Direct printed removable appliances: A new approach for the Twin-block appliance.

Removable appliances are an important part of orthodontic treatment. The Twin-block is widely used for Class II correction. Traditionally, an impression, bite registration, and mounted plaster casts are required to fabricate the acrylic appliance, which usually requires a specialized laboratory. This makes the process expensive and also time-consuming. This paper aims to present an innovative approach for the virtual design and direct printing of removable orthodontic appliances, particularly the Twin-block, that can be done in-office without the need for casts or a specialized laboratory.

CAD-CAM-fabricated mini-implant insertion guides for the delivery of a distalization appliance in a single appointment.

This article reports on the technical aspects of using a computer-aided design-computer-aided manufacturing (CAD-CAM) insertion guide for the placement of orthodontic mini-implants used for the purpose of providing anchorage support for maxillary molar distalization. A 10-year-old girl presented with a bilateral full-step Angle Class II molar relationship in the permanent dentition, with anterior arch-length insufficiency and blocked out maxillary canine teeth. The primary treatment objective was to provide an esthetic and functional occlusal outcome, and secondarily to avoid the removal of multiple premolar teeth. The patient was initially treated with an implant-supported distalization device, and the occlusion was subsequently detailed with preadjusted fixed orthodontic appliances. The CAD-CAM procedure facilitates the safe and precise insertion of mini-implants in the anterior palate, potentially broadening the scope of use of palatal mini-implants for less experienced clinicians. The illustrated protocol allows for the insertion of mini-implants and fitting of a prefabricated appliance in a single office appointment.

Maxillary molar mesialization with the use of palatal mini-implants for direct anchorage in an adolescent patient.

A unique clinical challenge presents when dealing with a compromised first permanent molar. A compelling treatment option for consideration is the removal of a nonrestorable first permanent molar, with the subsequent "replacement" through controlled mesial tooth movement of viable second and third molars. To reinforce the anchorage support associated with such a planned movement, indirect or direct implant-supported mechanics may be used. With the use of direct anchorage, orthodontic brackets are not required and space closure can be commenced immediately. In this article, we report the clinical procedure and design of direct-anchorage mechanics used for the successful closure of a maxillary first permanent molar space with the use of an implant-supported appliance (Mesialslider). Treatment was completed in just under 12 months, with successful mesial movement of the maxillary second and third molars without the need for the bonding of orthodontic brackets on the anterior dentition. The result was determined to be stable over a 3-year period.

CAD-CAM design and 3-dimensional printing of mini-implant retained orthodontic appliances.

The objective of this article was to illustrate the digital process in the custom fabrication of metallic mini-implant supported appliances. An implant-supported appliance was produced for a patient using a CAD-CAM procedure without a physical impression or a printed model. The work flow consisted of mini-implant insertion into the palate, recording an intraoral digital scan, digital design with incorporation of a scanned expansion mechanism, direct 3-dimensional metal printing via laser melting, laser welding of the hyrax mechanism, insertion, and activation of the appliance. The favorable clinical outcome demonstrated that this procedure is an efficient and viable method for constructing an implant-supported palatal metallic appliance.

Three-Dimensional Analysis of Nasal Symmetry Following Primary Correction of Unilateral Cleft Lip Nasal Deformity.

OBJECTIVE: To evaluate nasal symmetry using three-dimensional photogrammetry following primary tip rhinoplasty with or without an internal splint in patients with unilateral complete cleft lip/palate. DESIGN: We captured three-dimensional images of patients with unilateral complete cleft lip/palate who underwent nasolabial repair by rotation-advancement of the lip and primary tip rhinoplasty, either with or without an internal resorbable splint, and normal control subjects. We assessed nasal symmetry by identifying the plane of maximum symmetry and the root-mean-square deviation between native and reflected surfaces. PATIENTS/PARTICIPANTS: We imaged 38 controls and 38 subjects with repaired unilateral complete cleft lip/palate (20 with, 18 without an internal splint). RESULTS: Nasal asymmetry root-mean-square deviation clustered between 0.19 and 0.50 mm (median = 0.24 ± 0.08 mm) for controls; whereas, those with repaired unilateral complete cleft lip/palate ranged from 0.4 to 1.5 mm (median = 0.75 ± 0.40 mm). Although root-mean-square deviation ranges overlapped, patients with repaired unilateral complete cleft lip/palate had significantly greater asymmetry than controls (P < .001). We found no difference in asymmetry between patients with or without an internal splint (P = .5). CONCLUSIONS: Three-dimensional photogrammetry was used to successfully compare symmetry among different patient and control groups. Although "normal" nasal symmetry was attained in some patients following cleft lip/nasal repair, most had persistent asymmetry compared with normal controls. Placement of a resorbable internal splint did not improve symmetry in patients with unilateral complete cleft lip/palate.

Wear-time recording during early Class III facemask treatment using TheraMon chip technology.

