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Background There is a growing body of evidence emphasizing the importance of research into patient-centred experience in orthodontics. Benefits following orthodontic treatment are mainly related to improved aesthetics and psychosocial outcomes. However, treatment experience from the perspective of orthodontic patients is yet to be fully understood. Objective To understand the past experiences and current perceptions of treatment outcomes of orthodontic patients. Study design A qualitative meta-ethnography. Selection criteria Qualitative studies and mixed-methods articles with a distinct qualitative component presenting patients' perception of outcomes and overall experiences after an active course of orthodontic treatment were included. Search methods Comprehensive electronic searches were conducted in MEDLINE, Scopus, Web of Science, PsycINFO, and EMBASE up to May 2021, supplemented by grey literature and manual searches. Data collection and analysis Two independent reviewers were involved in study selection, data extraction, and quality appraisal. The Critical Appraisal Skills Programme tool for qualitative research was used to assess the quality of included studies. Analysis of data was conducted using meta-ethnographic methods. Results Out of 801 retrieved search hits, six studies fulfilled the inclusion criteria and were included in the synthesis. The analysis revealed three main themes and associated sub-themes: (1) Reflection on the past treatment experience, (2) Patient satisfaction with treatment outcomes, and (3) Learning to live with retainers. Limitations Results express patients' opinions shortly after treatment, and the long-term impact of orthodontic treatment is yet to be understood. Conclusions Orthodontic patients mainly viewed their experiences and treatment results positively. Desirable aesthetic outcomes, psychosocial outcomes, and satisfaction with smiles were often reported in the studies reviewed. However, some barriers to optimal experiences were noticed concerning orthodontic retention. Registration PROSPERO (CRD42020180121). [ABSTRACT FROM AUTHOR]

Objectives To assess biomechanical properties of the lip muscles and to investigate their relationship with sex, age, body mass index (BMI), and cephalometric variables. Materials and methods Demographic information and BMI were collected from 83 study participants seeking orthodontic treatment at the University of Otago. Tone, stiffness, and elasticity of the lip muscles were measured thrice at four different anatomical sites using a digital palpation device. To estimate method error, a duplicate set of measurements in a subsample of 20 participants was taken a week later. Sagittal and vertical cephalometric classifications were based on ANB and FMPA angles, respectively. Data were analysed using mixed models. Results Biomechanical properties of lip muscles were remarkably consistent both within and between different recording sessions. The lower lip had higher tone and stiffness than the upper lip. Both the upper and lower lip stiffness and tone were higher in females than in males, whereas upper lip elasticity was higher in males. Thinner upper lips had higher tone and were stiffer than thicker upper lips, whereas thinner lower lips were less elastic than thicker lower lips. Muscle tone and stiffness of both the upper and lower lips were lower in Class III than in Class I and Class II individuals. The upper lip of hyperdivergent individuals was less elastic than that of normodivergent and hypodivergent individuals, and stiffer than that of hypodivergent individuals. Conclusions The biomechanical properties of perioral soft tissues can be reliably measured and vary with anatomical site, sex, and cephalometric measurements. [ABSTRACT FROM AUTHOR]

