Optimization of Loading Condition for Maxillary Molar Intrusion with Midpalatal Miniscrews by Using Finite Element Analysis

An anterior open bite is one of the most difficult malocclusions in orthodontic treatment. For such malocclusion, orthodontic miniscrew insertion into both buccal and palatal alveolar regions has been indicated for molar intrusion, but it involves a risk of tooth root injury. To solve the problem, a midpalatal miniscrew-attached extension arm (MMEA) is adopted. However, this method causes palatal tipping of the molar because intrusive loads were applied only from the palatal side. Currently, a transpalatal arch is added to avoi0d tipping movement, but it induces the patient’s discomfort. Hence, the objective of this study was to evaluate the loading conditions for maxillary molar intrusion without tipping movement, only by MMEA through finite element (FE) analysis. FE models of maxillary right first molar and surrounding tissues were created. Three hook positions of MMEA were set at 6.0 mm perpendicular intervals in the occluso-apical direction along the mucosal contour. An intrusive unit load was applied from the palatal side of the molar, and various counter loads were applied from the buccal side. An optimal counter load for molar intrusion without palatal tipping was observed in each hook position. In conclusion, an ideal maxillary molar intrusion can be achieved only by MMEA with an optimal counter load.

A realidade da morfologia endodôntica nas raízes vestibulares fusionadas dos segundos molares superiores

There is doubts about the endodontic morphology of the buccal region of the upper second molar when it showed the buccal roots fusioned. This paper was performed to determine the number of root canal when the tooth presents the buccal roots fusioned. Fifthy nine upper second molars that presented the buccal roots fusioned, extracted for different reasons without atention to age, sex or race, was used. After the cross-cuting at the anatomic neck the root canal was opened by endodontic instruments and painted with black ink, for best visualisation. Finaly the roots were sliced with burs in the cervico-apical direction. We found four groups of teeth based in the number of root canal and/or apex foramen.

A more complex basal complex: novel components mapped to the Toxoplasma gondii cytokinesis machinery portray an expanded hierarchy of its assembly and function

The basal complex (BC) of Toxoplasma gondii has an essential role in cell division but details on the mechanism are lacking. To promote insights in this process, reciprocal proximity based biotinylation was used to map the basal complex proteome. An assembled protein map was interrogated by spatiotemporal characterization of critical components as well as functionally by disrupting the expression of the components. Spatially, this revealed four proteins sub-complexes with distinct sub-structural BC localization. Temporally, several patterns were differentiated based on their first appearance and/or disappearance from the BC corresponding with different steps in BC development (initiation, expansion, constriction, maturation). We also identified a protein pre-ceding BC formation (BCC0) laid out in a 5-fold symmetry. This symmetry marks the apical annuli and site of alveolar suture formation. From here, it was determined that the apical cap is assembled in the apical direction, whereas the rest of the IMC expands in the basal direction, inspiring a new bi-directional daughter budding process. Furthermore, we discovered BCC4, an essential protein exclusively localizing to the BC during cell division. Although depletion of BCC4 did not prevent BC formation, it led to BC fragmentation at the mid-point of cell division. Based on these data, a model is presented wherein BCC4 and MORN1 stabilize each other and form a rubber band that implies an essential role for the BC in preventing the fraying of the basal end of the assembling daughter cytoskeleton scaffolds. Furthermore, one new component of the Myosin J and Centrin2 cluster was BCC1, a hypothetical protein whose depletion prevents the non-essential last step of BC constriction. Overall, the BC is a highly dynamic, multi-functional structure that is critical to the hierarchical assembly of the daughter parasites.

