Download Two Phase Orthodontic Treatment: A Case Report

Case Report
Two Phase Orthodontic Treatment: A Case Report
S Vinaya1, Priyanka Basu1, U S Krishna Nayak2, Ashutosh Shetty3, U S Arjun Nayak1, Aneesh Katyal1
Post-graduate Student, Department of Orthodontics & Dentofacial Orthopaedics, AB Shetty Memorial Institute of Dental Sciences, Nitte University,
Mangalore, Karnataka, India, 2Head and Dean, Department of Orthodontics & Dentofacial Orthopaedics, AB Shetty Memorial Institute of Dental
Sciences, Nitte University, Mangalore, Karnataka, India, 3Professor, Department of Orthodontics & Dentofacial Orthopaedics, AB Shetty Memorial
Institute of Dental Sciences, Nitte University, Mangalore, Karnataka, India
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Myofunctional appliances become active through muscular forces that bring about the dentoalveolar and skeletal changes. Functional
appliances can be both removable or fixed. Twin block appliance given by William Clark is one of the most popular functional appliance
owing to its ease of fabrication for the orthodontist and its ease of wear for the patient. It is known to bring about both skeletal and dental
changes and has been used extensively in Class II growing patients. This was a case report of a 12-year-old patient treated in two phases, first
the functional phase using the twin block, followed by the second phase of fixed orthodontic appliance.
Keywords: Class II malocclusion, Functional phase, Twin block appliance
INTRODUCTION
Myofunctional appliances become active through muscular
forces that bring about the dentoalveolar and skeletal changes.
Functional appliances can be removable or fixed. The mode of
action differs depending on the design; however, their effect
is produced from the forces generated by the stretching of the
muscles (Mills and McCulloch, 1998).1 There are a number
of clinical indications for the use of functional appliances to
correct Class II malocclusion (Lund and Sandler, 1998).2
The twin block appliance (TBA) was developed by Clark in 1988
used to treat Class II malocclusions, and has been described as
one of the most patient compliant appliances. The TBA along
with good patient compliance gives fast and excellent results
and perhaps this is why it has become a popular choice for
growth guidance in Class II division one malocclusion.3-5
with a Class II skeletal pattern with an average mandibular
plane angle. She presented with no asymmetry. Intra orally
except for the right maxillary canine, all teeth were present
in both the arches. Furthermore, she presented with 4 mm of
lower anterior imbrication. Both over jet (8 mm) and overbite
(5 mm) were increased. The midlines did not coincident,
and the molar relationship on the right side was end on and
Class I on the left side.
Cephalometrically ANB was 6° suggesting a Class II skeletal
pattern. The vertical measurements were within the normal
range. The lower incisors inclination was at 95°.
Treatment objectives
Phase-I:
1. Achieve normal overbite and over jet
2. Achieve super Class I molar relationship.
The TBA consists of two sets of acrylic blocks inclined at 70°
to induce occlusal forces that guide the mandible forward.
This treatment modality stimulates mandibular growth and
simultaneously restricts maxillary growth.
Phase-II:
1. Level and align the arches
2. Achieve Class I molar and canine relationship
3. Maintain facial balance and esthetics.
The following is a case report of a 12-year-old patient treated
in two phases, first the functional phase using the twin block,
followed by the second phase of fixed orthodontic appliance.
Treatment rationale
The functional phase of the treatment aided in a reduction
of over jet and correction of Class II molar relationship
by forward posturing of the mandible and simultaneous
restrictive action on maxillary growth. Furthermore, it is
known that there is the theoretical advantage of improving
the patient’s profile by causing a small skeletal change
(O’Brien et al., 2003b).6 The maxillary component of the
twin block had an acrylic baseplate covering the palate
and occlusal surfaces of first molars and second premolars.
CASE REPORT
Etiology and diagnosis
The patient reported to the Department of Orthodontics
and Dentofacial Orthopedics with the chief complaint of
proclined upper anterior teeth. On diagnosis, she presented
Corresponding Author:
Dr. U.S. Krishna Nayak, Department of Orthodontics, AB Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore, Karnataka, India.
