Subjective perception of craniofacial growth asymmetries in patients with deformational plagiocephaly.

OBJECTIVES: The present investigation aimed to evaluate the subjective perception of deformational cranial asymmetries by different observer groups and to compare these subjective perceptions with objective parameters. MATERIALS AND METHODS: The 3D datasets of ten infants with different severities of deformational plagiocephaly (DP) were presented to 203 observers, who had been subdivided into five different groups (specialists, pediatricians, medical doctors (not pediatricians), parents of infants with DP, and laypersons). The observers rated their subjective perception of the infants' cranial asymmetries using a 4-point Likert-type scale. The ratings from the observer groups were compared with one another using a multilevel modelling linear regression analysis and were correlated with four commonly used parameters to objectively quantify the cranial asymmetries. RESULTS: No significant differences were found between the ratings of the specialists and those of the parents of infants with DP, but both groups provided significantly more asymmetric ratings than did pediatricians, medical doctors, or laypersons. Moreover, the subjective perception of cranial asymmetries correlated significantly with commonly used parameters for objectively quantifying cranial asymmetries. CONCLUSIONS: Our results demonstrate that different observer groups perceive the severity of cranial asymmetries differently. Pediatricians' more moderate perception of cranial asymmetries may reduce the likelihood of parents to seek therapeutic interventions for their infants. Moreover, we identified some objective symmetry-related parameters that correlated strongly with the observers' subjective perceptions. CLINICAL RELEVANCE: Knowledge about these findings is important for clinicians when educating parents of infants with DP about the deformity.

Characteristic dental pattern with hypodontia and short roots in Fraser syndrome.

Fraser syndrome (FS) is a rare autosomal recessive multiple congenital malformation syndrome characterized by cryptophthalmos, cutaneous syndactyly, renal agenesis, ambiguous genitalia, and laryngotracheal anomalies. It is caused by biallelic mutations of FRAS1, FREM2, and GRIP1 genes, encoding components of a protein complex that mediates embryonic epithelial-mesenchymal interactions. Anecdotal reports have described abnormal orodental findings in FS, but no study has as yet addressed the orodental findings of FS systematically. We reviewed dental radiographs of 10 unrelated patients with FS of different genetic etiologies. Dental anomalies were present in all patients with FS and included hypodontia, dental crowding, medial diastema, and retained teeth. A very consistent pattern of shortened dental roots of most permanent teeth as well as altered length/width ratio with shortened dental crowns of upper incisors was also identified. These findings suggest that the FRAS1-FREM complex mediates critical mesenchymal-epithelial interactions during dental crown and root development. The orodental findings of FS reported herein represent a previously underestimated manifestation of the disorder with significant impact on orodental health for affected individuals. Integration of dentists and orthodontists into the multidisciplinary team for management of FS is therefore recommended.

Craniofacial growth in infants with deformational plagiocephaly: does prematurity affect the duration of head orthosis therapy and the extent of the reduction in asymmetry during treatment?

OBJECTIVE: Although prematurity is a risk factor for developing deformational plagiocephaly (DP), to our knowledge, there are no studies that have analyzed the impact of a premature birth on the duration of head orthosis therapy and the extent of the reduction in asymmetry during treatment. MATERIALS AND METHODS: We examined 239 patients with DP who were undergoing head orthosis therapy. Depending on the gestational age, they were assigned to either a premature (gestational age of < 37 weeks) or a full-term (gestational age of ≥ 37 weeks) group. Head shape was analyzed using 3D-stereophotogrammetry at the start and end of treatment. We performed multiple linear regression analyses to evaluate the impact of prematurity on the duration of therapy and the extent of the reduction in asymmetry, taking age and the initial asymmetry of an infant's head into account. RESULTS: Head orthosis therapy led to a significant reduction in asymmetry in both groups. Using multiple linear regression analyses, we demonstrated that age at the start of treatment, the initial asymmetry and prematurity, significantly influenced the duration of therapy. Patients who were born at an earlier gestational age experienced a shorter treatment length. However, prematurity did not affect the extent of the reduction in cranial asymmetry that was achieved. CONCLUSIONS: Along with age at the start of treatment and the initial asymmetry, prematurity is significantly correlated with the duration of head orthosis therapy, but not with the extent of the reduction in asymmetry achieved. CLINICAL RELEVANCE: Knowledge of these findings is important for clinicians when planning treatment and discussing the effectiveness of head orthosis therapy with the parents of premature infants with DP.