Evaluation of the Efficacy of EASYDO ACTIVATOR Irrigation Technique in Intracanal Smear Layer and Debris Removal from Mature Permanent Teeth

EASYDO ACTIVATOR (EA) is a continuously vibrational device for root canals irrigation, but its cleaning effectiveness has not been evaluated by any published reports. We were aiming to evaluate whether EA results in a greater intracanal smear layer and debris removal than conventional needle irrigation (NI) and passive ultrasonic irrigation (PUI). Twenty-seven single-rooted teeth were used. Canals were sized to R30 and irrigated with 3% sodium hypochlorite. Species were divided into three groups: Group 1: NI; Group 2: PUI; Group 3: EA. Canal walls were subjected to scanning electron microscopy. NI- and PUI-group canal cleanliness decreased from the coronal to apical direction (P < 0.05), except for EA group in the apical third. PUI removed more smear layer from the coronal and middle thirds than EA and NI (P < 0.05). PUI and EA were superior to NI regarding debris removal (P < 0.05). The smear layer and debris from the coronal and middle thirds were effectively removed with EA and PUI. More effective removal occurred from the apical third for EA compared with PUI (P < 0.05). Both methods removed smear layer and debris better than NI, providing a theoretical basis for the clinical application of EA.

Application of an active oxygen (blue®m) with free connective graft technique for root coverage – a case report

Gingival recession occurs due to the migration of the gingiva in the apical direction, leading to compromising local aesthetics and root hypersensitivity. Connective tissue graft is the gold standard treatment in these cases improving both functional and aesthetics aspects.The purpose of this case is to report root coverage using the free connective tissue graftingtechnique (CTG) associated with topical application of active oxygen oral gel and mouthwash (blue®m). A 27-year-old female sought care with the main complaint of root hypersensitivity and the presence of gingival recession in the anterior region of the mandible. Clinical examination revealed the presence of type 1 gingival recession in the left mandibular central incisor. The treatment of choice was a modified graft (free connective graft). The graft and recipient bed received applications of blue®m oral gel. The patient was instructed to use blue®m mouthwash and blue®m oral gel after the surgery for 10 days. At 60 days, the patient showed satisfactory healing in the area of the free CTG, with gain of keratinized tissue and partial covering of the gingival recession. Free CTG with the support of the gel and the mouthwash with active oxygen release makes the technique viable, preventing graft necrosis and achieving root coverage and keratinized tissue.

Uncomplicated crown fracture management

Background: Trauma-related injuries of the maxillofacial region occur more often these days and dentists are facing this condition frequently in their regular practice life. Traumatic dental injuries affects the same region with different frequencies in different age groups. It should be noted that upper central incisors are mostly traumatized by injuries compare to the other incisors. The maxillary central incisors were about 72%, while premolars, canine, mandibular incisors, the upper lateral incisors injury rate is up to 8%. A strong impact most often affects the crown and a weak and dull impact on the root apical direction and may result in avulsion of tooth and root fracture. Dental injuries caused by trauma have been an emergency condition, treatment options depend on the severity of injuries and clinical condition of the tooth at that moment. Combination treatment for a traumatic fracture of the tooth includes fixation of the tooth, the performance of surgical manipulation, determination of the need for endodontic treatment, restoration, and orthodontic consultations. Problem: In our case patient has an uncomplicated crown fracture. Solution: Direct composite restoration. Update Dent. Coll. j: 2021; 11 (1): 20-22

The use of CBCT to asses buccal bone thickness overlying mandibular anterior teeth

Objectives: the aim of this study was to determine the relationship between gingival width with respect to the underlying bone thickness in mandibular anterior sextant.Material and metods: 40 CBCT were included. Buccal bone thickness was measured at 3, 4.5, 6, 8 mm apical to the cement–enamel junction (CEJ). In addition, the apicoincisal gingival width was measured.Results: at 3 mm from the cement-enamel junction, the buccal bone plate was in 69.4% of cases, the average thickness of buccal bone plate for all teeth was less than 1.0 mm, at the level of 4.5 and 6 mm in 30,6% of cases “Absence” of the external cortical plate, the thickness of which gradually increased in the apical direction (8 mm). When the efficiency is less than 2 mm, the effect of the absence of the external cortical plate according to CBCT data was more often observed.Conclusion: in this study revealed the relationship between the gingival width and the anatomical features of the buccal bone plate.

