Facial soft tissue dynamics before and after primary lip repair

The Ability to Sustain Facial Expressions

To gain more insight into facial muscle function, imaging during action would be optimal. Magnetic resonance imaging is highly suitable for visualizing facial muscles. However, magnetic resonance imaging requires the individual to remain as still as possible for a while. Knowledge of the ability to sustain facial expressions is requisite before scanning individuals. This could help adapting the scanning protocol to obtain optimal quality of imaging the muscles in action. A study, including 10 healthy volunteers, was done to perceive the extent of movement while holding facial expressions of smiling and pouting. During 6 minutes, 3-dimensional photographs were taken every consecutive minute while the participants maintained their facial expressions as motionless as possible. The movement was objectified by creating distance maps between the 2 models and calculating the Root Mean Square using the software 3DMedX. The results showed that most movements occurred in the first minute, with a decrease of the intensity of the expression. After the first minute, the expression, although less intense, could be held stable. This implies that magnetic resonance imaging scanning during facial expression is possible, provided that the scanning starts after the first minute has elapsed. In addition, results demonstrated that more slackening of the muscles while smiling compared with pouting.

Relation between Maximum Oral Muscle Pressure and Dentoalveolar Characteristics in Patients with Cleft Lip and/or Palate: A Prospective Comparative Study

BACKGROUND

Perioral muscle function, which influences maxillofacial growth and tooth position, can be affected in patients with oral clefts due to their inherent anatomical characteristics and the multiple surgical corrections performed. This research aims to (1) compare the maximum oral muscle pressure of subjects with and without isolated cleft palate (CP) or unilateral cleft lip and palate (UCLP), (2) investigate its influence on their dentoalveolar characteristics, and (3) investigate the influence of functional habits on the maximum oral muscle pressure in patients with and without cleft.

MATERIAL AND METHODS

Subjects with and without CP and UCLP seeking treatment at the Department of Orthodontics of University Hospitals Leuven between January 2021 and August 2022 were invited to participate. The Iowa Oral Performance Instrument (IOPI) was used to measure their maximum tongue, lip, and cheek pressure. An imbalance score was calculated to express the relationship between tongue and lip pressure. Upper and lower intercanine (ICD) and intermolar distance (IMD) were measured on 3D digital dental casts, and the presence of functional habits was reported by the patients. The data were analyzed with multivariable linear models, correcting for age and gender.

RESULTS

44 subjects with CP or UCLP (mean age: 12.00 years) and 104 non-affected patients (mean age: 11.13 years) were included. No significant differences in maximum oral muscle pressure or imbalance score were detected between controls and clefts or between cleft types. Significantly smaller upper ICDs and larger upper and lower IMDs were found in patients with clefts. A significant difference between controls and clefts was found in the relationship between oral muscle pressure and transversal jaw width. In cleft patients, the higher the maximum tongue pressure, the wider the upper and lower IMD, the higher the lip pressure, the smaller the upper and lower ICD and IMD, and the higher the imbalance score, the larger the upper and lower IMD and lower ICD. An imbalance favoring the tongue was found in cleft patients. The influence of functional habits on the maximum oral muscle pressure was not statistically different between clefts and controls.

CONCLUSION

Patients with CP or UCLP did not present reduced maximum oral muscle pressure compared with patients without a cleft. In cleft patients, tongue pressure was consistently greater than lip pressure, and those who presented a larger maxillary width presented systematically higher imbalance scores (favoring the tongue) than those with narrow maxillae. Therefore, the influence of slow maxillary expansion on maximum oral muscle pressure in cleft patients should not be underestimated.

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.

An Innovative Assessment of the Dynamics of Facial Movements in Surgically Managed Unilateral Cleft Lip and Palate Using 4D Imaging

OBJECTIVE

Assess facial asymmetry during maximum smile in patients with surgically managed unilateral cleft lip and palate (UCLP), using a dynamic 3-dimensional (3D) imaging (4-dimensional) system.

DESIGN

Prospective 2 cohort comparative study.

