Dentofacial Morphology Research Articles

Assessment and Correlation of Dentofacial Morphology and Lateral Cephalometric Parameters with Smile Characteristics in Lateral and Oblique View: Short Study

Aim: This study evaluated and established correlations between the dentofacial morphology of Angle’s Cl II and Cl I malocclusions, lateral cephalometric parameters, and smile characteristics assessed through lateral and oblique smile views. Methods: A sample of 20 random patients (>15 years, with prior orthodontic treatment) were selected for this study according to their arrival at the department. The selected individuals were grouped according to Angle’s classification of malocclusion, i.e., Angle’s Cl I and Angle’s Cl II malocclusion. Pretreatment records were taken for the study, including lateral cephalogram and extra-oral smile photographs (one lateral smiling and one oblique smiling). In the lateral cephalogram, skeletal, dental, and facial parameters were recorded, and in lateral and oblique smile views, lateral smile index, commissure angle, and incisal displays were recorded. Results: The results showed no significant difference in most cephalometric parameters except for UFH/LFH, which was higher in Angle’s Cl II. Additionally, smile analysis revealed significant differences between the two groups. In addition, significant differences were found in the incisal display, which was greater in Angle’s Cl II malocclusion. Conclusion: Smile characteristics differ between Angle Cl I and Cl II malocclusions. There was a significant difference in lateral and oblique smile parameters when Angle’s malocclusions classified as Cl I and Cl II were evaluated. Lateral and oblique smile index decreased from Cl I to Cl II malocclusion, whereas lateral and oblique smile commissure angle and lateral smile incisor display increased in Cl II malocclusion.

Long-term follow-up of corrective jaw surgery including distraction osteogenesis in 32 patients with juvenile idiopathic arthritis

Dentofacial deformity following juvenile idiopathic arthritis (JIA) with temporomandibular joint (TMJ) involvement is associated with functional, aesthetic, and psychosocial impairment. Corrective surgical treatment includes combinations of orthognathic surgeries (OS). The aims of this study were to assess orofacial symptoms, functional and aesthetic status, and stability after OS including mandibular distraction osteogenesis (MDO). A prospective study was conducted of 32 patients with JIA of the TMJ and dentofacial deformities who underwent MDO as the only surgery or in combination with bilateral sagittal split osteotomy, Le Fort I, and/or genioplastybetween 2003 and 2018. Data from clinical examinations and cephalograms performed pre- and postoperative and at long-term (mean 4 years) were analysed. Patients experienced unchanged orofacial symptoms (all P > 0.05), short-term TMJ functional impairment (all P < 0.001), and long-term morphological improvements in SNB angle (P < 0.001), anterior facial height (P < 0.001), mandibular length (P = 0.049), overjet (P < 0.001 and P = 0.005), and posterior facial symmetry (P = 0.046). MDO as the only surgery or with secondary adjunctive OS improved dentofacial morphology in terms of mandibular advancement, anterior facial height, posterior facial symmetry, and incisal relationships without long-term deterioration in TMJ function or orofacial symptoms.

Effects of orthopedic treatment (distraction splint) on dentofacial deformities in patients with juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) frequently affects the temporomandibular joint (TMJ), which can alter mandibular growth and development and result in dentofacial deformities. To assess the outcomes of orthopedic treatment with distraction splint (DS) in patients with JIA-related dentofacial deformity. The retrospective study involved 30 patients with JIA and unilateral TMJ involvement, another study group of 20 patients with JIA and bilateral TMJ involvement, and a control group of 18 non-JIA orthodontic patients with Class II and III malocclusions. The inclusion criteria were DS treatment and cone-beam computed tomography (CBCT) scans before (T0) and 2 years after treatment (T1). Dentofacial morphology and deformity were evaluated based on a validated three-dimensional CBCT-based morphometric analysis. Intergroup differences in outcome measures were compared at T0 and T1, and intragroup changes between T0 and T1 were assessed using the Kruskal-Wallis test. Initial evaluations at T0 revealed significant differences between the unilateral and bilateral JIA groups and the control group for three out of eight dentofacial deformity variables: inter-side difference in total posterior mandibular height, mandibular axial angle, and posterior/anterior face height (ratio). At follow-up (T1), significant inter-group differences were only observed in total posterior mandibular height indicating that intergroup differences were less pronounced after splint treatment. Assessing inter-group changes between T0 and T1 showed that all parameters remained constant except posterior/anterior face height ratio, which significantly decreased between T0 and T1. The findings demonstrate the potential of DS treatment for patients with JIA and unilateral or bilateral TMJ involvement to generally support normal dentofacial growth or at least limit further deterioration of dentofacial deformities.

