Abnormal Jaw Research Articles

Upper motor neuron signs in primary lateral sclerosis and hereditary spastic paraplegia.

The frequency and distribution of upper motor neuron (UMN) signs in primary lateral sclerosis (PLS) are unknown. We aimed to study the spectrum of UMN signs in PLS and compare it with hereditary spastic paraplegia (HSP). We retrospectively analyzed the frequency of different UMN signs, including hyperreflexia (limbs and jaw), limb and tongue spasticity, Babinski, and Hoffman signs, in PLS patients at first observation and compared this respect to onset region and symptom duration. We also compared PLS versus HSP patients. We included 34 PLS and 20 HSP patients, with a median symptom duration at first visit of 3.0 (interquartile range, IQR = 4.0) and 19.0 (IQR = 22.0) years, respectively. In PLS patients, hyperreflexia of upper (UL) (88.2%) and lower (LL) (91.2%) limbs, and LL spasticity (79.4%) were the most common findings. Spasticity of LL was significantly (p = .012) more frequent in LL-spinal onset subgroup, tongue spasticity in bulbar-onset subgroup (p = .021), and Hoffman sign in UL-spinal onset subgroup (p = .024). The PLS subgroup with shorter disease duration had a higher frequency of abnormal jaw jerk reflex (p = .037). Compared with HSP, PLS patients had a higher frequency of UL hyperreflexia (88.2% vs. 42.1%, p < .001) and UL spasticity (44.1% vs. 0.0%, p < .001). Asymmetric distribution of UMN signs was present in PLS and not in HSP. In PLS, UL UMN signs are nearly always present and UMN sign distribution appears to be associated with onset region. At first observation, bulbar involvement, asymmetrical distribution of UMN signs and UL spasticity may indicate PLS versus HSP.

Prosthodontic Rehabilitation of a Completely Edentulous Arch with an Abnormal Jaw Relation: A Case Report

Prosthodontic Rehabilitation of a Completely Edentulous Arch with an Abnormal Jaw Relation: A Case Report

THE ANALYSIS OF INTERINCISAL AND VERTICAL ANGLES ON CONVEX FACIAL PROFILE ACCORDING TO STEINER (STUDY OF JAVANESE ORTHODONTIC PATIENTS IN BANYUMAS REGENCY)

Background: Orthodontic treatment focuses on correcting abnormal teeth and jaw positions for better facial esthetics. Abnormal teeth can be corrected by interincisal angle, while vertical angle can determine the facial growth pattern. Purpose: Analyze the interincisal and vertical angles on convex facial profiles of Javanese orthodontic patients in the Banyumas Regency. Method: Analytical descriptive research was conducted with a cross-sectional design. A purposive sampling technique was used to obtain lateral cephalograms totaling 33 based on inclusion and exclusion criteria from three locations. The lateral cephalogram was traced using tracing paper, while the interincisal and vertical angles were measured based on Steiner’s analysis. Two operators carried out measurements, starting with tracing validation and the Kappa test. Furthermore, the results were from the average measurement of the two operators. Result: The mean interincisal and vertical angles were 115.30° and 37.04° with a protrusive inclination and hyperdivergent face, respectively. The correlation test showed a p-value of 0.432 (p &gt; 0.05), meaning there was no relationship between the interincisal and vertical angles in Javanese orthodontic patients. Conclusion: There is no relationship between the interincisal and vertical angles in the convex facial profile of Javanese orthodontic patients in the Banyumas Regency.

Prevalence of Sleep Bruxism and Respiratory Disorders in Schoolchildren Aged 8 - 11 Years in Kerman, Iran: Pre-COVID Pandemic Phase