METHODS

Twenty-five surgically managed UCLP cases and 75 controls at 8 to 10 years of age were recruited. Facial movements during maximum smile were recorded using video stereophotogrammetry at a rate of 60 3D facial images per second. Maximum smile took approximately 3 seconds and generated 180 3D facial images for the analysis. A generic facial mesh which consists of more than 7000 quasi landmarks was used for the assessment of facial asymmetry at 5 key 3D frames representing the pattern of maximum smile.

RESULTS

Statistically significant differences were seen regarding the magnitude of facial asymmetry between the UCLP group and the noncleft controls. Higher average asymmetry in the UCLP group was seen in the 3D frame midway between maximum smile and rest (frame 4) followed by the frame at peak expression of maximum smile (frame 3). The average magnitude of nasolabial asymmetry of the control group was within 0.5 mm in comparison with the UCLP cases which was about 1.8 mm.

CONCLUSION

This study provided for the first time, an objective tool for analysis of the dynamics of muscle movements which provided an unprecedented insight into the anatomical basis of the residual dysmorphology. The research demonstrates the limitations of the primary lip repair in achieving symmetrical results and underpins the required refinements to improve the quality of surgical repair of cleft lip.

Class II functional appliance treatment and dynamic three-dimensional mimic muscle evaluation

BACKGROUND

Functional appliances have skeletal and dentoalveolar treatment effects, but knowledge on their effect on facial expressions is limited.

OBJECTIVE

To analyse changes in facial expressions, using three-dimensional (3D) mimic muscle evaluation, in growing children with Class II malocclusion and large overjet, undergoing functional appliance treatment.

METHODS

Fifteen growing children with Class II division 1 malocclusion, selected prospectively, had dynamic 3D recordings of facial expressions prior to and 12 months after commencing functional appliance treatment. Facial expressions recorded were smile and lip pucker, and the movements of the oral commissures were analysed, as well as mouth width and its symmetry. A control group of fifteen age- and sex-matched growing children without immediate need for orthodontic treatment had similar recordings prior to and after a 12-month observation period.

RESULTS

In the treatment group, the Class II malocclusion in all children improved after 12 months of functional appliance wear. With regard to movements of the oral commissures, the initial recordings of the treatment group did not show any significant differences to the control group for neither smile nor lip pucker. Differences were noted however when looking at mouth width asymmetry, where this tended to become more symmetrical in the functional appliance treatment group, during rest and during smiling, while it became more asymmetrical in the untreated control group.

CONCLUSION

The use of removable functional appliances in children with Class II division 1 malocclusion may have a positive effect on mouth width symmetry when smiling, making it more symmetrical.

A comparison of orofacial profiles in 5- and 10-year-old Swedish children with and without cleft lip and/or palate

OBJECTIVES

The objectives of this study were to assess orofacial profiles in 5- and 10-year-old children with cleft lip and/or palate (CL/P) compared to controls and to estimate a possible association between orofacial dysfunction and caries frequency.

MATERIALS AND METHODS

A total of 133 children with CL/P (77 5-year-olds and 56 10-year-olds) and 308 controls (142 5-year-olds and 166 10-year-olds) were included in the study. Orofacial function was evaluated with Nordic Orofacial Test-Screening (NOT-S), and caries were scored according to the International Caries Detection and Assessment System (ICDAS).

RESULTS

The total NOT-S score was higher in children with CL/P compared to controls (mean 3.2 vs 0.9, p < 0.001). The domains frequently scored in CL/P children were speech (82%), face at rest (72%), and facial expression (58%). There was a significantly positive correlation between NOT-S scores and caries frequency.

CONCLUSIONS

Children with CL/P have impaired orofacial function compared to controls. There seems to be a correlation between orofacial function and caries.

CLINICAL RELEVANCE

Impaired orofacial function seen in children with CL/P can be one of many risk factors for caries development, and it is suggested to be a part of caries risk assessment.

