Select Language ▼

Home About Us Events Consultancy Articles Advertisement Magazine Contact Us

login

Articles Orthodontics VERTICAL CONTROL: A KEY TO SUCCESSFUL TREATMENT OF CLASS II

DIVISION 1 HIGH ANGLE CASES

VERTICAL CONTROL: A KEY TO SUCCESSFUL TREATMENT OF CLASS II DIVISION 1 HIGH ANGLE CASES

Author: Dr. Shirish M. Bapat, Professor and Head, Department of Orthodontics , KD Dental College and

Hospital, Mathura, UP.

INTRODUCTION

Class II Division 1 malocclusion is one of the most commonly found malocclusion. It is characterized by

Class II molar relationship, increased overjet, narrow dental arches with crowding of anterior teeth. The

overbite is increased in horizontal growers and decreased in vertical growers. There may be maxillary

excess, or mandibular deficiency or both. This malocclusion has anteroposterior, transverse, and vertical

components. If the maxillary arch is narrow in relation to the mandibular arch, the mandible cannot close

normally, but gets retruded to occlude in a distal relationship with the opposing arch. In the vertical growers,

the excess vertical growth of maxilla and eruption of the posterior teeth in both arches causes mandible to

rotate backward accentuating horizontal discrepancy. This opens anterior bite. For every 1 mm eruption of

teeth in the posterior region, the bite opens anteriorly by 2 mm.1

Various factors have been described to contribute to the etiology of this malocclusion. They include:

heredity, genetic disorders, trauma to the mandible, habits, and various syndromes affecting growth of

mandible. As the vertical growth worsens this malocclusion, it seems natural that the control of the vertical

growth of maxilla and eruption of the upper and lower posterior teeth will improve the occlusion by causing

anterior rotation of the mandible. 

CONTROL OF THE VERTICAL GROWTH AND ERUPTION

Control of vertical growth of the maxilla and eruption of the upper and lower posterior teeth can be done by

various treatment approaches as stated below.

Functional Appliances with Bite blocks and Headgear

The most effective approach to growth modification involving vertical maxillary excess(VME) and Class II

relationship is a combination of extraoral force in the form of high-pull headgear to the maxilla(fig. 1), and a

functional appliance with posterior bite blocks to anteriorly reposition the mandible and control

eruption.1,2 The extraoral force increases the control of the maxillary growth and functional appliance allows the force to be delivered to the whole maxilla rather than simply to the permanent first molars. The high-pull headgear improves retention of the functional appliance. The outer bow is turned up to pass the force close to the estimated center of resistance of maxilla. The head cap is connected with the outer bow and the force is adjusted to 400-500 g per side in upward and backward direction. The functional appliance provides the possibility of enhancing the sagittal mandibular growth while controlling the eruption of posterior teeth by bite block effect.

Fig 1: High Pull Headgear.

While registering the bite for construction of the functional appliance, the mandible is brought downward 4-5

mm and forward 5-6 mm. The bite must be opened past the normal resting vertical dimension if molar

eruption is to be affected. The viscoelastic forces resulting from stretch of the soft tissues, including

muscles, exert a vertical intrusive force on the posterior teeth. In children with anterior openbites, the bite

block covers only the posterior teeth and the anterior teeth are allowed to erupt. Whereas, in long face

patients without openbite, bite block covers all teeth. As the vertical growth of the maxilla and eruption of the

posterior teeth are controlled, the mandible would rotate in an upward and forward direction i.e. anti

clockwise.1

As the maxillary anterior teeth are subjected to a distal force by the functional appliance, the incisors tend to tip backward. If this needs to be prevented, the torquing springs(fig. 2) may be incorporated as described by Stockli and Teuscher3 for bodily retraction of the maxillary incisors. Langerstrom et al2 studied 40 subjects with Class II Division 1 malocclusion with at least 5 mm overjet treated with high-pull headgear-activator combination. All patients were instructed to wear the activator-headgear only during sleeping hours. The headgear was adjusted to provide about 300 g force to the maxilla and the upper dentition. The results showed that Class II correction was achieved by distal repositioning of the maxillary teeth(mean, 0.07 mm) and mesial repositioning of the mandibular teeth(mean, 3.3 mm) with wide range of variation. The mean total Class II correction was 3.29 mm + 2.16 mm. The maxillary prognathism often remained

unchanged with a slight vertical lowering of the maxilla. Mandibular prognathism was often found to increase during treatment. The mean anterior relocation of pogonion was 2.81 mm + 1.70 mm. The mandibular plane inclination showed no statistically significant change. Kurosava et al4 obtained 3.10 counterclockwise rotation of the mandible in a Class II division 1 malocclusion case with high mandibular plane angle corrected by 2 phase treatment. The first phase involved treatment with quad-helix appliance followed by high-pull headgear with bionator. The second phase involved treatment with fixed edgewise appliance after extractions of four first premolars. Mesial movement of the upper and lower molars was carried out, which accounted for the mandibular forward rotation.Fig. 2: Activator with headgear tubes and torquing springs.

