Search Results (9)

Background and Objectives: The occlusal–temporomandibular disorder (TMD) relation is a contentious issue in dentistry to date. This scoping review’s purpose was to map the existing literature on occlusal abnormalities and their potential role in the development and progression of TMD. Materials and Methods: A search in PubMed, Scopus, Cochrane Library, Embase, Lippincott, Medknow, and ClinicalKey was conducted. Articles researching the relationship between TMD and occlusion have been selected. A narrative data synthesis was conducted to chart and summarize the main findings from the included studies. Results: A total of 29 articles were included in this review. These studies confirm that angle class II and angle class III malocclusions, deep bite, and crossbite have a high prevalence of symptoms of TMD, including mandibular deviation, arthritic pain, and tenderness of the muscles. Malocclusion, edentulous spaces, and a reduced vertical dimension of occlusion (VDO) also contribute to the severity of TMD, most prominently in older adults. TMD is also seen with high prevalence in females, with a female-to-male ratio of 2:1 to 20:1, according to studies. Bruxism, premature occlusal contacts, and occlusal interferences also contribute towards symptoms of TMD, in agreement with multiple facets of the disorder. Conclusions: Occlusal abnormalities have a significant association with TMD, but causality cannot be established with most observational studies. This review emphasizes the need for early occlusal examination and intervention to reduce TMD risk. Full article

Background: Unilateral condylar hyperplasia (UCH) is characterized by slow progression and enlargement of the condyle, accompanied by elongation of the mandibular body, resulting in facial asymmetry, occlusal disharmony, and joint dysfunction. This condition can be defined as “active” or “inactive”: the active form is characterized by continuous growth and dynamic histologic changes, whereas the inactive form indicates that the growth process has stabilized. Since there are few microscopic studies on the inactive form, this study aims to investigate the histological features and expression of key proteins and bone markers in patients diagnosed with inactive UCH. Methods: A total of 15 biopsies from patients aged 28 to 36 years were examined by light microscopy and immunofluorescence for collagen I and II, metalloproteinases 2 (MMP-2) and 9 (MMP-9), receptor activator of nuclear factor- kappa B (RANK), and osteocalcin. Results: Our findings indicate that during inactive UCH, the ongoing process is not entirely stopped, with moderate expression of collagen, metalloproteinases, RANK, and osteocalcin, although no cartilage islands are detectable. Conclusions: The present study shows that even if these features are moderate when compared to active UCH and without cartilage islands, inactive UCH could be characterized by borderline features that could represent an important trigger-point to possible reactivation, or they could represent a long slow progression that is not “self-limited”. Full article

Scientific studies have shown that dysfunctional problems associated with dysmorphisms are the base of malocclusion. The position of the mouth and the head is a component of the general postural arrangement, so any head misalignment creates disharmonies and tensions among the neck muscles. Elastodontics is a treatment based on the use of removable elastomeric devices. These functional appliances are made of elastomeric material, acting tridimensionally on a neuromuscular system with orthopaedic and dental effects. Bioactivators have a vestibular and lingual flange with a free central area that permits them to position teeth without constraints. The flanges are linked by an occlusal plane that maintains the two skeletal bases and teeth in first-class normocclusion with propulsive and retropulsive effects on the maxilla and mandible. Elastomeric devices are generally well tolerated by patients requiring simple collaboration and management. This review aim is to describe the indications and limits of orthodontic therapy with elastomeric devices to provide an overview of elastodontics. Full article

Skeletal class III malocclusion with severe skeletal disharmonies and arch discrepancies is usually treated via the conventional orthodontic-surgical approach. However, when associated with tooth impaction and periodontal risks, the treatment is more challenging and complex. The esthetic, occlusal, and periodontal stability of the treatment outcome is more difficult to obtain. The 16-year-old female patient in this case was diagnosed with dental and skeletal Class III malocclusion, bilateral impacted maxillary canines, and scalloped thin gingiva. The multidisciplinary management included a segmental arch technique, extracting two premolars, a subepithelial connective tissue graft surgery, and orthognathic surgery. The esthetic facial profile, pleasant smile, appropriate occlusion, and functional treatment results were obtained and maintained in 8-year follow-up. Full article

Treatment of third-class malocclusions often presents a challenge for orthodontists. Skeletal disharmony is often associated with dental malposition. There are several therapeutic choices, including the use in combination of transverse expansion of the maxilla with rapid palatal expander (RPE) and posterior-anterior traction with a Delaire face mask (FM). The purpose of the study is to verify whether there are significant differences in the treatment outcome in the case of use of a face mask followed by a palatal expander or with the sequence of these auxiliaries reversed. Subject and Methods: The two groups were both made up of 13 patients, subdivided into group A, i.e., those whose sequence involved the use of extraoral traction first and then the disjunctor, and those with an inverted sequence in group B. Some cephalometric parameters and dento-skeletal characteristics were evaluated pre-treatment (t0) and at the end of therapy (t1). Results: Considering the T1–T0 of group A (Delaire + rapid palatal expander), the evaluation of the results obtained in this work allows us to observe how within group A there is a significant improvement in the Witts and Nanda indices and facial convexity. Group B (treated with the palate disjunctor sequence followed by traction with Delaire’s mask) showed a significant improvement in ANB, in AoBo, and AppBpp values and in convexity. The two groups were comparable, and no statistically significant difference was highlighted. Discussion: The early therapy of the third skeletal classes by means of a rapid palate expander and face mask is effective. There is no statistically significant difference in the two groups who performed the therapy in reverse mode. This suggests that the clinician should choose the treatment sequence based on the skeletal and occlusal conditions of their patients at the start of treatment. Conclusion: Early therapy of third skeletal classes with sagittal expansion using a rapid palate expander can be performed earlier or later than posterior-anterior traction with a Delaire mask. Full article