Permanent maxillary central incisor and first molar rotations in the mixed dentition in repaired complete unilateral cleft lip and palate and their relationship with absence of teeth in their vicinity

OBJECTIVES

To describe qualitatively and quantitatively the directions and magnitudes of rotations of permanent maxillary central incisors and first molars in the mixed dentition in repaired complete unilateral cleft lip and palate (UCLP) and study their associations with absence of teeth in their vicinity.

MATERIALS AND METHODS

Dental casts and orthodontic records taken prior to orthodontic preparation for alveolar bone grafting of 74 children with repaired UCLP (53 male, 21 female; aged 8.9 ± 1.0 years) were studied. Directions and magnitudes of permanent maxillary central incisor and first molar rotations were recorded. Tooth absence was confirmed from longitudinal radiographic records. Incisor and molar rotations were analyzed in relation to the absence of teeth in their vicinity.

RESULTS

Distolabial rotation of the permanent maxillary central incisor was noted in 77.14% on the cleft side, while distopalatal rotation was noted in 82.19% on the noncleft side. Incisor rotation was greater when a permanent tooth was present distal to the cleft side central incisor, in the greater segment. The permanent maxillary first molar showed mesiopalatal rotation, which was greater on the cleft side and when there was absence of one or more teeth in the buccal segment.

CONCLUSIONS

Presence and absence of teeth were associated with the severity of incisor and molar rotations in UCLP. Crowding of anterior teeth in the greater segment was associated with a greater magnitude of rotation of the cleft side permanent central incisor. Absence of one or more buccal segment teeth was associated with greater magnitude of rotation of the molar.

A novel three-dimensional smile analysis based on dynamic evaluation of facial curve contour

The influence of three-dimensional facial contour and dynamic evaluation decoding on factors of smile esthetics is essential for facial beauty improvement. However, the kinematic features of the facial smile contour and the contribution from the soft tissue and underlying skeleton are uncharted. Here, the cheekbone-maxilla contour and nasolabial fold were combined into a “smile contour” delineating the overall facial topography emerges prominently in smiling. We screened out the stable and unstable points on the smile contour using facial motion capture and curve fitting, before analyzing the correlation between soft tissue coordinates and hard tissue counterparts of the screened points. Our finding suggests that the mouth corner region was the most mobile area characterizing smile expression, while the other areas remained relatively stable. Therefore, the perioral area should be evaluated dynamically while the static assessment outcome of other parts of the smile contour contribute partially to their dynamic esthetics. Moreover, different from the end piece, morphologies of the zygomatic area and the superior part of the nasolabial crease were determined largely by the skeleton in rest, implying the latter can be altered by orthopedic or orthodontic correction and the former better improved by cosmetic procedures to improve the beauty of smile.

Evaluation of the Reproducibility of Nonverbal Facial Expressions Using a 3D Motion Capture System

Objective

To evaluate the reproducibility of three nonverbal facial expressions using a three-dimensional motion capture system.

Design

Prospective, cross-sectional, controlled study.

Setting

Glasgow Dental Hospital and School, University of Glasgow, United Kingdom.

Patients and Participants

Thirty-two subjects, 16 males and 16 females.

Methods

With a three-dimensional video passive stereophotogrammetry imaging system, maximal smile, cheek puff, and lip purse were captured for each subject. Anatomical facial landmarks were digitized on the first frame and then tracked automatically. The same facial expressions were captured 15 minutes later.

Main Outcome Measures

The magnitude of each expression and speed of landmark displacement were calculated. The landmark motion curves were spatially and temporally aligned to calculate the similarity of the dynamic movements of the same landmarks between the captures.

Results

There were no significant differences between individuals for magnitude ( P = .892) or for speed ( P = .456). There were significant differences in landmark movement similarity ( P = .011); similarity was more reproducible for maximal smile. There was no significant gender effect on the difference in magnitude. There was a significant gender effect on speed to reach maximal smile ( P = .044) and a pursed-lip expression ( P = .038). There was a significant gender effect on landmark movement similarities ( P = .031) for cheek puff expression.

Conclusions

There were no differences in magnitude and speed for maximal smile, cheek puff, and lip purse between the two captures for all participants. For individual expressions, maximal smile expression had the highest similarity value for individual landmarks.