Changes in Dento-Facial Morphology Induced by Wind Instruments, in Professional Musicians and Physical Exercises That Can Prevent or Improve Them-A Systematic Review.

The aim of this study is to highlight the changes that occur regarding dento-facial morphology, facial, and masticatory muscles in musicians who play wind instruments. Anatomical and functional changes may occur after the long-term use of each type of wind instrument. We considered studies of the impact of playing the wind instrument on the masticatory muscle activity and the resulting modifications. Both children and adults can be affected by playing wind instruments in regard to tooth positioning and facial morphology. These changes relate to the type of wind instruments, the type of vowels and tones used by instrumentalists. There most valuable breathing techniques have been identified that improve the redistribution of pressure, with a minimizing effect on the morphological changes in the oral cavity and cephalic extremity, implicitly on the masticatory functional disorders. In addition to these beneficial effects on the stomatognathic system, these breathing techniques favorably increase lung capacity. Furthermore, a series of toning exercises for neck muscles-which are actively involved and overworked by wind instrument-playing artists-was identified. The study concludes that less experienced instrumentalists demonstrate increased facial muscle engagement, possibly leading to excessive strain, while experienced instrumentalists exhibit more optimized patterns of muscle activity. The novelty of this research lies in its interdisciplinary approach to understanding the influence of wind instruments on dento-facial morphology, addressing preventive and corrective measures to mitigate undesirable outcomes.

The effect of myotonic dystrophy type 1 on temporomandibular joint and dentofacial morphology: A CBCT analysis.

Myotonic dystrophy type 1 (DM1) is a neuromuscular multisystem disease. Early involvement of facial muscles may produce an extra load on the temporomandibular joint (TMJ) in DM1. This study aimed to investigate the morphological analyses of the bone components of temporomandibular joint (TMJ), and dentofacial morphology in myotonic dystrophy type 1 (DM1) patients by cone-beam computed tomography (CBCT). Sixty-six individuals (33 DM1, and 33 healthy subjects) age ranging from 20 to 69 were included in the study. Clinical examinations of the patients' TMJ regions and evaluation of dentofacial morphology (maxillary deficiency, open-bite, deep palate and cross-bite) were performed. Dental occlusion was determined based on Angle's classification. CBCT images were evaluated regarding mandibular condyle morphology (convex, angled, flat and round) and osseous changes observed in the condyle (normal, osteophyte, erosion, flattening, sclerosis). DM1-specific morphological and bony TMJ alterations were determined. DM1 patients showed a high prevalence of morphological and osseous TMJ changes, and statistically significant skeletal alterations. The analysis of CBCT scans indicated the prevalent condylar shape among patients with DM1 was flat, the main osseous abnormality was flattening, there was a tendency towards skeletal Class II and a posterior cross-bite was frequently detected in DM1 patients. There was no statistically significant difference between the genders on the parameters evaluated in both groups. Adult patients with DM1 presented a high frequency of crossbite, tendency to skeletal Class II and morphological osseous alterations of TMJ. The analysis of the morphological condylar alterations in patients with DM1 may be beneficial in the diagnosis of TMJ disorders. This study reveals DM1-specific morphological and osseous TMJ alterations to provide an appropriate orthodontic/orthognathic treatment planning to patients.

