Facial fluctuating asymmetry is not associated with childhood ill-health in a large British cohort study

The idea that symmetry in facial traits is associated with attractiveness because it reliably indicates good physiological health, particularly to potential sexual partners, has generated an extensive literature on the evolution of human mate choice. However, large-scale tests of this hypothesis using direct or longitudinal assessments of physiological health are lacking. Here, we investigate relationships between facial fluctuating asymmetry (FA) and detailed individual health histories in a sample (n = 4732) derived from a large longitudinal study (Avon Longitudinal Study of Parents and Children) in South West England. Facial FA was assessed using geometric morphometric analysis of facial landmark configurations derived from three-dimensional facial scans taken at 15 years of age. Facial FA was not associated with longitudinal measures of childhood health. However, there was a very small negative association between facial FA and IQ that remained significant after correcting for a positive allometric relationship between FA and face size. Overall, this study does not support the idea that facial symmetry acts as a reliable cue to physiological health. Consequently, if preferences for facial symmetry do represent an evolved adaptation, then they probably function not to provide marginal fitness benefits by choosing between relatively healthy individuals on the basis of small differences in FA, but rather evolved to motivate avoidance of markers of substantial developmental disturbance and significant pathology.

Clinical care in craniofacial microsomia: a review of current management recommendations and opportunities to advance research

Craniofacial microsomia (CFM) is a complex condition associated with microtia, mandibular hypoplasia, and preauricular tags. It is the second most common congenital facial condition treated in many craniofacial centers and requires longitudinal multidisciplinary patient care. The purpose of this article is to summarize current recommendations for clinical management and discuss opportunities to advance clinical research in CFM.

Determining the threshold for asymmetry detection in facial expressions

OBJECTIVES/HYPOTHESIS

To quantify the threshold for human perception of asymmetry for eyebrow elevation, eye closure, and smile, and to ascertain whether asymmetry detection thresholds and perceived severity of asymmetry differ in distinct facial zones.

STUDY DESIGN

Online survey.

METHODS

Photographs of a female volunteer performing eyebrow elevation, eye closure, and smile were digitally manipulated to introduce left-to-right asymmetry in 1-mm increments from 0 mm to 6 mm. One hundred and forty-five participants viewed these photographs using an online survey, measuring accuracy of asymmetry detection and perceived expression unnaturalness (on a scale of 1-5).

RESULTS

Photographs of facial asymmetries were correctly judged as asymmetrical over 90% of the time for 2 mm or more of asymmetry in eyelid closure, and 3 mm or more of asymmetry during smiling. Identification of eyebrow elevation asymmetry gradually rose from 23% correct to 97% correct across the range of 1 mm to 6 mm of asymmetry. Greater degrees of asymmetry were ranked as significantly more unnatural across all expressions (3 tests; X(2) (6, N = 145) = 405.52 to 656.27, all P <0.001).

CONCLUSION

Thresholds for asymmetry detection vary across different zones of the face; once detected, asymmetry in eyelid position is perceived as more unnatural than asymmetries in either brow elevation or smile. These data will inform counseling of patients with segmental facial weakness and may provide more objective goals for facial reanimation procedures.

LEVEL OF EVIDENCE

4.

Three-dimensional assessment of facial appearance following surgical repair of unilateral cleft lip and palate

BACKGROUND AND OBJECTIVE

Objective assessment of postsurgical facial asymmetry can be difficult, but three-dimensional (3D) imaging techniques have made this possible. The objective of this study was to assess residual asymmetry in surgically repaired unilateral cleft lip (UCL) and unilateral cleft lip and palate (UCLP) patients and to compare this with noncleft controls.

DESIGN

Retrospective multicohort comparative study.

PATIENTS AND METHODS

Fifty-one 10-year-old children with surgically managed UCLP and 44 children with UCL were compared with a control group of 68 ten-year-olds. The 3D facial models at rest and with maximum smile were created using a 3D imaging system. Asymmetry scores were produced using both anatomical landmarks and a novel method of facial curve analysis.