Head orthosis therapy in positional plagiocephaly: longitudinal 3D-investigation of long-term outcomes, compared with untreated infants and with a control group.

Background: As there are very few long-term studies on the effects of head orthosis on deformational plagiocephaly (DP), we investigated the outcomes of patients, including facial symmetry and dental occlusion. Methods: Forty-five infants with DP [cranial vault asymmetry index (CVAI) > 3.5 per cent] were divided into two groups: one treated with head orthosis (32 infants) and another without (13 infants). Another group without head asymmetry (CVAI ≤ 3.5 per cent) served as control. Using 3D-stereophotogrammetry, cranial asymmetry was analysed using symmetry-related variables [CVAI, posterior cranial asymmetry index (PCAI), and ear offset]. Data acquisition was performed before (T1) and at the end of treatment (T2), and at the age of 4 years (T3) for the treated group and at T1 and T3 for the remaining groups. Parameters of facial symmetry and dental occlusion were assessed at T3 for infants with DP. Results: Symmetry-related variables (∆T1-T3) improved significantly more in the treated than the control group, whereas these parameters did not differ significantly between the untreated and control group. Comparing the treated and untreated groups between T1 and T3, the reduction in the asymmetry at the treated group was significantly higher for the CVAI and PCAI. In follow-up, the untreated group showed higher incidences of facial asymmetries than the treated group. Seventy-five per cent of all lateral crossbites found in patients with DP were contralateral to the posterior flattening. Limitations: Due to ethical reasons, the investigation is a non-randomized study. Parameters of facial symmetry were only assed for the treated and untreated groups. Conclusion: Head orthosis therapy in patients with DP leads to significantly better long-term outcomes. Facial asymmetries are more frequent in patients with DP who do not receive this treatment.

Wild-type isolates of Porphyromonas gingivalis derived from periodontitis patients display major variability in platelet activation.

In vitro studies revealed that Porphyromonas gingivalis (Pg), a pathogen intimately associated with the onset and progression of periodontitis, is able to activate platelets, thus linking periodontal inflammation with the endangerment of vascular health. As wild-type Pg strains are characterized by major genetic heterogeneity, the commonness of platelet-activating Pg strains in periodontitis patients is unknown as of yet. Therefore, this study evaluated the platelet activation capacity of wild-type Pg isolates sampled from patients with aggressive periodontitis. METHODS: Extent and velocity of platelet aggregation were determined by light transmission aggregometry. Platelet surface expression of P-selectin was measured by flow cytometry, activation of p38 MAP kinase, and protein kinase C by Western blot using phospho-specific antibodies. RESULTS: Pg isolates displayed high variability regarding extent and velocity of platelet activation, as well as the involved activating pathways. Corresponding results were observed for platelet P-selectin expression, activation of p38 MAP kinase, or protein kinase C. Inhibitors of platelet immune receptor FcγRIIA and protease-activated receptors revealed several, diverging pathways of activation. Some isolates induced platelet aggregation even in the presence of potent therapeutical platelet inhibitors. CONCLUSIONS: Chronic bacteremia involving specific, platelet-activating Pg strains may constitute a substantial hazard for the integrity of cardiovascular health.

Combining wrist age and third molars in forensic age estimation: how to calculate the joint age estimate and its error rate in age diagnostics.

