Decision Considerations and Strategies for Lip Surgery in Patients with Cleft lip/Palate: A Qualitative Study.

Objective: To qualitatively assess surgeons decision making for lip surgery in patients with cleft lip/palate (CL/P). Design: Prospective, non-randomized, clinical trial. Setting: Clinical data institutional laboratory setting. Patients Participants: The study included both patient and surgeon participants recruited from four craniofacial centers. The patient participants were babies with a CL/P requiring primary lip repair surgery (n=16) and adolescents with repaired CL/P who may require secondary lip revision surgery (n=32). The surgeon participants (n=8) were experienced in cleft care. Facial imaging data that included 2D images, 3D images, videos, and objective 3D visual modelling of facial movements were collected from each patient, and compiled as a collage termed the Standardized Assessment for Facial Surgery (SAFS) for systematic viewing by the surgeons. Interventions: The SAFS served as the intervention. Each surgeon viewed the SAFS for six distinct patients (two babies and four adolescents) and provided a list of surgical problems and goals. Then an in-depth-interview (IDI) was conducted with each surgeon to explore their decision-making processes. IDIs were conducted either in person or virtually, recorded, and then transcribed for qualitative statistical analyses using the Grounded Theory Method. Results: Rich narratives/themes emerged that included timing of the surgery; risks/limitations and benefits of surgery; patient/family goals; planning for muscle repair and scarring; multiplicity of surgeries and their impact; and availability of resources. For diagnoses/treatments, surgeons agreed, and level of surgical experience was not a factor. Conclusions: The themes provided important information to populate a checklist of considerations to serve as a guide for clinicians.

Personalised psychotherapy in primary care: evaluation of data-driven treatment allocation to cognitive-behavioural therapy versus counselling for depression.

BACKGROUND: Various effective psychotherapies exist for the treatment of depression; however, only approximately half of patients recover after treatment. In efforts to improve clinical outcomes, research has focused on personalised psychotherapy - an attempt to match patients to treatments they are most likely to respond to. AIM: The present research aimed to evaluate the benefit of a data-driven model to support clinical decision-making in differential treatment allocation to cognitive-behavioural therapy versus counselling for depression. METHOD: The present analysis used electronic healthcare records from primary care psychological therapy services for patients receiving cognitive-behavioural therapy (n = 14 544) and counselling for depression (n = 4725). A linear regression with baseline sociodemographic and clinical characteristics was used to differentially predict post-treatment Patient Health Questionnaire (PHQ-9) scores between the two treatments. The benefit of differential prescription was evaluated in a held-out validation sample. RESULTS: On average, patients who received their model-indicated optimal treatment saw a greater improvement (by 1.78 PHQ-9 points). This translated into 4-10% more patients achieving clinically meaningful changes. However, for individual patients, the estimated differences in benefits of treatments were small and rarely met the threshold for minimal clinically important differences. CONCLUSION: Precision prescription of psychotherapy based on sociodemographic and clinical characteristics is unlikely to produce large benefits for individual patients. However, the benefits may be meaningful from an aggregate public health perspective when applied at scale.

Trajectories of depression and generalised anxiety symptoms over the course of cognitive behaviour therapy in primary care: an observational, retrospective cohort.

BACKGROUND: Cognitive-behavioural therapy (CBT) has been shown to be an effective treatment for depression and anxiety. However, most research has focused on the sum scores of symptoms. Relatively little is known about how individual symptoms respond. METHODS: Longitudinal models were used to explore how depression and generalised anxiety symptoms behave over the course of CBT in a retrospective, observational cohort of patients from primary care settings (n = 5306). Logistic mixed models were used to examine the probability of being symptom-free across CBT appointments, using the 9-item Patient Health Questionnaire and the 7-item Generalised Anxiety Disorder scale as measures. RESULTS: All symptoms improve across CBT treatment. The results suggest that low mood/hopelessness and guilt/worthlessness improved quickest relative to other depressive symptoms, with sleeping problems, appetite changes, and psychomotor retardation/agitation improving relatively slower. Uncontrollable worry and too much worry were the anxiety symptoms that improved fastest; irritability and restlessness improved the slowest. CONCLUSIONS: This research suggests there is a benefit to examining symptoms rather than sum scores alone. Investigations of symptoms provide the potential for precision psychiatry and may explain some of the heterogeneity observed in clinical outcomes when only sum scores are considered.