RESULTS

Asymmetry for the whole face was significantly higher in both cleft groups compared with controls (P < .001). UCLP asymmetry was higher than UCL (P < .001). In cleft patients, the upper lip and nasal rim were the most asymmetric (P < .001 to .05). Control subjects also displayed a degree of facial asymmetry. Maximum smile did not significantly affect the symmetry of the whole face, but it increased asymmetry of the vermillion border and nasal rim in all three groups (P < .001).

CONCLUSIONS

Despite surgical intervention at an early age, asymmetry remains significant in cleft patients at 10 years of age. Three-dimensional imaging is a noninvasive objective assessment tool that identifies specific areas of the face responsible for asymmetry. Facial curve analysis describes the face more comprehensively and characterizes soft tissue contours.

Posttraumatic temporomandibular joint disorders

The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding, and with opposing approaches. The following article explores various treatment options for problems presenting as a result of a history of trauma to the TMJ.

Quantitative Assessment of Facial Asymmetry Using Three-Dimensional Surface Imaging in Adults: Validating the Precision and Repeatability of a Global Approach

OBJECTIVE

Comparison of global versus landmark analyses of facial asymmetry using three-dimensional photogrammetry to establish a precise method for evaluating facial asymmetry.

DESIGN

The landmark-based approach utilized anthropometric data points. Our global approach involved registration of mirror images, independent of a midplane, to calculate a root mean square (RMS) value. We analyzed precision and technical and operator error of both methods.

PARTICIPANTS

Three hundred fifty adults participated in this study.

RESULTS

We found that the global method has better precision and repeatability with a significantly lower error rate than the landmark-based method. In adults, the average RMS was 0.6253 mm with a standard deviation of 0.16.

CONCLUSIONS

Our facial asymmetry measurement is more accurate than landmark-based measurements. This method is quick, reliable, and results in generation of a RMS score and a corresponding color-coded facial map that highlights regions of higher and lower asymmetry. This method may be used as a screening tool for asymmetry in both the clinical and research settings.

Exploratory genotype-phenotype correlations of facial form and asymmetry in unaffected relatives of children with non-syndromic cleft lip and/or palate

Family relatives of children with nonsyndromic cleft lip with or without cleft palate (NSCL/P) who presumably carry a genetic risk yet do not manifest overt oral clefts, often present with distinct facial morphology of unknown genetic etiology. This study investigates distinct facial morphology among unaffected relatives and examines whether candidate genes previously associated with overt NSCL/P and left-right body patterning are correlated with such facial morphology. Cases were unaffected relatives of individuals with NSCL/P (n = 188) and controls (n = 194) were individuals without family history of NSCL/P. Cases and controls were genotyped for 20 SNPs across 13 candidate genes for NSCL/P (PAX7, ABCA4-ARHGAP29, IRF6, MSX1, PITX2, 8q24, FOXE1, TGFB3 and MAFB) and left-right body patterning (LEFTY1, LEFTY2, ISL1 and SNAI1). Facial shape and asymmetry phenotypes were obtained via principal component analyses and Procrustes analysis of variance from 32 coordinate landmarks, digitized on 3D facial images. Case-control comparisons of phenotypes obtained were performed via multivariate regression adjusting for age and gender. Phenotypes that differed significantly (P < 0.05) between cases and controls were regressed on the SNPs one at a time. Cases had significantly (P < 0.05) more profile concavity with upper face retrusion, upturned noses with obtuse nasolabial angles, more protrusive chins, increased lower facial heights, thinner and more retrusive lips and more protrusive foreheads. Furthermore, cases showed significantly more directional asymmetry compared to controls. Several of these phenotypes were significantly associated with genetic variants (P < 0.05). Facial height and width were associated with SNAI1. Midface antero-posterior (AP) projection was associated with LEFTY1. The AP position of the chin was related to SNAI1, IRF6, MSX1 and MAFB. The AP position of the forehead and the width of the mouth were associated with ABCA4-ARHGAP29 and MAFB. Lastly, facial asymmetry was related to LEFTY1, LEFTY2 and SNAI1. This study demonstrates that, genes underlying lip and palate formation and left-right patterning also contribute to facial features characteristic of the NSCL/P spectrum.