Successful intervention in a developing Class III malocclusion with facemask protraction therapy depends on a patient's ability to adhere to the recommendations for duration of appliance wear. In this article, we report the introduction of a novel approach for tracking of the duration of application of a protraction facemask, with the incorporation of a "FaceMon" sensor (TheraMon, microelectronic system; MC Technology GmbH, Hargelsberg, Austria) to track wear time. A 9-year-old boy with a Class III malocclusion was successfully treated with a modified alternate rapid maxillary expansion and constriction protocol and intermittent application of a hybrid hyrax-protraction facemask combination. The average duration of wear of the facemask was measured at 10.8 hours per day. The use of an objective measuring device may have implications for the development of treatment strategies, since patient responses may be able to calibrated in relation to compliance.

Closure of an open bite using the 'Mousetrap' appliance: a 3-year follow-up.

Recently, skeletal anchorage devices have been used as anchorage units for upper molar intrusion as a way of correcting an anterior open bite malocclusion. To avoid the surgical procedures associated with the placement of miniplates in the zygomatic area, mini-implants may be inserted palatally or buccally in the alveolar process. However, consideration must be given to the potential risks of root damage and a higher failure rate associated with the placement of temporary anchorage devices (TADs) in the interradicular area. The anterior hard palate provides a safer and more stable alternative for TAD placement. The current paper describes the biomechanical principles and the clinical procedures of 'Mousetrap' mechanics using mini-implants in the anterior palate for upper molar intrusion. The stomatognathic response of maxillary molar intrusion is an autorotation of the mandible and so the sagittal implications for each patient must be considered. The presented patient demonstrates successful correction and stability of the treatment result at a three-year review.

Nasolabial soft tissue changes after Le Fort I advancement.

PURPOSE: To identify the nasolabial soft tissue changes that occur after Le Fort I advancement. MATERIALS AND METHODS: A prospective study of patients who had Le Fort I advancement at the Children's Hospital Boston from 2005 to 2007. The pre- and postoperative anthropometeric nasolabial measurements were recorded by a single examiner. RESULTS: A total of 37 patients with a mean age of 18.6 years at the time of operation and a mean follow-up of 12.6 months were recruited. Nearly one half of the study sample (16 of 37) had cleft lip/palate. Direct anthropometry showed a reduction of the nasal length by 1.3 mm while the nasal tip protrusion increased by 1.1 mm. The nasofrontal angle decreased by 9.8° and the upper lip moved forward by 4.15 mm, reflecting the advancement in the maxilla. The height of the cutaneous upper lip increased by 0.4 mm. No significant differences were found in the soft tissue response observed between the cleft and noncleft subjects. CONCLUSIONS: Le Fort I advancement produces elevation of the nasal tip, as seen by a reduction in the nasal length, an increase in the nasal tip protrusion, and a concomitant reduction in the nasofrontal angle. Additionally, the cutaneous lip height increased, most likely due to an unfurling of the upper lip.

Craniofacial growth in patients with FGFR3Pro250Arg mutation after fronto-orbital advancement in infancy.

BACKGROUND: The facial features of children with FGFR3Pro250Arg mutation (Muenke syndrome) differ from those with the other eponymous craniosynostotic disorders. We documented midfacial growth and position of the forehead after fronto-orbital advancement (FOA) in patients with the FGFR3 mutation. METHODS: We retrospectively reviewed all patients who had an FGFR3Pro250Arg mutation and craniosynostosis. Only patients who had FOA in infancy or early childhood were included. The clinical records were evaluated for type of sutural fusion; midfacial hypoplasia and other clinical data, including age at operation; type of procedures and fixation (wire vs resorbable plate); frequency of frontal readvancement, forehead augmentation, midfacial advancement; and complications. Preoperative and postoperative sagittal orbital-globe relationship was measured by direct anthropometry. Outcome of FOA was graded according to the Whittaker classification as category I, no revision; category II, minor revisions, that is, foreheadplasty; category III, alternative bony work; category IV; redo of initial procedure (ie, secondary FOA). Midfacial position was determined by clinical examination and lateral cephalometry. RESULTS: A total of 21 study patients with Muenke syndrome (8 males and 13 females) were analyzed. The types of craniosynostosis were bilateral coronal (n=15), of which 3 also had concurrent sagittal fusion, and unilateral coronal (n=5). Two patients had early endoscopic suturectomy, but later required FOA. Mean age at FOA was 22.9 months (range, 3-128 months). Secondary FOA was necessary in 40% of patients (n=8), and secondary foreheadplasty in 25% (n=5) of patients. No frontal revisions were needed in the remaining 35% of patients (n=7). Mean age at initial FOA was significantly younger in the group requiring repeat FOA or foreheadplasty compared with patients who did not require revision (P<0.05). Location of synostosis, type of fixation, and bone grafting did not significantly affect the need for revision. Only 30% (n=6) of patients developed midfacial retrusion. CONCLUSIONS: The frequency of frontal revision in patients with Muenke syndrome who had FOA in infancy and early childhood is lower than previously reported. Age at forehead advancement inversely correlated with the incidence of relapse and need for secondary frontal procedures. Midfacial retrusion is relatively uncommon in FGFR3Pro250Arg patients.

Submucous cleft palate and velopharyngeal insufficiency: comparison of speech outcomes using three operative techniques by one surgeon.