Relationship between change in social evaluation learning and mood in early antidepressant treatment: A prospective cohort study in primary care.

BACKGROUND: Antidepressants are proposed to work by increasing sensitivity to positive versus negative information. Increasing positive affective learning within social contexts may help remediate negative self-schema. We investigated the association between change in biased learning of social evaluations about the self and others, and mood during early antidepressant treatment. METHOD: Prospective cohort assessing patients recruited from primary care in South West England at four timepoints over the first 8 weeks of antidepressant treatment (n = 29). At each timepoint, participants completed self-report measures of depression (Beck Depression Inventory II (BDI-II) and Patient Health Questionnaire 9 (PHQ-9)), anxiety (Generalised Anxiety Disorder Questionnaire 7 (GAD-7)), and a computerised task measuring learning of social evaluations about the self, a friend and a stranger. RESULTS: We did not find evidence that learning about the self was associated with a reduction in PHQ-9 (b = 0.08, 95% CI: -0.05, 0.20, p = 0.239) or BDI-II scores (b = 0.10, 95% CI: -0.18, 0.38, p = 0.469). We found some weak evidence that increased positive learning about the friend was associated with a reduction in BDI-II scores (b = 0.30, 95% CI: -0.02, 0.62, p = 0.069). However, exploratory analyses indicated stronger evidence that increased positive learning about the self (b = 0.18, 95% CI: 0.07, 0.28, p = 0.002) and a friend (b = 0.22, 95% CI: 0.10, 0.35, p = 0.001) was associated with reductions in anxiety. CONCLUSIONS: Change in social evaluation learning was associated with a reduction in anxiety but not depression. Antidepressants may treat anxiety symptoms by remediating negative affective biases towards socially threatening information directed towards the self and close others. However, our findings are based on exploratory analyses within a small sample without a control group and are therefore at risk of type 1 errors and order effects. Further research with larger samples is required.

Challenges in realising the potential of wastewater-based epidemiology to quantitatively monitor and predict the spread of disease.

Researchers around the world have demonstrated correlations between measurements of SARS-CoV-2 RNA in wastewater (WW) and case rates of COVID-19 derived from direct testing of individuals. This has raised concerns that wastewater-based epidemiology (WBE) methods might be used to quantify the spread of this and other diseases, perhaps faster than direct testing, and with less expense and intrusion. We illustrate, using data from Scotland and the USA, the issues regarding the construction of effective predictive models for disease case rates. We discuss the effects of variation in, and the problem of aligning, public health (PH) reporting and WW measurements. We investigate time-varying effects in PH-reported case rates and their relationship to WW measurements. We show the lack of proportionality of WW measurements to case rates with associated spatial heterogeneity. We illustrate how the precision of predictions is affected by the level of aggregation chosen. We determine whether PH or WW measurements are the leading indicators of disease and how they may be used in conjunction to produce predictive models. The prospects of using WW-based predictive models with or without ongoing PH data are discussed.

The early impact of COVID-19 on primary care psychological therapy services: A descriptive time series of electronic healthcare records.

