June, 2009

A Camouflage Treatment of Class II, Division 1 Malocclusion

Dr. K. S. NEGI, BDS, MDS (Lko.)

In our daily practice we treat a great percentage of skeletal discrepancies. There are three possible approaches to treat a skeletal Class II malocclusion: 1) modification of growth 2) Camouflage (displacing the teeth to obtain proper functional occlusion despite the skeletal discrepancy), and 3) surgical repositioning of the jaws. [1]

But in adult cases, where growth no longer occurs, camouflage and surgery are the only treatment options. Which of these is the best approach is highly controversial. The effects of surgical orthodontics versus camouflage treatment can be measured in terms of the clinical outcome produced by the treatment, i.e. the changes in dental occlusion, cephalometric measurements, and esthetic changes that occur. When comparing the alternative treatment plans, it also is important to evaluate treatment efficiency, determined by whether and to what extent the treatment goals were met by improving dental relationships and dentofacial esthetics. [2]

One of the camouflage options available is the extraction of the maxillary premolars, correcting the canine to a normal class I relationship, leaving the molars in a class II relationship. Treatment with 2 premolar extractions gives a better occlusal result than treatment with 4 premolars extractions. [3]

The present case report demonstrates the camouflage treatment of an adult Class II, Div. 1 malocclusion using a K-SIR archwire, to overcome the common problem of controlling a deep bite and anterior torque during space closure and retraction of the maxillary anterior teeth. This archwire has the biomechanical property of simultaneous intrusion and retraction. Above all, it has the advantage of easy fabrication, patient comfort and requires minimal patient compliance. [4]

Diagnosis

A 29 year old Indian female reported to the Dept. of Orthodontics & Dentofacial Orthopedics, H. P. Govt. Dental College Shimla, for orthodontic treatment with the chief complaint of forwardly displaced teeth and unable to close her lips, leading to embarrassment in social gatherings. Clinical examination revealed a symmetrical, mesocephalic facial type, convex profile, lip trap, deep mentolabial fold and an acute nasolabial angle. The patient shows a good range of motion and no TMJ symptoms. The patient has an overjet of 11mm and palatal impingement of the lower incisors. A V-shaped arch form, as the maxillary arch is severely protruded caused by a pernicious thumb sucking habit; though she is reluctant to give any history of a past digit sucking habit. Both the maxillary and mandibular incisors were proclined, a severe curve of Spee and molars occluding in an end-on relationship (Fig.1).

Figure 1. 29 yr old female with Class II div 1 malocclusion before treatment

Before treatment

The cephalometric analysis confirmed a skeletal class II malocclusion with an ANB of 5 degrees, a Wits of 7mm and proclined maxillary incisors (Table 1).

Table 1. Cephalometric Analysis

  Norm Pre-treatment Post-treatment
SNA 82 80 80
SNB 80 75 75
ANB 2 5 5
Wits -1 8mm 8
GoGn-SN 32 33 33
OP- SN 14 12 11
1 – NA 4mm / 22 15mm / 50 5mm / 24
1 – NB 4mm / 25 7mm / 23 7mm / 24
1 – SN 104 130 104
S/Line-U/L 0 +4mm 0
L/L 0 +4mm +1mm

Treatment

Treatment objective were to:

  1. Achieve lip competence and reduce the mentolabial fold.
  2. Eliminate palatal impingement
  3. Develop an ideal overjet & overbite.
  4. Correct the anteroposterior relationship.
  5. Achieve occlusal intercuspation with a Class I canine relationship.
  6. Improve the profile and facial esthetics.

The treatment plan involved:

  1. Extraction of maxillary first premolars and one mandibular central incisor.
  2. Alignment & leveling of the arches.
  3. En masse retraction of the maxillary anterior segment, with a K-SIR archwire.
  4. Closing the extraction space and leveling the curve of Spee without increasing arch perimeter.
  5. Final consolidation of space and settling of the occlusion.

Treatment Progress

The maxillary first premolars were extracted. The fist molars were banded and the maxillary arch was bonded from second premolar to second premolar with a .022 x 0.28 pre-adjusted edgewise brackets. The maxillary arch was aligned with a .016 Niti wire. After a month, a K-SIR .019 x .025 TMA archwire was fabricated and placed in the upper arch and activated (Fig. 2).

Figure 2. 019x.025 TMA K-SIR maxillary archwire with activation

Maxillary archwire with activation

After three activations every 6 weeks, the overjet was reduced to 4mm with controlled tipping of maxillary incisors and closing of more than 3/4th of the extraction space (Fig. 3).