High-pull Headgear to a Maxillary Splint

A more effective headgear approach for children with excessive vertical development is the use of a plastic

occlusal splint(fig. 3) to which a facebow is attached. This allows vertical force to be directed against all the

maxillary teeth- not just the molars- and appears to have a substantial maxillary dental and skeletal effect

with good vertical control.1,5 The maxillary splint limits dental eruption better than the headgear just to the

maxillary first permanent molars. Unfortunately, this type of appliance allows mandibular posterior teeth to

erupt freely. This effect will prevent the upward and forward rotation of the mandible. Hence a posterior bite

block may be added to the maxillary splint to prevent molar eruption by forces generated by stretch of the

facial soft tissues created by the bite block, and a lingual arch may be placed in the lower arch to prevent

compensatory eruption of the lower molars. To achieve both skeletal and dental correction, the patient must

be compliant throughout what could be a long treatment period, if not, a fixed maxillary splint is preferred

instead of a removable splint.1,5

Fig. 3: Maxillary splint with headgear tubes.

Fotis et al6 used full coverage maxillary splint for treatment of Class II Division1 cases. Splint formed a bite

plate occlusally with even contact on all lower teeth. A Kloehn type face bow was inserted in the tubes

embedded in the splint in the molar region. A 500 g headgear force was applied 450 upward and backward

in relation to the occlusal plane on each side. They observed a slight anterior rotation of the mandible in

most of the cases with 4.9 mm improvement in the molar relationship. In a study of 47 patients with a mean

age of 10.19 years for girls and 11.23 years for boys with maxillary dentoalveolar protrusions and Class II,

Division 1 malocclusions treated with high-pull headgear attached to a full coverage heat cured plastic

maxillary occlusal splint, Caldwell et al 7 found significant inhibition of vertical development of the maxilla,

and slight intrusion of the maxillary dentition with no significant increase in the mandibular plane angle. Only

the mandibular anterior teeth contacted the splint, which encouraged eruption of the mandibular posterior

teeth and leveling of the curve of Spee. Patients were instructed to wear the appliance 24 hours a day

except while eating and during sports activities. The ANS moved down 1.52 mm and PNS moved down 1.07

mm in the matched control group, whereas a decrease of 0.1 mm and 0.55 mm was registered in the

treatment group. The palatal plane was observed to rotate clockwise only 0.160 in the control group, and 10

clockwise in the traction splint group. SNA angle remained the same in the control group, but it decreased

1.310 in the treatment group. Whereas the mean SNB value increased 0.220 in the controls, it decreased

0.300 in the treated sample. The mean ANB angle decreased 0.210 in the control sample and 0.870 in the

treatment sample. The upper incisor retroclined 7.80 in relation to the SN plane, and retracted 1.28 mm in

the treatment group, but proclined slightly in the controls. Overbite decreased an average 2 mm in the

treated sample, whereas no significant change in overbite was demonstrated in the controls. Maxillary

incisor extruded 2.3 mm in the controls but intruded 0.25 mm in the treatment group. The maxillary molar

moved an average 1.4 mm distally in relation to point A in the treatment group, but mesially an average 0.24

mm in relation to point A in the control group. In the vertical plane, maxillary molar elongated by 2.4 mm in

the controls, but it intruded by 0.4 mm in the treatment sample. The maxillary molar tipped mesially 0.70 in

the controls, but tipped distally 3.30 in the treatment group relative to the palatal plane. The palatal plane

rotated clockwise 0.840 more in the treatment group than due to growth in the short period. The high-pull

traction holds the anterior part of the palate in position while the posterior part is displaced superiorly. The

lower molar erupted 1.1 mm to maintain occlusal contact as the upper molar was intruded in the treatment

sample. There was significant inhibition of vertical development of the mandibular incisors which can be

attributed to the contact of these teeth on the splint serving to retard their eruption. The lower incisor erupted

1.09 mm in the controls as against only 0.24 mm in the treatment group. The treatment resulted in effective

vertical control of the maxilla and maxillary molars. Mandibular plane opened only slight by 0.340. Overbite

decreased an average 2 mm in the treated patients, whereas no significant change in overbite was

demonstrated in the controls. Treatment group showed significant overjet reduction averaging 4.24 mm in

the treatment period ranging from 4-20 months.