BACKGROUND: There are growing concerns about the impact of the COVID-19 pandemic on mental health. With government-imposed restrictions as well as a general burden on healthcare systems, the pandemic has the potential to disrupt the access to, and delivery of, mental healthcare. METHODS: Electronic healthcare records from primary care psychological therapy services (Improving Access to Psychological Therapy) in England were used to examine changes in access to mental health services and service delivery during early stages of the COVID-19 pandemic. A descriptive time series was conducted using data from five NHS trusts to examine patterns in referrals to services (1st January 2019 to 24th May 2020) and appointments (1st January 2020 to 24th May 2020) taking place. FINDINGS: The number of patients accessing mental health services dropped by an average of 55% in the early weeks after the March 2020 lockdown was announced, reaching a maximum reduction of 74% in the initial 3 weeks after lockdown in the UK, which gradually recovered to a 28% reduction by May. We found some evidence suggesting changes in the sociodemographic and clinical characteristics of referrals. Despite a reduction in access, the impact on appointments appeared limited with service providers shifting to remote delivery of care. INTERPRETATION: Services appeared to adapt to provide continuity of care in mental healthcare. However, patients accessing services reduced, potentially placing a future burden on service. Despite the observational nature of the data, the present study can inform the planning of service provision and policy. FUNDING: AD and TS were funded by Innovate UK (KTP #11,105).

Effective dose 50 method as the minimal clinically important difference: Evidence from depression trials.

OBJECTIVE: Previous research on the minimal clinically important difference (MCID) for depression and anxiety is based on population averages. The present study aimed to identify the MCID across the spectrum of baseline severity. STUDY DESIGN AND SETTINGS: The present analysis used secondary data from 2 randomized controlled trials for depression (n = 1,122) to calibrate the Global Rating of Change with the PHQ-9 and GAD-7. The MCID was defined as a change in scores corresponding to a 50% probability of patients "feeling better", given their baseline severity, referred to as Effective Dose 50 (ED50). RESULTS: MCID estimates depended on baseline severity and ranged from no change for very mild up to 14 points (52%) on the PHQ-9 and up to 10 points (48%) on the GAD-7 for very high severity. The average MCID estimates were 3.7 points (23%) and 3.3 (28%) for the PHQ-9 and GAD-7 respectively. CONCLUSION: The ED50 method generates MCID estimates across the spectrum of baseline severity, offering greater precision but at the cost of greater complexity relative to population average estimates. This has important implications for evaluations of treatments and clinical practice where users can use these results to tailor the MCID to specific populations according to baseline severities.

Nasolabial fold dynamics: Implications for facial paralysis and facial reanimation surgery.

OBJECTIVES: In patients with facial paralysis, facial reanimation surgery may be needed to normalize facial soft tissue function/movements. Critical for this normalization is the dynamics of the nasolabial folds (NLFs). The objective of this prospective, observational study was to determine the 3D morphologic dynamics of the NLFs in patients with unilateral facial palsy and normal subjects. SETTINGS AND SAMPLE POPULATION: 3D facial soft tissue movement data collected from adults with unilateral, facial paralysis (Bell's Palsy, n = 36); and (2) an age- and sex-frequency matched control group (n = 68). MATERIALS AND METHODS: Movement data were collected during repeated animations from participants using a video-based motion capture system. Movement in terms of displacement and asymmetry of the NLFs, nasal and circumoral regions were analyzed in the lateral, vertical and depth planes; as well as movement of the commissure and NLFs relative to the lower lip midline. Two-sample t tests were used to test for significant group differences. RESULTS: Patients NLFs had less mean displacement, greater mean asymmetry and uncoordinated movements compared with the controls. For both groups during smiling, the NLF and commissure landmarks had approximately similar magnitudes of displacement (control range = 11-14mm; patient range = 7-10mm). CONCLUSION: NLF dynamics during smiling were as significant as oral commissure excursion. Thus, an immobile NLF is an unnatural feature of facial animations. Surgical treatments that address impaired NFL movements must be considered to create a more natural surgical outcome especially during smiling.

Facial mobility and recovery in patients with unilateral facial paralysis.

