Severe anterior open-bite malocclusion

This case report describes the treatment of a severe anterior open bite, Class II malocclusion with a history of dummy sucking. The 9-year-old girl presented with a significant anteroposterior and vertical discrepancy. Her face was convex with procumbent lips. She had an anterior open bite of 9 mm, an overjet of 8 mm, and a transverse maxillary deficiency. In consultation with the parents and patient, a nonsurgical therapy was elected, with the goals of reducing protrusion and closing the anterior open bite.     

Microscrew anchorage in skeletal anterior open-bite treatment

OBJECTIVE: To evaluate the effectiveness of miniscrew anchorage for intrusion of the posterior dentoalveolar region to correct skeletal open bite. MATERIALS AND METHODS: The study was comprised of 12 patients (aged 14.3 to 27.2 years; mean 18.7 years) with anterior open bites. All the patients presented a Class II skeletal pattern and excessive posterior growth. Self-drilling miniscrew implants were inserted into the posterior midpalatal area and the buccal alveolar bone between the lower molars. A transpalatal and a lingual arch were used to maintain the molars on each side in order to avoid overrotation during intrusion. A force of 150 g was applied to the microscrews on each side to intrude the posterior teeth. Lateral cephalograms of all 12 patients were taken preintrusion and immediately after completion of the intrusion. The cephalometric films were measured and compared. RESULTS: The results showed that the anterior open bites in 12 patients were all corrected in a mean of 6.8 months. Overbite increased by a mean of 4.2 mm (P < .001), from -2.2 mm in preintrusion to 2.0 mm in postintrusion. The maxillary and mandibular first molars were intruded for an average of 1.8 mm (P < .001) and 1.2 mm (P < .001), respectively. The mandibular plane angle was reduced by 2.3 degrees (P < .001), which led to a counterclockwise rotation of the mandible with a significant decrease in the anterior facial heights (mean of 1.8 mm; P < .001). CONCLUSION: Miniscrew anchorage has the advantages of being a simpler procedure, being minimally invasive, and requiring minimal patient cooperation.     

Skeletal Class III oligodontia patient treated with titanium screw anchorage and orthognathic surgery

This article reports the successful treatment of a patient, aged 15 years 8 months, with a Class III malocclusion and oligodontia; a titanium screw was used for absolute anchorage during treatment. The patient had a concave profile because of mandibular excess and asymmetric spaces in both arches. Titanium screws were implanted in the retromolar area during intraoral vertical ramus osteotomy combined with LeFort I osteotomy. Absolute anchorage was provided with anchorage wires extending from the screws to the left canine and the right lateral incisor. After orthodontic space closure, the mandibular molars were moved mesially without lingual tipping of the mandibular incisors. A good interincisal relationship was achieved. Our results suggest that titanium screws and anchorage wires in the retromolar area are useful for the mesial movement of mandibular molars.     

Noncompliance open-bite treatment with zygomatic anchorage

OBJECTIVE: To evaluate the dentoalveolar and skeletal effects of the new-generation open-bite appliance. SUBJECTS AND METHODS: The study group was composed of 11 subjects with a mean age of 19.5 years who underwent intrusion of the posterior dentoalveolar segment using an open-bite appliance supported by bilateral zygomatic implants. The study was carried out on lateral cephalograms of the subjects taken before treatment and after intrusion. The mean intrusion time was 9.6 months. RESULTS: The mean intrusion measured as the distance of the U6 to the palatal plane was 3.6 +/- 1.4 mm (P < .001). This resulted in an average of 3.0 degrees +/- 1.5 degrees of closure of the Go-Gn-SN angle (P < .001). The gain in the overbite was 5.1 +/- 2.0 mm (P < .001), and the overjet was reduced by 1.4 +/- 1.5 mm (P < .01). The change in the occlusal plane angle was an average of 2.4 degrees +/- 1.4 degrees counterclockwise rotation (P < .001). The lower facial height was also decreased significantly by 2.9 +/- 1.3 mm (P < .001). No significant changes were observed in the SNA angle and incisor positions (P > .05), except for the interincisal angle, which was increased by 3.5 degrees (P < .05). CONCLUSION: Zygomatic anchorage can be used effectively for open-bite correction through posterior dentoalveolar intrusion.     