X-ray tеsting of structures of keratinized gum and external cortical plate in the field of intact frontal teeth on the upper jaw

Objectives. Сomparison of radiological parameters of the keratinized gum and the external cortical plate in the area of the front teeth on the upper jaw. Material and methods. Сlinical examination of 50 patients aged 18 to 60 years was carried out in order to perform the work. These patients underwent 3D computed tomography which allowed to study the thickness of the keratinized gums in the dental area 1.1, 1.2, 1.3, 2.1, 2.2, 2.3. Results. The results of the research revealed a similar trend at each level of measurement for the central and lateral incisors. The average values of the gum thickness decreased in the direction of the tooth crown. The thickness of the outer cortical plate had the lowest values in all studied teeth at the level of the alveolar crest apex and gradually increased in the apical direction. The thinnest external cortical plate and gums were revealed in canines. Conclusion. The performed study showed that thickness of the gum is directly related to the thickness of the cortical plate. In percentage terms the gum thickness is 132 9.5% of the thickness of the cortical plate.

Synthesis, molecular and crystal structure of a heterometallic Cu(II)–Ge(IV) complex with 2-hydroxy-1,3-diaminopropane-N,N,N',N'-tetracetic acid and 2,2'-bipyridine

A novel synthesis method was developed which allows isolating a new coordination compound with polymeric structure {[Ge2(OH)2(3-hpdta)2Cu2(bipy)2]2Н2О}n (І) (where hpdta5– – anion of 2-hydroxy-1,3-diaminopropane-N,N,N',N'-tetracetic acid, bipy – 2,2'-bipyridine) in solid state. Elemental composition, features of thermal decomposition, and molecular and crystalline structure of the synthesized complex were established. According to the data of X-ray diffraction analysis, complex I is a coordination polymer. The polymer chain is formed due to the bridging function of deprotonated ligands hpdta5–, which are simultaneously coordinated with germanium and copper atoms. Ge(1) and Ge(2) atoms have the same coordination environment and distorted octahedral polyhedrons. The coordination polyhedron of Ge(2) is formed due to the coordination of oxygen atoms of two carboxylate and one deprotonated hydroxyl groups of one ligand hpdta5–_1 and carboxylate group of the second ligand hpdta5–_2 in the equatorial direction. In the axial direction, the Ge atom coordinates with the nitrogen atom of the ligand hpdta5–_1 and the hydroxo-ligand. The coordination polyhedrons of Cu(1) and Cu(2) are square pyramids, in which molecules of bipy are coordinated with Cu2+ by two nitrogen atoms. One nitrogen atom and one oxygen atom of the carboxylate group of the hpdta5– ligand are located in the base of a square pyramid. In the apical direction, copper coordinates with deprotonated hydroxyl group of the same hpdta5– ligand. A –-stacking interaction was detected in the crystal between the -systems of bipyridines of two neighboring coordination polymer chains directed along the crystallographic axis a that form double chains with the cavities of 623.04 Å3.

A Suggested Approach of Managing Excessive Maxillary Gingival Display in Terminal Dentition

The aim of this paper is to report a suggested approach for the management of excessive maxillary gingival display with terminal dentition. A segmental osteotomy of the maxillary process was performed, and the latter used as grafting material for lateral sinus augmentation that was performed simultaneously. Following the graft maturation period, implants were inserted and rehabilitated with a fixed dentogingival prosthesis. Consequently, the mandible was prosthetically restored following the new occlusal plane dictated by the rehabilitated maxilla. Clinically, the procedure showed a drastic improvement in the patient’s appearance, eliminating the excessive gingival display. Radiologically, it led to a vertical translation of the maxillary process level in an apical direction. Nevertheless, the resected process used as grafting material was noticed to have a suboptimal behavior as long as it showed increased intrasinusal resorption, barely sufficient for a regular implant accommodation. The described therapy concept seems to be a plausible approach when it comes to manage excessive maxillary gingival displays in edentulous patients or those presenting a terminal dentition. However, at the time of sinus augmentation, authors recommend to graft a mixture of resected maxillary process and a bone substitute material, in order to get more stable results.