OBJECTIVE: (a) To quantify longitudinal 3D changes in facial soft tissue movements in adults with unilateral facial paralysis, and (b) to compare the patients' movements with an age- and sex-frequency matched control group. SETTINGS AND SAMPLE POPULATION: Prospective 3D facial movement data of 36 patients and 68 control participants. Patients' data were collected within 6 weeks of onset of symptoms (baseline) and then at 3 and 12 weeks after baseline. MATERIALS AND METHODS: The 3D facial movement data were collected during different facial animations. Mean group measurements of displacement, velocity and asymmetry were computed. Two sample t tests were used to test for significant group differences, and linear mixed models were fit to test for significant changes over time in the patient group. Also, 3D dynamic modelling and vector plots were computed to isolate the patients' abnormal movements and/or paralysis. RESULTS: The patients' mean baseline movements were significantly less for both the paralysed and contralateral sides of the face with much greater movement asymmetry than the controls. Patients' mean measures improved significantly from baseline to 12 weeks. The measures were closer to, but fell short of, the control values. CONCLUSION: In unilateral facial paralysis, the contralateral facial side was affected by the paralysis and may be tethered or limited in its movement by the paralysed side. The comprehensive measurement set and 3D facial mapping effectively tracked patient recovery and isolated paralysed facial regions. The 3D measures can be used for diagnosis and outcome assessment of different treatments.

Facial Soft-tissue Mobility: Baseline Dynamics of Patients with Unilateral Facial Paralysis.

BACKGROUND: The aims of this observational study were 2-fold: (1) To demonstrate a method and measures to quantify impaired facial soft-tissue movements in patients with facial paralysis; and (2) To quantify the differences in magnitude and velocity of facial soft-tissue movements between patients with facial paralysis and control participants. METHODS: The study sample that addressed both aims consisted of 20 adults with acute, unilateral, flaccid facial paralysis who presented at the onset of their paralysis, and a control group of 20 healthy adults. Dynamic 3D facial movement data were collected from each participant during 11 facial animations. To compare the movements between the patients and control participants, dynamic modeling comparisons of mean facial movements were computed as well as plots of movement vectors for each animation, in addition, measures of maximum displacement, movement velocity, and asymmetry were computed. RESULTS: Dynamic 3D modeling of critical facial landmarks provided precise profiles of zone-specific asymmetries and customized reporting that highlighted areas of importance for individual patients. The dynamic 3D movement data confirmed that the nonparalyzed side of patients' faces had abnormal directional movements. As expected, the controls had significantly higher excursive facial movements during all animations except during gentle eye closure, which was greater for the patients and the controls had significantly greater movement velocity than the patients. The patients had significantly greater asymmetry for all the animations, and the hierarchy of the asymmetry was such that maximum smile > lip purse > grimace > cheek puff. CONCLUSION: Dynamic 3D modeling appeared to be an effective tool to provide precise profiles of zone-specific asymmetries and customized reports for patients with facial paralysis.

Quantifying Soft Tissue Shape and Symmetry: Patients with Cleft Lip/Palate and Facial Paralysis.

BACKGROUND: The objective of this study was to demonstrate simple three-dimensional analyses of facial soft tissue shape and asymmetry. METHODS: There were 2 study samples: one retrospective comprised patients with repaired cleft lip and palate (CL/P) and control subjects; and the other prospective comprised patients with unilateral facial paralysis (FP) and control subjects. The data collected were digitized three-dimensional facial landmarks. Scores for shape and asymmetry of subjects' faces and for different facial regions were generated using Procrustes methods. Pivotal bootstrap methods and analysis of variance were used to test for significant differences in the scores between the patients and controls, and plots of the scores were generated to compare differences among the subjects. RESULTS: (1) Shape scores: The CL/P patients demonstrated significant overall and regional facial differences (P ≤ 0.01). The patients were further from the control mean, especially those with unilateral CL/P. Patients with FP demonstrated significant differences (P ≤ 0.05) for the lower face only. (2) Asymmetry scores: CL/P and FP patients demonstrated significant overall and regional facial differences (CL/P, P ≤ 0.0001; FP, P ≤ 0.01). CL/P and FP patients were more asymmetric and were further from the control mean, and patients with unilateral CL/P were more asymmetric than the bilateral CL/P patients. CONCLUSION: Clinicians can use the analyses to isolate differences and/or changes in the face due to shape or asymmetry, or a combination of both; based on the score plots, the extent of the shape and asymmetry differences can be compared among subjects and the extent of changes due to surgery measured.

