Upper Airway Changes and OSAS Risk in Patients after Mandibular Setback Surgery to Treat III Class Skeletal Malocclusion.

INTRODUCTION: Mandibular setback surgery (MSS) is one of the treatment options to resolve mandibular prognathism in patients suffering from skeletal class III malocclusion, which cannot be treated with simple orthodontic treatment. The mandibular setback surgical operation can involve changes in the pharyngeal morphology, resulting in a narrowing of the posterior airway space (PAS). This aspect is associated with an increase in airflow resistance, which increases the risk of developing snoring or obstructive sleep apnea syndrome (OSAS). The aim of this study is to evaluate the medium- and long-term effects of mandibular setback surgery on the upper airways and its possible association with OSAS in patients suffering from class III skeletal malocclusion. MATERIAL AND METHODS: A total of 12 patients (5 males and 7 females) were enrolled in this study. The statistical tests highlighted a significant change in the PAS and BMI values in relation to T0, before surgery (PAS: 12.7 SD: 1.2; BMI: 21.7 SD: 1.2), and T1, after surgery (PAS: 10.3 SD: 0.6, p < 0.01; BMI: 23.8 SD: 1.2, p < 0.05). Sample size was calculated to detect an effect size of 0.9, with statistical power set at 0.8 and the significance level set at 0.05. RESULTS: No statistically significant correlation was found between the extent of mandibular setback, PAS and BMI change. CONCLUSION: This study confirms the effects of mandibular setback surgery on the upper airways, reporting a statistically significant PAS reduction in the medium- and long-term follow-up. On the other hand, no direct correlation was identified with OSAS risk, at least for the small mandibular setback (<8 mm), despite the statistically significant increase in BMI.

Craniofacial Evolution: From Australopithecus to Modern Man.

ABSTRACT: Through the analysis and evaluation of the size and morphology of teeth and jaws, it is possible to differentiate animal species including man, allowing the theory of human evolution to be established. Hominin evolution is characterized by two main features, the transition to bipedality and the increase in brain size. This had an important impact on the structure and function of the hominine skull. The aim of this article is to retrace the evolutionary steps that led to Homo Sapiens, the direct ancestor of modern man. For the following paper, scientific articles from Medline (PubMed) and Google Scholar database were used from 1929 to 2018. Hominid evolution is characterized by 2 main features, the transition to bipedality and the increase in brain size. The fossils found show that both trends have had an important impact on the morphology and function of the skull of modern man. The basicranial flexion and growth have led to the facial modifications typical of modern man. The main changes concern the mandibular evolution with the appearance of the chin, the formation of the Spee curve due to mandibular arch growth, the formation of the temporomandibular joint as a hinge joint with a sliding socket as the condyle and a better function and maximum efficiency than its predecessors thanks to respect for the divine proportions of the face. Knowledge of ontogenesis allows us to know the factors underlying human form and function, analyze and evaluate them in the clinical context.

The Effect of Different Condition of Pulpal Pressure on Microtensile Bond Strength of Several Dentin Bonding Agents on Deep and Superficial Dentin.

The objective of this study was to examine the effect of different conditions of simulated hydrostatic pulpal pressure on the µTBS of HEMA-based and HEMA-free dentin bonding agents (DBAs). The influence of dentin location (deep and superficial) on µTBS was also evaluated. Flat coronal dentin surfaces of extracted human molars were prepared. Three groups of resin-bonded specimens were exposed to different pulpal pressures. Pulpal pressure was maintained for 20 min for each group. A flowable resin composite was used for coronal build-up. The bonded teeth were sectioned and, after 24 h of water storage, stressed to failure using the microtensile tester (µTBS). Failed samples were analyzed by SEM inspection. HEMA-based DBAs were much more sensitive to pulpal pressure conditions than non-HEMA-containing DBAs. Pulpal pressure had a greater influence in deep dentin. The HEMA-free DBA was insensitive to the presence or absence of pulpal pressure condition. SEM inspection confirmed a relationship between the presence of voids inside the HEMA-based DBAs layer and the lower µTBS results. HEMA-based DBAs are more sensitive to pulpal pressure conditions than HEMA-free DBAs. Interestingly, HEMA-free DBA showed a greater number of water droplets at resin-dentin interface in all tested conditions.