Does two-dimensional vs. three-dimensional surgical simulation produce better surgical outcomes among patients with class III facial asymmetry?

The aim of this study was to compare the outcomes of traditional two-dimensional planning (2DP) and three-dimensional surgical simulation (3DS) in the surgical correction of skeletal class III with facial asymmetry. This retrospective cohort study included 37 consecutive adult Taiwanese patients. Preoperative and postoperative three-dimensional cephalometric measurements were obtained from cone beam computed tomography scans. The outcome variables were the differences in preoperative and postoperative linear and angular measurements and the differences between the two groups after surgery. When the surgical result was compared between the 2DP and 3DS groups, significant differences were found for four cephalometric variables: the distance from gonion on the non-deviated side to the midsagittal plane (MSP), mid-gonion to the MSP, upper first molar on the non-deviated side to the Frankfort horizontal plane, and the yaw angle. In the 3DS group, mandibular symmetry was achieved because the centre between the bilateral gonions was improved, and because there was no significant difference in the horizontal gonion (Go to the MSP) between the deviated and non-deviated sides after surgery. 3DS provides all the necessary information for planned surgical movements for the correction of facial asymmetry; it should be considered during surgical planning to improve surgical outcomes, particularly the achievement of bilateral mandibular contour symmetry.

Management of patients with condylar hyperplasia: A diverse experience with 18 patients

PURPOSE

The purpose was to report the clinical experience with patients diagnosed with Condylar Hyperplasia (CH).

MATERIALS AND METHODS

Eighteen patients with CH underwent condylar growth assessment using clinical and radiographic examinations. Seven patients with suspected active condyles underwent single photo emission computed tomography (SPECT) examination. A total of patients with asymmetry and malocclusion were treated with orthognathic surgery. Three patients with intact occlusion; underwent inferior border osteotomy with nerve repositioning. All patients were followed up for 3 years without any complications.

CONCLUSION

There is great diversity in the clinical and radiographic presentation in cases with CH. Assessment of condylar growth activity is the cornerstone in managing these cases. After that each case has its own diverse treatment plan to achieve a satisfactory facial symmetry.

Botulinum Toxin Type A to Improve Facial Symmetry in Facial Palsy: A Practical Guideline and Clinical Experience

Unilateral peripheral facial nerve palsy jeopardizes quality of life, rendering psychological consequences such as low self-esteem, social isolation, anxiety, and depression. Among therapeutical approaches, use of Botulinum toxin type A (BoNT-A) on the nonparalyzed side has shown promising results and improvement of quality of life. Nevertheless, the correct technique is paramount, since over-injection of the muscles can result in lack of function, leading to a "paralyzed" appearance, and even worse, functional incompetence, which may cause greater distress to patients. Therefore, the objective of this article is to provide a practical guideline for botulinum toxin use in facial palsy. To this aim, adequate patient assessment, BoNT-A choice, injection plan and dosage, and injection techniques are covered.

Three-dimensional skeletal changes after early proportional condylectomy for condylar hyperplasia