Background: Bruxism is a parafunctional oral activity defined as excessive teeth grinding or jaw clenching. This disorder causes damage to the teeth and deforms them. Objectives: This is the first phase of the sleep bruxism and respiratory disorders assessment study in Kerman, Iran, which evaluated respiratory disorders and sleep bruxism in schoolchildren aged 8 - 11 years between 2018 - 2019. Methods: A total of 573 primary school students aged 8 - 11 years were recruited for this cross-sectional study in Kerman between 2018 - 2019. The subjects were chosen randomly from 20 schools located throughout the city. Following permission from officials, 30 students from each school were admitted to the study randomly. The parents were invited to fill out a checklist that included a history of respiratory and sleep problems and signs of bruxism or abnormal jaw movements. Additionally, an examination was performed, and the symptoms of bruxism, such as tooth wear and restoration fractures, were documented. Results: The parents of 573 children were recruited to the study. The prevalence of bruxism and respiratory diseases was observed to be 20.6% (n = 118) and 26.5% (n = 152), respectively. The children with sound production had 2.3 times higher odds of bruxism prevalence than those without sound production (P = 0.004). However, children with temporomandibular joint and paranasal sinus sensitivity had 4.5 (P = 0.001) and 3.8 (P = 0.001) times higher odds, respectively. Additionally, the odds of bruxism prevalence were 1.4 times higher in children with respiratory disorders than those without (P = 0.001). Conclusions: Bruxism was common in children who had a respiratory disorder. Given the potential impact of bruxism on children’s dental health, it is important to pay special attention to the health status of children with respiratory disorders.

Reliability of the Clinician’s Tardive Inventory (CTI)

AbstractObjectivesCurrently utilized clinician-rated symptom scales for tardive dyskinesia (TD) have not kept up with the expanding spectrum of TD phenomenology. The objective of this study was to develop and test the reliability of a new instrument, the CTI.MethodsA movement disorder neurologist devised the outline of the scale. A steering committee (four neurologists and two psychiatrists) provided revisions until consensus was reached. The resulting instrument assesses frequency of abnormal movements of the eye/eyelid/face, tongue/mouth, jaw, limb/trunk, complex movements (e.g., handwringing, self-caressing), and vocalizations. The CTI rates symptoms from 0–3 with 0 = absent, 1 = infrequent/intermittent or only present with activating maneuvers, 2 = frequent intermittent, brief periods without movements, 3 = constant or nearly constant. Functional impairments including activities of daily living (ADL), social impairment, symptom bother, and harm are rated 0–3 with 0 = patient is unaware or unaffected, 1 = symptoms mildly impact patient, 2 = symptoms moderately impact patient, 3 = symptoms severely impact patient. Following institutional review board approval, the CTI underwent inter-rater and test-retest reliability testing. Videos of patient TD examinations were obtained and reviewed by two movement disorder specialists to confirm the diagnosis of TD by consensus and the adequacy to demonstrate a TD-consistent movement. Vignettes were created to include patients’ symptom descriptions and functional, social, or occupational impairments/limitations. Four clinicians rated each video/vignette. Selected videos/vignettes were also subject to an intra-rater retest. Interrater agreement was analyzed via 2-way random-effects interclass correlation (ICC) and test-retest agreement assessment utilizing Kendall’s tau-b.Results45 video/vignettes were assessed for interrater reliability, and 16 for test-retest reliability. ICCs for movement frequency were as follows: abnormal eye movement .89; abnormal tongue/mouth movement .91; abnormal jaw movement .89; abnormal limb movement .76; complex movement .87; abnormal vocalization .77; and functional impairments including harm .82; social embarrassment .88; ADLs .83; and symptom bother .92. Retests were conducted on mean (SD) 15 (3) days later with scores ranging from .66–.87.ConclusionsThe CTI is a new instrument with good reliability in assessing TD symptoms and functional impacts. Future validation study is warranted.FundingNeurocrine Biosciences

A three-dimensional investigation of mandibular deviation in patients with mandibular prognathism

BackgroundCraniofacial disharmony in cases of jaw deformity associated with abnormal lateral deviation of the jaw mostly involves both the maxilla and mandible. However, it has been still difficult to capture the jaw deviation aspect in a 3-dimensional and quantitative techniques. In this study, we focused on 3-dimensional mandibular morphology and position of the condylar head in relation to the base of the skull in patients with mandibular prognathism, one of the most common jaw deformities. We used cluster analysis to quantify and classify deviation and clarified its characteristics. We also investigated the degree of correlation between those findings and menton (Me) deviation measured on frontal cephalograms, which is a conventional indicator of jaw deformity.ResultsFindings obtained from 100 patients (35 men, 65 women) were classified into the following three groups based on mandibular morphology and condylar position relative to the skull base. Then, reclassification using these parameters enabled classification of cluster analysis findings into seven groups based on abnormal jaw deviation characteristics. Comparison among these seven groups showed that the classification criteria were ramus height, mandibular body length, distance from the gonion to the apex of the coronoid process, and the lateral and vertical positions of the mandible. Weak correlation was also found between Me deviation on frontal cephalograms and each of the above parameters measured on 3D images.ConclusionsFocusing on mandibular morphology and condylar position relative to the skull base in patients with mandibular prognathism, we used cluster analysis to quantify and classify jaw deviation. The present results showed that the 3D characteristics of the mandible based on mandibular morphology and condylar position relative to the skull base can be classified into seven groups. Further, we clarified that Me deviation on frontal cephalograms, which has been used to date, is inadequate for capturing jaw deviation characteristics.