BACKGROUND: Forensic age estimation in living adolescents is based on several methods, e.g. the assessment of skeletal and dental maturation. Combination of several methods is mandatory, since age estimates from a single method are too imprecise due to biological variability. The correlation of the errors of the methods being combined must be known to calculate the precision of combined age estimates. AIM: To examine the correlation of the errors of the hand and the third molar method and to demonstrate how to calculate the combined age estimate. SUBJECTS AND METHODS: Clinical routine radiographs of the hand and dental panoramic images of 383 patients (aged 7.8-19.1 years, 56% female) were assessed. RESULTS: Lack of correlation (r = -0.024, 95% CI = -0.124 to + 0.076, p = 0.64) allows calculating the combined age estimate as the weighted average of the estimates from hand bones and third molars. Combination improved the standard deviations of errors (hand = 0.97, teeth = 1.35 years) to 0.79 years. CONCLUSION: Uncorrelated errors of the age estimates obtained from both methods allow straightforward determination of the common estimate and its variance. This is also possible when reference data for the hand and the third molar method are established independently from each other, using different samples.

Expanding the spectrum of PTH1R mutations in patients with primary failure of tooth eruption.

OBJECTIVES: Primary failure of tooth eruption (PFE) is a rare autosomal-dominant disease characterized by severe lateral open bite as a consequence of incomplete eruption of posterior teeth. Heterozygous mutations in the parathyroid hormone 1 receptor (PTH1R) gene have been shown to cause PFE likely due to protein haploinsufficiency. To further expand on the mutational spectrum of PFE-associated mutations, we report here on the sequencing results of the PTH1R gene in 70 index PFE cases. MATERIALS AND METHODS: Sanger sequencing of the PTH1R coding exons and their immediate flanking intronic sequences was performed with DNA samples from 70 index PFE cases. RESULTS: We identified a total of 30 unique variants, of which 12 were classified as pathogenic based on their deleterious consequences on PTH1R protein while 16 changes were characterized as unclassified variants with as yet unknown effects on disease pathology. The remaining two variants represent common polymorphisms. CONCLUSIONS: Our data significantly increase the number of presently known unique PFE-causing PTH1R mutations and provide a series of variants with unclear pathogenicity which will require further in vitro assaying to determine their effects on protein structure and function. CLINICAL RELEVANCE: Management of PTH1R-associated PFE is problematic, in particular when teeth are exposed to orthodontic force. Therefore, upon clinical suspicion of PFE, molecular DNA testing is indicated to support decision making for further treatment options.

Developing the Benchmark: Establishing a Gold Standard for the Evaluation of AI Caries Diagnostics.

Background/Objectives: The aim of this study was to establish a histology-based gold standard for the evaluation of artificial intelligence (AI)-based caries detection systems on proximal surfaces in bitewing images. Methods: Extracted human teeth were used to simulate intraoral situations, including caries-free teeth, teeth with artificially created defects and teeth with natural proximal caries. All 153 simulations were radiographed from seven angles, resulting in 1071 in vitro bitewing images. Histological examination of the carious lesion depth was performed twice by an expert. A total of thirty examiners analyzed all the radiographs for caries. Results: We generated in vitro bitewing images to evaluate the performance of AI-based carious lesion detection against a histological gold standard. All examiners achieved a sensitivity of 0.565, a Matthews correlation coefficient (MCC) of 0.578 and an area under the curve (AUC) of 76.1. The histology receiver operating characteristic (ROC) curve significantly outperformed the examiners' ROC curve (p < 0.001). All examiners distinguished induced defects from true caries in 54.6% of cases and correctly classified 99.8% of all teeth. Expert caries classification of the histological images showed a high level of agreement (intraclass correlation coefficient (ICC) = 0.993). Examiner performance varied with caries depth (p ≤ 0.008), except between E2 and E1 lesions (p = 1), while central beam eccentricity, gender, occupation and experience had no significant influence (all p ≥ 0.411). Conclusions: This study successfully established an unbiased dataset to evaluate AI-based caries detection on bitewing surfaces and compare it to human judgement, providing a standardized assessment for fair comparison between AI technologies and helping dental professionals to select reliable diagnostic tools.

Three-dimensional analysis of positional plagiocephaly before and after molding helmet therapy in comparison to normal head growth.

