Craniofacial Cephalometric Characteristics and Open Bite Deformity in Individuals with Amelogenesis Imperfecta-A Systematic Review and Meta-Analysis.

BACKGROUND: Individuals with amelogenesis imperfecta (AI) often present with malocclusions, especially a dental or skeletal anterior open bite (AOB). OBJECTIVES: To evaluate the craniofacial characteristics in individuals with AI. MATERIAL AND METHODS: A systematic literature search was conducted with the PubMed, Web of Science, Embase and Google Scholar databases to identify studies relating to the cephalometric characteristics of individuals with AI, without any language or publication date restrictions. The grey literature was searched using Google Scholar, Opengrey and Worldcat. Only studies with a suitable control group for comparison were included. Data extraction and a risk of bias assessment were carried out. A meta-analysis was performed using the random effects model for cephalometric variables that were evaluated in at least three studies. RESULTS: The initial literature search yielded 1857 articles. Following the removal of duplicates and a screening of the records, seven articles were included in the qualitative synthesis, representing a total of 242 individuals with AI. Four studies were included in the quantitative synthesis. The meta-analysis results showed that individuals with AI present a smaller SNB angle and larger ANB angle than those of control groups in the sagittal plane. In the vertical plane, those with AI present a smaller overbite and larger intermaxillary angle than those without AI. No statistically significant differences were found for the SNA angle when comparing the two groups. CONCLUSIONS: Individuals with AI seem to present with more vertical craniofacial growth, leading to an increased intermaxillary angle and decreased overbite. This possibly leads to a more retrognathic mandible with a larger ANB angle due to an anticipated posterior mandibular rotation.

Development of a surgical guide for minimally invasive corticotomies with a complete digital intraoral and laboratory workflow.

AIM: Surgically facilitated orthodontic treatment is increasingly being used, especially for adults, to facilitate tooth movements and reduce the duration of orthodontic treatment. The present article reports on an innovative, safe, and minimally invasive technique to perform flapless corticotomies using a dedicated surgical guide produced with a complete digital intraoral and laboratory workflow. MATERIALS AND METHODS: A 51-year-old man presented with maxillary and mandibular anterior crowding. He required rapid treatment with limited use of braces. Corticotomies were planned for both arches before the use of orthodontic appliances. The matching of the stereolithographic files obtained from the digital prints of the full arches and the cone beam computed tomography images allowed for the positioning of the cutting planes for corticisions. The guide was printed with a transparent, biocompatible, and photopolymerizable resin, and cold sterilized. Minimally invasive corticotomies were performed using a piezoelectric instrument. The orthodontic treatment started immediately after surgery. RESULTS: No adverse events were recorded during surgery. The piezoelectric instrument was guided accurately, and precise application of the corticisions prevented all the anatomical elements from being injured. The healing was uneventful and the patient experienced no pain. CONCLUSION: The present report shows that a surgical guide specifically and digitally produced for corticotomies allowed for the performance of a minimally invasive flapless technique and accurate piezosurgery. The use of such a guide was easy to implement, made the procedure safer, and reduced postoperative pain.

[Diagnosis and management of ankylosed permanent maxillary incisors: proposal for a decision tree]. / Diagnostic et gestion des incisives maxillaires ankylosées : proposition d'un arbre décisionnel.

INTRODUCTION: Ankylosis of a maxillary incisor involves evolutive resorption for which clinical management is difficult for both general practitioners and orthodontists. This anomaly can give rise to potentially major aesthetic, functional and occlusal defects. The ankylosed tooth will be lost, in the short or long term, depending on the bone remodeling. MATERIALS AND METHODS: The aim of this review was to determine the different therapeutic options known to date and allow the construction of several clinical decision support systems (summary tables and decision tree). RESULTS: The different techniques were classified in three categories: abstention, conservative treatments and surgical treatments. The therapeutic objectives, indications and potential complications were listed for each technique. The possible persistence of an ankylotic zone or the ability to move the tooth after treatment was also recorded. DISCUSSION: The therapeutic solution is decided on after a precise diagnosis in order to evaluate the extent of the resorption and its localization. The chosen treatment will be more or less stable, conservative, aesthetic and expensive, and will have varying success rates. The time component must be taken into account and an individualised diagnosis and treatment plan are necessary to select the most appropriate therapeutic option for patients.