Modelling a response as a function of high-frequency count data: The association between physical activity and fat mass.

Accelerometers are widely used in health sciences, ecology and other application areas. They quantify the intensity of physical activity as counts per epoch over a given period of time. Currently, health scientists use very lossy summaries of the accelerometer time series, some of which are based on coarse discretisation of activity levels, and make certain implicit assumptions, including linear or constant effects of physical activity. We propose the histogram as a functional summary for achieving a near lossless dimension reduction, comparability between individual time series and easy interpretability. Using the histogram as a functional summary avoids registration of accelerometer counts in time. In our novel method, a scalar response is regressed on additive multi-dimensional functional predictors, including the histogram of the high-frequency counts, and additive non-linear predictors for other continuous covariates. The method improves on the current state-of-the art, as it can deal with high-frequency time series of different lengths and missing values and yields a flexible way to model the physical activity effect with fewer assumptions. It also allows the commonly made modelling assumptions to be tested. We investigate the relationship between the response fat mass and physical activity measured by accelerometer, in data from the Avon Longitudinal Study of Parents and Children. Our method allows testing of whether the effect of physical activity varies over its intensity by gender, by time of day or by day of the week. We show that meaningful interpretation requires careful treatment of identifiability constraints in the light of the sum-to-one property of a histogram. We find that the (not necessarily causal) effect of physical activity on kg fat mass is not linear and not constant over the activity intensity.

Influence of objective three-dimensional measures and movement images on surgeon treatment planning for lip revision surgery.

Objective : To determine whether a systematic evaluation of facial soft tissues of patients with cleft lip and palate, using facial video images and objective three-dimensional measurements of movement, change surgeons' treatment plans for lip revision surgery. Design : Prospective longitudinal study. Setting : The University of North Carolina School of Dentistry. Patients, Participants : A group of patients with repaired cleft lip and palate (n = 21), a noncleft control group (n = 37), and surgeons experienced in cleft care. Interventions : Lip revision. Main Outcome Measures : (1) facial photographic images; (2) facial video images during animations; (3) objective three-dimensional measurements of upper lip movement based on z scores; and (4) objective dynamic and visual three-dimensional measurement of facial soft tissue movement. Results : With the use of the video images plus objective three-dimensional measures, the operating surgeon changed the problem list of the surgical treatment plan for 86% of the patients (95% confidence interval, 0.64 to 0.97) and the surgical goals for 71% of the patients (95% confidence interval, 0.48 to 0.89). The surgeon group varied in the percentage of patients for whom the problem list was modified, ranging from 24% (95% confidence interval, 8% to 47%) to 48% (95% confidence interval, 26% to 70%) of patients, and the percentage for whom the surgical goals were modified, ranging from 14% (94% confidence interval, 3% to 36%) to 48% (95% confidence interval, 26% to 70%) of patients. Conclusions : For all surgeons, the additional assessment components of the systematic valuation resulted in a change in clinical decision making for some patients.

Facial soft tissue dynamics before and after primary lip repair.

