Outcome measures of the surgery first approach for orthognathic correction of dentofacial deformities

Background: In the surgery-first approach (SFA) the orthognathic surgery is performed without the need for presurgical orthodontic treatment. Aim: This study was aimed at assessing the treatment durations and occlusal outcomes for a consecutive cohort of patients, with a range of dentofacial deformities, who have completed orthognathic treatment using the SFA. Methodology: The duration of orthognathic treatment was measured. The overall change in occlusion, and the quality of the final occlusion, were evaluated using the patients’ study casts. A single independent, calibrated, operator carried out the occlusal scores, using the validated Peer Assessment Rating (PAR) index. This was repeated to test intra-operator reliability. Results: A total of 51 patients completed surgery-first treatment during the study period. The mean age at surgery was 23.3 years. The pre-treatment skeletal jaw relationship was Class III in 39 cases, and Class II in 12 cases. The mean overall treatment duration was 11.7 months (SD = 5.7). The intra-examiner reliability of assessing the occlusion was high. The PAR scores confirmed a significant improvement in the quality of occlusion at the completion of treatment, which compares favourably with previous studies on the conventional orthodontics-first approach. Conclusion: The SFA can be effective at correcting both Class 2 and Class 3 malocclusion types with reduced treatment times

A multi-centre audit to assess the effectiveness of the British Orthodontic Society 'Hold that Smile' retainer videos

Introduction: Retention is a crucial part of orthodontic treatment, however patients often do not wear their retainers as advised. The British Orthodontic Society developed the ‘Hold that Smile’ campaign in 2017, to improve patient knowledge about retention. Information is provided in two formats: a cartoon and a conventional film. / Objective: To assess if patients find the ‘Hold that Smile’ videos useful, and if they improved patients’ intended retainer wear. The gold standard was that 90% of patients should intend to wear their retainers long-term following watching the videos. / Design: National multi-centre audit. / Setting: Nine units in the UK. / Methods: Patients 10 years old and over, in fixed appliances or retention, watched the retainer videos and then completed a questionnaire that was designed specifically for this audit. Each unit collected data for approximately 30 patients. / Results: Data was collected for 278 patients in total. The average age was 17.9 years; 64.4% of patients were female and 35.6% male. Most patients (86.3%) watched both videos and, of these, 44.1% preferred the film, 31.3% preferred the cartoon and 24.6% had no preference. The majority of patients (81.3%) felt that the film provided them with new information, compared with a lower percentage (48.5%) for the cartoon and more patients said they would recommend the film (76.3%) compared with the cartoon (63.3%). Prior to watching the videos, 77.0% of patients felt they knew about long-term retainer wear and 74.3% of those intended to wear their retainers long-term. After watching the videos, 96.4% of all patients thought they would now wear their retainers long-term. / Conclusion: After watching the videos, there was a notable increase in the number of patients planning to wear their retainers long-term and the gold standard was met. Therefore, these videos may be beneficial in improving understanding and compliance with retention

Design and characterisation of multi-mode interference reflector lasers for integrated photonics

InAs quantum dot ridge waveguide lasers comprising single-port multi-mode-interference-reflectors (MMIR) and single-cleaved reflectors are designed, fabricated, and characterised, to demonstrate capability for optoelectronic-integrated-circuits. Simulations of an MMIR show high values of fundamental mode reflectivity ( >80%) and good selectivity against higher order modes. Deep-etched MMIR lasers fabricated with 0.5 mm long cavities have a threshold current of 24 mA, compared to 75 mA for standard Fabry–Perot cleaved–cleaved FP-RWG lasers of the same length, both at 25 °C, and 56 mA compared to 102 mA at 55 °C. MMIR lasers exhibit stable ground state operation up to 50 °C and show promise as small footprint sources for integrated photonics

