Maxillary expansion in Class II correction with orthopedic cervical headgear. A posteroanterior cephalometric study

Class-II, division-1 malocclusion appears to be associated with a narrow maxilla. A Class-II malocclusion may be corrected to a Class-I relationship in children using a cervical headgear provided that the narrow maxilla is expanded. This expansion is possible using headgear by dental cast analysis, but this has not been confirmed by cephalometry. We studied the effects of orthopedic cervical headgear on dental and skeletal facial widths in 40 children aged 9.1 (7.2-11.5) who had Class-II, division-I malocclusions. The headgear consisted of a long outer bow bent 15 degrees upward and a large inner bow expanded by 10 mm. Posteroanterior cephalographs and dental casts were taken before and after treatment. The results were compared with the control values presented in the literature. The malocclusion was treated to a Class-I relationship in all children. The average treatment time was 1.6 (0.3-3.1) years. The maxilla was widened significantly (P < .0001). The upper first molar width (um-um) and maxillary width (mx-mx) increased 3.2 and 1.6 mm/y, respectively. Maxillary widening was also observed in the nasal structure as indicated by an increase in lateronasal width (lap-lap) by 1.0 mm/y (P < .005). With maxillary widening, the mandibular dental arch widened spontaneously. The lower first molar width (lm-lm) increased 0.8 mm/y, which was more than the increase in the controls (P < .0001). However, the antegonial width (ag-ag) remained unaffected. By using a widened inner bow in headgear therapy with Class-II malocclusions, a widening of maxilla and nasal cavity may be obtained.     

Orthopedic cervical headgear with an expanded inner bow in class II correction

Forty consecutively referred children, 20 boys and 20 girls, with a Class II division I malocclusion and protrusive maxilla were treated with orthopedic cervical headgear with a 10 mm expanded inner bow and a long outer bow bent 15 degrees upwards. The mean age of the children at the beginning of treatment was 9.3 years (SD 1.3, range 6.6 to 12.4 years), and the average treatment time was 1.8 years (SD 0.6, range 0.8 to 3.1 years). In all patients Class II molar relationships were successfully corrected to Class I molar relationships. This was accompanied by a marked widening of both maxillary and mandibular dental arches. The cephalometric analysis suggested that the observed improvement of the occlusion was due to an inhibition of forward growth of the maxilla and anterior downward rotation of the palate.     

Vertical changes in high-angle Class II, division 1 patients treated with cervical or occipital pull headgear.

Before, after, and 2 years after treatment serial radiographs of two samples of patients with high mandibular plane angle Class II, Division 1 nonextraction who were treated were evaluated retrospectively. One sample comprised patients treated with cervical headgear (CHG), and the other was treated with occipital headgear (OPHG). No significant differences were found when mandibular plane angle or facial height changes, anterior or posterior, were compared. Regarding vertical changes, only maxillary molar height, relative to both sella-nasion and palatal plane, and occlusal plane angle changes were significantly different when cervical and occipital-pull headgear were compared. In both groups of patients, responses to treatment were highly variable and only subtle vertical differences were apparent between mean changes in the cervical and occipital-pull samples.     

Mandibular changes in skeletal class II patients treated with Kloehn cervical headgear.

This study evaluated the posttreatment and long-term anteroposterior and vertical mandibular changes in skeletal Class II Division 1 patients (ANB angle >or= 5 degrees ) treated with Kloehn cervical headgear. The sample consisted of 40 patients (18 males, 22 females, average age 10.5 years at pretreatment [T1], 13.5 years at posttreatment [T2], and 23.5 years at postretention [T3]) treated with cervical traction with an expanded inner bow (4-8 mm) and a long outer bow bent upwards off the horizontal 10 degrees to 20 degrees in relation to the inner bow. The force applied averaged 450 g, and the recommended use of the appliance was 12 to 14 hours per day, with monthly adjustments. The Student t test was used for comparison between stages. Results showed that during treatment no significant change was found in the mandibular plane angle, but a significant decrease was detected at T3. Kloehn cervical headgear was efficient in the skeletal Class II correction. The superimposition of tracings suggests that much of the treatment effect occurs when the mandible is displaced forward. Skeletal Class II correction with Kloehn cervical headgear was found to be stable over the long term.     