Stuani Sasso et al8 used high-pull headgear applied to a modified Thurow appliance, which was an occlusal

splint covering canine to last molar with expansion screw. The inner bow of the face bow was incorporated

in acrylic covering the occlusal surfaces of the posterior teeth. The mandibular plane angle reduced by

50 and facial axis angle increased by 40, indicating change in the facial growth from vertical to horizontal

probably due to the control of the maxillary vertical growth.

High-pull Headgear to the Maxillary First Permanent Molars

Early use of a high-pull headgear has been proposed for treating patients with high angle Class II Division 1

malocclusion. It causes restriction of the horizontal and vertical maxillary growth and also causes distal

movement of the maxillary molars. Firouz et al9 treated 12 adolescent patients with Class II Division 1

malocclusion, having skeletal age of 9.5 to 12.5 years, with a high-pull headgear force applied to the

maxillary first permanent molars. A force of 500 g was used for each side so that the resultant force was

directed through the level of trifurcation of the maxillay molars, approximately at a 200 angle to the occlusal

plane. Thus the appliance generated a force including intrusive, as well as distally directed component. The

intrusive force on the molars was estimated as 500 g., sin 200. Each patient wore the headgear for a 6-

month period, minimum 12 hours a day. A 0.032x0.032 stainless steel passive transpalatal arch was tied to

the lingual brackets welded to the first permanent molar bands to maintain symmetry and prevent molar

rotation. After 6 months of treatment maxillary molars were distally displaced an average 2.56 mm and

intruded an average of 0.54 mm. In contrast, the maxillary molars in the control group were mesially

displaced on the average 0.23 mm and erupted 0.42 mm. The distal molar movement in the treatment group

significantly contributed to the correction of the Class II molar relationship. Overall, the displacement of the

maxillary molars was in the form of translation-like tooth movement. In fact, the roots of these molars were

displaced slightly further 2.50 distally than the crowns. The lower molars did not show a compensatory

eruption in response to the maxillary molar intrusion. Anteroposterior growth of the maxilla was reduced in

the treatment group relative to the control group by 0.5 mm. Horizontally, the maxilla in the treatment group

moved distally by an average of 0.33 mm. Whereas in the controls, A point moved forward (mean 0.5 mm).

The headgear not only restricted or redirected the anteroposterior growth of the maxilla, but also exerted an

orthopedic effect by moving the maxilla distally. In the vertical plane the palate grew downward less than half

the amount of downward growth that was observed in the controls. In a female patient aged 9 years of age

with Class II Division1 malocclusion, 16 mm overjet, anterior openbite, bilateral crossbite, excessive gingival

display, and high mandibular plane angle with short ramus, Sabri10started phase1 treatment with high-pull

headgear therapy using 16 ounce force per side through the center of resistance of the permanent maxillary

first molars. Definite intrusion of the maxillary first molars was noticed after 10 months of headgear wear.

Phase II, which started at 10 years of age, was initiated with rapid maxillary expansion for 3 weeks and 10

mm of arch expansion was achieved. The same appliance was continued for stabilization for 4 months after

giving a double tie through screw holes. After that the expander was removed and high-pull headgear was

reinitiated. By 11 years of age, openbite and overjet were significantly reduced and the cross bite was

corrected. The headgear was continued in phase III of the treatment which involved nonextraction treatment

with 0.022x0.028” edgewise fixed orthodontic appliance. Class I occlusion was achieved at the end of the

treatment. The mandibular plane angle reduced by 20 which indicated that the mechanics used controlled

the vertical movement of the teeth. The angle SNA reduced by 20 and angle SNB increased by 20. Cozza et

al11 treated 12 year 6 months old boy with skeletal Class II Division 1 malocclusion with severe gummy

smile with high-pull headgear to the maxillary first permanent molars and achieved Class I molar relationship

after 6 months of treatment. Spontaneous distal drifting of the maxillary premolars occurred. This was

followed by a fixed orthodontic appliance therapy. Anterior rotation of the mandibular plane was observed

with 30 reduction of the mandibular plane angle and palatal plane rotated anteriorly downward by 50

Trans-Palatal Arch(TPA)