The Application of the Divine Proportion for the Construction of the Visualized Treatment Objective in Craniofacial Surgery.

ABSTRACT: Aesthetics and function of maxillofacial district are closely related and could interfere with patient psychological conditions. The aim of this paper is to describe and to analyze the procedures necessary for a proper surgical visualized treatment objective (VTO) realization through the use of the tracing on lateral head film, applying the divine proportion (or golden ratio) in certain steps. The method described is easy to realize, cheap and help both orthodontist and maxillo-facial surgeon to communicate each other and to the patients.For the following article, digital research and handheld research on surgical VTO planning for patients with skeletal or dentoalveolar severe deformities managed by surgeons and orthodontics were used. The research included articles in English published on dental and maxillofacial surgery journals.The surgical VTO consists of a "previsualization" of the objectives in order to make the desired changes for the individual patient. The result can thus be visualized and pre-evaluated rather than just imagined by the mind's eye. To simplify the procedure, the surgical VTO has been divided into 11 steps. The accurate model of the surgical result is fundamental in the treatment of dentofacial deformities. These predictions are intended to guide the treatment towards the desired result, to give the patient a reasonable preview of the outcome, and to ensure communication between the orthodontist and the surgeon.This technique proves to be effective in planning surgical treatment and it allows the clinician to view changes before, during, and after orthognathic surgery. The skeletal, dental, and aesthetic complete cephalometric evaluation is the key point to the long-term success of the results.

Occlusal Plane and Skeletal Changes After Cervical Headgear Treatment With and Without Lower Utility Arch in Class II Growing Patients.

ABSTRACT: The purpose of this study was to investigate skeletal and dental changes affecting occlusal plane inclination after cervical headgear treatment with and without lower utility arch. In order to distinguish the orthodontic changes from natural growth a control group was employed.The sample of this study consisted by 20 Class II subjects (10 males, 10 females; mean age 8.54) treated by using cervical headgear, 19 class II children (19 males, 9 females; mean age 8.64) treated with cervical headgear and utility arch, and 21 Class II patients (11 males, 10 females; mean age 8.41) who had no therapy.Lateral head films were studied for all the patients before treatment (T1) and after therapy (T2) for all the treated groups and at the beginning and at the end of observational period for the control group; cephalometric analysis was carried out in order to seek for the modifications between time points and between groups.Means and standard deviation have been analyzed for all the groups. In order to compare the modification between the time points within the same group the ANOVA test was applied. The ANOVA test was used to compare the mean differences (T2-T1) of 3 groups.The study revealed that there were significant changes in occlusal plane inclination after the different treatment modalities employed instead control group. The treatment with cervical headgear and utility arch is more effective than cervical headgear alone in lowering occlusal plane posteriorly when it is compared with controls.

Changes in canine inclination after rapid and slow maxillary expansion compared to untreated controls.

OBJECTS: Palatally displaced canines (PDC) might represent condition causing several clinical problems, such as roots resorption and malocclusion, and can develop palatal canine impaction. Some interceptive treatments such as rapid maxillary expansion were suggested in order to foster maxillary canine eruption. Among expansion protocols, no data are available about differences between rapid and slow maxillary expansion on maxillary canine eruption. The aim of this study was therefore to evaluate α-angle changes in palatally displaced canines using rapid and slow maxillary expansion compared to untreated control patients. SETTING AND SAMPLE POPULATION: The final sample comprised 19 patients treated with rapid maxillary expansion (RME group), 17 treated with slow maxillary expansion (SME group) and 22 control patients (Control group). MATERIALS AND METHODS: α-angle was measured on panoramic films to detect canine inclination at the beginning, and at the end of maxillary expansion treatment or observation, time and changes over time were compared. RESULTS: In the comparisons among groups, RME group was the only group showing a decrease in α-angle measurements that was statistically significant also when compared to the other groups, except for the left side when compared to SME group. CONCLUSION: RME treatment significantly and positively affected canine position when compared to SME treatment and control group.