OBJECTIVE: Stereophotogrammetry enables a simple and radiation free longitudinal analysis of skull asymmetries: in a three-dimensional coordinate system various distances (length, breadth, cephalic index, oblique diameters, ear shift, head circumference) can be analyzed. We also defined separate volume sections in order to further quantify the degree of asymmetry in the posterior and anterior components of both sides of the head. PATIENTS AND METHODS: In 51 infants (mean age, 6 months; SD 0.97) with positional plagiocephaly, we determined these parameters at the beginning as well as at the end of molding helmet therapy (mean therapy time 4.9 months). Thirty-seven infants without positional deformity (mean age, 6.4 months; SD 0.3) served as control group and provided data about what appears to be normal and how these parameters change during growth over a comparable period of time. RESULTS: Compared with the control group, the plagiocephalic heads were more brachycephalic, but closely approximated the normal shape under molding therapy. The striking volume difference between the left and right posterior sections in the plagiocephalic children (the mean volume of the flattened side being 21% smaller than the one on the contralateral side) improved as well (to a residual difference of mean 8%) and ended up with a value close to the control group (mean 6%). CONCLUSION: There is a broad clinical application area for stereophotogrammetry analyzing skull morphology: In plagiocephalic infants we demonstrate impressive changes of head shape under molding therapy; in normal-looking infants we describe the extent of unperceived asymmetry.

The impact of spur therapy in dentoalveolar open bite.

AIM: A longitudinal casecontrol study, designed to analyse the isolated effect of attached palatal spurs in patients displaying a dentoalveolar anterior open bite, is presented. METHODS: Thirty-one patients (mean age of 13.3 years +/- 3.17 years) underwent a standardised treatment protocol with fixed anterior spurs for 8.3 months. Lateral cephalograms and plaster casts were analysed before (T1) and after spur therapy (T2). The data were tested using paired t-tests with a significance level of p < 0.05. RESULTS: The cephalometric analysis showed significant elongation of the height of the maxillary (mean +1.22 mm) and the mandibular (mean +1.39 mm) alveolar processes, as well as uprighting of the lower anterior teeth. The plaster cast analysis showed an increase in maxillary intermolar width (mean +0.98 mm) and a decrease in intercanine distance (mean -0.96 mm). The mandibular anterior width and dental arch length reduced. Overall, spur therapy resulted in a significant increase in overjet and overbite. CONCLUSION: The use of spurs produced a resolution of the open bite in all patients. Therefore, spurs could be considered an effective mechanism for the management of anterior open bite in selected adolescent patients.

Assessment of the quality of different commercial providers using artificial intelligence for automated cephalometric analysis compared to human orthodontic experts.

PURPOSE: The aim of this investigation was to evaluate the accuracy of various skeletal and dental cephalometric parameters as produced by different commercial providers that make use of artificial intelligence (AI)-assisted automated cephalometric analysis and to compare their quality to a gold standard established by orthodontic experts. METHODS: Twelve experienced orthodontic examiners pinpointed 15 radiographic landmarks on a total of 50 cephalometric X­rays. The landmarks were used to generate 9 parameters for orthodontic treatment planning. The "humans' gold standard" was defined by calculating the median value of all 12 human assessments for each parameter, which in turn served as reference values for comparisons with results given by four different commercial providers of automated cephalometric analyses (DentaliQ.ortho [CellmatiQ GmbH, Hamburg, Germany], WebCeph [AssembleCircle Corp, Seongnam-si, Korea], AudaxCeph [Audax d.o.o., Ljubljana, Slovenia], CephX [Orca Dental AI, Herzliya, Israel]). Repeated measures analysis of variances (ANOVAs) were calculated and Bland-Altman plots were generated for comparisons. RESULTS: The results of the repeated measures ANOVAs indicated significant differences between the commercial providers' predictions and the humans' gold standard for all nine investigated parameters. However, the pairwise comparisons also demonstrate that there were major differences among the four commercial providers. While there were no significant mean differences between the values of DentaliQ.ortho and the humans' gold standard, the predictions of AudaxCeph showed significant deviations in seven out of nine parameters. Also, the Bland-Altman plots demonstrate that a reduced precision of AI predictions must be expected especially for values attributed to the inclination of the incisors. CONCLUSION: Fully automated cephalometric analyses are promising in terms of timesaving and avoidance of individual human errors. At present, however, they should only be used under supervision of experienced clinicians.