Background: The reliable assessment of craniofacial morphological changes during growth requires invariant regions for image registration. As these regions have not yet been identified in three dimensions, intra-osseous implants are required as fiducial markers for the reliable assessment of three-dimensional (3D) mandibular growth changes. The objective of this study was to develop an animal model for the assessment of the 3D morphological changes of the mandible during growth, using implants as fiducial markers. Materials and methods: Titanium implants were placed in the body of the mandible of six New Zealand White rabbits. Cone beam computed tomography (CBCT) scans were taken 1-week following implant placement and after an additional 8-weeks of growth. Segmentations of CBCT images were exported into custom-made scripts, implant centroids were identified, implant stability during growth calculated, and the segmented mandibles were registered on the implant centroids. Results: The buccal cortical bone of the body of the mandible was stable during growth and suitable for fiducial marker placement. Bilateral implants resulted in more accurate rigid registration of the growing rabbit mandible than only unilateral implants. 3D mandibular growth changes were visualised by means of semi-transparencies. Conclusions: This animal model appears to be feasible for the assessment of the 3D morphological changes occurring during mandibular growth. To the best of our knowledge this is the first time that the implant superimposition method has been combined with 3D imaging to accurately reveal mandibular growth changes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the perceived level of improvement in facial attractiveness as assessed by people with different backgrounds in skeletal Class II patients treated by mandibular advancement with bilateral sagittal split osteotomy (BSSO). The frontal and lateral pre- and post-operative photographs of 10 Caucasian patients were selected. Changes in frontal and profile attractiveness were assessed by 10 orthodontists, 10 art students, and 10 laypersons. Frontal and lateral pre- and post-operative photographs were randomly distributed throughout two surveys. For each photograph, the evaluators ranked the attractiveness of face, chin, and lips on visual analogue scales. A third survey was administered to orthodontists only, by presenting the same pre and post-operative photographs but paired side-by-side with pre- and post-operative status disclosed. Overall, attractiveness scores after BSSO showed an 11.5 per cent improvement (95 per cent confidence intervals: 9.4–13.5 per cent) on the lateral post-operative photographs and a 7.5 per cent improvement (95 per cent confidence intervals: 5.4–9.5 per cent) on the frontal post-operative photographs. Attractiveness scores differed significantly between the groups (P = 0.015), with orthodontists being more generous with their improvement ratings and the art students tending to give a more critical assessment. There were no significant differences between male and female evaluators (P > 0.05). Ratings of before–after attractiveness almost doubled when the pre- and post-operative status was disclosed as compared to blinded evaluations, thus indicating that prior knowledge of pre- and post-treatment status markedly influences aesthetic evaluations, with a bias towards a more favourable outcome. [ABSTRACT FROM PUBLISHER]

The aim of the present study was to determine any association between tooth transposition and bridging of the sella turcica, given the evidence of common embryonic origins associated with these structures and a genetic basis underlying these two conditions. Clinical records of subjects demonstrating dental transposition and normal controls were collected from several hospital orthodontic departments and specialist orthodontic practices. All cases and controls were documented with good quality lateral cephalometric radiographs and dental panoramic tomograms (DPTs). The study sample consisted of 21 Caucasian subjects (7 males and 14 females; mean age 14.5 years; SD 2.2 years), demonstrating either maxillary or mandibular dental transposition. The control group, matched for age and gender to the study sample, comprised 70 Caucasians (31 males and 39 females; mean age 13.8 years; SD 1.8 years) without dental anomalies randomly selected from subjects referred for orthodontic treatment within the same departments. The extent of sella turcica bridging was quantified from each profile radiograph using comparative measurement of length and diameter.Sella turcica bridging was found more frequently in subjects diagnosed with dental transposition than in the controls, with the difference being statistically significant [chi-square = 7.4; degrees of freedom (df) = 2; P = 0.025; Fisher's exact test; P = 0.042]. The increased frequency of complete and partial bridging of the sella turcica in subjects with dental transposition provides further evidence of a genetic basis to this condition. As calcification and bridging of this region can present during early childhood, it may act as a useful diagnostic predictor of susceptibility to local dental problems. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate the short-term effects of orthodontic pain on the pressure pain threshold (PPT) of the masseter and anterior temporalis muscles, and on their electromyographic (EMG) activity during clenching and chewing. Orthodontic pain was induced in 14 healthy subjects (mean age 26.6, SEM 1.1) by placing orthodontic separators. The subjects were randomly assigned to an experimental and to a control session in a double-blind crossover study. PPT was significantly reduced (Student's t-test; P < 0.001) after experimental sessions for both the masseter and the anterior temporalis muscles, whereas no significant differences were found during control sessions (P > 0.05). EMG activity during clenching and chewing was significantly reduced (0.001 ≤ P ≤ 0.05) after experimental sessions for both masseter and anterior temporalis muscles, whereas no significant differences were found during control sessions (P > 0.05). The decrease of PPT found in this study can be related to the occurrence of muscle pain and headache reported by patients during orthodontic or other dental treatment. The decrease of EMG activity of the jaw muscles associated with orthodontic pain is consistent with the pain adaptation model and should be considered as a potential factor for loss of occlusal anchorage during orthodontic treatment. [ABSTRACT FROM AUTHOR]