Dental occlusion and sport performance.

INTRODUCTION: In recent years, interest has been given to the relationship between dental occlusion and athletes' performance. A correct occlusion allows for a correct position of the mandible in space and could be reached by wearing a splint made by a dentist. Achieving this condition appears to be an advantage for all athletes, and especially for those who have TMJ dysfunction. The purpose of the study was to investigate the hypothesis and common belief that correcting the occlusion or the use of a splint could improve an athlete's performance. EVIDENCE ACQUISITION: A search on electronic database has been performed and obtained 141 results; then, following the application of the inclusion criteria, only 11 articles were selected. EVIDENCE SYNTHESIS: A good occlusion seems to be an advantage for the athletes. CONCLUSIONS: The use of an occlusal splint should be evaluated in different sports, because the occlusion and TMJ conditions of the athletes are different and the efforts in which they are subjected could not be generalized because the sports have various rules and characteristics that involves the stomatognathic system differently.

Changes of Occlusal Plane in Growing Patients With Increased Vertical Dimension During Class II Correction by Using Cervical Headgear.

This retrospective research aimed to highlight the changes of occlusal plane in Class II hyperdivergent subjects that received cervical headgear treatment and compared them to untreated controls in order to evaluate the occlusal changes that might be connected to a potential mandibular rotation.The sample of this investigation was represented by 20 hyperdivergent Class II subjects (10 males, 10 females; mean age 8.54) corrected by using cervical headgear (treated group) and 21 Class II patients (11 males, 10 females; mean age 8.41) hyperdivergent who had no therapy (control group). Lateral head films were studied for all the patients before treatment (T1) and after therapy (T2) for both groups; cephalometric analysis was used in order to seek the modifications between time points and between groups.Means and standard deviation have been computed for both groups. In order to confront the modification between the time points within the same group the Wilcoxon test was applied. The Mann-Whitney U test was applied to confront the dissimilarities between groups at T2.As a result of the Class II correction by using the cervical headgear treatment the occlusal plane was lowered and flattened compared to T1 and to the control group; the upper molars showed extrusion to the palatal plane, there was a significant forward rotation of mandible and the vertical dimension was not significantly modified. Downward and backward displacement of the upper jaw occurred.

Correlations between Malocclusion and Postural Anomalies in Children with Mixed Dentition.

The aim of this study was to investigate the possible relationship between malocclusion and body posture anomalies. The original sample involved 127 children (45 males and 82 females) with mixed dentition. Clinical examination of oral cavity was performed by an orthodontist, who recorded molar and canine relationship, cross-bite, lower middle-line deviation, and centric relation (CR) considering mono or bilateral contacts in CR. Orthopedic examination of the body posture was clinically carried out by an orthopedist who detected anomalies such as scoliosis, false scoliosis or paramorphism, kyphosis and lordosis. Of the 127 subjects of the sample, 18 children were orthopedically normal, 80 patients had false scoliosis, 22 scoliosis and 7 showed kyphosis. In our study, we don't consider the 7 patients with kyphosis for the exiguity of the sample; so, our analysis was performed on 120 children (42 males and 78 females). The results obtained revealed that the cross-bite was more frequent when scoliosis became worse. We also found that the relationship between left cross-bite and contralateral side of deviation of the curve of the spine in subjects with scoliosis is statistically significant (p = 0.002). Furthermore, the relationship between lower midline and contralateral side of deviation of the curve of the spine in patients with false scoliosis is statistically significant (p = 0.003). In conclusion, it seems that posture anomalies are correlated to cross-bite and mandible abnormal position.

TMJ Dysfunctions Systemic Implications and Postural Assessments: A Review of Recent Literature.

