Appropriateness of standard cephalometric norms for the assessment of dentofacial characteristics in patients with cleidocranial dysplasia

Objectives: Cleidocranial dysplasia (CCD) is a rare skeletal syndrome affecting craniofacial and dental development. As a consequence, conventional cephalometric landmarks may not be valid for CCD patients, and the appropriateness of norms used for the general population should be critically discussed. Methods: Five patients 9 to 22 year-old (three females, two males) with CCD were included. Lateral-cephalograms, orthopantomographies, and intra oral photos were retrospectively analysed. Lateral-cephalograms of fifty normal controls (ten for each CCD patient) matched for age and sex were selected from an online database. Cephalometric measurements of each CCD patients were compared with average values of matched controls using Wilcoxon signed-rank test for paired values (α = 0.05). Results: In CCD patients, a shortening of the cranial base was present (ΔSN = −17.1 mm, p = 0.043). Thus, the mandible (ΔSNPg =+9.5°, p = 0.043) and the maxilla (ΔSNA =+11.2°, p = 0.043) showed protrusion compared to the cranial base, despite a reduced maxillary (ΔCo-A = −15.1 mm, p = 0.043) and mandibular (ΔCo-Gn −15.2 mm, p = 0.080) length. The mandibular divergence was reduced (ΔSN/GoGn = −6.4°, p = 0.043), a negative overjet was present (ΔOverbite = −2.9 mm, p = 0.043), and the interincisal angle was increased (ΔInterincisalAngle =+13.7°, p = 0.043), mainly due to retro-inclination of lower incisors. Conclusions: Standard cephalometric norms for the assessment of horizontal jaw position may not be applicable to CCD patients because of a reduced anterior cranial base length compared to normal subjects. Vertical relationships may not be affected, and mandibular hypodivergency was confirmed.

Occlusal Splints and Exercise Performance: A Systematic Review of Current Evidence

The role of the dento-mandibular apparatus and, in particular, occlusion and jaw position, received increased attention during last years. In the present study, we aimed to systematically review, on the light of the new potential insights, the published literature covering the occlusal splint (OS) applications, and its impact on exercise performance. A structured search was carried out including MEDLINE®/PubMed and Scopus databases with additional integration from external sources, between March and June 2021. To meet the inclusion criteria, studies published in the English language, involving humans in vivo, published from 2000 to 2021 and that investigated the role of occlusal splints on athletes’ performance were selected. Starting from the 587 identified records, 17 items were finally included for the review. Four main aspects were considered and analyzed: (1) occlusal splint characteristics and occlusion experimental conditions, (2) jump performance, (3) maximal and explosive strength, and (4) exercise technique and biomechanics. The results of the systematic literature analysis depicted a wide heterogenicity in the experimental conditions and suggested the application of the OS as a way to improve athletes’ or individuals’ oral health, and as a potential tool to optimize marginal aspects of exercise performance.

TMJ MORPHOLOGICAL FEATURES OF DIFFERENT TYPES OF MALOCCLUSION CAUSING PATHOLOGICAL LOWER JAW POSITION ASYMMETRY

According to Russian researchers, the prevalence of temporomandibular joint dysfunction ranks third in the structure of dental morbidity among adults. In recent decades, the attention of clinicians to the problem of TMD has been growing rapidly due to the difficulties in the diagnosis and treatment of patients with malocclusion, complicated by joint pathology. The purpose of this article is to search for new knowledge that will improve quality of diagnosis of dysfunctional changes in the TMJ of patients with various malocclusion pathologies by identifying correlations between anatomical and morphological features of the joint and dentoalveolar anomalies. Understanding the trends in the development of characteristic morphofunctional disorders will make it easier for doctors to plan treatment for orthodontic patients and increase its effectiveness. Such patients require special attention from orthodontists. When writing this article, we have studied a lot of modern literature, as well as studies of foreign and Russian scientists who is involved in the treatment of dysfunction. However, we have not found the information that would show a direct relationship between anatomical and morphological features and malocclusion pathology, which was the purpose of our work. The article describes in detail the morphological and functional changes that occur at different stages TMD, the relationship between the shape of the glenoid fossa morphology process, included classification of the forms condyloid process described features of the development of bone structures of the TMJ depending on the type of pathological occlusion. Revealed statistics demonstrate the dependence of the frequency of dysfunction on the shape of the articular head and fossa. The analysis of computer tomograms of patients of the Department of Pediatric Dentistry and Orthodontics of the First Sechenov Moscow State Medical University allows us to conclude that the oval shape of the TMJ head and the rounded shape of the articular surface of the temporal bone can become a prerequisite for the development of dysfunctional changes. The results of our study will help orthodontists improve the quality of diagnostic measures and the effectiveness of treatment of patients with suspected TMD.