[Contribution of 3D imaging using 3DNEO(®) software in surgical-orthodontic treatment of impacted teeth]. / Apport de la reconstruction tridimensionnelle à l'aide du logiciel 3DNEO(®) dans le traitement chirurgico-orthodontique des dents incluses.

OBJECTIVES: The aim of this investigation was to present and evaluate an original method of mini-invasive oral surgery and orthodontics based on 3D images from a computed tomography software (3DNEO(®), 3DNEOVISION). MATERIALS AND METHODS: Three patients with impacted teeth were examined and their data were analyzed with this software based on the "region growing" method. RESULTS: Several clinical interests emerge : locate and visualize precisely the relationships of the impacted tooth with the adjacent anatomical elements under the desired angle, associate/dissociate the different elements of the 3D scene, measure the distances, calculate the axes of traction, materialize the way of traction and the optimal point for bonding, prepare virtually the surgical exposure and orthodontic treatment plan. CONCLUSION: This 3D method might provide information for improved diagnosis and treatment plans in order to ultimately result in more successful treatment outcomes and better care for patients.

Tonic and phasic descending dopaminergic controls of nociceptive transmission in the medullary dorsal horn.

The transfer of nociceptive information at the level of dorsal horn is subject to extensive processing by both local segmental and supraspinal mechanisms, including descending dopaminergic controls, originating from the hypothalamic A11 nucleus. The inhibitory role of dopamine on evoked pain via activation of D2-like receptors at the level of the dorsal horn is well established. Here, by use of behavioral, electrophysiological, and anatomical techniques, we examined within the trigeminal sensory complex, first, whether descending dopaminergic controls also modulate pain behavior after an inflammatory insult, and second, under which physiological conditions these descending dopaminergic controls are actually recruited. We show that D2 receptors are mostly located within superficial medullary dorsal horn where trigeminal nociceptive fibers abut. Activating these D2-like receptors inhibits, whereas blocking them enhances, both formalin- and capsaicin-evoked pain behavior and C-fiber-evoked action potential firing of trigeminal wide dynamic range (WDR) neurons. Moreover, windup and diffuse noxious inhibitory controls (DNIC), 2 dynamic properties of C-fiber-evoked firing of WDR neurons, are inhibited by activating and blocking, respectively, these D2-like receptors. Altogether, our results are consistent with a tonic inhibition of the trigeminal nociceptive input by descending dopaminergic controls via activation of D2-like receptors at the level of superficial medullary dorsal horn. Such dopamine-dependent tonic inhibition of nociceptive information can be dynamically modulated by pain. This suggests that dysregulation of descending dopaminergic controls should translate in patients into diffuse, cephalic, and extracephalic pain symptoms--spontaneous pain, decreased pain thresholds, deficient DNIC, or some combination of these.

[Can orthodontic treatment generate temporomandibular disorders and pain? A review]. / Le traitement orthodontique peut-il générer des algies et/ou dysfonctionnements articulaires ou musculaires (ADAM) ? Une revue de littérature.

While considered for years to play the primary role in the etiology of temporo-mandibular joint disturbances (TMD), occlusal discrepancies are now considered to be just one causative factor among many. Recent studies, literature reviews or meta-analyses, and longitudinal studies with follow-up of children treated for many years all conclude that there is no risk of orthodontic treatment giving rise to episodes of temporo-mandibular disorders. The signs of TMD appearing during the course of orthodontic treatment should be considered in the context of the epidemiology of the disorder, which is characterized by a strong increase in its occurrence during adolescence. In conclusion, it should be stated that if orthodontic treatment can no longer be considered as one of the etiopathogenic factors in the TMD complex, there are no scientific arguments to justify the converse, that there are indications for orthodontic treatment whose sole goal would be the treatment of TMD.