Cases of correlations between posture and the temporomandibular joint have long been reported in the literature. In particular, occlusal anomalies, and therefore malocclusion, could have negative implications for the spine. The objective of this study was to review the literature and bring to light any correlations between temporomandibular joints (TMJ) and posturology. The literature search was conducted in the PubMed and Embase scientific search engines with the aim of obtaining the most possible results in the initial search, the number of results initially obtained was 263. Subsequently, the inclusion and exclusion criteria were reduced first to 83 and subsequently to manual analysis of the articles, those included remained only 11. The results show a correlation between anomalies of the TMJ and dysfunctions of the vertebral column. Not all the articles considered are in agreement with each other regarding epidemiological data, but surely this study can represent an important starting point for a much more careful evaluation of the dental patient and at the same time for the request for counseling by a dentist in case of postural abnormalities.

Elastics Selector Gauge as Orthodontics Device Applied to Inter-Maxillary Traction during Malocclusion Correction.

Elastics are the simplest device that can be used during a class correction in orthodontics, and despite the simplicity of a latex band, they are very effective and powerful. The resultant inter-maxillary force affects not only the teeth, but even the mandibular position, and consequently the temporomandibular joints (TMJ). The purpose of our work is to simplify the use of elastics, and to reduce the amount of inventory for orthodontists, because there is a lot of merceology available on the market, and different ways of using the elastics. The use of elastics in clinical practice is based on the force extension values, which are given by the manufacturer for the different sizes of the elastics, generally when they are stretched to three times their lumen size. Various configurations allow for the correction of different malocclusions. We propose a new classification and a new device, the elastic selector gauge, in order to allow clinicians to quickly and easily choose the right elastic in all conditions.

Upper First Premolar Positioning Evaluation for the Stability of the Dental Occlusion: Anatomical Considerations.

The present study aimed to find the proper distorotation of the upper first premolar to achieve the therapeutic ideal advocated for the stability of the human occlusion. Normal teeth were analyzed and occlusal photocopies of upper arch were made to perform the 2 measurements. The first parameter was the angle formed by the perpendicular to the wire through the buccal cusp and a line connecting the buccal and the lingual cusps of the upper first premolar. The second one was the angle from the buccal line and the sagittal plane of the model. The amount of distorotation was calculated and a method to bond the bracket was suggested.

Facial Bone Reconstruction Using both Marine or Non-Marine Bone Substitutes: Evaluation of Current Outcomes in a Systematic Literature Review.

The aim of the present investigation was to systematically analyse the literature on the facial bone reconstruction defect using marine collagen or not and to evaluate a predictable treatment for their clinical management. The revision has been performed by searched MEDLINE and EMBASE databases from 2007 to 2017. Clinical trials and animal in vitro studies that had reported the application of bone substitutes or not for bone reconstruction defect and using marine collagen or other bone substitute material were recorded following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The first selection involved 1201 citations. After screening and evaluation of suitability, 39 articles were added at the revision process. Numerous discrepancies among the papers about bone defects morphology, surgical protocols, and selection of biomaterials were found. All selected manuscripts considered the final clinical success after the facial bone reconstruction applying bone substitutes. However, the scientific evidence regarding the vantage of the appliance of a biomaterial versus autologous bone still remains debated. Marine collagen seems to favor the dimensional stability of the graft and it could be an excellent carrier for growth factors.

Oxidative Stress Evaluation in Patients Treated with Orthodontic Self-ligating Multibracket Appliances: An in Vivo Case-Control Study.