The purpose of this study was to evaluate volumetric and dentoskeletal changes in 21 patients with active unilateral condylar hyperplasia (AUCH) after proportional condylectomy. A split-mouth design was used: control group healthy joints (HS, healthy side) and test group affected joints (AS, affected side) (21 per group). Cone beam tomography scans were obtained at T0 (preoperative), T1 (10days after the intervention), and T2 (approximately 12 months post-surgery). The condylar unit volume (CUV), articular cavity volume (ACV), and dentoalveolar units (DAUs) were measured. CUV showed a difference of 1.12cm³ between T0 and T1, increasing 0.4cm³ between T1 and T2 on AS. There was no difference between T0 and T2 on HS. ACV increased 0.65cm³ between T0 and T1 on AS, after which it decreased by 0.36cm³ at T2 (0.30cm³ larger than the initial articular cavity at T0). ACV showed no post-surgery differences on HS. Midline DAU showed extrusion of 0.20mm for maxilla and 0.52mm for mandible, while in the lateral area, maxilla was extruded by 0.3mm on HS and was intruded 0.12mm on AS. For the mandible, both sides showed extrusion (0.4-0.6mm). In the distal to canine and molar areas, intrusion of 0.2mm and 0.9mm, respectively, was observed on AS; there was extrusion of 0.6mm distal to the canine on HS. At the mandibular level, AS distal to the canine showed extrusion of 1mm, while intrusion of 0.2mm was observed in the molars. For HS, only extrusion at the molar level (0.2mm) was observed. In conclusion, after proportional condylectomy, a neocondyle forms within 12 months to equal the healthy contralateral side. The articular cavity, which is reduced in the initial stage, increases in size after surgery and the volume gradually approaches that of the healthy side. Dentoalveolar changes occur at the anterior and posterior levels, causing intrusion and extrusion of the interdental crests. An early proportional condylectomy as the sole surgical treatment for patients with AUCH allows normalization of the maxillomandibular relationship.

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

BACKGROUND

Juvenile idiopathic arthritis (JIA) affecting temporomandibular joints (TMJ) in growing patients results in maxillofacial deformities, especially if only one condyle has been affected by the rheumatic disease. Mandibular hypoplasia is the most common issue and it may be associated with maxillary hypoplasia. The aim of this retrospective case-control study is to evaluate the effects of rapid maxillary expansion (RME) in these patients.

METHODS

25 growing patients affected by maxillary hypoplasia, currently in a quiescent phase of JIA for at least one year and monolateral involvement of the TMJs, were treated with RME. Data gathered from posteroanterior and lateral cephalograms before and after 1 year from RME were compared to those of 25 non-JIA controls.

RESULTS

Nasal cavity width, maxillary width and upper and lower intermolar width statistically increased. Maxillary and mandibular symmetry indexes presented a statistically significant increase, so did the skeletal class. No signs or symptoms of TMJ activity of JIA occurred according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) criteria. No difference was found when comparing JIA and non-JIA patients apart from the better improvement of several mandibular symmetry indexes in the affected TMJ side of JIA patients. This event is allegedly due to a worse baseline asymmetry in JIA patients that underwent a bigger relative improvement after treatment.

CONCLUSIONS

Results suggest that solving maxillary hypoplasia and, therefore, premature contacts are likely to have allowed mandibular repositioning and condylar growth. RME is a safe and effective solution that can substantially improve maxillary and mandibular symmetry in growing patients affected by JIA with TMJ involvement.

Three-dimensional assessment of facial asymmetry: A systematic review

For patients with facial asymmetry, complete and precise diagnosis, and surgical treatments to correct the underlying cause of the asymmetry are significant. Conventional diagnostic radiographs (submento-vertex projections, posteroanterior radiography) have limitations in asymmetry diagnosis due to two-dimensional assessments of three-dimensional (3D) images. The advent of 3D images has greatly reduced the magnification and projection errors that are common in conventional radiographs making it as a precise diagnostic aid for assessment of facial asymmetry. Thus, this article attempts to review the newly introduced 3D tools in the diagnosis of more complex facial asymmetries.

A novel measurement method for the morphology of the mandibular ramus using homologous modelling

OBJECTIVES

It is important to assess the mandibular morphology when orthognathic surgery, especially mandibular ramus osteotomy, is performed. Several studies on three-dimensional (3D) facial asymmetry have reported differences in linear and angle measurements between the deviated and contralateral sides in asymmetric mandibles. However, methods used in these studies cannot analyse the 3D morphology of the ramus. In this study, we aimed to evaluate the differences in mandibular ramus between the deviated and contralateral sides in asymmetric mandibles using traditional measurements as well as 3D shape analysis.