PTHR1 loss-of-function mutations in familial, nonsyndromic primary failure of tooth eruption.

Tooth eruption is a complex developmental process requiring coordinated navigation through alveolar bone and oral epithelium. Primary failure of tooth eruption (PFE) is associated with several syndromes primarily affecting skeletal development, but it is also known as a nonsyndromic autosomal-dominant condition. Teeth in the posterior quadrants of the upper and lower jaw are preferentially affected and usually result in an open bite extending from anterior to posterior. In this study, we show that familial, nonsyndromic PFE is caused by heterozygous mutations in the gene encoding the G protein-coupled receptor for parathyroid hormone and parathyroid hormone-like hormone (PTHR1). Three distinct mutations, namely c.1050-3C > G, c.543+1G > A, and c.463G > T, were identified in 15 affected individuals from four multiplex pedigrees. All mutations truncate the mature protein and therefore should lead to a functionless receptor, strongly suggesting that haplo-insufficiency of PTHR1 is the underlying cause of nonsyndromic PFE. Although complete inactivation of PTHR1 is known to underlie the autosomal-recessive Blomstrand osteochondrodysplasia (BOCD), a lethal form of short-limbed dwarfism, our data now imply that dominantly acting PTHR1 mutations that lead to haplo-insufficiency of the receptor result in a nonsyndromic phenotype affecting tooth development with high penetrance and variable expressivity.

Visual face perception of adults with unilateral cleft lip and palate in comparison to controls--an eye-tracking study.

OBJECTIVE: To assess how faces with a cleft lip and palate are perceived and to study how faces with and without a unilateral cleft lip and palate are viewed by individuals with a unilateral cleft lip and/or palate in comparison to nonaffected controls. DESIGN: Prospective clinical study. SETTING: Department of Orthodontics and Department of Psychology, University of Wuerzburg. PARTICIPANTS: Thirty-three participants (20 men and 13 women; mean age, 25.4 ± 6.6 years) with a unilateral cleft lip and/or palate and a control group of 30 participants (15 men and 15 women; mean age, 26.8 ± 3.4 years) were enrolled in this study. MAIN OUTCOME MEASURES: Eye movements were analyzed via an eye-tracking camera while all participants looked at pictures of faces with and without a unilateral cleft lip and palate. RESULTS: The nose and the mouth area of pictures of faces with a unilateral cleft lip and palate were looked at significantly longer by both groups. Additionally, the participants with a unilateral cleft lip and/or palate looked at faces with and without a unilateral cleft lip and palate differently, taking more time to view the nose and less time to view the eyes compared with the participants without a cleft lip and palate. CONCLUSION: When perceiving a face with a unilateral cleft lip and palate, the observer's gaze is distracted to the nose and mouth area. Moreover, participants with a unilateral cleft lip and/or palate themselves focused greater attention on those features that are anomalous on their own faces in comparison to participants without a cleft lip and palate. Specifically, this different scanpath is reflected in the cumulative duration of the eye movements as well as in the initial facial scan pattern.

Treatment modalities of infants with upper airway obstruction--review of the literature and presentation of novel orthopedic appliances.

OBJECTIVE: To present a new orthopedic method for treatment of infants with Pierre Robin sequence (PRS) and upper airway obstruction (UAO) as an alternative to other established nonsurgical and surgical techniques such as positioning, nasopharyngeal or endotracheal intubation, tongue-lip adhesion, extension, distraction, or tracheostomy. DESIGN: Review of the literature and presentation of novel orthopedic appliances. SETTING: Department of Orthodontics, Dental Clinic, Medical Faculty of the University of Wuerzburg, Germany, Department and Clinic of Pediatrics, Medical Faculty of the University of Wuerzburg, Germany, 2005 to 2008. PATIENTS: Seven patients with significant respiratory and feeding difficulties between 0 and 6 months of age. Both patients with nonsyndromic PRS and patients with syndromic PRS were included. INTERVENTIONS: The type of respiratory tract obstruction was defined by nasopharyngoscopy. Patients with type 1 obstruction received a plate with an epiglottic spur; whereas, patients with obstruction type 2, 3, or 4 received a plate with a pharyngeal tube. RESULTS: All patients were successfully treated with orthopedic appliances alone. Under plate therapy they showed good oxygen saturation and could consequently be better nourished orally. CONCLUSIONS: The presented novel method is a noninvasive technique in treatment of infants with UAO.