Comparative analysis of the effectiveness of the use of various orthodontic appliances in the correction of malocclusion of the II class in children and adolescents

This study is dedicated to a comparative analysis of effectiveness of using orthodontic appliances when treating class II malocclusion in children and adolescents. It was shown that treatment with the Invisalign system with a change of the lower jaw position is the most effective method for correcting class II malocclusion in growing patients. Using Invisalign aligners showed not only the best efficacy according to teleroentgenograms. but also made the treatment process comfortable for patients at all its stages. Moreover, higher level of compliance was demonstrated with treatment using the Invisalign system compared to the Twin-block appliance.

Accelerometry-Enhanced Magnetic Sensor for Intra-Oral Continuous Jaw Motion Tracking

Currently available jaw motion tracking methods require large accessories mounted on a patient and are utilized in controlled environments, for short-time examinations only. In some cases, especially in the evaluation of bruxism, a non-restrictive, 24-h jaw tracking method is needed. Bruxism oriented, electromyography (EMG)-based devices and sensor-enhanced occlusal splints are able to continuously detect masticatory activity but are uninformative in regards to movement trajectories and kinematics. This study explores a possibility to use a permanent magnet and a 3-axial magnetometer to track the mandible’s spatial position in relation to the maxilla. An algorithm for determining the sensor’s coordinates from magnetic field values was developed, and it was verified via analytical and finite element modeling and by using a 3D positioning system. Coordinates of the cubic test trajectory (a = 10 mm) were determined with root-mean-square error (RMSE) of 0.328±0.005 mm. Possibility for teeth impact detection by accelerometry was verified. Test on a 6 degrees-of-freedom (DOF), hexapod-based jaw motion simulator moving at natural speed confirmed the system’s ability to simultaneously detect jaw position and the impacts of teeth. Small size of MEMS sensors is suitable for a wearable intra-oral system that could allow visualization of continuous jaw movement in 3D models and could enable new research on parafunctional jaw activities.

Effects of the lower jaw position on athletic performance of elite athletes

When an athlete wears a mouthguard, the position of the lower jaw is changed by virtue of the teeth being unable to occlude. Little research is available in in this area, which have indicated both positive impact and no positive impact.ObjectivesThis study aims to explore the influence of the lower jaw position on athletic performance in elite athletes.MethodsA repeated measures study compared two lower jaw positions, the athlete’s normal (habitual) bite and the lower jaw position when the muscles of mastication are at physiological rest (physiological rest bite). 15 athletes completed a medicine ball putt (upper body power), vertical jump (lower body power), sit and reach (composite hamstring flexibility), passive knee flexion (hamstring muscle length) and star excursion balance (stability and balance) tests in each condition.ResultsPaired t-tests showed the physiological rest bite had significant (p<0.05) positive effect on athletic performance for each test. On average the physiological rest bite provided an increase of lower body power (5.8%), upper body power (10%), hamstring flexibility (14%) and balance and stability (4.8%) compared to the habitual bite.ConclusionThis study provides evidence of the need for further research to confirm if the lower jaw position can be optimised for athletic performance in athletes.