Dentoskeletal and soft tissue changes after treatment of crowding with premolar extractions: a 50-year follow-up.

The long-term effects on dentofacial morphology of interceptive treatment with premolar extractions, in the absence of subsequent orthodontic treatment, have not been fully explored. The aim was to investigate the effects of premolar extractions (without subsequent orthodontic treatment) on the dentoskeletal and soft tissue profile of patients aged between 12 and 62 years with Class I malocclusion with severe crowding, as compared to untreated controls. The Extraction group (N = 30 with Class I crowding malocclusion) had their first premolars removed in early adolescence without subsequent orthodontic treatment. The Control group included 30 untreated subjects with Class I normal occlusion. Cephalograms were taken at 12 (T1), 15 (T2), 30 (T3), and 62 (T4) years of age. A superimposition-based cephalometric method was used to assess the dentoskeletal and soft tissue changes. There were no significant differences between the Extraction and Control groups in terms of skeletal sagittal relation, incisor inclination, and protrusion, or most of the soft tissue parameters throughout the observation period. However, significant differences were observed between the groups with respect to the vertical relations in T2-T3, such that the Extraction group showed more-pronounced decreases in the ML/NSL, ML/NL, and Gonial angles and more-pronounced increases in facial heights. Treatment for subjects with Class I malocclusion with severe crowding by the extraction of four premolars, without subsequent orthodontic treatment, does not affect the long-term dentoskeletal and soft tissue profile, as compared to an untreated Control group. The degree of crowding, rather than changes in dentofacial morphology, is crucial in deciding on extraction therapy.

Restricted upper airway dimensions in patients with dentofacial deformity from juvenile idiopathic arthritis

BackgroundThis retrospective, cross-sectional study aimed to assess the pharyngeal airway dimensions of patients with juvenile idiopathic arthritis (JIA) and moderate/severe JIA-related dentofacial deformity (mandibular retrognathia/micrognathia), and compare the results with JIA patients with a normal mandibular appearance and a group of non-JIA patients.MethodsSeventy-eight patients were retrospectively included in a 1:1:1 manner as specified below. All patients had previously been treated at the Section of Orthodontics, Aarhus University, Denmark. All had a pretreatment cone beam computed tomography (CBCT). Group 1 (JIA+); 26 JIA patients with severe arthritis-related dentofacial deformity and mandibular retrognathia/micrognathia. Group 2 (JIA-); 26 JIA patients with normal mandibular morphology/position. Group 3 (Controls); 26 non-JIA subjects. Dentofacial morphology and upper airway dimensions, excluding the nasal cavity, were assessed in a validated three-dimensional (3D) fashion. Assessment of dentofacial deformity comprised six morphometric measures. Assessment of airway dimensions comprised nine measures.ResultsFive morphometric measures of dentofacial deformity were significantly deviating in the JIA+ group compared with the JIA- and control groups: Posterior mandibular height, anterior facial height, mandibular inclination, mandibular occlusal inclination, and mandibular sagittal position. Five of the airway measurements showed significant inter-group differences: JIA+ had a significantly smaller nasopharyngeal airway dimension (ad2-PNS), a smaller velopharyngeal volume, a smaller minimal cross-sectional area and a smaller minimal hydraulic diameter than JIA- and controls. No significant differences in upper airway dimensions were seen between JIA- and controls.ConclusionJIA patients with severe arthritis-related dentofacial deformity and mandibular micrognathia had significantly restricted upper airway dimensions compared with JIA patients without dentofacial deformity and controls. The restrictions of upper airway dimension seen in the JIA+ group herein were previously associated with sleep-disordered breathing in the non-JIA background population. Further studies are needed to elucidate the role of dentofacial deformity and restricted airways in the development of sleep-disordered breathing in JIA.

