retrognathia

In Brazil, Class II malocclusions affect approximately one-third of children in the primary dentition period, and approximately two-thirds of the adolescent population. According to many authors, this type of malocclusion worsens with time, due to facial growth during childhood, both in terms of quantity and quality, and the facial pattern is established at an early age. The application of the Planas Direct Tracks concept and technique may represent an interesting tool for the correction and prevention of Class II malocclusion in an early treatment approach, working 24 hours a day, 7 days a week, applying oral functions and muscle activity to correct the malocclusion.

This prospective Herbst study analyzed the sagittal dental and skeletal changes contributing to Class II correction in young adults. Additionally, the alteration in skeletal and soft tissue convexity occurring during treatment was assessed. Early adolescent subjects in the ...

Transverse expansion or proclination of the teeth are valid alternatives to extraction in cases of crowding, but lack of stability and development of bone dehiscences have been demonstrated as side effects subsequent to anterior displacement of the incisors. The aim of this study was to repair the osseous dehiscence associated with incisor proclination. The multiple adjacent bone dehiscences were treated with a titanium membrane and bone matrix. Exposed root surfaces were covered with newly formed tissues. The patients in this study are the first to demonstrate the treatment of bone dehiscences that may occur as a result of orthodontic proclination.

The purpose of this study was to determine the facial profile preferences in a sample of 1,189 Asian teenagers (aged 15.3 +/- 3.2 years). Five facial profile types were computer-generated by trained personnel (orthodontists and oral maxillofacial surgeons) to represent distinct facial types. Subjects were asked to rank the profiles in descending order of attractiveness. The ranking was as follows: orthognathic profile, bimaxillary retrusive profile, bimaxillary protrusive profile, mandibular retrognathic profile, and mandibular prognathic profile. The differences in rank scores between all the profile types were statistically significant (p < 0.05). Assessment of profile types among lay personnel could provide clinicians an indication into the relative attractiveness among profile types and health care workers in treatment prioritization among dysmorphic facial types.

Patients whose facial esthetics are not severely compromised but who need surgical intervention for the correction of a dentoskeletal problem can be treated by repositioning of the whole mandibular alveolar segment in the direction needed to allow for such correction. The challenge to achieve efficient and relatively stable results with the use of combined orthodontic and surgical methods has been met by the use of various surgical techniques. The lower total alveolar osteotomy is another viable surgical technique that could be considered when treatment is being planned in an orthognathic surgical case. Its indications, contraindications, advantages, and disadvantages are described, and cases are reported to exemplify problems that can be corrected with this approach.

Class II division 1 malocclusion represents the most common skeletal discrepancy which orthodontists see in daily practice. The understanding of the morphology is a key element in planning dentofacial orthopedic treatment for this type of malocclusion. The purpose of the present study was to examine prepubertal children with Class II division 1 malocclusion and to evaluate maxillary and mandibular skeletal positions in comparison with normal growth standards by means of cephalometric measurements used by clinical practitioners. For the study casts and cephalograms of 86 consecutive patients with Class II division 1 malocclusion were used. The Class II division 1 malocclusion demonstrates broad variation in its skeletal and dental morphology. The retrognathic mandible (60%), maxillary prognathism (55.8%) and reduce vertical skeletal jaw relationship is the most common characteristic of Class II division 1 malocclusion. The optimal correction of the anteroposterior and vertical dental...

This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case.

Hemimandibular hyperplasia (HH), also known as hemimandibular hypertrophy, is characterised by excessive unilateral three-dimensional growth of the mandible after birth. Vertical unilateral elongation of the mandible becomes clinically evident as a rare form of vertical facial asymmetry. Aberrant growth of the facial skeleton affects the developing dentition and the dental compensatory mechanism is usually unable to maintain optimal occlusal relationships. The resulting malocclusion is effectively managed by combined surgical-orthodontic care to address the facial, skeletal and dental problems that confront clinicians. Orthodontists are advised to assess patients with HH during the post-treatment retention stage for continuing mandibular growth and assess the stability of treatment outcomes with long-term follow-up and records as required. To present a case of hemimandibular hyperplasia treated successfully by combined surgical-orthodontic care and evaluated for stability over a sev...

The extraction of an upper lateral incisor for orthodontic purposes is rare and must be adequately justified. The present case report describes the management of a skeletal Class II crowded malocclusion that was facilitated by the extraction of upper lateral incisors and lower first premolars. A 14-year-old male patient presented with a skeletal Class II crowded malocclusion with associated speech and chewing difficulties. Phase I of treatment involved the extraction of the upper lateral incisors and functional appliance therapy. Phase II included the extraction of lower first premolars and mechanotherapy using full fixed appliances. An improvement in aesthetics and sagittal relations was achieved during phase I therapy as the mandible was advanced over a period of eight months. Mandibular skeletal change was 6.5 mm observed at pogonion. During phase II therapy, the maxillary canines were substituted for lateral incisors and a functional occlusion was achieved. The skeletal correcti...

A skeletal Class III malocclusion is one of the most difficult to treat. The incidence of this malocclusion in the Caucasian population has been reported to be 1–5 per cent (Massler and Frankel, 1951; Haynes, 1970; Thilander and Myberg, 1973). In the Chinese and Japanese ...

This manuscript describes the use of a tooth indicated for extraction due to orthodontic reasons as an anchorage aid to receive undesirable side effects caused by orthodontic uprighting of a contralateral molar tooth. The mandibular right second molar was mesially tipped as a result of loss of the adjacent first molar. Since the treatment plan involved extraction of the mandibular left first premolar, undesirable side effects associated with the molar uprighting movement were transferred to this tooth. Once the second molar was vertical, the premolar was extracted and the treatment continued. The results suggest that treatment time can be reduced if undesirable orthodontic mechanical side effects can be directed to a tooth whose extraction is indicated.