Transpalatal Arches are aimed to cause molar rotation, molar expansion, molar stabilization, reinforcement

of molar anchorage and molar intrusion in the maxillary arch. For all functions except the last, the palatal

arch is placed 1-2 mm away from the palate(fig. 4). For molar intrusion, the palatal arch is placed further

away to transmit intrusive forces of tongue on the molars. Kydd and Toda12 reported that tongue pressure on

the hard palate during swallowing has a range of 37-240 g/cm2(0.36-2.35 N/CM2) with an average of

112g/cm2(1.10N/cm2). Yuhi et al13 found that the tongue pressure exerted on TPA during swallowing showed

a tendency to increase when the loop of the palatal arch was positioned more distally. The tongue pressure

on the TPA placed between first permanent molars was 1.57 and 1.71 N/cm2 for distances of 4 mm and 6

mm from the palate. Maximum pressure was noted when the loop of the TPA was placed in the palatal

midline between the right and left second permanent molars. The maximum tongue pressure was seen

when the loop of TPA was 6 mm from the palatal mucosa in the second molar region(2.23 N/cm2). The difference in force level between the 6 mm position and 4 mm position (1.96 N/cm) of the loop of TPA from the palate was not significant. Hence they recommended positioning the loop of the TPA 4 mm from palate for practical application.Fig. 4: Transpalatal arch.

S pena and Gracco14 inserted a transpalatal arch between maxillary first permanent molars with an acrylic

button added to improve patient comfort and increase tongue contact surface in an 8 year old patient with

skeletal openbite. A high-pull headgear was used to generate vertical intrusive force on the maxillary molars.

TPA was progressively lowered in the palatal vault to increase the action of the tongue in intruding or, at

least, counteracting the extrusion or eruption of the molars. Loss of the occlusal contact occurred in the

molar region. Hence deciduous molar cusps were ground with a diamond bur to reestablish contact of

permanent molars. This was continued until the anterior openbite closed by forward rotation of the

mandible. 

Chin Cup 

A vertical-pull chin cup(fig. 5) has been successfully used with conventional orthodontic appliances for

openbite malocclusions.1,15 Pearson15reported 3.90 decrease in the mandibular plane angle in 20 patients

treated with the extraction of 4 premolars and a vertical pull chin cup for 9 months. Redlich et al16 treated an

8 year old female patient with severe high-angle Class II Division1 malocclusion having vertical maxillary

excess and gummy smile in two phases. Phase 1 treatment which lasted 14 months consisted of maxillary

expansion with Hyrax appliance followed by removable expansion plate to hold expansion achieved by the

Hyrax appliance. This was followed by a high-pull headgear in conjunction with a chin cup which was

continued in an intermediate phase of 2 years. The phase 2 treatment which started at the age of 13 years

involved fixed orthodontic appliance therapy with high-pull headgear for vertical control. The high-pull

headgear with chin cup decreased the mandibular plane angle by 30 at the end of phase1 and further

reduced it by 10 at the end of phase2. Chin cup has also been used during active RPE therapy to minimize

the vertical displacement of the maxilla, control the opening of the mandibular plane angle, and reduce the

gonial angle.17,18 Sankey et al,18 using a high-pull chin cup in combination with a bonded palatal expander

that infringed on the freeway space by 2-3 mm and activated slowly by 1/4 tuen per week, in combination with

a high-pull chin delivering 16-20 ounces of force per side at 450to the occlusal plane at least 14 hours per

day for 6 month in the children with mean age of 8.2 years demonstrated relative intrusion of the maxillary

molars, vertical control of the mandibular molars, and increased eruption of the maxillary incisors that

contributed to the improvement of occlusion. There was no increased vertical displacement of ANS or PNS.

Condylar growth of 3.8 mm occurred which was in a more anterosuperior direction, and the posterior face

height increased significantly. The mandible showed almost three times more forward rotation than expected

and the chin moved forward almost twice as much as in the controls. The Gonial angle reduced by 1.20. Mandibular Crozat appliance controlled vertical eruption of the lower molars while expanding the lower arch. There was improvement in all three planes of space. The authors stated that their results support the axiom, “the whole is greater than the sum of its parts.”Fig. 5: Chin cup with High-pull headgear.

Posterior Bite Blocks

Posterior bite blocks(fig. 6) have been shown to effectively modify vertical skeletal patterns to control

anterior facial heights in animal models and humans.18,19However, they hinge the mandible open beyond its

resting position which tends to increase the gonial angle.19 Animal studies evaluating repelling magnets

embedded in the bite block appliances show superoanterior maxillary displacement and molar intrusion.