Figure 3. Passive form of K-SIR archwire after second activation came for next activation

Passive form of K-SIR archwire after second activation came for next activation

After the last activation, the K-SIR archwire was removed, and the extraction site was stabilized with a figure eight ligation between canine, second premolar and molar. An .018 x .025 Niti archwire was placed to level the arch, especially between the canine and second premolar. The mandibular arch was bonded with a .022 x .028 pre-adjusted edgewise brackets from second premolar to second premolar with molar bands on first molars and a mandibular central incisor was extracted. A 016x.022 Niti archwire was placed in the mandibular arch (Fig.4).

Figure 4. Maxillary .018x.025 Niti archwire for slot leveling. Mandibular incisor extracted and .016x.022 Niti archwire for alignment and leveling.

Maxillary .018x.025 Niti archwire for slot leveling. Mandibular incisor extracted and .016x.022 Niti archwire for alignment and leveling.

After alignment and leveling of the mandibular arch, .018 x .025 stainless steel coordinated ideal arch wires with accentuated maxillary and mandibular reverse curve of Spee were placed, and final consolidation of spaces was carried out with an elastomeric chain (Fig. 5).

Figure 5. Maxillary and mandibular .018x.025 stainless steel coordinated ideal archwire

Maxillary and mandibular .018x.025 stainless steel coordinated ideal archwire

Then the same archwire was kept for six weeks and finally, for occlusal settling, .014 S.S. wires were placed for a month. After debonding, Hawley wraparound retainers were delivered and scheduled regular follow-up visits every month.

Treatment Result

Lip competence and a decrease in the mentolabial fold were achieved, improving the patient’s facial appearance. A functional occlusion with Class I canine and Class II molar relationship was achieved (Fig. 6).

Figure 6. Post-Treatment

Post-Treatment

Cephalometric superimposition demonstrate controlled uprighting of maxillary incisors, changing maxillary incisor inclination (1-NA) 50o/15mm to 24O/5mm (Fig. 7). Deep curve of Spee leveled with minimum proclination of the mandibular incisors and with no increase of arch perimeter. There was intrusion of maxillary and mandibular incisors and mesial movement of maxillary molars, which was desirable to correct the end-on molar relation to a Class II relation.

Figure 7. Cephalometric Tracing

Cephalometric Tracing

A number of studies undertaken in recent years have lead to the common conclusion that the extractions of premolars in any sequence, if undertaken after a thorough individual diagnosis, are unlikely to lead to negative profile effect. [5,6,7,8] The study also shows that with camouflage treatment, patient satisfaction was similar to that achieved with a surgical orthodontic approach. [9]

A well chosen treatment plan, undertaken with appropriate control of orthodontic mechanics, is likely to provide patients with a satisfactory overall facial result. So that an individualized and flexible treatment plan should be made to satisfy the needs of each particular patient, rather than the patient receiving the one general treatment plan known to the clinician.

References

1. Proffit WR, Phillips C, Dann C. Who seeks surgical-orthodontic treatment? Int J Adult Orthod Orthogn Surg.5:153-60, 1990.

2. Proffit, W.R.; Phillips, C.; and Douvartzidis, N.: A comparison of outcomes of orthodontic and surgical orthodontic treatment of Class II malocclusion in adults, Am. J. Orthod.101:556-565, 1992.

3. G Janson, AC Brambilla, JFC Henriques, MR de. Class II treatment success rate in 2- and 4-premolar extraction protocols, Am. J. Orthod.125(4):472 – 479, 2004

4. Varun Kalra : Simultaneous intrusion and retraction of anterior teeth, JCO Vol. XXXI (9):535-540, Sept 1998.

5. Moseling K, Woods MG. Lip curve changes in females with premolar extraction or non-extraction treatment. Angle Orthod.74:51-62, 2004.

6. Conley SR, Jernigan C. Soft tissue changes after upper premolar extraction in Class II camouflage therapy. Angle Orthod.76:59-65, 2006.

7. Ramos AL, Sakima MT, Pinto AS, Bowman SJ. Upper lip changes correlated to maxillary incisor retraction – a metallic implant study. Angle Orthod.75:499-505, 2005.

8. Tadic N, Woods MG. Incisal and soft tissue effects of maxillary premolar extraction in Class II treatment. Angle Orthod.77:808-816, 2007.

9. Mihalik, C.A; Proffit, W.R; and Phillips, C.: Long-term follow up of class II adults treated with orthodontic camouflage: A comparison with orthognathic surgery outcomes, Am.J.Orthod. 123:266-278, 2003.


Contributed by:

Dr. K. S. NEGI, BDS, MDS (Lko.)
Assistant Professor, Department of Orthodontics & Dentofacial Orthopedics
H. P. Government Dental College & Hospital, Shimla, India

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