Skeletal anchorage system for open-bite correction

A skeletal anchorage system was developed for tooth movements. It consists of a titanium miniplate that is temporarily implanted in the maxilla or the mandible as an immobile anchorage. In this article, we introduce the skeletal anchorage system to intrude the lower molars in open-bite malocclusion and evaluate the results of treatment in two severe open-bite cases that underwent orthodontic treatment with the system. Titanium miniplates were fixed at the buccal cortical bone around the apical regions of the lower first and second molars on both the right and left sides. Elastic threads were used as a source of orthodontic force to reduce excessive molar height. The lower molars were intruded about 3 to 5 mm, and open-bite was significantly improved with little if any extrusion of the lower incisors. No serious side-effects were observed during the orthodontic treatment. The system was also very effective for controlling the cant and level of the occlusal plane during orthodontic open-bite correction. (Am J Orthod Dentofacial Orthop 1999;115:166-74)     

New generation open-bite treatment with zygomatic anchorage

This technical note aims to present the fabrication and application of a new generation of posterior intrusion appliances using zygomatic anchorage. The use of zygomatic anchorage enables en masse impaction of the posterior segment without any side effects such as labial flaring. A 14-year-old, female Class II patient with an anterior open bite was treated with a new generation posterior intrusion appliance. At the end of treatment, a Class I canine and molar relationship and a correction of the anterior open bite were achieved. The molars were impacted 3.6 mm, and this impaction was maintained throughout the treatment. The mandibular plane showed a counterclockwise autorotation of 4 degrees. This case report demonstrates that zygomatic anchorage can be used effectively for molar intrusion and anchorage maintenance. However, further clinical studies with larger samples are required to confirm its effectiveness.     

Closing anterior open bites by intruding molars with titanium miniplate anchorage

The intent of this study was threefold: (1) to validate true intrusion of molars in adults, (2) to test the stability of miniplates as anchorage for intruding posterior teeth in the maxilla, and (3) to record the skeletal and dental changes of open-bite closure. Four adult patients who had anterior open-bite malocclusions were selected to undergo posterior intrusion with miniplate anchorage to close the open bite; all had true intrusion of the maxillary molars. Mean molar intrusion was 1.99 mm (range, 1.45-3.32 mm). No movement of miniplates occurred at any time during their use or before intentional clinical removal. Open-bite closure was achieved for all 4 patients. Mean closure of incisors was 3.62 mm (range, 3.0-4.5 mm) as the mandibular plane closed 2.62 degrees (range, 1.5 degrees -4.5 degrees ), and the occlusal plane decreased 2.25 degrees (range, 1.0 degrees -3.5 degrees ). Anterior facial heights decreased as the mandible closed and B-point rotated anteriorly and upward.     

Treatment of anterior skeletal open-bite deformity.

Two patients with severe skeletal anterior open-bite have been presented. Treatment of these patients was accomplished mainly by mandibular repositioning (Case 1 by orthodontic means and Case 2 by a combination of surgery and orthodontics) and by an orthodontic change in the mandibular occlusal plane. A review and a discussion of the cause of this deformity were presented.     

微螺钉种植体支抗压低磨牙矫治前牙开(牙合)

近些年来各种骨性支抗系统被开发并应用于临床,来完成牙齿各种类型的运动.微型种植体用于垂直支抗控制方面比传统方法有着更多的优势.本文病例通过应用自攻型微钛钉种植体支抗压低上下颌后部牙齿槽,治疗严重的骨性前牙开(牙合)畸形,证明自攻型微钛钉种植体提供垂直支抗控制的能力.本文也提示通过简单有效的骨性支抗手段,可以提供一种治疗较复杂骨性开(牙合)畸形的全新方法.     