However, they also show greater potential for root resorption due to excessive intrusive forces and deviated

mandibular jaw posture that could produce skeletal asymmetries and unilateral crossbites due to the

shearing forces created by the repelling magnets.18,19 Iscan and associates18,19 compared the effects of a

spring loaded bite blocks worn for 6 months to a passive bite block with a vertical chin cup worn for 8

months. Both groups showed similar amounts of forward maxillary displacement, increase in the mandibular

length, posterior molar intrusion, forward mandibular autorotation, increased overbite, and reduction of the

anterior facial height. Dellinger21 used active vertical corrector comprising repelling magnets embedded in the bite blocks and acrylic shields to prevent lateral jaw deviations in conjunction with a vertical chin cup. He found intrusion of the posterior teeth, forward mandibular autorotation and reduction of the anterior face height after 4-7 months of treatment.Fig. 6: Maxillary appliance with Posterior bite blocks.

Chewing/Masticatory Exercises

It has been found that the short face individuals have higher and long face persons have lower biting forces

than those with normal vertical dimension.1 In the cases with muscle weakness syndrome, there is a

downward and backward rotation of the mandible associated with excessive eruption of the posterior

teeth.1 However, Proffit and Fields1 found that there was no difference in the amount of bite force in the

children with long face, normal face and short face. Hence they stated that the different biting force is an

effect rather than a cause of the malocclusion. Buschang et al19 stated that there is a considerable evidence

showing smaller and less active muscles and weaker biting forces among hyperdivergent subjects. Garcia-

Morales et al22 found that greater hyperdivergence was related to poorer mechanical advantage and lower

maximum bite force among children, as reported among adults. Patients with myotonic dystrophy have been

found to have 2-3 times less EMG activity of the temporalis and masseter muscles during maximum

clenching, lower maximum bite forces, anterior openbite malocclusions, and hyperdivergent growth

patterns.23,24 These findings support the hypothesis that reduced muscle function may cause changes in

the craniofacial morphology. 

English and Olfert25 used masticatory muscle exercises as an adjunctive treatment for open bite

malocclusions. They treated these cases at an average age of 9.3 years. First, expansion of the narrow

maxilla was done with bonded rapid palatal expander. It was followed by a TPA with an acrylic button of 15

mm diameter, 2-3 mm off the palatal shelf. High-pull headgear was then used 12 hours per day with 500 g

force per side. Fixed lower lingual arch was placed to maintain arch length and avoid molar extrusion in the

lower arch. After expansion, patients in the expansion group were instructed to clench a soft bite wafer for 1

minute 5 times a day. Each 1 minute session included 5 seconds of isometric clenching followed by 5

seconds of rest and repeated six times for a total 1 minute. The exercise regimen was continued for one

year. Exercise in combination with high-pull headgear produced favourable results. Gonial angle reduced by

average 1.30, and the mandibular plane angle reduced by average 4.80. Thus chewing exercises helped to

control the vertical dimension and the mandible autorotated anteriorly. Kondo26 treated adult patient with

Skeletal Class II openbite by maxillary expansion plate initially to expand tongue space. This was followed

by a fixed edgewise appliance treatment with myofunctional therapy consisting of masticatory and cervical

muscle training which involved chewing gum exercises and neck muscle massage from start to the end of

the treatment. Increased masticatory muscle activity by biting exercises caused intrusion of the overerupted

mandibular molars. This facilitated anterior movement and upward and forward rotation of the mandible.

This demonstrates the usefulness of the excellent treatment method of “muscle wins” philosophy i.e.

restoring normal muscle function by muscle exercises. The malocclusion was corrected in a short period of

25 months.

Role of Extractions in the Vertical Control

Garlington and Logan27 showed that second premolar extractions could be useful in treating anterior

openbite by reducing the posterior vertical dimension. Aynur28reported that in the subject with skeletal

openbite extending to the posterior teeth treated with extractions of the second premolars or the first

permanent molars led to a closing rotation of the mandible by -1.060 and -1.50 respectively. This occurred

because the posterior teeth were protracted out of the palato-mandibular wedge. The difference was

probably due to the fact that the molars in first molar extraction cases had a greater forward movement

compared with those in the second premolar extraction cases. However, there was no decrease in the

mandibular plane angle when molars were protracted forward in the first premolar extraction cases. Martina

et al29 obtained 60 reduction in the mandibular plane angle in a case of skeletal openbite treated by

protraction of upper and lower second molars with closing loop arch wires following extractions of

hypoplastic maxillary and mandibular first permanent molars. The extraction treatment has been reported to

cause supraeruption of molars during space closure which prevents forward mandibular rotation and

reduction in or even maintenance of the vertical facial and dentoalveolar heights. Combined high-pull

headgear and extraction treatment produces similar results. The vertical movements of the upper molar are

better controlled, but the lower molar shows even greater compensatory supraeruption.19 This effect should

be controlled for better results. Orthodontic implants have recently enabled orthodontist to control eruption or

even cause active intrusion of the posterior teeth during this phase of treatment.