Mobile: +91-9845242020. E-mail: [email protected]
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Vinaya, et al.: Two phase orthodontic treatment
Two Z springs were used for guiding the eruption of the
unerupted canines. The mandibular component had a
lingual baseplate covering the edge of the incisors. Adams
clasps on the first molars were used to provide posterior
retention, and the inclined planes were angulated at 70°.
This phase was followed by fixed appliance therapy.
and it is suitable to use in a permanent and mixed dentition.
Since the patient’s chief complaint was the proclined upper
anterior, and the functional phase reduced the over jet, the
patient’s confidence improved and also the risk of sustaining
trauma to the upper incisor was minimized (O’Brien et al.,
2003c).7
As an alternate treatment plan, using Class II intermaxillary
traction with only fixed therapy was an option but the
disadvantage would be difficulty in achieving Class I molar
relation.
An anterior bite plane was given during the transient phase
to manage the posterior open bite and during the fixed
therapy by coordinating the arch wires.
Moreover, anchorage reinforcement would be mandatory as
any anchorage loss by mesial movement of the upper molars
would compromise on our treatment objectives.
Treatment Progress
The functional phase was completed in 9 months. The
over jet reduced by 2° cause of lower anterior proclination.
During the fixed therapy phase, which lasted for 12 months
both arches were leveled and aligned along with correction
of molar relation. Total treatment time was 23 months
including 9 months of Phase 1 and 2 months transient phase
and 12 months of Phase 2.
During treatment, SNA and SNB increased by 1° and
4° respectively improving the profile toward Class I
pattern. The N-A-Pog reduced from 23° to 10°. The
L1 to MP increased from 95° to 101°. The interincisal
angle increased from 111° to 117°. The nasolabial angle
increased from 75° to 78°. The upper lip to E line reduced
from 2 mm to −2 mm and the lower lip to the E plane
Treatment Results
The patient profile improved post treatment. Forward
growth of the mandible aided in correction of the over
jet. Lower incisor proclination helped in correction of the
imbrications. Both molar and canine relationships were
Class I at the end of treatment. The growth changes and
the superimposition are demonstrated in the cephalometric
tracings done on the lateral cephalograms.
DISCUSSION
Twin block functional appliance has several well-established
advantages including the fact that it is well-tolerated by
patients (Harradine and Gale, 2000), robust, easy to repair
Figure 1: Pre-treatment extra oral photos
Figure 2: Pre-treatment intra oral photos
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Vinaya, et al.: Two phase orthodontic treatment
was reduced by 1 mm. The superimposition of the
lateral cephalograms demonstrated a favorable growth
direction. The mandible grew downward and forward
with a slight anterior growth rotation. The lower incisors
were proclined despite the use of acrylic capping, which
Table 1: pre treatment cephalometric values
Figure 3: Pre-treatment lateral cephalogram and hand wrist radiograph
Cephalometric values
SNA
SNB
ANB
Angle of convexity
Wits
FMA (Tweed’s)
SN‑Go‑Gn
Jarabaks
Bjorks sum
Upper incisor to NA
Lower incisor to NB
Lower incisor to mandibular plane
NA
Pre‑treatment
82°
76°
6°
23°
0 mm
30°
31°
64.7%
391
26°/6 mm
34°/7 mm
95°
75°
FMA: Frankfort mandibular plane angle, NA: Nasolabial angle
Figure 4: Pre-treatment orthopantomogram
Figure 5: Twin block appliance
Figure 7: Post-treatment extra oral photos
Figure 6: Post-twin block intra oral photos
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Vinaya, et al.: Two phase orthodontic treatment
Figure 8: Post-treatment intra oral photos
Figure 9: Post-treatment lateral cephalogram
Figure 11: Pre and post treatment extra oral changes
Figure 12: Pre and post treatment intra oral changes
(Lee et al., 2007). However, in this case, the functional phase
Figure 10: Superimposition
aided the fixed phase dramatically.
was reported to reduce the amount of lower incisors
proclination.