Fish as Model Systems to Study Epigenetic Drivers in Human Self-Domestication and Neurodevelopmental Cognitive Disorders

Modern humans exhibit phenotypic traits and molecular events shared with other domesticates that are thought to be by-products of selection for reduced aggression. This is the human self-domestication hypothesis. As one of the first types of responses to a novel environment, epigenetic changes may have also facilitated early self-domestication in humans. Here, we argue that fish species, which have been recently domesticated, can provide model systems to study epigenetic drivers in human self-domestication. To test this, we used in silico approaches to compare genes with epigenetic changes in early domesticates of European sea bass with genes exhibiting methylation changes in anatomically modern humans (comparison 1), and neurodevelopmental cognitive disorders considered to exhibit abnormal self-domestication traits, i.e., schizophrenia, Williams syndrome, and autism spectrum disorders (comparison 2). Overlapping genes in comparison 1 were involved in processes like limb morphogenesis and phenotypes like abnormal jaw morphology and hypopigmentation. Overlapping genes in comparison 2 affected paralogue genes involved in processes such as neural crest differentiation and ectoderm differentiation. These findings pave the way for future studies using fish species as models to investigate epigenetic changes as drivers of human self-domestication and as triggers of cognitive disorders.

Zebrafish larvae: A new model to study behavioural effects and metabolism of fentanyl, in comparison to a traditional mice model.

In an effort to find alternatives to study in vivo the so-called New Psychoactive Substances (NPS), the present work was undertaken to investigate the use of zebrafish larvae as animal model in pharmaco-toxicology, providing behavioural and metabolism information. For this purpose, fentanyl, the progenitor of an extremely dangerous group of NPS, was administered at different doses to zebrafish larvae (1, 10, 50, 100 µM) in comparison to mice (0.1, 1, 6, 15 mg/kg), as a well-established animal model. A behavioural assay was performed at the time of the peak effect of fentanyl, showing that the results in larvae are consistent with those observed in mice. On the other hand, several morphological abnormalities (namely yolk sac edema, abnormal pericardial edema, jaw defect and spinal curvature) were found in larvae mostly at high fentanyl doses (50, 100 µM). Larva extract and mice urine were analyzed by using liquid chromatography coupled to high resolution mass spectrometry to identify the metabolic pathways of fentanyl. The main metabolites detected were norfentanyl and hydroxyfentanyl in both the tested models. In conclusion, the present study provides evidence that fentanyl effects on zebrafish larvae and metabolism are similar to rodents and consequently support the hypothesis of using zebrafish larvae as a suitable rapid screening tool to investigate new drugs, and particularly NPS.

Advances in the Study of Upper Airway Characteristics in Children with Malocclusion

Malocclusion is the malformation of teeth, jaw and skull caused by congenital genetic factors or acquired environmental factors in the process of children's growth and development, such as diseases, bad oral habits, abnormal substitute teeth, such as irregular arrangement of teeth, abnormal relationship between upper and lower dental arch, abnormal jaw size and shape, etc. Malocclusion is also accompanied by respiratory diseases and dysfunction, such as obstructive sleep apnea (OSA). Conversely, abnormal occlusion also leads to respiratory tract developmental disorders and dysfunction. The cranio-maxillofacial morphology is closely related to the upper airway morphology. They are cause and effect each other. In recent years, it has been found that orthodontic treatment can not only improve the malocclusion, but also has a significant effect on the upper airway volume. The abnormal upper airway in childhood will affect children's breathing, cause children's sleep apnea, and affect children's growth and development. At the same time, with the development of society, we pay more attention to children's face. Therefore, at present, the upper airway morphological characteristics, influencing factors and correction methods of malocclusion have become the focus of research.