METHODS

15 Japanese females with jaw deformities treated by orthodontic surgery were enrolled. 3D CT images were reconstructed, and 14 landmarks were identified on the model surface. Ten linear and four angle measurements were calculated using these landmarks. Homologous ramus models were constructed for each sample, and after converting all homologous models to the right side, 30 homologous models of the ramus were analysed using principal component analysis.

RESULTS

Firstly, eight principal components explained >80% of the total variance. Differences between the deviated and contralateral sides in measurements and scores of the eight principal components were tested. Significant difference at the 5% level between the deviated and contralateral sides was observed in five linear measurements, three angle measurements and the third principal component. The variance of the deviated side was significantly larger in the diameter between the mandibular notch and coronoid process, horizontal dilated angle of the mandibular ramus and vertical dilated angle of the mandibular ramus. The variance of the contralateral side was significantly larger in the height of mandibular ramus, height of posterior of mandibular ramus, condylar width, height of condylar head and mandibular angle. The squared multiple correlation coefficient adjusted for the degrees of freedom was 0.815. The third principal component showed the difference between the deviated and contralateral sides. Shape variation represented by the third principal component visually indicated that the contralateral side was larger and had inwardly directed coronoid process and the deviated side had a mandibular angle that was turned inwards to a greater extent.

CONCLUSIONS

In conclusion, we successfully created a homologous model of the mandibular ramus and demonstrated the effectiveness of this model in the 3D comparison of the ramus morphology between the contralateral and deviated sides in asymmetric mandibles.

Hemifacial microsomia in cat-eye syndrome: 22q11.1-q11.21 as candidate loci for facial symmetry

Cat-Eye syndrome (CES), (OMIM 115470) also known as chromosome 22 partial tetrasomy or inverted duplicated 22q11, was first reported by Haab [1879] based on the primary features of eye coloboma and anal atresia. However, >60% of the patients lack these primary features. Here, we present a 9-month-old female who at birth was noted to have multiple defects, including facial asymmetry with asymmetric retrognathia, bilateral mandibular hypoplasia, branchial cleft sinus, right-sided muscular torticollis, esotropia, and an atretic right ear canal with low-to-moderate sensorineural hearing loss, bilateral preauricular ear tag/pits, and two skin tags on her left cheek. There were no signs of any colobomas or anal atresia. Hemifacial microsomia (HFM) was suspected clinically. Chromosome studies and FISH identified an extra marker originated from 22q11 consistent with CES, and this was confirmed by aCGH. This report expands the phenotypic variability of CES and includes partial tetrasomy of 22q11.1-q11.21 in the differential diagnosis of HFM. In addition, our case as well as the previous association of 22q11.2 deletions and duplications with facial asymmetry and features of HFM, supports the hypothesis that this chromosome region harbors genes important in the regulation of body plan symmetry, and in particular facial harmony.

Facial asymmetry in head and neck rhabdomyosarcoma survivors

INTRODUCTION

Radiotherapy is essential for achieving and maintaining local control in head and neck rhabdomyosarcoma (HNRMS) patients. However, radiotherapy may cause outgrowth disturbances of facial bone and soft tissue, resulting in facial asymmetry. The aim of this study was to develop a method to visualize and measure facial asymmetry in HNRMS survivors using three-dimensional (3D) imaging techniques.

METHODS

Facial deformity was evaluated in a multidisciplinary clinical assessment of 75 HNRMS survivors, treated with external beam radiotherapy (EBRT, n = 26) or Ablative surgery, MOulage brachytherapy, and REconstruction (AMORE, n = 49). Individual facial asymmetry was measured using 3D photogrammetry and expressed in a raw asymmetry index and a normalized sex-age-ethnicity-matched asymmetry signature weight. Facial asymmetry was also compared between British and Dutch controls and between survivors and their matched controls.