In terms of soft tissue changes, a study aimed to identify
and quantify soft tissue changes during treatment with twin
block and dynamax appliance using the techniques of threedimensional optical surface laser scanning, cephalometric,
and clinical measurements (Lee et al., 2007) and it was
concluded that soft tissue difference after treatment was
clinically relevant.
(Mills and McCulloch, 1998).1 There was mesial movement
of the lower molars. It has been proved in the literature that
functional appliances do not produce long-term skeletal
changes, and most of their effects are dento-alveloar
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Vinaya, et al.: Two phase orthodontic treatment
Table 2: Cephalometric values pre,mid and post treatment
Cephalometric
values
Pre‑treatment
Mid
treatment
Post‑treatment
SNA
SNB
Wits
N‑A‑Pg
Upper incisor to NA
82°
76°
0 mm
23°
26°/6 mm
83°
80°
1 mm
10°
27°/5 mm
Lower incisor to NB
34°/7 mm
95°
82°
81°
0 mm
10°
26°/6
mm
35°/6
mm
100°
111°
75°
2 mm
3 mm
6 mm
5 mm
117°
78°
2 mm
2 mm
4 mm
6 mm
Lower incisor to
mandibular plane
Inter‑incisal angle
Nasolabial angle
Upper lip to E line
Lower lip to E line
Upper lip to S line
Lower lip to S line
35°/6 mm
101°
117°
78°
−2 mm
2 mm
4 mm
6 mm
NA: Nasolabial angle
Patient was put on retention immediately, with an upper
Hawley’s retainer and a lower fixed lingual retaine, and it
was well-explained to the patient that long-term wear of
the retainer is required to ensure stability (Little, 1999).8
CONCLUSION
TBAs mainly bring about dento-alveolar with a few skeletal
changes. When used, functional appliances bring about
maximum correction in growing patients. In this case, the
patient was treated in 2 phases, i.e., functional, followed by
fixed mechanotherapy bringing about desirable outcome.
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REFERENCES
1. Mills CM, McCulloch KJ. Treatment effects of the twin block
appliance: A cephalometric study. Am J Orthod Dentofacial
Orthop 1998;114:15-24.
2. Lund DI, Sandler PJ. The effects of Twin Blocks: A prospective
controlled study. Am J Orthod Dentofacial Orthop 1998;113:
104-10.
3. Clark WJ. The twin block technique. A functional orthopedic
appliance system. Am J Orthod Dentofacial Orthop 1988;93:1-18.
4. Al-Anezi SA. Class II malocclusion treatment using combined Twin
Block and fixed orthodontic appliances - A case report. Saudi Dent
J 2011;23:43-51.
5. O’Brien K, Wright J, Conboy F, Sanjie Y, Mandall N, Chadwick S,
et al. Effectiveness of treatment for Class II malocclusion with the
Herbst or twin-block appliances: A randomized, controlled trial.
Am J Orthod Dentofacial Orthop 2003a;124:128-37.
6. O’Brien K, Wright J, Conboy F, Sanjie Y, Mandall N, Chadwick S, et al.
Effectiveness of treatment for Class II malocclusion with the Herbst
or twin-block appliances: A randomized, controlled trial. Am J
Orthod Dentofacial Orthop. Part 1: Dental and skeletal effects.
Am J Orthod Dentofacial Orthop 2003b;124:234-43.
7. O’Brien K, Wright J, Conboy F, Sanjie Y, Mandall N,
Chadwick S, et al. The effectiveness of treatment of class II
malocclusion with the twin block appliance: A randomised,
controlled trial. Part 2: Psychological effects. Am J Orthod
Dentofac Orthop 2003c;124:488-95.
8. Little RM. Stability and relapse of mandibular anterior
alignment: University of Washington studies. Semin Orthod
1999;5:191-204.
How to cite this article: Vinaya S, Basu P, Nayak USK, Shetty A, Nayak USA,
Katyal A. Two phase orthodontic treatment: A case report. IJSS Case Reports
& Reviews 2014;1(3):26-30.
Source of Support: Nil, Conflict of Interest: None declared.
IJSS Case Reports & Reviews| August 2014 | Vol 1 | Issue 3