Activator Treatment in a Girl with Skeletal Class II Malocclusion with Lower Lip Biting Habit

Abnormal oral habits interfere with normal growth of the maxillofacial complex due to imbalance of the muscles involved. In skeletal Class II malocclusion, lip biting habit which emerges as a compensation for excessive overjet can inhibit the forward growth of the mandible. In this case report, the patient had a habit of biting the lower lip, which was trapped between the upper and lower incisors, showing large overjet, deep bite, and retruded mandible. It was necessary to correct the abnormal teeth and jaw relations to break the habit. Orthodontic treatment began with myofunctional therapy for lip seal training and a 2 by 4 appliance to reduce the overjet and make an aesthetic smile. After removing the bonded appliance, an activator was used to accelerate the mandible growth and lip training was continued. Lower lip biting habit disappeared with decreased overjet, leading to balanced facial growth.

Masticatory Function Assessment of Adult Patients With Cleft Lip and Palate After Orthodontic Treatment.

To determine whether orthodontically treated patients with cleft lip and palate (CLP) possess a different masticatory function than those of untreated patients with normal occlusion. Occlusal contact area, occlusal force, as well as masseter and anterior temporal muscular activity were measured during maximum voluntary clenching (MVC) tests. Mandibular left and right lateral movements during mastication were also assessed. To further elucidate the nature of masticatory function, especially to determine the rate of abnormal jaw movement patterns, a parametric error index (EI) was set. Finally, masticatory efficiency was evaluated with a glucose sensitive measuring device. Fifteen patients with CLP who had previously completed the orthodontic treatments required to achieve an acceptable and more harmonious occlusion accepted to volunteer in this study along with 21 untreated patients who already possessed a normal occlusion. Patients with CLP showed a significantly lower occlusal force, reduced occlusal contact area, and decreased masticatory efficiency as well as significantly higher EI value when compared with controls. However, there was no significant difference when analyzing muscle activity, although masticatory efficiency was significantly different between the 2 groups. Despite this result, the scores obtained by the patients with CLP in the masticatory efficiency tests were still in the normal range. Orthodontic treatment for adult patients with CLP provides a satisfactory result for the patients' masticatory ability albeit significantly less ideal compared with untreated patients with normal occlusion.

De Novo Missense Variants in FBXW11 Cause Diverse Developmental Phenotypes Including Brain, Eye, and Digit Anomalies

The identification of genetic variants implicated in human developmental disorders has been revolutionized by second-generation sequencing combined with international pooling of cases. Here, we describe seven individuals who have diverse yet overlapping developmental anomalies, and who all have de novo missense FBXW11 variants identified by whole exome or whole genome sequencing and not reported in the gnomAD database. Their phenotypes include striking neurodevelopmental, digital, jaw, and eye anomalies, and in one individual, features resembling Noonan syndrome, a condition caused by dysregulated RAS signaling. FBXW11 encodes an F-box protein, part of the Skp1-cullin-F-box (SCF) ubiquitin ligase complex, involved in ubiquitination and proteasomal degradation and thus fundamental to many protein regulatory processes. FBXW11 targets include β-catenin and GLI transcription factors, key mediators of Wnt and Hh signaling, respectively, critical to digital, neurological, and eye development. Structural analyses indicate affected residues cluster at the surface of the loops of the substrate-binding domain of FBXW11, and the variants are predicted to destabilize the protein and/or its interactions. In situ hybridization studies on human and zebrafish embryonic tissues demonstrate FBXW11 is expressed in the developing eye, brain, mandibular processes, and limb buds or pectoral fins. Knockdown of the zebrafish FBXW11 orthologs fbxw11a and fbxw11b resulted in embryos with smaller, misshapen, and underdeveloped eyes and abnormal jaw and pectoral fin development. Our findings support the role of FBXW11 in multiple developmental processes, including those involving the brain, eye, digits, and jaw.

Airway sonography fails to detect difficult laryngoscopy in an adult Veteran surgical population

ObjectiveTo evaluate ultrasound's utility to detect difficult laryngoscopy in a preoperative setting. MethodsThis single-site, prospective, cross-sectional, within-subjects study was performed at a Veterans Affairs Medical Center with 144 subjects. The sonographic independent variables included sonographic hyomental distance (HMD) and anterior neck thicknesses at the hyoid bone (HB), thyrohyoid membrane (THM), and vocal cords (VC). Additional independent variables were standard airway indicators of BMI, neck circumference, obstructive sleep apnea, snoring, abnormal upper teeth, jaw mobility, interincisor gap, Mallampati score, thyromental distance and neck range of motion. The outcome variable was the modified Cormack-Lehane Grade (CLG). ResultsThere was no significance found among the four sonographic measurements or their derived ratios in predicting difficult laryngoscopy. Correlation analysis between the sonographic measurements did find significance of the HMD:HB (p = 0.040) and the HB:THM (p = 0.44) ratios. However these ratios had a weak correlation at −0.172 and −0.168 respectively. Standard airway indicators did not demonstrate significance in predicting the difficult airway, sans obese patient with neck circumference (p = 0.016). DiscussionThis study demonstrated ultrasonography in predicting difficult laryngoscopy lacked utility. Ultrasound utilization as an efficacious means of difficult airway assessment requires further research with a larger sample size. Further studies using sonography on those patients with known difficult airways may provide data to determine if ultrasound has utility in predicting difficult laryngoscopy.