OBJECTIVE: Our purpose was to compare speech outcomes among three primary procedures for symptomatic submucous cleft palate (SMCP): two-flap palatoplasty with muscular retropositioning, double-opposing Z-palatoplasty, or pharyngeal flap. DESIGN: Retrospective review. SETTING: Tertiary hospital. PATIENTS, PARTICIPANTS: All children with SMCP treated by the senior author between 1984 and 2008. INTERVENTIONS: One of three primary procedures: two-flap palatoplasty with muscular retropositioning, double-opposing Z-palatoplasty, or pharyngeal flap. MAIN OUTCOME MEASURES: Speech outcome and need for a secondary operation were analyzed among procedures. Success was defined as normal or borderline competent velopharyngeal function. Failure was defined as persistent borderline insufficiency or velopharyngeal insufficiency with recommendation for a secondary operation. RESULTS: We identified 58 patients with SMCP who were treated for velopharyngeal insufficiency. We found significant differences in median age at operation among the procedures (p < .001). Two-flap palatoplasty with muscular retropositioning (n = 24), double-opposing Z-palatoplasty (n = 19), and pharyngeal flap (n = 15) were performed at a median of 2.5, 3.6, and 9.5 years, respectively. There were significant differences in success among procedures (p = .018). Normal or borderline competent function was achieved in 6/20 (30%) patients who underwent two-flap palatoplasty, 10/15 (67%) following double-opposing Z-palatoplasty, and 11/12 (92%) following pharyngeal flap. Among patients treated with palatoplasty, success was independent of age at operation (p = .16). CONCLUSIONS: Double-opposing Z-palatoplasty is more effective than two-flap palatoplasty with muscular retropositioning. For children older than 4 years, primary pharyngeal flap is also highly successful but equally so as a secondary operation and can be reserved, if necessary, following double-opposing Z-palatoplasty.

Differences in craniofacial structures and obesity in Caucasian and Chinese patients with obstructive sleep apnea.

STUDY OBJECTIVES: To explore differences in craniofacial structures and obesity between Caucasian and Chinese patients with obstructive sleep apnea (OSA). DESIGN: Inter-ethnic comparison study. SETTING: Two sleep disorder clinics in Australia and Hong Kong. PATIENTS: 150 patients with OSA (74 Caucasian, 76 Chinese). INTERVENTIONS: Anthropometry, cephalometry, and polysomnography were performed and compared. Subgroup analyses after matching for: (1) body mass index (BMI); (2) OSA severity. MEASUREMENTS AND RESULTS: The mean age and BMI were similar between the ethnic groups. Chinese patients had more severe OSA (AHI 35.3 vs 25.2 events/h, P = 0.005). They also had more craniofacial bony restriction, including a shorter cranial base (63.6 +/- 3.3 vs 77.5 +/- 6.7 mm, P < 0.001), maxilla (50.7 +/- 3.7 vs 58.8 +/- 4.3 mm, P < 0.001) and mandible length (65.4 +/- 4.2 vs 77.9 +/- 9.4 mm, P < 0.001). These findings remained after correction for differences in body height. Similar results were shown in the BMI-matched analysis (n = 66). When matched for OSA severity (n = 52), Chinese patients had more craniofacial bony restriction, but Caucasian patients were more overweight (BMI 30.7 vs 28.4 kg/m2, P = 0.03) and had a larger neck circumference (40.8 vs 39.1 cm, P = 0.004); however, the ratios of BMI to the mandible or maxilla size were similar. CONCLUSIONS: Craniofacial factors and obesity contribute differentially to OSA in Caucasian and Chinese patients. For the same degree of OSA severity, Caucasians were more overweight, whereas Chinese exhibited more craniofacial bony restriction.

Randomized trials published in the journal of dental research are cited more often compared with those in other top-tier non-specialty-specific dental journals.

BACKGROUND AND AIM: Randomized controlled trials (RCTs) are viewed as the gold standard for clinical research. Oftentimes the citation counts serve as an important measure for assessing the significance of an RCT to promote the dissemination of science. This study attempts to identify the factors associated with the number of times RCTs are cited within the first 24 months since publication. MATERIALS AND METHODS: RCTs published between January 1, 2002, and November 30, 2006, in 4 journals (Journal of Dental Research, European Journal of Oral Sciences, Journal of Dentistry, and Clinical Oral Investigations) were selected for analysis. Citation counts of RCTs in the first 24 months since publication was the outcome variable. The independent variables included journal of publication, geographic region of origin of study, number of authors, financial support, number of references, presentation of a statistically significant result, and if the study was conducted on animals. Bivariate associations between the outcome and independent variables were examined by Kruskal-Wallis test, Mann-Whitney U test, and Spearman rank correlations where appropriate. A multivariable negative binomial regression model was also built to examine the association. RESULTS: A total of 163 RCTs were selected for analysis. The mean citation count for the first 24 months count was 2.61. Close to 20% of RCTs were not cited even once in this observation period. RCTs published in the highest impact factor journal (Journal of Dental Research) tended to be cited most often (P < .05). CONCLUSION: Based on our initial analysis of 4 journals, publishing randomized trials in high-impact journals will likely provide better dissemination of research findings.