Digital Diagnostics and Orthodontic Practice

Orthodontic diagnosis is mostly dependent on the patient's dental and medical history, clinical examination, study models, and cephalometric radiographs, which are the most important tool for orthodontic diagnosis since they are used to identify abnormalities in the dental and craniofacial skeleton. An ever-increasing array of digital technologies is transforming dental therapy in a variety of ways. Digital dental models, the use of digital dental set-ups to simulate the eventual result of orthodontic therapy, and three-dimensional imaging of the dentofacial region are among the technological advances that provided new choices for patient documentation. Digital records allow for a three-dimensional evaluation of a patient's dentofacial morphology, which is critical for orthodontic diagnostics and treatment planning. Additionally, these digital records increase record storage, access, conservation, communication with patients, and duplication possibilities. The purpose of this research is to review the available information about the digital diagnostics and orthodontic practice. Since the introduction of threedimensional techniques, which have found different uses in orthodontics as well as oral and maxillofacial surgery, imaging technology in the dentistry sector has emerged as one of the most significant parts of identifying and managing oral problems. With the growing availability of cone-beam computed tomography, three-dimensional depiction of dentition, maxillofacial skeleton, and soft tissues in all phases of interactions is now possible. In orthodontics, digital scanning can be utilized for a variety of purposes. However, more research is needed to generate evidence-based results regarding the utilization of digital diagnostics in orthodontics.

Challenging malocclusion in orthodontics

The term open bite is referred as no contact between anterior or posterior teeth. The complexity of open bite is attributed to a combination of skeletal, dental and habitual factors. Etiology of open bite can be attributed to genetics, anatomic and environmental factors. However, the tendency toward relapse after conventional or surgical orthodontic treatment has been indicated. Therefore, open bite is considered one of the most challenging dentofacial deformities to treat. The aim of this article is to emphasize on early etiological diagnosis, dentofacial morphology and classification, which are essential for the successful outcome of the technical intervention. Failure of tongue posture adaptation subsequent to orthodontic and/or surgical treatment might be the primary reason for relapse of open bite. Prolonged retention with fixed or removable retainers is advisable and necessary in most cases of open bite treatment. The treatment of open bite remains a tough challenge to the clinician; careful diagnosis and timely intervention with proper treatment modalities and appliance selection will improve the treatment outcomes and long-term stability.

A logistic analysis prediction model of TMJ condylar erosion in patients with TMJ arthralgia

BackgroundIn terms of diagnostic and therapeutic management, clinicians should adequately address the frequent aspects of temporomandibular joint (TMJ) osteoarthritis (OA) associated with disk displacement. Condylar erosion (CE) is considered an inflammatory subset of OA and is regarded as a sign of progressive OA changes potentially contributing to changes in dentofacial morphology or limited mandibular growth. The purpose of this study was to establish a risk prediction model of CE by a multivariate logistic regression analysis to predict the individual risk of CE in TMJ arthralgia. It was hypothesized that there was a closer association between CE and magnetic resonance imaging (MRI) indicators.MethodsThis retrospective paired-design study enrolled 124 consecutive TMJ pain patients and analyzed the clinical and TMJ-related MRI data in predicting CE. TMJ pain patients were categorized according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I protocol. Each patient underwent MRI examination of both TMJs, 1–7 days following clinical examination.ResultsIn the univariate analysis analyses, 9 influencing factors were related to CE, of which the following 4 as predictors determined the binary multivariate logistic regression model: missing posterior teeth (odds ratio [OR] = 1.42; P = 0.018), RDC/TMD of arthralgia coexistant with disk displacement without reduction with limited opening (DDwoR/wLO) (OR = 3.30, P = 0.007), MRI finding of disk displacement without reduction (OR = 10.96, P < 0.001), and MRI finding of bone marrow edema (OR = 11.97, P < 0.001). The model had statistical significance (chi-square = 148.239, Nagelkerke R square = 0.612, P < 0.001). Out of the TMJs, 83.9% were correctly predicted to be CE cases or Non-CE cases with a sensitivity of 81.4% and a specificity of 85.2%. The area under the receiver operating characteristic curve was 0.916.ConclusionThe established prediction model using the risk factors of TMJ arthralgia may be useful for predicting the risk of CE. The data suggest MRI indicators as dominant factors in the definition of CE. Further research is needed to improve the model, and confirm the validity and reliability of the model.