CONCLUSION

Effective vertical control during treatment of Class II Division1 cases produces improvement in the sagittal

discrepancy of the upper and lower dental arches. There is individual variation in the treatment response in

different patients. All cases do not respond positively. As the vertical growth ceases the last, this control

needs to be maintained for a prolonged duration, preferably till end of the mandibular growth. The relapse of

the correction of the mandibular plane angle and the gonial angle due to reverting of the growth trend after

treatment to the pretreatment pattern necessitates such a prolonged control. Early treatment is critical as it

gives a psychological benefit to the child and reduces need for invasive surgical procedures like corticotomy

and orthognathic surgery later in the postadolescent phase. 

REFERENCES

1. Proffit WR, Fields HW Jr. Contemporary Orthodontics. 3rd ed. St Lousis: Mosby; 2000. p.

133,135,268,501-508.

2. Langerstrom LO, Nielson IL, Lee R, Issacson RJ. Dental and skeletal contributions to occlusal correction

in patients treated with highpull headgear-activator combination. Am J Orthod Dentofacial Orthop

1990;97:495-504.

3. Stockli PW, Teuscher VM. Combined activator headgear orthopedics. In. Graber TM, Vanarsdall RI.

Editors. Orthopedics: Current principles and techniques. St Louis, Mosby.

4. Kurosawa M, Ando K, Goto S, Class II division I malocclusion with a high mandibular plane angle

corrected with 2-phase treatment. Am J Orthod Dentofacial Orthop 2009;135:241-245.

5. Orten HS, Slattery DA, Orten S. The treatment of severe ‘gummy’ Class II division1 malocclusion using

the maxillary intrusive splint. Eur J Orthod 1992;14:216-223.

6. Fotis V, Melson B, Williams S, Droschi H. Vertical control as an important ingradient in the treatment of

severe sagittal discrepancies. Am J Orthod 1984;85:224-232.

7. Caldwell SF, Hymas TA, Timm TA. Maxillary traction splint: A cephalometric evaluation. Am J Orthod

1984;85:376-384.

8. Sasso SMB, Sasso SA, Sasso SA. Modified Thurow appliance; A clinical alternative for correcting skeletal

open bite. Am J Orthod Dentofacial Orthop 2005;128:118-125.

9. Firouz M, Zernik J, Nanda R. Dental and orthopedic effects of high-pull headgear in treatment of Class II

Division 1 malocclusion. Am J Orthod Dentofacial Orthop 1992;102:197-205. 

10. Sabri R. Non surgical correction of a Skeletal Class II Division 1 malocclusion with bilateral cross bite

and anterior open bite. Am J Orthod Dentofacial Orthop 1998;114:189-194. 

11. Cozza P, Mario A, Franchi L. A nonsurgical approach to treatment of high angle Class II malocclusion.

Angle Orthod 2008;78:553-560.

12. Kydd WL, Toda JM. Tongue pressures exerted on the hard palate during swallowing. J Am Dent Assoc

1962;65:319-330.

13. Yuhi C, Mitsuru M, Shinkichi N. Tongue pressure on loop of transpalatal arch during deglutition. Am J

Orthod Dentofacial Orthop 2003;123:29-34.

14. Spena R, Gracco A. Vertical control in nonextraction treatment of growing patients with anterior skeletal

open Bite. J Clin Orthod 2008;39:443-449.

15. Pearson LE. Vertical control in the treatment of patients having backward rotational growth tendencies.

Angle Orthod 1978;48:132-140.

16. Redlich M, Mazor Z, Brezniak N. Severe high angle Class II Division 1 malocclusion with vertical

maxillary excess and gummy smile: A case report. Am J Orthod Dentofacial Orthop 1999;116:317-320. 

17. Majourau A, Nanda R. Biomechanical basis of vertical dimension control during rapid palatal expansion

therapy. Am J Orthod Dentofacial Orthop 1996;106:322-328. 

