, Thailand. MATERIALS AND METHODS: Thirty-five nanofill composite resin specimens/group were subjected to four surface preparation techniques as follows: (1) sandblast using aluminium oxide powder of 90 microm; (2) abrasion using diamond bur; (3) hydrofluoric acid etching for 2 min; and (4) 37% orthophosphoric acid etching for 30 s. Plastic conditioner was applied then brackets were bonded. Shear bond strength tests were carried out on a universal testing machine. MAIN OUTCOME MEASURES: Shear bond strength (MPa) and debonding force (N) were analyzed using Weibull analysis. RESULTS: The maximum stress and debonding force levels with a 95% probability of survival ranking from highest to lowest were: (1) sandblast group (4.2 MPa, 45.5 N); (2) diamond bur group (2.2 MPa, 25.3 N); (3) orthophosphoric group (1.9 MPa, 19.8 N); and (4) hydrofluoric group (0.8 MPa, 10.9 N). There was a significant difference in the adhesive remnant index scores between the surface preparation techniques (chi squared P<0.001). CONCLUSION: Bonding orthodontic brackets to nanofill composite resin materials may result in lower bond strengths and special surface preparation techniques might be required to avoid increased numbers of bond failures. Surface treatment with sandblasting followed by plastic conditioner could increase the survival probability. The use of a diamond bur, orthophosphoric etching or hydrofluoric etching cannot be recommended.

Survival analyses of surgical miniscrews as orthodontic anchorage.

INTRODUCTION: The objectives of this study were to determine the survival rate of titanium surgical miniscrews and the clinical parameters that posed the highest risks for failure. METHODS: Ninety-seven titanium surgical miniscrews (diameter, 1.2 mm; length, 8-12 mm) were placed in the maxilla of 49 patients, at either a high level (nonkeratinized area) or a medium level (mucogingival junction), with the 1-stage or the 2-stage surgical technique. Survival time, event of each screw (survival or failure), and 7 clinical parameters were gathered for survival analysis. Age and latency factors were analyzed with t tests. RESULTS: The cumulative survival rates were 85% at 6 months and 57% at 1 year. The Kaplan-Meier log rank test indicated significant differences in 3 explanatory variables: surgical stage, level of placement, and tissue response. Cox proportional hazards regression indicated that the 2-stage surgical procedure had a higher risk than the 1 stage. Placement at the high level had a greater risk than placement at the medium level. Inflammatory hypertrophy tissue reaction showed a higher risk than normal or mild inflammation. The t test showed that age and latency period were not significant. CONCLUSIONS: Titanium surgical miniscrews can be satisfactorily used as orthodontic anchorage. Controlling some aspects of the surgical protocol could reduce the failure rate.

The effectiveness of corticotomy and piezocision on canine retraction: A systematic review.

The aim of this systematic review was to evaluate the effectiveness and complications of corticotomy and piezocision in canine retraction. Five electronic databases (PubMed, SCOPUS, Web of Science, Embase, and CENTRAL) were searched for articles published up to July 2017. The databases were searched for randomized control trials (RCTs), with a split-mouth design, using either corticotomy or piezocision. The primary outcome reported for canine retraction was either the amount of tooth movement, rate of tooth movement, or treatment time. The secondary outcome was complications. The selection process was based on the PRISMA guidelines. A risk of bias assessment was also performed. Our search retrieved 530 abstracts. However, only five RCTs were finally included. Corticotomy showed a more significant (i.e., 2 to 4 times faster) increase in the rate of tooth movement than did the conventional method. For piezocision, both accumulative tooth movement and rate of tooth movement were twice faster than those of the conventional method. Corticotomy (with a flap design avoiding marginal bone incision) or flapless piezocision procedures were not detrimental to periodontal health. Nevertheless, piezocision resulted in higher levels of patient satisfaction. The main limitation of this study was the limited number of primary research publications on both techniques. For canine retraction into the immediate premolar extraction site, the rate of canine movement after piezocision was almost comparable to that of corticotomy with only buccal flap elevation.

Treatment outcome differences between pass and fail scores and correlation between cephalometric changes and cast-radiograph evaluation of the American Board of Orthodontics.

OBJECTIVE: Using the cast-radiograph evaluation (CRE) score of the American Board of Orthodontics (ABO), the purpose of this study was 1) to find the post-treatment discrepancies that contributed to low-quality outcomes and 2) to identify if there might be any correlation between cephalometric changes and post-treatment discrepancies. MATERIALS AND METHODS: About 200 records submitted for the Thai Board of Orthodontics examination were analyzed. Overall, 23 parameters of the CRE scores and 12 cephalometric changes were collected. Based on the total CRE score, the cases were classified into three categories: pass (score <20), undetermined (score 20-30), and fail (score >30). Kruskall-Wallis was used to analyze the differences of mean CRE scores among these three categories. In addition, the cases were further classified into fixed appliance, two-phase and orthognathic surgery groups. Correlation tests were carried out to determine if there might be any association between cephalometric changes and CRE parameters. RESULTS: Significant differences of mean CRE scores were found for all CRE components except interproximal contacts. Significant correlation coefficients with the total CRE scores were found for all parameters except interproximal contacts. Significant moderate association was found between lower incisor changes and CRE scores in the two-phase and orthognathic surgery group. CONCLUSIONS: In order to improve treatment outcome quality, the top four parameters that orthodontists should pay attention to are occlusal contacts, occlusal relationship, marginal ridges, and alignment and rotations. Cephalometric changes were not suitable as weighting factors for total CRE scores.

Force-deflection characteristics of the fatigue-resistant device spring: an in vitro study.

AIM: The Forsus fatigue-resistant device spring is a 3-piece telescoping compression spring used for Class II correction. The aims of this study were: (1) to measure the mean force delivered at different amounts of deflection; (2) to determine and compare the mean stiffness between loading and unloading; and (3) to determine the resilience of the fatigue-resistant device springs. MATERIAL AND METHODS: Twelve fatigue-resistant device springs were tested with a universal testing machine and Winrcon software, with the load cell of 100 N, crosshead speed at 0.5 mm/second. Force-deflection data during loading and unloading were recorded at 2-mm intervals up to 12 mm compression. RESULTS: (1) The mean force-deflection loading and unloading curves generally were linear, with a small area of hysteresis; (2) the loading mean stiffness (19.4 g/mm) was significantly greater than the unloading mean stiffness (18 g/mm), although this is clinically insignificant; (3) fatigue-resistant device springs exhibited good resiliency. A calibrated table of force-deflection of fatigue-resistant device springs is presented for clinicians to select the appropriate length of the device for the particular orthodontic force needed.