Comparative Analysis of the Differences in Dentofacial Morphology According to the Tongue and Lip Pressure.

The aim of this study was to evaluate the effects of the tongue and lip pressure on dentofacial morphology. The subjects comprised 194 patients with malocclusion. Anterior and posterior tongue elevation and lip pressures were evaluated using the Iowa Oral Performance Instrument (IOPI) device. The lateral cephalograms of each subject were traced and digitized to perform the analysis. Statistical analysis was used to investigate the relationship between perioral muscle force and the cephalometric variables. Anterior and posterior tongue pressure was both higher in males than in females. No sex difference in lip pressure was observed. The group with a low posterior tongue pressure showed a short ramus height, short posterior facial height, and clockwise-rotated mandible. On the other hand, lip pressure had a significant influence on maxillary incisor angulation. Skeletal pattern was not found to be significantly related with lip pressure. The anterior tongue pressure appeared as a mixed pattern of the two results. Tongue pressure was related to skeletal measurements, such as short posterior facial height, and lip pressure was related to the angulation of the anterior teeth. This study suggests that there may be differences in dentofacial morphology according to the differences in perioral muscle force.

Quick septoplasty in children: Long-term effects on nasal breathing and dentofacial morphology. A prospective cephalometric study

ObjectiveMany authors have investigated the most appropriate surgical approach to the deviated septum in childhood, considering the obligate mouth-breathing habit a possible cause of malocclusion and disharmonious development of the facial skeleton in growing kids. Nevertheless, controversies still remain about the long-term functional/esthetic results of such procedures, mainly due to the duration of the follow-up and possible confounding factors. Methods111 Caucasian children (age range: 6–13 years) were submitted to a personal “Quick” septoplasty surgical technique between 2005 and 2010. Preoperative otorhinolaryngological examination using flexible nasal endoscopy, anterior active rhinomanometry (AAR), Nasal Obstruction Septoplasty Effectiveness (NOSE) questionnaire, and dentofacial evaluation (including cephalometry) were performed. Postoperative AAR, NOSE questionnaire and cephalometric assessment were carried out in all patients at the age of 18 years. Informed consent was obtained from children's parents as appropriate. ResultsNo surgical complication was recorded. Among our patients, a significant (p <0.001) improvement of nasal breathing resistances at AAR and NOSE questionnaire scores was found after surgery. A significant improvement in cephalometric/dental parameters (gonial angle values, anterior facial height, prevalence of class I occlusion, maxillary intermolar width, and cross-bite frequency) was noticed after the follow-up with respect to preoperative conditions. ConclusionThe “Quick” septoplasty technique described is a practical and conservative procedure with a low complication rate that offers long-term favourable results for the correction of nasal septum deviations in children. Nasal-breathing restoration may favor a physiological and harmonious development of craniofacial and dental structures in offspring.

A study of dentofacial morphology in yemeni adults with normal occlusions a cross sectional prospective study

OBJECTIVE:The purpose of this study was to describe the dentofacial morphology of Yemeni adults.MATERIALS AND METHODS:The lateral cephalograms of 100 Yemeni adults (50 males, 50 females) were included in the study. All subjects were born to Yemeni parents and grandparents. They all had Class I occlusions with minor or no crowding, well-aligned upper and lower dental arches, good facial harmony, all teeth present except third molars, and no history of orthodontic therapy or maxillofacial surgery. Five angular and eighteen linear measurements were analyzed to determine the soft tissue, skeletal, and dental features. The differences for each measurement between Yemeni males and females were calculated using unpaired t–tests.RESULTS:Significant sexual and racial differences were found for three linear parameters in the skeletal analysis, one angle, and four linear dental measurements, and for all soft tissue linear parameters. Yemeni adults showed a tendency to a facial pattern of Class II, convex profile, reduced prominence of chin, increased lower facial height, and a clockwise rotation of the mandibular plane angle.CONCLUSION:Yemeni adults have different dentofacial parameters when compared to other racial standards, and these differences could aid in diagnosis and treatment planning.