Oral dysfunction as a cause of malocclusion.

Structured This narrative review surveys current research demonstrating how oral dysfunction can escalate into malocclusion, acquired craniofacial disorder and contribute to generational dysfunction, disorder and disease.IntroductionBaseline orthodontic consultations are generally recommended beginning age seven. However, the dysmorphic changes that result in malocclusion are often evident years earlier. Similarly, following orthodontic treatment, patients require permanent retention when the bite is not stable, and without such retention, the malocclusion can return.Setting and PopulationNarrative review article including research on infants, children and adults.Materials and MethodsThis review is a brief survey of the symptomology of orofacial myofunctional disorder and outlines 10 areas of oral function that impact occlusal and facial development: breastfeeding, airway obstruction, soft tissue restriction, mouth breathing, oral resting posture, oral habits, swallowing, chewing, the impact of orofacial myofunctional disorder (OMD) over time and maternal oral dysfunction on the developing foetus.ConclusionMalocclusions and their acquired craniofacial dysmorphology are the result of chronic oral dysfunction and OMD. In order to achieve long‐term stability of the face, it is critical to understand the underlying pathologies contributing to malocclusion, open bite and hard palate collapse.

Prevalence of temporomandibular disorders and its clinical signs in Chinese students, 1979-2017: A systematic review and meta-analysis.

This study intends to assess the prevalence of temporomandibular disorders and its clinical signs in Chinese students. Search strategies were performed in seven electronic databases, and the reference lists from potentially relevant studies were searched manually. Only observational studies that met the eligibility criteria were selected. A validated instrument was used to evaluate the quality of the included studies. A random-effects model was used to calculate the pooled prevalence of temporomandibular disorders and its clinical signs. Twenty-three articles that met the eligibility criteria were included in this review and meta-analysis. The prevalence of temporomandibular disorders was 29.1% (95% confidence interval [CI], 23.7-35.1; n=12,702), and a significant difference was observed between males and females. The most prevalent sign was temporomandibular joint sounds (17.4%; 95% CI, 13.8-20.6; n=6,615) followed by abnormal jaw movement (12.3%; 95% CI, 9.1-16.7; n=5,496) and pain (9.9%; 95% CI, 7.4-13; n=4,552). The overall prevalence of temporomandibular disorders in Chinese students was approximately 29.1%, and a statistically significant difference was observed between males and females. The most prevalent sign was temporomandibular joint sounds (17.4%), followed by abnormal jaw movement (12.3%) and pain (9.9%).

Management of Occlusion in a Completely Edentulous Patient with Abnormal Jaw Relation

Management of Occlusion in a Completely Edentulous Patient with Abnormal Jaw Relation

Periodontal mechanoreceptors and bruxism at low bite forces

ObjectiveIn this study, we examined if 6–9 Hz jaw tremor, an indirect indicator of Periodontal Mechanoreceptor (PMR) activity, is different in bruxists compared to healthy participants during production of a low-level constant bite force. MethodsBite force and surface EMG from the masseter muscle were recorded simultaneously as participants (13 patients, 15 controls) held a force transducer between the upper and lower incisors very gently. ResultsTremor in 6–9 Hz band for bruxists was greater on average compared to controls, but the difference was not significant, both for force recordings and EMG activity. ConclusionsThe low effect sizes measured with the current protocol contrast highly with those of our previous study, where larger, dynamic bite forces were used, and where jaw tremor was markedly different in bruxists compared with controls. SignificanceWe have now gained important insight into the conditions under which abnormal jaw tremor can be elicited in bruxism. From a scientific standpoint, this is critical for understanding the ‘abnormality’ of PMR feedback in bruxism. From a clinical perspective, our results represent progress towards the development of an optimal protocol in which jaw tremor can serve as a biological marker of bruxism.