Quantitative anatomical analysis of facial expression using a 3D motion capture system: Application to cosmetic surgery and facial recognition technology

The topography of the facial muscles differs between males and females and among individuals of the same gender. To explain the unique expressions that people can make, it is important to define the shapes of the muscle, their associations with the skin, and their relative functions. Three-dimensional (3D) motion-capture analysis, often used to study facial expression, was used in this study to identify characteristic skin movements in males and females when they made six representative basic expressions. The movements of 44 reflective markers (RMs) positioned on anatomical landmarks were measured. Their mean displacement was large in males [ranging from 14.31 mm (fear) to 41.15 mm (anger)], and 3.35-4.76 mm smaller in females [ranging from 9.55 mm (fear) to 37.80 mm (anger)]. The percentages of RMs involved in the ten highest mean maximum displacement values in making at least one expression were 47.6% in males and 61.9% in females. The movements of the RMs were larger in males than females but were more limited. Expanding our understanding of facial expression requires morphological studies of facial muscles and studies of related complex functionality. Conducting these together with quantitative analyses, as in the present study, will yield data valuable for medicine, dentistry, and engineering, for example, for surgical operations on facial regions, software for predicting changes in facial features and expressions after corrective surgery, and the development of face-mimicking robots.

Oral strength in subjects with a unilateral cleft lip and palate

PURPOSE

Facial appearance and speech outcome may affect psychosocial functioning in girls and boys. Several studies reported dissatisfaction with facial appearance and more specifically the lip and mouth profile in children with cleft lip and palate (CLP). The purpose of this controlled study was to measure the tongue and lip strength and endurance in boys and girls with CLP.

METHODS

Twenty-five subjects (mean age: 10.6 years) with a unilateral CLP and a gender- and age- matched control group were selected. All subjects with an unilateral CLP consulted the same craniofacial team and had undergone an identical surgical procedure. Surgical procedure of the lip was performed using a modified Millard technique without primary nose correction at an average age of 5.5 months. The Iowa Oral Performance instrument was used to measure lip and tongue strength and tongue endurance.

RESULTS

The results of the Iowa Oral Performance measurement showed no significant differences between the subjects with an unilateral cleft lip and palate and the age and gender matched control group without a cleft lip and palate.

CONCLUSION

There is no significant differences regarding oral strength more specifically the lip and tongue strength and endurance between subjects with and without an unilateral cleft lip and palate. ENT specialists and speech pathologists must be aware of this aspect of the normal lip and tongue functions.

[Beauty judgment: review of the literature]

Esthetic judgments are surely subjective, but as surely, that does not preclude them being studied objectively through rigorous scientific methods. The factual basis of a science of esthetics is not to settle whether some person or image is "objectively beautiful" but rather to determine whether some representative set or sets of individuals judge or experience him/her/it as beautiful or unattractive. The aim of this paper is to review the definitional, theoretical and methodological aspects pertaining to the perception of facial/dental attractiveness by a group of representative individuals. The first part lays down the basic principles of the perception of facial/dental attractiveness: the perception involves a jury, a field of investigation and a test providing quantitative data; the following general determinants of beauty perception are reviewed: the average morphology, the judge's cultural background, the numerology, the judge's ethnical origin. Indirect determinants are the dentition, the osseous architecture and the muscular envelope. Some disruptive factors might alter the judges' facial perception. They might be qualified as either peripheral to the face or psycho-social factors. Peripheral factors include hair style and color, skin hue, wrinkles, lips color... Psycho-social factors cover the personality of the subject being evaluated, his/her intelligence or behavior. The second part deals specifically with the methodology used to determine facial attractiveness and to correlate this latter with a specific morphology. Typically such a study aims to determine average esthetic preferences for some set of visual displays among a particular jury, given a specific task to judge esthetic quality or qualities. The sample being studied, the displays, the jury or jurys, the rating procedure must all be specified prior to collecting data. A specific emphasis will be given to the rating process and the associated morphometrics, the ultimate goal being to discriminate morphologies judged as attractive among our patients.