Cephalometric evaluation of Class II malocclusion treatment with cervical headgear and mandibular fixed appliances

The present study aimed to evaluate the cephalometric changes in Class II patients treated exclusively with cervical headgear (CHG) in the maxillary arch and fixed appliances in the mandibular arch as compared with a control group. The sample comprised 82 lateral cephalograms obtained pre- (T1) and post- (T2) treatment/observation of 41 subjects, divided into two groups: group 1-25 Class II division 1 patients (20 females and five males), with a mean pre-treatment age of 10.4 years, treated for a mean period of 2.5 years and group 2-16 Class II untreated subjects (12 females and four males), with a mean initial age of 9.9 years, followed for a mean period of 2.2 years. Treatment changes between the groups were compared by means of t-tests. The results showed restriction of maxillary forward displacement and also a restriction in maxillary length growth, improvement in the maxillomandibular relationship, restriction of mandibular incisor vertical development, reduction in overjet and overbite, and improvement in molar relationship. It was concluded that this treatment protocol corrected the Class II malocclusion characteristics primarily through maxillary forward growth restriction.     

Comparative long term post-treatment changes in hyperdivergent Class II Division 1 patients with early cervical traction treatment

This was a retrospective study of 45 Class II Division I hyperdivergent patients treated in the mixed dentition with cervical traction and an incisor biteplane. The interjaw or "B" angle (mandibular plane to palatal plane angle) was used to determine hyperdivergency. The treated sample was subdivided into 2 groups reflecting whether the mandibular or palatal plane contributed the greatest amount to the more than 1 standard deviation of the "B" angle from the mean value of the "B" angle present in the 89 untreated Class I controls. Complete records including lateral cephalometric head films were acquired at the start of treatment and 18 to 91 months after discontinuing all retention. Null hypotheses were designed to determine if any significant changes in the "B" angle, mandibular plane angle, or palatal plane angle occurred in the control group or the treated group. Thirty-two angular, linear, and proportional data were accumulated to determine the presence or absence of significant differences. The only significant angular differences found were in the group in which the palatal plane inclination was increased relative to Frankfort Horizontal. In this group, the palatal plane became more nearly parallel to Frankfort Horizontal than in the control group, and showed an increase instead of a decrease in the Y-axis. Proportional and linear data indicated the palatal plane change was a lack of descent of Posterior Nasal Spine while the descent of Anterior Nasal Spine was equal to that of the control group. The increase in the Y-axis was not the result of bite opening, but a lack of mandibular horizontal development as indicated by less of an increase in the Facial Angle. Of the 45 patients, only 4 (9%) required 2 phases of treatment and 1 of those required extraction. Thirty patients (67%) completed treatment with alignment and retraction of the maxillary anterior segment and 11 (24%) had additional alignment of the mandibular anterior segment.     

Molar changes with cervical headgear alone or in combination with rapid maxillary expansion

OBJECTIVE: To test the hypothesis that there is no difference in the distal movement of the maxillary first permanent molars when cervical headgear is used alone or in combination with rapid maxillary expansion. MATERIALS AND METHODS: The sample was composed of 36 subjects (aged 9 to 13 years), treated in the Faculty of Dentistry, Pontifícia Universidade Cat;aaolica, Rio Grande do Sul, Brazil. The individuals were in good health and in their pubertal growth period. All had Class II division 1 malocclusion. The patients were divided into two groups: group 1 (22 subjects), Class II, with a normal transverse maxilla treated with cervical traction headgear (HG) 400 g 12 h/d, and group 2 (14 subjects), Class II maxillary transverse deficiency treated with rapid maxillary expansion plus cervical traction headgear (RME + HG). An additional group 3 (17 subjects) served as a control group and included individuals with the same characteristics. All subjects had two lateral cephalograms: initial (T1) and progress (T2), taken 6 months later. Differences between T1 and T2 were compared with the Student's t-test, and three groups were compared by the analysis of variance and Tukey multiple comparison test. RESULTS: Results showed greater distal tipping and greater distal movement of the first permanent molars in group 1 (HG) than in group 2 (RME + HG), P < .05. No extrusion of first permanent molar occurred in either group (P > .05). CONCLUSION: The hypothesis was rejected. Cervical traction headgear alone produced greater distal movement effects in maxillary first permanent molars when compared with rapid maxillary expansion associated with cervical headgear.     

