1/6. Long-term outcome of skeletal Class II Division 1 malocclusion treated with rapid palatal expansion and Kloehn cervical headgear.The treatment of a patient with a skeletal Class II Division 1 malocclusion, with excessive overjet, complete overbite, airway obstruction, and severe arch length deficiency in the mandibular dental arch, is presented. The maxilla was narrow compared with the mandible, and the posterior teeth were compensated, with the maxillary teeth inclined buccally and the mandibular teeth inclined lingually. The palatal vault was extremely high. Treatment included rapid palatal expansion to correct the transverse maxillary deficiency and Kloehn cervical headgear to correct the anteroposterior skeletal discrepancy. Long-term stability (12-year follow-up) is reported.- - - - - - - - - - ranking = 1keywords = mandible (Clic here for more details about this article) |
2/6. Craniofacial morphology in an unusual case with nasal aplasia studied by roentgencephalometry and three-dimensional CT scanning.OBJECTIVE: To examine the three-dimensional morphology of internal structures of the craniofacial region and present the orthodontic problems in an unusual case with nasal aplasia. PATIENT: The patient was an 11.5-year-old boy with aplasia of the nose and nasal cavity with extremely constricted nasopharyngeal airway. He did not have mental or somatic retardation. The patient had dacryostenosis. The morphology of the craniofacial structures was characterized by absence of septal structures, including cribriform plate, perpendicular plate of ethmoid bone, vomer, and septal cartilage; bony hypotelorism; midface hypoplasia; short and retrognathic maxilla with Class III jaw relationship; average mandibular plane angle; high arched palate; severe anterior open bite with bilateral posterior crossbites; and dental anomalies (agenesis of four maxillary permanent teeth, microdontia, taurodontism, and short roots). Thus, the patient had characteristic dentofacial phenotype, which might be caused by a combination of the primary anomaly and the functional disturbances secondary to the nasal obstruction.- - - - - - - - - - ranking = 0.084721018005821keywords = jaw (Clic here for more details about this article) |
3/6. Redirecting the growth pattern with rapid maxillary expander and chin cup treatment: changing breathing pattern from oral to nasal.AIM: This study was undertaken to assess the possibility of redirecting the growth pattern by using rapid maxillary expansion and a light-force chin cup for a short period of time, with limited patient cooperation, during the pre-growth and growth-spurt stages. methods: The study included a series of 60 patients, 24 males and 36 females from 7 to 14 years of age, with crossbite or midfacial deficiencies. Treatment involved wearing a chin cup 24 hours a day to force mouth closure during rapid maxillary expansion activation, which was 2 turns per day to rapidly expand the midpalatal suture and enhance nasal breathing. Lateral cephalograms and intraoral and facial photographs were taken 2 years before treatment, at the time of rapid maxillary expansion, 3 weeks following rapid maxillary expansion activation, 3 months after the cessation of rapid maxillary expansion activation, and 1 to 3 years post-rapid maxillary expansion activation. RESULTS: Despite the severity, the crossbite would always improve within 21 days following rapid maxillary expansion activation. The cephalograms and photographs demonstrated forward movement of the nasal bridge and maxilla, with backward rotation of the mandible. The bite depth remained nearly the same as pretreatment. CONCLUSION: The results suggested that 24 hours of light-force chin cup wear, while expanding the midpalatal suture, is the major factor to force mouth closure and enhance nasal breathing. As a result, there is advancement of the maxilla, avoidance of tongue encroachment upon the mandible, and deceleration of horizontal mandibular growth.- - - - - - - - - - ranking = 2keywords = mandible (Clic here for more details about this article) |
4/6. Dynamic MRI evaluation of tongue posture and deglutitive movements in a surgically corrected open bite.tongue thrust usually develops in the presence of anterior open bite in order to achieve anterior valve function. In the literature, tongue thrust is described both as the result and the cause of open bite. If it is an adaptation to malocclusion, then tongue posture and deglutitive tongue movements should change after treatment. In this case report, an adult who had skeletal open bite and Class II malocclusion caused by mandibular retrusion was treated surgically. The mandible was advanced in a forward and upward direction with a sagittal split osteotomy. The open bite and Class II malocclusion were corrected and an increase in the posterior airway space (PAS) was observed. Pretreatment and posttreatment dynamic magnetic resonance imaging (MRI) revealed that tongue tip was retruded behind the incisors and contact of the tongue with the palate increased. It was also determined that the anterior and middle portions descended, whereas the posterior portion was elevated at all stages. Advancement of the mandible, correction of open bite, and an increase in PAS affected not only the tongue posture and deglutitive movements, but also the breathing pattern of the patient.- - - - - - - - - - ranking = 2keywords = mandible (Clic here for more details about this article) |
5/6. The pharyngeal effect of partial nasal obstruction.The case histroy and cinematoradiographic findings of a baby with partial nasal obstruction are presented. This infant's restriction to air entry at the nose led to severe airway obstruction during inspiration by a forward movement of the posterior pharyngeal wall and backward movement of the tongue and lower jaw. At the height of inspiration, there was total airway occlusion in the pharynx. These events can be explained by the pressure drop that takes place behind a restriction if air is sucked through it forcibly from an area of atmospheric pressure. Studies of postpalatal pressures in adults and infants demonstrate such a drop in pressure during nasal breathing if the nose is partly obstructed. If the adult or infant is able to respond to the diminished nasal airway by mouth breathing, there is no postpalatal pressure drop. It is suggested that partial nasal obstruction in a sleeping obligatory nasal-breathing infant could result in a sucking back of the tongue over the larynx in this "cafe coronary" type of situation. This could be the mechanism of the obstructive type of apnea recorded by Steinschneider, and of the asphyxial type of death that is suggested by autopsies on some "cot death" victims. This hypothesis is consistent with the frequency of infection of rhinitis and pharyngitis in victims of sudden infant death syndrome and with the seasonal incidence. Prevention of this obstructive type of apnea would depend on the recognition of infants showing inspiratory and expiratory changes in pharyngeal airway size as can be seen externally by the movements in the carotid triangle of the neck and confirmed by roentgenography or cinematoradiography.- - - - - - - - - - ranking = 0.084721018005821keywords = jaw (Clic here for more details about this article) |
6/6. Two Class II, division 1 patients with congenitally missing lower central incisors.Although orthodontic treatment objectives and procedures for apparent protrusion of the maxillary teeth vary among orthodontists and specific cases, the differences are even greater where there is disharmony of jaw relationship between the maxilla and the mandible. The two cases presented in this article resemble each other in appearance, but the growth patterns and reactions to appliance, as well as treatment progress, are quite different. The initial excessive overjet seemed equally severe. Treatment was started at the same age, both patients were eldest daughters, both had a convex type facial pattern and an abnormal perioral muscle function with mouth breathing. In addition to the marked overjet, deep bite, and Class II molar relationship, lower central incisors were missing, and second molars had not erupted. They both had a steep curve of Spee, disharmony between the upper and lower arch forms, and slight diastemata. The facial appearance has been improved significantly in both, and patient satisfaction is high. A Kloehn-type cervical headgear was used in both cases. Case 1 showed improvement in the relationship between the maxilla and the mandible with reduction of the overjet. However, in Case 2, the sagittal relationship became worse, and an open bite developed. The obvious question is why the big difference in treatment response? What role did clearing of the nasopharyngeal airway play?- - - - - - - - - - ranking = 2.0847210180058keywords = mandible, jaw (Clic here for more details about this article) |