Knockdown of Crispld2 in zebrafish identifies a novel network for nonsyndromic cleft lip with or without cleft palate candidate genes.

Orofacial development is a multifaceted process involving tightly regulated genetic signaling networks, that when perturbed, lead to orofacial abnormalities including cleft lip and/or cleft palate. We and others have shown an association between the cysteine-rich secretory protein LCCL domain containing 2 (CRISPLD2) gene and nonsyndromic cleft lip with or without cleft palate (NSCLP). Further, we demonstrated that knockdown of Crispld2 in zebrafish alters neural crest cell migration patterns resulting in abnormal jaw and palate development. In this study, we performed RNA profiling in zebrafish embryos and identified 249 differentially expressed genes following knockdown of Crispld2. In silico pathway analysis identified a network of seven genes previously implicated in orofacial development for which differential expression was validated in three of the seven genes (CASP8, FOS, and MMP2). Single nucleotide variant (SNV) genotyping of these three genes revealed significant associations between NSCLP and FOS/rs1046117 (GRCh38 chr14:g.75746690 T > C, p = 0.0005) in our nonHispanic white (NHW) families and MMP2/rs243836 (GRCh38 chr16:g.55534236 G > A; p = 0.002) in our Hispanic families. Nominal association was found between NSCLP and CASP8/rs3769825 (GRCh38 chr2:g.202111380 C > A; p < 0.007). Overtransmission of MMP2 haplotypes were identified in the Hispanic families (p < 0.002). Significant gene-gene interactions were identified for FOS-MMP2 in the NHW families and for CASP8-FOS in the NHW simplex family subgroup (p < 0.004). Additional in silico analysis revealed a novel gene regulatory network including five of these newly identified and 23 previously reported NSCLP genes. Our results demonstrate that animal models of orofacial clefting can be powerful tools to identify novel candidate genes and gene regulatory networks underlying NSCLP.

Jaw fracture classification using meta heuristic firefly algorithm with multi-layered associative neural networks

Jaw fracture is one of the common facial injuries in human body. The jaw fracture disease is one of the tenth most injuries in human body. Jaw fracture may result from high physical injuries impacts and medical conditions that weaken the looseness of the teeth, jaw stiffness, swelling and so on. Due to the various symptoms of this disease, diagnosis is difficult at an early stage. Therefore, different machine learning and data mining techniques are used to detect jaw fracture because of the severe effects of the disease. Initially, jaw related data is randomly collected from the patient, which includes information such as the patient name, age, height, weight, osteoporosis risk factors, prediction, fracture level, and so on. After collecting jaw fracture information, unwanted data is discarded by applying normalization techniques; optimized features are then selected using the metaheuristic firefly algorithm. The selected data is then classified using the multi-layer neural network training based on associative neural networks. The classifier then successfully categorizes the abnormal jaw fracture feature. Then, the efficiency of the system is examined with the help of the mean square error rate, precision, recall, and accuracy.

Facial attractiveness of skeletal class I and class II malocclusion as perceived by laypeople, patients and clinicians.

Physical attractiveness is dependent on facial appearance. The facial profile plays a crucial role in facial attractiveness and can be improved with orthodontic treatment. The aesthetic assessment of facial appearance may be influenced by the cultural background and education of the assessor and dependent upon the experience level of dental professionals. This study aimed to evaluate how the sagittal jaw relationship in Class I and Class II individuals affects facial attractiveness, and whether the assessor's professional education and background affect the perception of facial attractiveness. Facial silhouettes simulating mandibular retrusion, maxillary protrusion, mandibular retrusion combined with maxillary protrusion, bimaxillary protrusion and severe bimaxillary protrusion in class I and class II patients were assessed by five groups of people with different backgrounds and education levels (i.e., 23 expert orthodontists, 21 orthodontists, 15 maxillofacial surgeons, 19 orthodontic patients and 28 laypeople). Straight facial profiles were judged to be more attractive than convex profiles due to severe mandibular retrusion and to mandibular retrusion combined with maxillary protrusion (all P<0.05). Convex profiles due to a slightly retruded position of the mandible were judged less attractive by clinicians than by patients and laypeople (all P<0.05). Convex facial profiles are less attractive than Class I profiles. The assessment of facial attractiveness is dependent on the assessor's education and background. Laypeople and patients are considerably less sensitive to abnormal sagittal jaw relationships than orthodontists.