Objectives: Patients with occlusal disharmony (OD) may be susceptible to depression. The hypothalamus–pituitary–adrenal axis, 5-HT and 5HT_2AR in the prefrontal cortex (PFC), amygdala, and hippocampus are involved in the modulation of emotion and depression. This study investigated whether OD affects the HPA axis and 5-HT system and, subsequently, produces depression-like behaviors in rats. Materials and methods: OD was produced by removing 0.5 and 0.25 mm of hard tissue from the cusps of the maxillary molars in randomly selected sides of Sprague–Dawley rats. CUS involved exposure to 2 different stressors per day for 35 days. OD-, CUS-, and OD + CUS-treated groups and an untreated control group were compared in terms of behavior, endocrine status and brain histology. Results: There were significant differences among the four groups in the behavior tests (p < 0.05), especially in the sucrose preference test, where there was a significant decrease in the OD group compared to the control group. ACTH and CORT concentrations were significantly higher in the OD + CUS group than the control group (p < 0.05). Expression of GR and 5-HT_2AR in the PFC, amygdala and hippocampal CA1 was significantly higher in the OD, CUS and OD + CUS groups than the control group (p < 0.05). Conclusion: OD promotes depression-like behaviors through peripheral and central pathways via the HPA axis, GR and 5-HT system. Full article

Reconstruction of mandibular defects following tumor resection in infants is a particular challenge. Although autogenous rib grafts have no relevance in the restoration of mandibular bone defects occurring after ablative tumor surgery due to limited bone stock and the availability of other donor areas, they are a useful surgical alternative following tumor surgery in infants. We here report on a 2, 5, 8, and 15-year follow-up of four children who were diagnosed with benign tumors of the mandible with osseous destruction at the age of 4, 6, 15, and 18 months, respectively. Histologic diagnoses were melanotic neuroectodermal tumor (n = 2), hemangioendothelioma of the mandible (n = 1), and ameloblastoma (n = 1). Following continuity resection of the mandible, lateromandibular bone defects were restored using autogenous rib grafts. Both clinical and radiologic follow-up visits were performed for all children to assess growth of the facial skeleton and the mandible. One child was already further reconstructed using bone augmentation at the age of 15 years. Cephalometric measurements on panorex films and three-dimensional computed tomographic scans revealed a slight vertical growth excess and transversal growth inhibition of the reconstructed mandible compared with the nonoperated side. Although further growth of rib grafts is difficult to predict and occlusal disharmony may occur due to physiologic maxillary growth and growth of the unaffected mandible, we believe that autogenous rib grafts can be ideally used for the restoration of mandibular continuity defects in newborns and young children. Clinical follow-up visits on a yearly basis and orthodontic controls are useful for early orthodontic treatment of growth deficits. Further corrective surgery with bone augmentation or osseous distraction is required following completion of growth of the facial skeleton. Full article

The tongue trust and anterior projection through the dental arcades during swallowing is known as Adapted Swallowing (AS) and is a common finding during mixed dentition. The authors studied the morphologic dentofacial characteristics through cephalometric measures in 38 girls and 35 boys, aged seven to nine years, presenting AS, as determined by the speech therapist evaluation. Cephalometric evaluation was obtained by Radiocef 2.0 software. The measurements studied were the mandibular and maxillary relations to the cranial base, the nasolabial angle, and the upper airway patency, as proposed by McNamara Jr (1984), and the convexity and facial axis angles and maxillary height from Ricketts (1960; 1981). Results, analyzed in relation to sex and racial group, showed an association of Class II facial convexity with the African Brazilian children with dark black skin. This classification does not reflect an abnormality as all African Brazilians studied were classified as class II, due to the fact that the standard measurements are based in the white American population. These findings point to the need of specific racial normative standard for evaluating orofacial and dental structures. Full article

Adapted swallowing (AS) and its effects on dentofacial balance are frequently observed in children with orofacial myofunctional alterations. The preliminary objective of this research was to identify the frequency of cases of adapted swallowing in a population of school children, and targeting early treatment to prevent morphofunctional alteration of the face and its consequences on dentofacial harmony. One hundred school children between seven and nine years old attending the Children and Adolescents’ Supporting Program (PRODECAD) of the State University of Campinas (UNICAMP) Brazil were selected at random and examined. Orofacial myofunctional assessments were carried out through standardized protocol. Results indicated the prevalence of adapted swallowing associated with resting posture alterations of dentofacial structures and mastication with dentofacial disharmony was 57%. Adapted swallowing without alteration of dentofacial form was observed in 19% of cases, and 24% of cases had a swallowing pattern within normal limits. The high prevalence of alterations suggests the need for early professional intervention. Full article