Impact of thermal oxidation uniformity on 150 mm GaAs- and Ge-substrate VCSELs

Vertical cavity surface emitting laser (VCSEL) devices and arrays are increasingly important in meeting the demands of today’s wireless communication and sensing systems. Understanding the origin of non-uniform wet thermal oxidation across large-area VCSEL wafers is a crucial issue to ensure highly reliable, volume-manufactured oxide-confined VCSEL devices. As VCSEL wafer diameters approach 200 mm, germanium (Ge) is emerging as an alternative substrate solution. To this end, we investigate the uniformity of 940 nm-emitting VCSEL performance across 150 mm diameter GaAs- and Ge-substrates, comparing the oxidation method in each case. Nominally identical epitaxial structures are used to evaluate the strain induced wafer bow for each substrate type with Ge exhibiting a reduction of over 100 μm in the peak-to-valley distortion when compared with GaAs. This wafer bow is found to be the principal cause of centre-to-edge oxidation non-uniformity when utilising a conduction-heated chuck furnace, in comparison to a convection-heated tube furnace. Using on-wafer testing of threshold current, differential resistance, and emission wavelength, device performance is demonstrated for the first time across a 150 mm Ge wafer, and is shown to be comparable to performance on GaAs substrates, when the effects of oxidation uniformity are removed. These results provide evidence that there is a realistic path to manufacturing high yield VCSELs, over wafer diameters approaching those used in Si-photonics, via Ge substrates

Realisation of multi-mode reflector lasers for integrated photonics

The epitaxial growth of III-V materials on silicon is an alternative approach to combining silicon photonics with the active laser source. Substantial progress has been made to reduce the defects created at the III-V / Si interface to a level that has a negligible impact on laser operating current and lifetime, providing quantum dot gain materials are utilized [1], [2]. A number of issues remain for the integration of III-V structures with silicon, not least that of reducing the footprint and ensuring the fabrication required is as simple as possible. While the laser reflectors can be fabricated in the silicon here we focus on using the III-V material, which removes the need to have the III-V / Silicon interface and its associated losses within the laser cavity

Monolithic InAs QDs based active-passive integration for photonic integrated circuits

We demonstrated 20 nm relative blue shifted III-V passive waveguides monolithically integrated with InAs QDs active laser diode emitting at 1290 nm through selective area proton implantation and post-annealing method. This work is promising for low-loss monolithic Photonic Integrated Circuits

Multi-mode interference reflector for integrated photonics

1-port and 2-port InAs-QD MMIR lasers are designed, fabricated, and characterized. MMIRs laser have lower threshold current densities compared to cleaved-cleaved FP lasers with the same cavity length, up to 40% less. They are promising for use in optoelectronic-integrated circuits

Cleft lip/palate: incidence of prenatal diagnosis in Glasgow, Scotland, and comparison with other centers in the United Kingdom

Objectives: To determine the proportion of children with cleft lip and/or cleft palate diagnosed prenatally between 1999 and 2008 in those referred for treatment to the Royal Hospital for Sick Children in Glasgow, Scotland (RHSC); and to compare the percentage prenatally diagnosed in 2008 versus other cleft treatment centers in the U.K. Method: A retrospective study was performed using medical records of the 459 cleft patients born and referred to RHSC between 1999 and 2008. Comparable data for year 2008 were requested from other U.K. units. Results: For the period studied, the percentage of all clefts diagnosed prenatally was 15%. This rose to 28% when only the cases of cleft lip with or without cleft palate (CL±P) were considered. An increase was seen in prenatal detection of CL±P from 11% in 1999 to 50% in 2008 (p  =  .011). Two of the six U.K. units that responded had a significantly higher percentage of CL±P cases diagnosed prenatally compared with RHSC in 2008 (p < .05). Conclusions: The percentage of CL±P cases diagnosed prenatally in this study is consistent with the literature and increased between 1999 and 2008. Routine ultrasound anomaly scanning is shown to significantly improve detection rates compared with scanning of high-risk pregnancies only. Cases of CL±P where the alveolus or the palate is involved have significantly higher detection rates than those involving only the lip