Evaluating the Reliability of CBCT Airway Measurement: A Pilot Study

Background Many studies have analyzed treatment effects on the airway using CBCT scans of the airway as evidence, but no study to date has been published that validates a repeatable protocol for acquiring CBCT airway measurements. Our objective is to evaluate a protocol for standardization of CBCT volume acquisition of the airway. Methods Ten participants (6 females and 4 males, median age 30.03 ± 3.53 years) were radiographed 2 times each (T1 and T2, the average time between T1-T2 was 15.8 ± 3.65 days), for a total of 20 CBCT scans. The participants’ head position was placed so that the Frankfort horizontal plane was parallel to the floor. Participants were given specific instructions regarding jaw position, tongue position, swallowing and breathing before each of the 2 scans. Minimum cross-sectional area (MCA) and total volume (TV) of each airway scan were measured between the distal most point of the hard palate (superior limit) and the superior most point of the epiglottis (inferior limit). T1 and T2 were compared to determine the repeatability of our proposed protocol for CBCT airway acquisition. Results There was no statistically significant difference between T1 and T2 measurements for TV and MCA. The average difference between T1 and T2 MCA and TV measurements for each participant was 34.18 ± 30.55 mm2 and 2.51 ± 2.05 cc, respectively. Conclusions Using our proposed standardization protocol, the measurements of MCA and TV of the airway were reliable to within 34.18 ± 30.55 mm2 and 2.51 ± 2.05 cc, respectively.

Perawatan ortodontik menggunakan protraction arch pada kasus prognati mandibula dengan anterior crossbite dan central diastemaOrthodontic treatment using protraction arch in prognathic mandibular with anterior crossbite and central diastema

Pendahuluan: Profil wajah cekung dan anterior crossbite merupakan gambaran morfologi wajah khas pada maloklusi kelas III dan diperkuat oleh hasil analisis sefalometri lateral. Terkadang maloklusi kelas III disertai dengan ukuran gigi yang lebih kecil dari normal sehingga menyebabkan terbentuknya gigi bercelah. Gambaran tersebut tentu semakin mengurangi estetika wajah pasien maloklusi kelas III. Tujuan laporan kasus ini adalah menyampaikan perawatan maloklusi kelas III yang memiliki malposisi anterior crossbite dan central diastema. Laporan kasus: Seorang pasien wanita usia 32 tahun, berprofesi sebagai jurnalis datang ke RSKGM FKG UI dengan keluhan gigi atas bercelah, gigi bawah maju serta merasa senyum kurang menarik. Perawatan ortodontik dilakukan menggunakan protraction arch dengan tujuan menghilangkan anterior crossbite serta menutup gigi bercelah. Hasil perawatan selama 18 bulan, anterior crossbite dan celah gigi sudah terkoreksi, tercapai overjet positif, gigi insisif atas memberi dukungan bagi bibir sehingga profil wajah menjadi lurus dan penampilan menjadi lebih baik. Simpulan: Perawatan ortodontik menggunakan protraction arch pada kasus prognati mandibula dengan anterior crossbite dan central diastema memberikan hasil yang cukup baik karena diskrepansi dentoalveolar masih tergolong ringan, tidak terdapat diskrepansi transversal dan didukung oleh pola pertumbuhan wajah dalam rentang normal atau cenderung ke arah horizontal dan dapat memperbaiki fungsi pengunyahan dan estetika.Kata kunci: Anterior crossbite, maloklusi kelas III, central diastema, protraction arch. ABSTRACT Introduction: Concave profile and anterior crossbite are common facial deformity appear in skeletal class III, besides the lateral cephalometric analysis. Frequently, small-sized teeth appear in class III malocclusion cases which causes spacing. Spaced teeth caused unpleasing appearance. This case report described conventional orthodontic treatment for skeletal class III with anterior crossbite and central diastema. Case report: A 32 years-old-female journalist came to the Dental Hospital of the Faculty of Dentistry University of Indonesia complaining about her central diastema in the upper arch, forwardly lower jaw position and unpleasant smile. The orthodontic treatment using protraction arch aimed at correcting anterior crossbite and eliminating spaced teeth. An 18-months treatment successfully fixed the anterior crossbite and spaced teeth. Ideal overjet was achieved, upper teeth camouflaged the mid-face deficiency; therefore, create a balanced facial profile. Conclusion: Orthodontic treatment using arch protraction in the case of mandibular prognosis with anterior crossbite and central diastema gives good results because dentoalveolar discrepancy is still relatively mild. There is no transversal discrepancy and supported by facial growth patterns in the normal range, or tends to be horizontal, and proven to be able to improve the mastication and aesthetical function.Keywords: Anterior crossbite, malocclusion class III, central diastema, protraction arch.