RESULTS

Facial asymmetry was more pronounced with increasing age (P < 0.01) in British controls compared with Dutch controls (P = 0.04). Survivors developed more facial asymmetry than matched controls (P < 0.001). The clinical assessment of facial deformity correlated with the raw asymmetry index (r = 0.60, P < 0.001).

DISCUSSION

3D imaging can be used for objective measurement of facial asymmetry in HNRMS survivors. The raw asymmetry index correlated with a clinical assessment of facial deformity. Comparisons between treatment groups seemed inappropriate given the differences in facial asymmetry between British and Dutch controls. In future studies, pretreatment images could act as matched controls for posttreatment evaluation.

Mandibular Condylar Hyperplasia and its correlation with Vascular endothelial growth factor

BACKGROUND

Condylar hyperplasia (CH) is a rare condition characterized by excessive unilateral growth of the mandibular condyle after cessation of growth on the contralateral side causing facial asymmetry, being more prevalent in the second and third decades.

OBJECTIVE

The aim of this study was to determine the utility of vascular endothelial growth factor (VEGF-A) as a diagnostic and prognostic factor in condylar hyperplasia, and to determine its potential viability as a therapeutic target.

METHODS

This is a case-control study, where seventeen mandibular condyles specimens were collected from seventeen patients treated for active mandibular condyle hyperplasia and three unaffected human mandibular condyles from cadavers will serve as the control group. The samples were immunostained with VEGF-A antibody and evaluated on both quantity and intensity of staining.

RESULTS

VEGF-A was qualitatively found to be greatly upregulated in patients with condylar hyperplasia.

CONCLUSION

VEGF-A was qualitatively found to be upregulated in patients affected by CH, validating VEGF-A as a potential diagnostic, prognostic, and therapeutic target.

Patient-Specific Implant for Residual Facial Asymmetry following Orthognathic Surgery in Unilateral Craniofacial Microsomia

Craniofacial microsomia (CFM) is a congenital anomaly with a variable phenotype. The most prominent feature of CFM is a predominantly unilateral hypoplasia of the mandible, leading to facial asymmetry. Even after correction of the midline, there is often a remaining hard- and soft-tissue deficiency over the body of the mandible and cheek on the affected side. This clinical report describes the skeletal augmentation of the mandible with a patient-specific implant to treat residual facial asymmetry in two female patients with unilateral CFM. Good aesthetic results were achieved in both patients treated with either a Medpor or polyetheretherketone implant without complications after a follow-up time of 55 and 30 months, respectively.

Correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism by combined orthognathic surgery and guiding templates and splints fabricated by rapid prototyping technique

The facial asymmetry associated with vertical maxillary excess and mandibular prognathism is one of the more complicated types in the field of oral and maxillofacial surgery. The purpose of this study was to investigate the efficacy of combined orthognathic surgeries, together with guiding templates and splints fabricated by rapid prototyping technique, for the correction of facial asymmetry. Fourteen patients with facial asymmetry associated with vertical maxillary excess and mandibular prognathism were included. A maxillary Le Fort I osteotomy, a sagittal split ramus osteotomy on the shorter side of the face, and an intraoral vertical ramus osteotomy on the longer side of the face were performed with the aid of guiding templates and splints fabricated by rapid prototyping technique. Parameters reflecting maxillary canting, ramal inclination, mandibular deviation, and chin inclination were measured before surgery, 7 days after surgery, and 1 year after surgery, and compared. Significant differences in these parameters were found between the two sides preoperatively, whereas no differences were observed postoperatively. Facial asymmetry was corrected in all patients with satisfactory outcomes. In conclusion, combined orthognathic surgery and guiding templates and splints can offer improvements in accuracy, complexity, and duration over traditional procedures for the correction of facial asymmetry associated with vertical maxillary excess and mandibular prognathism.