微螺钉种植体支抗压低磨牙矫治前牙开（牙合）

近些年来各种骨性支抗系统被开发并应用于临床,来完成牙齿各种类型的运动.微型种植体用于垂直支抗控制方面比传统方法有着更多的优势.本文病例通过应用自攻型微钛钉种植体支抗压低上下颌后部牙齿槽,治疗严重的骨性前牙开（牙合）畸形,证明自攻型微钛钉种植体提供垂直支抗控制的能力.本文也提示通过简单有效的骨性支抗手段,可以提供一种治疗较复杂骨性开（牙合）畸形的全新方法.     

Cephalometric evaluation of patients with anterior open-bite

Cephalometric evaluations of the skeletal pattern of 30 patients with anterior open-bite malocclusion were compared to those of 30 individuals with a normal overbite. The posterior/anterior face height ratio (PFH/AFH) was the only skeletal characteristic statistically different in the two groups. The other cephalometric measurements were not found to be statistically different in the malocclusion and normal overbite groups (SN-GoGn, SN-PP, gonial angle, LFH/AFH ratio), indicating that there is no skeletal origin in the group with anterior open-bite in this study.     

Cephalometric evaluation of anterior open-bite nonextraction treatment, using multiloop edgewise archwire therapy

There are very few reports of extensive and detailed cephalometric investigations of nonextraction treatment changes for patients with anterior open bite. The purpose of this study was to evaluate changes in dentomaxillofacial morphology by way of lateral and oblique cephalograms of patients who had undergone multiloop edgewise archwire (MEAW) therapy for anterior open-bite correction. The subjects consisted of 21 Japanese female patients who received MEAW therapy without premolar extraction. The mean pre- and posttreatment ages were 16 years 9 months and 19 years, respectively. Lateral and oblique cephalograms were taken before and after treatment. Fifteen angular and 29 linear measurements were obtained from the lateral cephalograms; 17 angular and 20 linear measurements were obtained from the oblique cephalograms. Treatment changes were evaluated by the paired t-test. The upward and forward rotational changes of the mandible consequent to the use of the MEAWs and anterior vertical elastics were larger than the downward and backward rotational changes of the mandible, due to the extrusion of the posterior teeth by leveling and alignment. The uprighting and retrusion of the premolars and molars, and the extrusion, uprighting, and/or retrusion of the incisors and canines played important roles in the anterior open-bite nonextraction treatment by dint of the MEAW technique.     

预成钛合金螺纹桩保留残根的临床修复观察

目的观察钛合金螺纹桩对残根残冠的修复效果。方法对2002年~2009年5月份期间采用钛合金螺纹桩加双固化树脂核修复的病例进行复诊观察并用预定标准评价修复效果。根据患牙的牙位、余留牙体组织量、桩与牙根的直径比及桩在根管内的密合程度对复诊的病例进行分组比较。结果复诊病例共40例,有49颗修复牙,门诊复诊病例23例共25颗修复牙。失败病例中桩折断两例,桩脱落三例。失败病例均发生在余留牙体组织量不理想组。结论螺纹桩在余留牙体组织量理想的情况下可以获得满意修复效果,在牙体缺损较多的情况下修复效果欠佳。     

前牙开(牙合)早期治疗的研究进展

前牙开(牙合)作为常见错牙合畸形影响患者口颌功能和颜面美观。其病因复杂,治疗难度大,复发风险高。早期开牙合治疗利用患者生长潜力,改善颌面部垂直向生长异常,减轻后期治疗负担,备受推崇。各类矫治器通过阻断口腔不良习惯、调节异常肌功能、抑制颌骨垂直向发育等作用解除开牙合。本文旨在探究前牙开牙合早期治疗时机以及各类矫治器的临床应用、疗效及稳定性。