18. Sankey WL, Buschang PH, English J, Owen AH. Early treatment of vertical skeletal dysplasia: The

hyperdivergent phenotype. Am J Orthod Dentofacial Orthop2000;118:317-327.

19. Buschang PH, Sankey W, English JD. Early treatment of hyperdivergent openbite malocclusions. Semin

Orthod 2002;8:130-140.

20. Iscan HN, Akkaya S, Koralp E. The effects of the spring loaded posterior bite block on the maxillo-facial

morphology. Eur J Orthod 1992;14:54-60.

21. Dellinger EL. A clinical assessment of the active vertical corrector : A nonsurgical alternative for skeletal

open bite. Am J Orthod Dentofacial Orthop 1986;89:428-436.

22. Garcia-Morales P, Buschang PH, Thockmorton GS, English JD. Maximum bite force, muscle efficiency,

and mechanical advantage in children with vertical growth patterns. Eur J Orthod 2003;3:265-272.

23. Kiliaridis S, Mejersjo C, Thilander B. Muscle function and craniofacial morphology: A clinical study in

patients with myotonic dystrophy. Eur J Orthod 1989;11:131-138.

24. Odman C, Kiliaridis S. Masticatory muscle activity in myotonic dystrophy patients. J Oral Rehab

1996;23:5-10. 

25. English JD, Olfert KDG. Masticatory muscle exercise as an adjunctive treatment for openbite

malocclusions. Semin Orthod 2005;11:164-169.

26. Kondo E. Non extraction and nonsurgical treatment of an adult with skeletal Class II openbite with

severe retrognathic mandible and temporomandibular disorders. World J Orthod 2007;8:261-276.

27. Garlington M, Logan LR. Vertical changes in high mandibular plane angle cases following enucleation of

second premolars. Angle Orthod 1990;60:263-267.

28. Aynur A. Vertical changes following orthodontic extraction treatment in skeletal openbite subjects. Eur J

Orthod 2002;24:407-416.

29. Martina R, Laino A, Michellotti A. Class I malocclusion with severe openbite skeletal pattern treatment.

Am J Orthod Dentofacial Orthop 1990;97:363-373.

FIGURES

Add comment

 Name (required)

 E-mail (required)

 Website

1000 symbols left

Notify me of follow-up comments

Refresh

Send

©Guident.net 2011 All right Reserved

Early Treatment

by Michael C. Alpern, DDS, MS

How the Bonded Rapid Palatal Expansion Bite Plane System can turn big problems into small ones.

With proper diagnosis and application, early interceptive orthodontic treatment can be important in promoting normal, healthy, and attractive facial growth of selected patients. That said, early orthodontic interceptive treatment is relatively easy on patients and hard on the orthodontist and the parents. This article will address the reasoning behind early treatment, as well as its benefits and risks.

The primary justifications for early treatment are correction of a crossbite or correction of a major problem that, if left uncorrected, will result in poor growth patterns.

The Bonded Rapid Palatal Expansion Bite Plane System

My approach to both of these is the Bonded Rapid Palatal Expansion (RPE) Bite Plane System. This system has the potential to change a number of important functional and skeletal growth problems, as well as correct crossbites.

The Bonded RPE Bite Plane System can do the following:

1. Increase functional tongue room without surgery. Increased functional tongue room can promote normal tongue posture and prevent anterior tongue thrusting and resulting anterior open bites.

2. Increase the ability of patients to breathe easier through their nose (in 90% of my patients, according to a 10-year unpublished study). Other studies do not agree, but do not use palatal expansion with bite planes. Regardless, nasal breathing is important in facial development. Mouth breathing is abnormal and can contribute to maxillary and mandibular width deficiency and diminished functional tongue room.

3. Correct or eliminate anterior and posterior crossbites. Anterior crossbites can be corrected by adding anterior lingual whip springs to the anterior arms of the palatal expander. The bite planes temporarily open the bite, permitting clearance to “jump” or permitting unencumbered freedom of movement of a maxillary lingual tooth buccally or anteriorly without occlusal interferences.

4. Redirect marked vertical growth patterns. Bonded palatal expanders are activated (by turning the screw) once per day for a period of 4 to 6 weeks. Then, we secure the expansion screw device with a stainless steel ligature and cover it with cured Triad for tongue comfort. The expander then stays in place for 4 months. This adds up to a total of 5 months in which selective bite plane thickness can orthopaedically restrain and/or redirect excessive vertical growth. In hyperdivergent (vertical growers) we build the bonded expanders bite planes more thickly (especially in back). These thick bite planes invade the freeway space. Most patients can exert from 250 to 350 pounds

per square inch of biting force. As the patient slightly clenches on the posterior, thick bite planes, orthopaedic forces are created, which restrain vertical growth and intrude posterior teeth (for closing anterior open bites).