Objectives : (1) To collect three-dimensional, dynamic facial images from two groups of infants: one group born with cleft lip and palate slated to have a primary lip repair and a second, age-matched, noncleft control group. (2) To develop analyses to determine differences in facial movement between infants with cleft lip with or without palate (CL±P) and noncleft control infants and to determine changes in facial movement before and after primary lip repair. Design : Longitudinal, prospective case-control study. Setting : Facial Animation Laboratory at the University of North Carolina School of Dentistry. Participants : Two groups of infants: one group with unrepaired CL±P slated to have primary lip repair (n = 15) and a second group of age-matched, noncleft controls (n = 15). Interventions : Movement testing before and 4 months after primary lip repair in infants with CL±P and at similar time points in noncleft infants. Main Outcome Measures : Seven measures of facial movement. Results : The range of facial movements increased by 17% for all infants during the 4-month period. Compared with the noncleft group (1) infants with unilateral CL±P had 50% less nasolabial movement, and this difference did not change due to the lip repair; and (2) infants with unilateral or bilateral CL±P had 58% and 118% greater lateral upper lip movement, respectively, and 3.67 and 3.56 times greater asymmetry of movement, respectively, before lip repair. The procedure almost entirely removed the hypermobility and decreased the asymmetry. Conclusions : Primary surgical lip repair decreased hypermobility and improved asymmetry of upper lip movement.

Modelling fat mass as a function of weekly physical activity profiles measured by actigraph accelerometers.

We show results on the Avon longitudinal study of parents and children (ALSPAC) using a new approach for modelling the relationship between health outcomes and physical activity assessed by accelerometers. The key feature of the model is that it uses the histogram of physical activity counts as a predictor function, rather than scalar summary measures such as average daily moderate to vigorous physical activity (MVPA). Three models are fitted: (1a) A regression of fat mass at age 12 (N = 4164) onto the histogram of accelerometer counts at age 12; (1b) A regression of fat mass at age 14 (N = 2403) onto the histogram of accelerometer counts at age 12 and (1c) a regression of fat mass at age 14 (N = 2413) onto the accelerometer counts at age 14. All three models significantly improve on models including MVPA instead of the histogram and improve the goodness of fit of models (2a), (2b) and (2c) from R(2) = 0.267, 0.248 and 0.230 to R(2) = 0.292, 0.263 and 0.258 for models (1a), (1b) and (1c) respectively. The proportion of time spent in sedentary and very light activity (corresponding to slow walking and similar activities) has a positive contribution towards fat mass and time spent in moderate to vigorous activity has a negative contribution towards fat mass.

Shape change along geodesics with application to cleft lip surgery.

Continuous shape change is represented as curves in the shape space. A method for checking the closeness of these curves to a geodesic is presented. Three large databases of short human motions are considered and shown to be well approximated by geodesics. The motions are thus approximated by two shapes on the geodesic and the rate of progress along the path. An analysis of facial motion data taken from a study of subjects with cleft lip or cleft palate is presented that allows the motion to be considered independently from the static shape. Inferential methods for assessing the change in motion are presented. The construction of predicted animated motions is discussed.

Functional outcomes of cleft lip surgery. Part I: Study design and surgeon ratings of lip disability and need for lip revision.

OBJECTIVE: Children with a cleft of the upper lip exhibit obvious facial disfigurement. Many require multiple lip surgeries for an optimal esthetic result. However, because the decision for lip revision is based on subjective clinical criteria, clinicians may disagree on whether these surgeries should be performed. To establish more reliable, functionally relevant outcome criteria for evaluation and treatment planning, a clinical trial currently is in progress. In this article, the design of the clinical trial is described and results of a study on subjective evaluations of facial form by surgeons for or against the need for lip revision surgery are presented. DESIGN: Parallel, three-group, nonrandomized clinical trial and subjective evaluations/ratings of facial views by surgeons. SUBJECTS: For the clinical trial, children with repaired cleft lip and palate scheduled for a secondary lip revision, children with repaired cleft lip and palate who did not have lip revision, and noncleft children. For the subjective evaluations, surgeons' facial ratings of 21 children with repaired cleft lip. ANALYSIS: Descriptive and Kappa statistics assessing the concordance of surgeons' ratings of (a) repeated facial views and (b) a recommendation of revision on viewing the prerevision and postrevision views. RESULTS: The surgeons' consistency in rating repeated views was moderate to excellent; however, agreement among the surgeons when rating individual participants was low to moderate. CONCLUSIONS: The findings suggest that the agreement among surgeons was poor and support the need for more objective measures to assess the need for revision surgery.