Comparison of dentofacial morphology between parents of children with and without craniofacial anomalies using cephalogram imaging.

To compare cephalometric parameters in parents of children with bilateral cleft lip and palate (BCLP) and parents of children without any craniofacial anomaly. A sample of 100 sets of parents were segregated into two groups of 50 parents each. The two groups included parents of children with BCLP and the parents of children with no craniofacial anomaly. Lateral cephalograms and postero-anterior (PA) cephalograms were examined for 100 parents of both the BCLP and control group, respectively. Tracings were scrutinized for 34 linear and angular parameters of dentocraniofacial skeleton. Data were analysed using unpaired Student's t-test. Result: Evaluated lateral cephalograms revealed 15 significant parameters in parents of children with BCLP including a significant increase in Ptm-S, maxillary length, SNA, articular angle and gonial angle. A significant decrease was noted in SN length, cranial base flexion, mandibular length, mandibular body length, total facial height, upper facial height, posterior facial height, Y-axis length and soft tissue total anterior facial height. Upon evaluation of PA cephalograms, four significant parameters were found in parents of children with BCLP. Cranial width, bizygomatic width, maxillary width and lateral interorbital width were significantly decreased in the parents of children with BCLP. Distinct dentocraniofacial morphological features have been found in parents of children with BCLP. Evaluation of these features might be the key to predicting the occurrence of clefts in their children and also planning for future linkage analysis studies amongst them.

Comparing Clinical and Radiological Manifestations of Adolescent Idiopathic Condylar Resorption and Juvenile Idiopathic Arthritis in the Temporomandibular Joint

This cross-sectional study compared orofacial manifestations at the time of diagnosis in 2 temporomandibular joint (TMJ) conditions: adolescent idiopathic condylar resorption (ICR) and TMJ involvement from juvenile idiopathic arthritis (JIA). This retrospective study included 19 JIAs, 19 ICRs, and 19 control patients, all treated at the Section of Orthodontics, Aarhus University Craniofacial Clinic, Denmark. From patient files, we retrieved radiological data from cone-beam computed tomographies along with information on symptoms and orofacial function at the time of diagnosis. Validated methodologies were used to evaluate TMJ and dentofacial morphology. We found no statistically significant intergroup differences in severity of deformation of TMJ structures (TMJ deformity) between JIA and ICR patients. However, the ICR group showed significantly greater signs of dentofacial deformity on 4 outcome variables: mandibular inclination, posterior/anterior lower face height ratio, mandibular sagittal position, and mandibular occlusal plane inclination. Significant intergroup differences in clinical presentation were seen in 5 of 20 variables. Thus, the JIA group reported significantly more symptoms of TMJ pain, TMJ morning stiffness, and TMJ pain on palpation during the clinical examination, whereas the ICR group reported significantly more TMJ clicking during function and had a higher proportion of patients with anterior open bite. Cone-beam computed tomography examination showed a similar degree of TMJ deformity in ICR and JIA patients at the time of diagnosis. ICR patients presented with a significantly higher degree of dentofacial deformity than JIA patients and healthy controls, which relates to the timing of the diagnosis. Arthralgia, TMJ morning stiffness, and TMJ palpitation pain were more common in JIA patients, whereas TMJ clicking during function and anterior open bites were more common in ICR patients.

