Orthognathic treatment for a patient with Class III malocclusion and surgically restricted mandible

Review of Etiology of Posterior Open Bite: Is There a Possible Genetic Cause?

Posterior open bite (POB) is one of the most severe malocclusions that can impair patients' masticatory functions, yet it is also a condition that is poorly understood and not well studied. Most reported cases are either sporadic or idiosyncratic with a diverse yet poorly understood etiology. Although primary failure of eruption (PFE), lateral tongue thrust, and certain medical syndromes or pathology of the temporomandibular joints have all been shown to cause POB, the complex interplay of environmental and genetic factors makes its etiopathogenesis a difficult subject to understand and investigate. Here, we provide a comprehensive review of the etiology of posterior open bite. Additionally, a genetic cause for POB is proposed through a report of an apparently non-syndromic familial case series with high POB penetrance across two generations. Further investigations of the gene(s) and mechanism(s) involved can not only provide a unique opportunity to better understand POB and the intricate muscular-occlusal relationship, but also offer powerful insight into the most effective approaches to clinical management of these (and potentially other) malocclusions.

Retreatment of a patient: Orthognathic surgery-first approach with customized lingual appliances combined with miniplate anchorage

Orthognathic surgery is necessary when a patient's major complaints include skeletal discrepancies that cannot be corrected with orthodontic treatment alone. Currently, orthognathic surgery can be performed through conventional and surgery-first approaches. Some advantages are attributed to the surgery-first approach, such as shortened treatment time and immediate esthetic improvement. The aim of this case report is to present the retreatment of a patient presenting with a skeletal Class III malocclusion, with maxillary retrusion and mandibular protrusion, who was successfully treated with the surgery-first approach and customized lingual appliances, combined with miniplate anchorage in the postoperative orthodontic treatment. The total orthodontic treatment time was 8 months.

Step by step full mouth rehabilitation of a class III edentulous patient by implant-supported prosthesis: A case report

Full mouth rehabilitation by dental implants is complex in class III patients. Prediction of the outcome of orthognathic surgery in edentulous patients with no dental index or record is challenging. This report describes rehabilitation of an edentulous patient by placement of dental implants after prediction of the outcome of orthognathic correction.

Combination of expansion and orthognathic surgery in a severe hyperdivergent skeletal Class III malocclusion

Class III malocclusions with a severe hyperdivergent growth pattern are very complex to plan and treat. This case report describes the treatment of an adult with a skeletal Class III malocclusion with a midface deficiency, severe bilateral posterior crossbite, and a severe hyperdivergent growth pattern by a combination of a bonded rapid maxillary expansion appliance and surgical procedure of Le Fort I osteotomy for maxillary advancement.

Cranial base, maxillary and mandibular morphology in Down syndrome

OBJECTIVE

To test the null hypothesis that there is no difference between craniofacial measurements of individuals with Down syndrome (DS) and normal controls.

MATERIALS AND METHODS

A cephalometric analysis including additional landmarks and measurements to study specific craniofacial features was undertaken on pretreatment cephalograms of 25 patients with DS (12 male, 13 female; mean age 15.1 years) treated at The Hospital for Sick Children, Toronto. Measurements were compared with those from cephalograms of racial groups age and gender matched, normal, Class I children, available from the Burlington Growth Center. Data were analyzed using paired t-tests.

RESULTS

Large reductions were measured in the size and spatial relationships of craniofacial structures in the DS group. The greatest differences included a larger cranial base angle; reduced elevation of sella from FHP; reduced anterior and posterior cranial base lengths; reduced anterior and posterior face heights; smaller maxilla with reduced anterior basal and apical dimensions; and smaller mandibular ramus, body and symphyseal dimensions and proclined symphysis. Maxillary incisors were severely proclined and undererupted, while mandibular incisors were undererupted. Alveolar heights were reduced. Anterior open bite was frequently noted. Maxillary and mandibular planes exhibited forward rotation patterns, promoting overclosure. Mandibular hypoplasia was less severe than cranial base and maxillary hypoplasia. Hypodontia of one or more permanent teeth was found in 92% of the sample.

CONCLUSIONS

The null hypothesis was rejected. Significant hypoplasia in endochondral, mesodermal, and ectomesenchymal derived structures of the cranium and face in subjects with DS was clearly evident. More severe platybasia than previously reported was found.