Functional outcomes of cleft lip surgery. Part II: Quantification of nasolabial movement.

OBJECTIVE: To explore nasolabial movements in participants with repaired cleft lip and palate. DESIGN: A parallel, three-group, nonrandomized clinical trial. SUBJECTS: Group 1=31 participants with a cleft lip slated for revision surgery (revision), group 2=32 participants with a cleft lip who did not have surgery (nonrevision), and group 3=37 noncleft control participants. METHODS: Three-dimensional movements were assessed using a video-based tracking system that captured movement of 38 landmarks placed at specific sites on the face during instructed maximum smile, cheek puff, lip purse, mouth opening, and natural smile. Measurements were made at two time points at least 1 week and no greater than 3 months apart. Summary measurements were generated for the magnitude of upper lip, lower lip, and lower jaw movements and the asymmetry of upper lip movement. Separate regression models were fitted to each of the summary measurements. RESULTS: Lateral movements of the upper lip were greater than vertical movements. Relative to the noncleft group, the revision and nonrevision groups demonstrated 6% to 28% less upper lip movements, with the smiles having the most restriction in movement and greater asymmetry of upper lip movement. Having an alveolar bone graft further increased the asymmetry, while a bilateral cleft lip decreased the asymmetry. Lower jaw movement caused a small increase in upper lip movement. CONCLUSIONS: The objective measurement of movement may be used as an outcome measure for cleft lip surgery.

Functional outcomes of cleft lip surgery. Part III: Measurement of lip forces.

OBJECTIVE: To investigate lip force dynamics among participants with a repaired cleft of the lip and noncleft control participants. DESIGN: A parallel, three-group, nonrandomized clinical trial. SUBJECTS: Forty-eight participants with cleft lip and 36 noncleft participants. ANALYSIS: Participants attended two separate visits. At each visit, they were instructed to produce fine motor control and maximum compression forces with each upper and lower lip in response to visual force targets. Measures of force were extracted, and the data were fit using regression techniques. RESULTS: The upper and lower lips of the participants with a cleft lip demonstrated less time on target, while the lower lips had shorter rise time but higher peak forces, a higher rate of force recruitment, and increased maxima of the first derivative of force compared with the noncleft participants. For all participants, there was a learning effect for certain force variables between the two visits and with increasing age. CONCLUSION: For participants with a cleft lip, force regulation of the circumoral region within the operating range presumed important for facial and speech animation is compromised because of impairments in force recruitment, gradation, fractionation, and stability. In the presence of a change in upper lip tissue mechanics due to scarring or neuromotor impairment, such as a cleft, the lower lip typically exhibits compensatory motor actions.

A computer algorithm for representing spatial-temporal structure of human motion and a motion generalization method.

Inspired by the generalized motor program (GMP) theory, this study presents a symbolic motion structure representation (SMSR) algorithm that identifies a basic spatial-temporal structure of a human motion. The algorithm resolves each joint angle-time trajectory of a multi-joint motion into a sequence of elemental motion segments and labels each motion segment with a symbol representing its shape ("U": monotonically increasing; "D": monotonically decreasing; "S": stationary). By concatenating symbols according to their order in time, the spatial-temporal structure of a joint angle-time trajectory is represented as a symbolic string. The structure of a multi-joint motion is then represented as a set of symbolic strings. A sample motion, whose structure is identified by the SMSR algorithm, can be generalized to produce an infinite number of similar motion variants. To generate a variant of a sample motion, segment boundary points of the sample motion are first relocated to new locations in the angle-time space, and then individual motion segments of the original joint angle trajectories are shifted and proportionally rescaled to fit the new segment boundary points. This motion generalization method provides a basis for developing GMP-based motion simulation models, and exploring ideas and hypotheses related to the GMP theory through simulation. As an application of the motion generalization method, a motion modification (MoM) algorithm is presented, which adapts existing reach motions for new target locations. Some examples generated by the MoM algorithm are illustrated.