The relationship between dentofacial morphology and smile characteristics in lateral and oblique views

Background/purposeThe purposes of this study were to develop smile measurements for lateral and oblique view photographs to help in orthodontic analysis and treatment planning, to quantitatively evaluate the relationship between smile esthetics and different types of malocclusion using lateral and oblique view photographs, to identify the cephalometric factors affecting smile measurements. Materials and methodsPatients who came to orthodontic department of a university hospital from 2014 to 2017 and met the inclusion criteria were included and divided into three groups according to Angle's classification. Thirteen variables were measured for cephalometric analysis. Twenty-one variables were developed and measured on pretreatment photographs for lateral and oblique smile analysis. ANOVA and Scheffe post hoc test were used to compare cephalometric and smile variables among three groups. Multiple linear regression analysis was performed to identify cephalometric factors affecting smile measurements. ResultsThree-hundred and ninety patients (287 females, 103 males) with mean age of 24.5 ± 7.6 years reached the criteria. All cephalometric variables differed significantly among three groups. Except for maxillary teeth exposure number, visible maxillary width, and lip thickness ratio, all smile variables differed significantly. Smile characteristics had significant correlation with some cephalometric measurements. ConclusionSmile patterns on the lateral and oblique view photographs can be affected by different types of malocclusion. Therefore, we suggest to include lateral and oblique smile view photographs in the data collection for orthodontic treatment planning.

Craniofacial characteristics of Syrian adolescents with Class II division 1 malocclusion: a retrospective study

BackgroundMalocclusion characteristics vary across different ethnic groups and populations. Limited data are available regarding the characteristics of Syrian adolescents with Class II division 1 (Class II-1) malocclusion, and the recent inflow of Syrian refugees and immigrants into Europe and many areas worldwide demonstrate the need for updated studies to discover the craniofacial characteristics of these new immigrants.ObjectivesThe present compound cephalometric and tooth-size study sought to assess the dentofacial morphology, upper-airway dimensions, and tooth-size characteristics of Syrian adolescents with Class II-1 malocclusion and compare the results with established Syrian population norms.Materials and MethodsThe study sample consisted of 43 Syrian patients including 24 females and 19 males with Class II-1 malocclusion (age: 14.3 (±1.5) years, mean (±SD)). Cephalometric radiographs and orthodontic casts were analyzed using special orthodontic software (OnyxCeph3™) and a universal digital caliper, respectively. Statistics were calculated using the SPSS software.ResultsIn Syrian adolescents with Class II-1 malocclusion, the position of the mandible relative to the nasion perpendicular (mean (95% confidence interval)) was −11.01 (−12.45, −9.57) mm. Facial axis angle showed a negative value: −6.25 (−7.65, −4.85) degrees. An obtuse nasolabial angle was observed: 104.05 (101.77, 106.33) degrees. The average width of the upper pharynx was 11.50 (10.53, 12.47) mm; however, there was no prevalence of an upper-pharyngeal width of 5 mm or less. The average value of the anterior tooth-size ratio was 80.69 (79.85, 81.53) percent. In total, 39.5% of the investigated subjects had anterior ratios outside two standard deviations from Bolton’s norm, while 25.6% of the investigated subjects had anterior ratios outside two standard deviations from Syrian population norm.ConclusionsIn this study, the inter-maxillary discrepancy of Class II-1 Syrian adolescents was a consequence of their hyperdivergent facial pattern. The observed small pharyngeal widths were not clinically significant, while the anterior tooth-size discrepancy might be clinically relevant.

Dentofacial biometry as a discriminant factor in the identification of remote Amazon indigenous populations