Cry melody in 2-month-old infants with and without clefts.

OBJECTIVE: To investigate cry melody properties in infants with clefts using objective methods and to identify early differences in cry development in relation to infants without clefts that may indicate special developmental risks. DESIGN: Melody analysis was carried out on cries from the second month of life. The cry properties of infants with a cleft lip and palate (CLP) and infants with a cleft palate only (CP) were quantitatively compared. Both groups were compared to infants without clefts. PARTICIPANTS: Twenty-one infants with nonsyndromic clefts, including 11 infants with CLP and 10 infants with CP, were compared to 50 healthy controls. MAIN OUTCOME MEASURES: Frequency spectrograms and melody diagrams of about 7000 cries were analyzed. For each infant's crying, melodic and rhythmic properties were investigated and expressed by appropriate quantitative indices. Based on previous studies, the degree of melody complexity in an infants' crying was used as an indicator of their present prespeech developmental status. RESULTS: The cleft groups did not significantly differ from each other with respect to their cry melody development. However, both groups were significantly different from the control group, exhibiting a lower proportion of complex cry melodies and a deviation in rhythmicity. No significant correlation to hearing performances was found that could explain the differences. CONCLUSIONS: Infants with clefts differ in their cry development from infants without clefts at 2 months of life. This early difference occurs before the infants undergo any surgical intervention or other treatment.

New model for surgical and nonsurgical therapy in adults with Class III malocclusion.

INTRODUCTION: Not all adult Class III malocclusion patients are candidates for surgical correction. In patient assessment and selection, major issues remain regarding diagnosis and treatment planning. The purpose of this investigation was to ascertain whether adding a transverse parameter to a discriminant analysis could improve the classification of adults with Class III malocclusion into 2 groups of patients: those who can effectively be treated by orthodontic therapy and those who require orthognathic surgery. METHODS: Cephalograms, plaster casts, and extraoral photos of 69 adults with Class III malocclusion were analyzed. A discriminant analysis was performed to identify the variables that best separate the 2 groups. RESULTS: Stepwise variable selection resulted in a new, highly significant (P <0.0001) model of 4 variables that provided the best discriminant function to distinguish between patients with and without indications for surgical correction. The resulting equation was the following: score = -10.988 + 0.243 * Wits + 0.055 * M/M ratio + 0.068 * NSAr - 0.589 * mand MLD. The percentage of patients correctly classified by this equation was 91.3%. The sensitivity was 0.92, and the specificity was 0.89. CONCLUSIONS: In the discriminant analysis, the mandibular midline deviation as a transverse component was included. The addition of the transverse variable led to an improved model concerning the predictive value in Class III malocclusion patients with surgical requirements.

Three-dimensional perception of facial asymmetry.

In orthodontic diagnosis, facial symmetry is important. The aim of the present study was to analyse the perception of various degrees of facial asymmetry exhibited by carefully designed virtual three-dimensional (3D) material. Three groups of raters (30 orthodontists, 30 maxillofacial surgeons, and 30 laymen) rated, using a six-point scale, the degree of asymmetry of eight randomly presented 3D faces exhibiting incremental soft tissue alterations. The faces were created by gradually transforming the nose or chin in increments of 2 mm away from the computed symmetry plane. Differences between the groups in analysis of facial asymmetry, the rating of facial stimulus, and right and left facial asymmetry were determined using a t-test. The results demonstrated that raters' profession did not influence the point at which they identified asymmetry. Even laymen were able to detect asymmetries when located near the midline of 3D faces. All raters identified asymmetries of the nose as more negative than those of the same degree of the chin. A left-sided deviation of the nose along the facial symmetry plane lead to a more negative rating of facial appearance, whereas a right-sided deviation of the chin was rated as less attractive. Nasal architecture plays a crucial role in the perception of symmetry. These findings provide clinicians with a greater understanding of how faces are perceived, a process which is of particular interest in treating orthognathic patients, and those with congenital anomalies.