A growth center of the mandible that contributes to its length and height is the mandibular condyle. Proliferation of prechondroblasts, followed by synthesis of the extracellular matrix and hypertrophy of the cartilage cells, governs the major part of condylar growth. The sample consisted of 54 male rats, weighing between 60 g and 80 g, divided randomly into three groups. Group I was the control group, group II was irradiated bilaterally, and group III was irradiated on the right side. Laser irradiation (lambda = 904 nm, 2000 Hz, pulse length 200 ns and output power 4 mW) was performed, and the procedure was repeated after a 50-day interval. Two months later, the rats were killed. In a single blind manner the lengths of denuded mandibles and the lengths of mandibles on soft tissue were measured. The growth of the mandibles in the unilaterally irradiated group (P < 0.001) and the bilaterally irradiated group (P < 0.05) was significantly more than that in the control group. Ther...

To evaluate the long-term outcome of treatment with reverse headgear in patients with skeletal Class III malocclusion diagnosed as maxillary deficient. Twenty-five patients (11 girls, 14 boys; mean age, 11.32 years) treated with a reverse headgear appliance were included in this study. Pretreatment, posttreatment, and 4-year follow-up cephalometric radiographs were obtained; linear, angular, and area measurements were performed. Comparison of treatment and observation changes was performed using a paired t-test. A significant increase was found in the forward movement of the maxilla, which was maintained 4 years after reverse headgear treatment. Treatment changes revealed significant increases in the sagittal dimensions and area of nasopharyngeal airway and remained significant at the end of the 4-year follow-up period. The oropharyngeal airway area increased nonsignificantly after the treatment, but significant increases occurred during the follow-up period. In young individuals di...

The aim of this study was the evaluation by using computerized tomography (CT) of craniofacial abnormalities in fibrodysplasia ossificans progressiva (FOP) patients regarding jaw restriction and retrognathia. Seven FOP patients were evaluated retrospectively in this observational study. Inclusion criteria were detection of ACVR1 gene mutation and complete craniofacial CT examination. The age of jaw restriction and presence of retrognathia were clinically determined. The features analyzed were skull base structures and heterotopic ossification (HO). Of this group (age range 4-23 years), the 3 oldest patients presented with jaw restriction and retrognathia as well as displayed elongation of the lateral pterygoid plate with HO of the pterygoid muscles that reached the medial surface of the right mandibular ramus. They had significant history of trauma or surgery. The other 4 patients did not have retrognathia or HO involving the facial or masticatory muscles, and the mouth opening was ...

Bidirectional or multidirectional distraction devices are commercially available to adjust for lengthening in two or more directions. 2,3 However, even these devices can result in open bite or lateral side effects at the end of distraction because it is difficult to predict the exact path a segment ...

Rehabilitation of the edentulous patient with atrophic ridges is a problem especially when compounded with a severe prognathic inter-arch relationship. It is difficult to rehabilitate these patients prosthetically without correction of the malrelation of the jaws. The established surgical techniques for correcting combined sagittal and vertical discrepancies of edentulous jaws are often prolonged and complex with attendant morbidity. This article presents a novel, simple method of correction of severe interarch sagittal discrepancy (more than 15 mm) by performing distraction osteogenesis at Le Fort I level using an internal maxillary distraction device. This method is a simple, predictable and stable option for the correction of a severe, unfavourable intermaxillary relation in edentulous patients.

Congenital retrognathia and glossoptosis characterize isolated Pierre Robin sequence (iPRS); the small mandible and its retracted position cause retrodisplacement of the tongue and reduction of the oropharyngeal airway. These neonates may be affected by airway obstruction, feeding difficulties, failure to thrive, and chronic hypoxaemia. To solve the respiratory problems secondary to glossoptosis, various treatments have been described including prone positioning, a nasopharyngeal tube, glossopexy, and mandibular distraction. Over the last 28 years, the authors have treated 118 neonates and infants affected by iPRS by carrying out traction of the mandible using two parasymphyseal wires, positioned under local anaesthesia. All the procedures were successful, with no major complication. The patients' respiratory problems and apnoea disappeared suddenly after beginning traction.

The aim of this study was to evaluate changes in the posterior airway space in patients following Biobloc therapy, using geometric morphometrics. Pre- and post-treatment lateral cephalographs of 53 children (mean age, 12.9 +/- 1.5 years; mean treatment time, 21.3 +/- 6.2 months) were scanned and 27 landmarks encompassing the airway were digitized. Mean configurations were computed using Procrustes superimposition, followed by principal components analysis (PCA) and finite-element scaling analysis (FESA). Marked shape-changes were identified using PCA for the airway following treatment (p < 0.01). Using pseudo-colored FESA, a relative 31% increase in nasopharyngeal airway area was found above and behind the soft palate. Additionally, a 23% increase in oropharyngeal airway area was located behind the base of the tongue with a 9% increase in hypopharyngeal area near the level of the hyoid bone. Functional airway improvements are associated with Biobloc treatment in actively growing ...

This study applies recent advances in 3D virtual imaging for application in the prediction planning of dentofacial deformities. Stereo-photogrammetry has been used to create virtual and physical models, which are creatively combined in planning the surgical correction of anterior open bite. The application of these novel methods is demonstrated through the surgical correction of a case.