This study aimed to examine the role of dentofacial morphology in discriminating semi-isolated indigenous groups. These populations present a similar pattern of dietary habits. Studies in human genetics have reported a large intertribal genetic distance and low intratribal variation. This study was conducted following the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Face dimensions were measured through facial photogrammetry, and dental arches and tooth size were evaluated using plaster models. A total of 98 subjects in the permanent dentition and belonging to 4 indigenous groups were analyzed: Arara-Iriri (n=20), Arara-Laranjal (n=33), Assurini (n=25), and Xicrin-Kayapó (n=20). The random and systematic errors were verified using the Dahlberg formula and the intraclass correlation coefficient (ICC), respectively. In order to evaluate the discrimination of the variables to identify the indigenous groups, a discriminant analysis was performed (P<0.05). A small causal error (Dahlberg, 0.13-1.81) and excellent replicability (ICC, 0.75-0.99) for face dimensions as well as for models (Dahlberg, 0.10-0.68; ICC, 0.94-0.99) were observed. The discriminant analysis allowed the identification of 4 populations by facial and dental arch dimensions and tooth size. Dentofacial biometry revealed an accuracy of 98% for females and 100% for males, which confirms a high intragroup homogeneity and considerable intergroup heterogeneity for dentofacial features. Biometric measurements of the human face added with tooth size and dental arch dimensions are very useful to identify remote indigenous populations with high accuracy. Supported by previous studies in human genetics, these findings reinforce the role of genetic variation in the determination of dentofacial features.

Differences in dentofacial morphology in children with sleep disordered breathing are detected with routine orthodontic records

BackgroundResidual snoring in children with obstructive sleep disordered breathing (SDB) may continue post-adenotonsillectomy. This study aims to identify baseline dentofacial differences in children with SDB using routine orthodontic records that might aid effective early intervention for the upper airway to prevent continued obstruction. MethodsChildren (6–16 years) with clinically diagnosed SDB from a paediatric Otolaryngology Clinic who required adenotonsillectomy were participants (n = 10). The control group (n = 9) comprised healthy non-snoring children from the community. Baseline overnight polysomnography (PSG), standardised frontal and right profile photographs and alginate impressions were taken of all children. Facial width, length, depth, convexity and mandibular position were measured from the photographs. The occlusion, arch width, arch depth, maxillary arch form, palatal height and volume were recorded from digitised dental models. Inter-group differences were compared. ResultsSDB patients had a significantly increased lower face height, maxillo-mandibular angle (1.73°; 95% CI 0.45–3.0) and a narrower maxillary arch in the upper posterior region. There was a trend towards a decreased palatal volume, increased posterior crossbite and Class II molar relationship. ConclusionDentofacial phenotypic differences between children with SDB and controls can be detected using facial photographs and dental models. Increased awareness of these features may help to identify children who to continue to snore post adenotonsillectomy.

Relationship between dentofacial morphology and mandibular movement from rest position to maximum intercuspation in Class II division 1 malocclusion patients

BACKGROUND: The objective of this study was to determine the relationship between dentofacial morphology and mandibular movement from rest position to maximum intercuspation in Class II division 1 malocclusion patients. MATERIALS AND METHODS: The sample comprised of 45 patients who were 10–14 years old and had Class II division 1 malocclusions. Eighteen cephalometric variables were evaluated to determine the dentofacial morphology using lateral cephalograms. Mandibular movements were recorded from mandibular rest position to maximum intercuspation using mandibular kinesiography. Spearman's correlation coefficient was used to analyze the relationships between mandibular movement and other dentofacial variables. RESULTS: Mandibular movement in the anteroposterior dimension was significantly negatively correlated with the curve of Spee (COS) (r = −0.45) and freeway space (r = −0.44) and positively correlated with the sella-nasion-mandibular plane (SN-MP) angle (r = 0.47) and the Frankfort-mandibular plane angle (FMA) angle (r = 0.44). Two types of mandibular movement in the anteroposterior dimension were observed. Twenty-six of 45 patients (57.8%) exhibited posterior mandibular movement from rest position to maximum intercuspation (backward group) and 19 subjects (42.2%) presented anterior movement (forward group). COS and freeway space were greater in the backward group. The SN-MP and FMA angles were higher in the forward group. CONCLUSIONS: COS, freeway space, and mandibular plane angle may relate to mandibular movement from rest position to maximum intercuspation in Class II division 1 malocclusion. Patients with deep COS combined with a large freeway space and smaller mandibular plane angle tend to present posterior mandibular movement from rest position to maximum intercuspation.