Orthognathic surgery has been used regularly to treat dentofacial deformities. The surgical procedures affect both the facial appearance as well as the posterior airway space (PAS). Our current literature indicates that setback procedures produce an inferior repositioning of the hyoid bone and posterior displacement of the tongue and the soft palate. These movements cause anteroposterior and lateral narrowing of the PAS. Most authors agree that these effects are permanent. The PAS changes in turn produce an adaptive posturing, with an increased craniocervical angle to open up the PAS. Even though most patients do not display snoring and obstructive sleep apnoea (OSA) post-surgery, there is certainly an increased possibility in patients with already compromised airways. Therefore, patients who are undergoing orthognathic surgery should be screened for excessive daytime somnolence, snoring, increased body mass index (BMI) and medical conditions related to OSA and sent for an overnight polysomnography (PSG) if OSA is suspected. Then the proposed treatment plan may be modified according to the risk of potential airway compromise or even to improve it. Conversely, advancement of the maxilla and mandible causes widening of the airway in both the anteroposterior and lateral dimensions. This effect would translate to better airflow and decreased airway resistance. This is supported by the evidence showing high success rates when orthognathic surgery, especially maxillomandibular advancement (MMA), is utilised to treat OSA.
Airway Obstruction ; etiology ; surgery ; Cephalometry ; Humans ; Malocclusion ; complications ; pathology ; surgery ; Malocclusion, Angle Class II ; surgery ; Malocclusion, Angle Class III ; surgery ; Mandibular Advancement ; Oral Surgical Procedures ; Osteotomy ; Treatment Outcome

OBJECTIVETo analyze the biologic principle of orthodontic treatment in patients with skeletal Class III malocclusion and open bite.

METHODSEleven pre-adolescent patients with severe skeletal Class III malocclusion and open bite (age range 7 - 9 years old, mean age 8.3 +/- 0.8) were included. All patients were surgical cases but the patients rejected surgery. The treatment methods used were face mask, rapid maxillary expansion occlusal splint and fixed appliance. Lateral cephalometric films were taken before and after treatment. Cephalometric analysis was performed.

RESULTSAfter the treatment SNA changed from (79.0 +/- 1.2) degrees to (81.9 +/- 0.8) degrees (P < 0.01). And the inclination of lower incisors was decreased from (25.6 +/- 2.1) degrees to (20.1 +/- 1.4) degrees when measured to the NB line (P < 0.01). The direction of the facial growth was maintained.

CONCLUSIONSGood orthodontic results could be achieved in patients with skeletal Class III malocclusion and open bite.

Child ; Female ; Humans ; Male ; Malocclusion, Angle Class III ; complications ; therapy ; Open Bite ; complications ; therapy ; Orthodontics, Corrective ; methods

Objective:To explore the effects of mouth opening breathing for different reasons on children's maxillofacial development. Methods:One hundred and fifty-one children were selected as the research objects of this experiment. They were divided into 49 cases of adenoid hypertrophy group（group A）, 52 cases of tonsillar hypertrophy group（group B） and 50 cases of adenoid with tonsillar hypertrophy group（Group C）. Healthy children in the same period were selected as the control group, a total of 45 cases. The reflex nasopharyngeal measurement parameters, facial development indexes and cephalometric parameters of group A, group B, group C and control group were analyzed, and the incidence of Angle ClassⅡand Angle Class Ⅲ in group A, group B and group C were studied. Results:Compared with the control group, the reflex nasopharyngeal measurement parameters in group A, group B and group C was significantly different（P<0.05）, and the cephalometric parameters changed with variation in groups（P<0.05）. The incidence of Angle Class Ⅱ facial pattern in group A and group C was higher, but the incidence of Angle Class Ⅲ facial pattern in group B and group C was higher（P<0.05）. Conclusion:Adenoid hypertrophy leads to mandibular retraction; tonsil hypertrophy leads to anterior mandibular arch; adenoid hypertrophy and tonsil hypertrophy are easy to lead to clockwise rotation of the mandible. In clinical practice, to avoid children's uncoordinated maxillofacial development, we should correct the maxillofacial situation of children as soon as possible.
Child ; Humans ; Maxillofacial Development ; Malocclusion, Angle Class III/complications* ; Nasopharynx ; Adenoids ; Palatine Tonsil ; Mouth Breathing/etiology* ; Hypertrophy/complications* ; Mouth

OBJECTIVETo analyze the relationship between Class III malocclusion and pathological changes in temporomandibular joint (TMJ) structures using magnetic resenonce imaging (MRI).

METHODSTwenty-four Class III malocclusion adult patients and 10 normal control cases were included in the study. The characteristics of lateral pertygoid muscle (LPM) in the sample group and the control group were assessed.

RESULTSMore pathological changes of LPM were found in Class III malocclusion adult patients (36 TMJ). The changes included hypertrophy, atrophy and contracture. And there was no relation between the pathological changes of LPM and the symptom of temporomandibular disorders (TMD).

CONCLUSIONSThe frequency of pathological changes of LPM was greater in patients with Class III malocclusion than in the control group.

Adolescent ; Adult ; Atrophy ; pathology ; Case-Control Studies ; Contracture ; pathology ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Malocclusion, Angle Class III ; complications ; pathology ; Pterygoid Muscles ; pathology ; Temporomandibular Joint ; pathology ; Temporomandibular Joint Disorders ; complications ; pathology ; Young Adult