Increased facial asymmetry in autism spectrum conditions is associated with symptom presentation

A key research priority in the study of autism spectrum conditions (ASC) is the discovery of biological markers that may help to identify and elucidate etiologically distinct subgroups. One physical marker that has received increasing research attention is facial structure. Although there remains little consensus in the field, findings relating to greater facial asymmetry (FA) in ASC exhibit some consistency. As there is growing recognition of the importance of replicatory studies in ASC research, the aim of this study was to investigate the replicability of increased FA in autistic children compared to nonautistic peers. Using three-dimensional photogrammetry, this study examined FA in 84 autistic children, 110 typically developing children with no family history of the condition, and 49 full siblings of autistic children. In support of previous literature, significantly greater depth-wise FA was identified in autistic children relative to the two comparison groups. As a further investigation, increased lateral FA in autistic children was found to be associated with greater severity of ASC symptoms on the Autism Diagnostic Observation Schedule, second edition, specifically related to repetitive and restrictive behaviors. These outcomes provide an important and independent replication of increased FA in ASC, as well as a novel contribution to the field. Having confirmed the direction and areas of increased FA in ASC, these findings could motivate a search for potential underlying brain dysmorphogenesis. Autism Res 2019, 12: 1774-1783. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study looked at the amount of facial asymmetry (FA) in autistic children compared to typically developing children and children who have siblings with autism. The study found that autistic children, compared to the other two groups, had greater FA, and that increased FA was related to greater severity of autistic symptoms. The face and brain grow together during the earliest stages of development, and so findings of facial differences in autism might inform future studies of early brain differences associated with the condition.

Identifying Three-Dimensional Facial Fluctuating Asymmetry in Normal Pediatric Individuals: A Panel Assessment Outcome Study of Clinicians and Observers

This study measured three-dimensional facial fluctuating asymmetry in 600 normal and healthy Taiwanese individuals (6 to 12 years old) and assessed the perceptions of increasing levels of facial fluctuating asymmetric severity by using a panel composed of 20 clinicians (surgical professionals), as well as 20 adult and 40 pre-adolescent observers. On average, this normal cohort presented a facial fluctuating asymmetry of 0.96 ± 0.52 mm, with 0.52 ± 0.05, 0.67 ± 0.09, 1.01 ± 0.10, and 1.71 ± 0.36 mm for levels I, II, III, and IV of severity, respectively. For all categories of raters, significant differences in the average symmetry-asymmetry scale values were observed, with level I < level II < level III = level IV (all p < 0.01, except for level III vs. IV comparisons with p > 0.05). For level I, pre-adolescent observers presented a significantly (p < 0.05) higher symmetry-asymmetry scale value than adult observers, with no significant (all p > 0.05) differences for other comparisons. For overall facial asymmetry and levels II, III, and IV, no significant (all p > 0.05) differences were observed. This study reveals that the normal pediatric face is asymmetric and the panel assessment of facial fluctuating asymmetry was influenced by the level of severity and the category of raters and contributes to the literature by revealing that pre-adolescent raters present a similar or higher perception of facial asymmetry than adult raters.

Longitudinal 3D Assessment of Facial Asymmetry in Unilateral Cleft Lip and Palate

OBJECTIVE

Longitudinal evaluation of asymmetry of the surgically managed unilateral cleft lip and palate (UCLP) to assess the impact of facial growth on facial appearance.

DESIGN

Prospective study.

SETTING

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

PATIENTS

Fifteen UCLP infants.

METHOD

The 3-D facial images were captured before surgery, 4 months after surgery, and at 4-year follow-up using stereophotogrammetry. A generic mesh which is a mathematical facial mask that consists of thousands of points (vertices) was conformed on the generated 3-D images. Using Procustean analysis, an average facial mesh was obtained for each age-group. A mirror image of each average mesh was mathematically obtained for the analysis of facial dysmorphology. Facial asymmetry was assessed by measuring the distances between the corresponding vertices of the original and the mirror copy of the conformed meshes, and this was displayed in color-coded map.