Impact of facial asymmetry in visual perception: a 3-dimensional data analysis.

INTRODUCTION: The aim of this controlled study was to analyze the degree and localization of 3-dimensional (3D) facial asymmetry in adult patients with cleft lip and palate (CLP) compared with a control group and its impact on the visual perception of faces. METHODS: The degree of 3D asymmetry was analyzed with a novel method without landmarks in 18 adults with complete unilateral CLP and 18 adults without congenital anomalies. Furthermore, the CLP and control faces were rated for appearance, symmetry, and facial expression by 30 participants. RESULTS: The results showed that adults with CLP had significantly greater asymmetry in their facial soft tissues compared with the control group. Moreover, the lower face, and particularly the midface, had greater asymmetry in the CLP patients. The perceptual ratings showed that adults with CLP were judged much more negatively than those in the control group. CONCLUSIONS: With sophisticated 3D analysis, the real morphology of a face can be calculated and asymmetric regions precisely identified. The greatest asymmetry in CLP patients is in the midface. These results underline the importance of symmetry in the perception of faces. In general, the greater the facial asymmetry near the midline of the face, the more negative the evaluation of the face in direct face-to-face interactions.

Bridging of the sella turcica in skeletal Class III subjects.

Several investigations have analysed the frequency of sella turcica anomalies in patients with severe craniofacial deviations. Until now, there have been no studies concerning the prevalence of sella turcica bridging in homogenous groups of patients. Therefore, the aims of this controlled study were to analyse the prevalence of sella turcica bridging and measure the size of the sella turcica in two well-defined groups of Caucasian individuals. In a multicentre retrospective study, 400 pre-treatment lateral cephalograms of adult patients (over 17 years of age) with a skeletal Class III (n = 250, 132 females and 118 males) or a skeletal Class I (n = 150, 94 females and 56 males) malocclusion were analysed. The morphology, length, depth, and diameter of the sella turcica were investigated. For statistical analysis, chi-square and t-tests were used. Skeletal Class III patients presented a significantly higher rate of sella turcica bridging, 16.8 per cent (P = 0.031), in comparison with skeletal Class I patients, whose rate was 9.4 per cent. No differences between females and males were detected for the length, depth, and diameter of the sella turcica. Bridging of the sella turcica could be seen radiographically in skeletal Class III subjects.

Artificial intelligence in orthodontics : Evaluation of a fully automated cephalometric analysis using a customized convolutional neural network.

PURPOSE: The aim of this investigation was to create an automated cephalometric X­ray analysis using a specialized artificial intelligence (AI) algorithm. We compared the accuracy of this analysis to the current gold standard (analyses performed by human experts) to evaluate precision and clinical application of such an approach in orthodontic routine. METHODS: For training of the network, 12 experienced examiners identified 18 landmarks on a total of 1792 cephalometric X­rays. To evaluate quality of the predictions of the AI, both AI and each examiner analyzed 12 commonly used orthodontic parameters on a basis of 50 cephalometric X­rays that were not part of the training data for the AI. Median values of the 12 examiners for each parameter were defined as humans' gold standard and compared to the AI's predictions. RESULTS: There were almost no statistically significant differences between humans' gold standard and the AI's predictions. Differences between the two analyses do not seem to be clinically relevant. CONCLUSIONS: We created an AI algorithm able to analyze unknown cephalometric X­rays at almost the same quality level as experienced human examiners (current gold standard). This study is one of the first to successfully enable implementation of AI into dentistry, in particular orthodontics, satisfying medical requirements.