OBJECTIVE: Oxidative stress is a pathologic event induced by a prevalence of oxidant agents on the antioxidant ones, with a consequent alteration of oxide-reducing balance. INTRODUCTION: Freeradicals produce damages both in cellular and extra-cellular components; phospholipid membranes, proteins, mitochondrial and nuclear DNA, are the target of the oxidative stress, that can finally cause cellular death due to apoptosis. MATERIALS & METHODS: Orthodontic appliances such as brackets, wires, resins and soldering have some components that can be considered as potential allergen, carcinogenic, cytotoxic and gene mutation factors. The primary aim of this research is to evaluate oxidative stress in the saliva of patients treated with multibracket self-ligating vestibular orthodontic appliances; the secondary purpose is to investigate the influence of orthodontic multibracket therapy on oral hygiene and the consequent effect on oxidative stress. Salivary specimens has been collected in a sample of 23 patients were enrolled (12 Female, 11 Male) between 12 and 16 years of age (mean age 14.2). For each patient has been collected a salivary specimen at the following time points; before orthodontic bonding (T1), five weeks (T2) and ten weeks (T3) after orthodontic appliance bonding. RESULTS: Samples has been analysed with a photometer due to SAT Test (Salivary Antioxidant Test). Data obtained show a mean of 2971 mEq/l of anti-oxidant agents before orthodontic treatment, and after five weeks from the bonding the mean was decreased to 2909 mEq/l, instead at ten weeks was increased to 3332 mEq/l. Repeated measures ANOVA did not reveal statistically significant differences between the time points (P = 0.1697). The study did not reveal any correlation between the level of dental hygiene and that of oxidative stress (Pearson Correlation Coefficient R = 0). CONCLUSION: Orthodontic treatment with multibrackets vestibular metallic appliance seems to be not able to affect oxidative stress during the first ten weeks of therapy.

FEM and Von Mises Analysis on Prosthetic Crowns Structural Elements: Evaluation of Different Applied Materials.

The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.

Cephalometric changes in growing patients with increased vertical dimension treated with cervical headgear.

PURPOSE: The aim of the present study was to investigate the cephalometric changes in patients with increased vertical dimension after treatment with cervical headgear compared to controls. METHODS: The sample of the present retrospective study consisted of 20 Class II patients (10 males, 10 females; mean age 8.54 ± 1.15 years) with increased vertical dimension treated with cervical headgear (treatment group) and 21 Class II patients (11 males, 10 females; mean age 8.41 ± 1.15 years) with increased vertical dimension who underwent no treatment (control group). Cephalograms were available for each subject at baseline (T1) and after treatment/observation time (T2) for both groups and cephalometric analysis allowed for evaluation of changes between time points and between groups. RESULTS: Regarding facial axis, N-ANS/ANS-Me, and overbite, there were no negatively significant changes in the treated group showing no significant worsening in the vertical dimension. Regarding facial angle, there was a significant increase in the treated group between the time points and when compared to the control group, showing counterclockwise rotation of the mandible in the treated group. CONCLUSIONS: The vertical dimension was not significantly altered after cervical headgear treatment although the anterior facial height was higher at the beginning of treatment. There was significant counterclockwise rotation of the mandible, and clockwise rotation and distal displacement of the maxilla after treatment.

Early predictive variables for upper canine impaction as derived from posteroanterior cephalograms.

The aim of this study was to identify a model of cephalometric variables for early diagnosis of the displacement of upper permanent canine and early prognosis of upper canine impaction. Postero-anterior (PA) cephalograms of 43 subjects (22 males and 21 females) with different types of malocclusions in the mixed dentition were analyzed at the time of first observation (mean age 8 years and 5 +/- 9 months). All subjects were reevaluated at the mean age of 14.3 years. At this time the sample was divided into 2 groups according to the presence of canine impaction: nonimpacted canine group (31 subjects) and impacted canine group (12 subjects). Stepwise variable selection on the measurements at the time of first observation identified 2 predictive variables on PA cephalograms, ie, the distance between the center of the canine crown and the midsagittal plane (A3cc to Cg Vertical) and the distance between the jugal process and the midsagittal plane (J to Cg Vertical). The closer the canine crowns to the midsagittal plane and the larger the posterior portion of the hemimaxilla, the higher the probability of canine impaction. Discriminant analysis assigned a classification power of 95.3% to the predictive model. On the basis of the equation generated by the multivariate statistical method, impaction of the maxillary canine for each new case at the age of 8 years can be predicted. The importance of PA cephalograms in the diagnosis and prediction of canine eruption disturbances is emphasized.