Longitudinal study of anteroposterior and vertical maxillary changes in skeletal class II patients treated with Kloehn cervical headgear

This is a study to evaluate the posttreatment and long-term anteroposterior and vertical maxillary changes in skeletal Class II Division 1 patients (ANB > or = 5 degrees) who had received Kloehn cervical headgear treatment. The sample consisted of 120 lateral cephalograms obtained at pretreatment (T1), posttreatment (T2), and postretention (T3) phases of 40 patients (18 males and 22 females). The patients were of an average age of 10% years in phase T1, 13% years in phase T2, and 23% years in phase T3. They were treated with cervical traction and an expanded inner bow (4-8 mm) and a long outer bow bent upwards off the horizontal 10-20 degrees in relation to the inner bow. After correction of the molar relationship on both sides, a conventional edgewise fixed appliance was used to complement the correction of the malocclusion. The onset of treatment was either at the late mixed dentition or at the beginning of the permanent dentition. The force applied for the 40 patients averaged 450 g and the recommended use of the appliance was 12-14 hours per day with monthly adjustments. F-Snedecor test was applied to the entire sample and multiple comparisons between phases were tested by the Bonferroni method. Results revealed that treatment had reduced maxillary protrusion, inclined the palatal plane with an increase in the SN-PP angle with reduction at long-term. In conclusion, Kloehn cervical headgear with elevated external bow and expanded inner bow was efficient in correcting the skeletal Class II in late mixed-early permanent dentition. Skeletal Class II correction with Kloehn cervical headgear was found to be very stable long term.     

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.     

Orthopedic cervical headgear in class II treatment: case report

Early treatment for Class II malocclusion was undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. A case of Class II, Division 1 malocclusion in the mixed dentition was corrected to Class I molar relationship using orthopedic cervical headgear, with nonextraction edgewise therapy. Cephalometric analysis indicated a reduction in the maxillomandibular discrepancy (ANB) correcting the Class II malocclusion to Class I malocclusion. The treatment showed that this was achieved by downward displacement and inhibition of the forward growth of the maxilla and growth of the mandible. There was no downward rotation of the mandible nor maxillary first molar extrusion. There was improvement in the jaw relationship.     

成人轻度骨性Ⅲ类错牙合不同拔牙模式矫治的侧貌分析

目的：比较不同拔牙模式矫治的轻度骨性Ⅲ类错牙合成人患者的侧貌变化。方法：选择40例诊断为设计拔除4个前磨牙或第三磨牙矫治的轻度骨性III类错牙合的成人病例,分为两组,每组各20例。用头影测量分析法比较矫治前后的变化以及软硬组织的相关性。结果：拔除前磨牙组变化主要在于内收上下前牙。拔除第三磨牙组在于唇倾上前牙,软组织改变分别是内收下唇和唇倾上唇代偿（P<0．05）。软硬组织的变化具有一定相关性（P<0．05）。结论：不同拔牙模式对轻度骨性Ⅲ类错牙合患者矫治后侧貌的改变是有差别的,但在一定程度上都能改善凹面型和颏部形态。     

The early management of Class III malocclusions using protraction headgear

Class III malocclusions affect approximately 3% of Caucasians. Treatment options include; growth modification, dental camouflage and, once growth has ceased, orthognathic surgery. Originally, Class III malocclusions were thought to arise primarily from an overdevelopment of the mandible, but it is now known that maxillary retrusion contributes in up to 60% of cases. Maxillary retrusion is best treated with a combination of protraction headgear and rapid maxillary expansion, preferably before the age of 9 years. This article provides an overview of the management of skeletal Class III cases using protraction headgear with particular guidance for the general dental practitioner on when and how to treat.