When we remove the palatal expander, we immediately place a palatal bar from maxillary first molar to first molar and bond flowable composite to the posterior molars. Thus, the posterior vertical restraint is continued after the expansion device has been removed.

Michael C. Alpern, DDS, MS

Another key component to this system is adding buccal external hooks to the expanders during construction. At the completion of maxillary expansion, with the expansion screw ligated, we immediately begin crossbite elastics from lingual hooks on mandibular first molar bands. Thus, we begin lingual uprighting of mandibular molars that may be lingually proclined into functional tongue space. The maxillary bite planes prevent over uprighting of the mandibular molars and give simultaneous vertical control to the mandibular molars.

Normally, during palatal expansion, no other forces are placed on the palatal expander to permit maximum sutural expansion and minimum alveolar tipping. Thus, anterior whip springs or crossbite elastics are not used during this time.”

The Custom Helmet

The only exception comes from the concepts that only during maxillary palatal expansion can the maxilla be moved forward without surgery. If maxillary protraction is planned, then we build Class III protraction hooks into the palatal expander. On the day the palatal expander is bonded into place, we immediately place a custom helmet designed by my wife, Ada Hinda Alpern, RDH. The helmet is custom built by an orthodontic assistant, and as soon as the expander is bonded, we fit the helmet on the patient and demonstrate attachment of elastics from the palatal expansion Class III protraction hooks to the hooks on the helmet.

Helmet wear involves 1 pound of force per side of elastic traction during the day. When patients are upright, most of the anchorage force is against the forehead. We encourage patients to sleep on their backs so that the weight of their heads is against the back of the helmet, permitting us to apply more protraction force—up to 2 pounds per side.

Before: The patient has severe maxillary width deficiency, impacted and transposed cuspids, and marked deficient functional tongue room.

After: The patient was treated with a bonded Rapid Palatal Expansion System with crossbite hooks and protraction hooks. After palatal expansion and protraction, a Cetlin palatal bar was placed along with partial bonding in the mandibular arch. Approximately 18 months from expansion, all of the permanent teeth were bonded and a series of square wires were used to complete treatment. The impacted and transposed cuspids are in normal position and there is normal functional tongue room—all without extraction of permanent teeth. 

We ask patients to wear the helmet for at least 18 to 20 hours per day for 8 weeks, and then wear it at night for 8 more weeks. Many children who are busy at school cannot complete this schedule. We have these patients wait until 1 month before school ends to come in for records and appliance construction. They then can devote the 18 to 20 hours for 8 weeks during their summer vacation. Patients and parents choose this therapy. I do not do this “to” the patient. They request it.

After Early Treatment

At the conclusion of 5 months of palatal expansion and stabilization and 5 to 6 months of a palatal bar and a banded lingual archwire, we remove the palatal bar and the mandibular lingual arch (not the bands) and place the patient in an observation period. At first, patients are seen every 6 to 8 weeks for observation of growth and development. Any minor problems with development can be handled with removable appliances.

Thus, early treatment takes approximately 1 year, and large problems have been reduced to smaller problems. Potential impacted maxillary cuspids now have adequate maxillary width for normal eruption and not impaction and/or transposition with maxillary incisors.

To read more articles by and about Alpern, search for his name in our online archives.

Later, we observe these patients every 3 months until all their permanent teeth are in with full root development. Then, full orthodontic bands and bonded brackets can be placed as the beginning of 12 to 18 months of full treatment instead of 3 to 4 years of extensive treatment. Many times, potential tooth extraction requirement can be eliminated. And, for the long term, the temporomandibular joints are more normal due to earlier correction of an occlusal trauma such as a crossbite.

In my 33-year orthodontic career, I have found that parents often forget (no matter how many times you tell them) that additional fees are required for full banded and bonded treatment following early treatment. As a result, we do not call this two-phase treatment; we base our fees on “Continuous Treatment.”

A final note on timing: Palatal expansion primarily uses the maxillary first permanent molars as the primary anchorage. Therefore, I never begin early treatment until I have full root development of the maxillary first permanent molars. To disregard this philosophy is to run the risk of marked root shortening, dilacerations, or a compromised root structure for the entire dentition.