RESULTS

There was a clear improvement in the facial asymmetry following the primary repair of cleft lip. Residual asymmetry was detected around the nasolabial region. The nasolabial region was the most asymmetrical region of the face; the philtrum, columella, and the vermillion border of the upper lip showed the maximum asymmetry which was more than 5 mm. Facial growth accentuated the underlying facial asymmetry in 3 directions; the philtrum of the upper lip was deviated toward the scar tissue on the cleft side. The asymmetry of the nose was significantly worse at 4-year follow-up ( P < .05).

CONCLUSION

The residual asymmetry following the surgical repair of UCLP was more pronounced at 4 years following surgery. The conformed facial mesh provided a reliable and innovative tool for the comprehensive analysis of facial morphology in UCLP. The study highlights the need of refining the primary repair of the cleft and the potential necessity for further corrective surgery.

Extended effect after a single dose of type A botulinum toxin for asymmetric masseter muscle hypertrophy

Facial asymmetry can either be physiological or pathological and is a common cosmetic concern. A 35-year-old Indian male presented with broad appearing lower face and prominent left jaw since adolescence. Parotid enlargement and other local disorders were ruled out. Ultrasonographic thickness of right masseter muscle was 13 mm while that of left was 14.9 mm, in unclenched state. Type-A botulinum toxin (T-ABT) was injected, evenly at five points, in both muscles within the “safe zone”. Using a 29 gauge needle, 15 and 25 international units were delivered to right and left masseters, respectively. Six months post — injection, a reduction of 2.9 mm and 4.4 mm was observed along with a reduced external facial asymmetry. At 24 months, patient maintains a satisfactory facial contour with no significant early or late post-injection complications. Intra-massteric injection of T-ABT can be used effectively as a primary or adjunct procedure for holistic oculo-facial sculpting.

Histomorphometric analysis of unilateral condylar hyperplasia in the temporomandibular joint: the value of the condylar layer and cartilage island

This study aimed to describe the condylar layer and cartilage island in subjects with unilateral condylar hyperplasia (UCH). Five individuals (15-18 years old) with a diagnosis of UCH, treated in a university hospital in Temuco, Chile, were included. The analysis examined the presence, extension, and thickness of the layers on the condylar surface, the number, depth, and area of the cartilage islands, and the argyrophilic proteins of the nucleolar organizer region (AgNOR) score. Statistical significance was set at P<0.05. The fibrocartilaginous layer was thickest (0.13±0.05mm) and the joint layer was thinnest (0.07±0.01mm) (P<0.05). With respect to the number, depth, and area of the islands, case 1 presented the highest values, followed by case 2; the cartilage island was related to the fibrocartilaginous layer (P<0.05). All cases had AgNOR proteins in the proliferative and fibrocartilaginous layers, as well as the islands with the greatest presence of chondrocytes (P=0.245). A relationship was observed between the histopathological alterations in the different layers on the condylar surface and the thickness of the fibrocartilaginous layer, as well as the thickness of the latter and the number, depth, and area of the cartilage islands in the trabecular bone.

Histopathological analysis of unilateral condylar hyperplasia: difficulties in diagnosis and characterization of the disease

The aim of this study was to perform a histological analysis of the conditions in patients undergoing surgery for unilateral condylar hyperplasia (UCH) using different histopathological analytical techniques and to describe the complications and existing controversy in order to better define the disease. A partial condylectomy was performed in five patients who had been diagnosed with UCH using clinical and imaging methods. The samples obtained were analyzed using routine histological techniques including haematoxylin-eosin, Van Gieson, picrosirius, alcian blue/haematoxylin-eosin, and AgNOR staining. The analyses were performed by an observer who was blinded to the clinical parameters of the disease. The cellularity, tissue layers, size of the anatomical structures, and the relationships between them were assessed. The analysis of these patients was complemented by a review of the scientific literature. Variability was observed in the analysis of the cases. The presence of connective tissue was detected at the bone level, with cartilage formation at different levels. Each island presented levels of involvement that could indicate various degrees of aggressiveness. Type I collagen was observed in most cases, although type III was also identified. The development of histological diagnostic methods to determine the aggressiveness or level of involvement in UCH is not currently possible. Further studies are needed to establish new histological classifications.