Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03481088 |
| Other study ID # |
Kavita |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 9, 2017 |
| Est. completion date |
June 30, 2018 |
Study information
| Verified date |
March 2018 |
| Source |
Postgraduate Institute of Dental Sciences Rohtak |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
It is a prospective descriptive study to evaluate TMJ disc-condyle-fossa relationship using
MRI scan following functional appliance therapy in skeletal Class II Division 2 malocclusion
in adolescent females.
All records, including MRI scans will be collected at three stages and will be traced for
various angular and linear measurements to document the alterations within the condyle
glenoid fossa complex
1. Stage- I (pre-treatment),
2. Stage- II (after pre-functional therapy)
3. Stage-III (After 6-8 months of functional appliance therapy that is after correction to
Class I molar relation
Description:
Angle's class II division 2 malocclusion is relatively rare. Its frequency lies between 1.5
and 5% of all occlusion in white western population while in north Indian population it is
5.8% Generally in Class II division 2 malocclusion mandibular denture is more distally placed
in relation to maxillary denture, a compensating effect in this type of mandibular retrusion
, which offsets some of the disharmony of the facial profile is that the chin point is
usually very pronounced3. It has been stated that patients with skeletal class II division 2
malocclusion ,when compared with normal class I or class II division I subject have larger
masticatory muscles that in addition are oriented in a more anterior direction. These
characteristics results in significant differences regarding their mechanical advantage and
magnitude of occlusal forces.5 Several investigators have also stated that the mandible is
locked posteriorly in Angle's Class II division 2 malocclusion with deep bite and the
treatment which unlocks the bite during an active growth period can allow the mandible to
grow or be repositioned forward much more than if treatment of unlocking of a bite were not
undertaken. In class II division 2 malocclusion the condyle is positioned posteriorly while
the disk is positioned anteriorly in relation to glenoid fossa. The articular disc in Angle's
class II Division 2 patients could take a relative protrusive position in comparison with the
other Angle's classes of malocclusion .
Successful treatment of many orthodontic problems depends to a great extent on the amount of
mandibular growth patients experience during treatment. Functional appliances have been used
for nearly 100 years in an attempt to induce mandibular growth by changing muscle function
and condyle glenoid fossa relationships. Several studies have shown that the treatment of
skeletal Class II patients with functional appliances is more successful when initiated
during the adolescent growth spurt.
MRI a multiplanar imaging technique, has the advantage of giving an accurate assessment of
both the bony and the soft tissues.It has high sensitivity for visualization of position and
configuration of disc . This technique is believed to be non-invasive, radiation free and
gives more superior contrast resolution than any other imaging modality. Recent studies have
shown that we can have greater confidence in MRI as diagnostic tool because of improved
quality.
MATERIALS AND METHODS- It is a prospective descriptive study to evaluate TMJ
disc-condyle-fossa relationship using MRI scan following functional appliance therapy in
skeletal Class II Division 2 malocclusion in adolescent females.
The present study will be conducted in the Department of Orthodontics and Dentofacial
Orthopedics, PGIDS, in association with the Department of Radiology, PGIMS, and Department of
Oral Radiology, PGIDS, Pt B. D. Sharma University of Health Sciences, Rohtak.
. Ethical clearance approved by institutional Ethics Committee,Post Graduate Institute of
Dental Sciences
Source of data:- The sample size consists of 15 subjects who were selected from the patients
attending regular OPD at the Department of Orthodontics and Dentofacial Orthopedics for
orthodontic treatment.
TARGET SAMPLE SIZE Sample size on= 13 for present study Calculation based on effect size of
1.23 with standard deviation of 10.5 at 95% confidence interval and 80% power n=2.{Z(
1-α/2)+Z(1-β)} 2/ ∆2 To compansate for 10 % dropout the final sample size will be 15
. INFORMED CONSENT OF THE PATIENT AND AGREEMENT TO BE RANDOMISED A valid, informed written
consent of the patient or parent/ guardian and an agreement to be randomized was obtained
from the patient before registering the patient in this clinical study. Patient or parent/
guardian was informed about all the theoretical risks and benefits of the intervention under
test.
INTERVENTION AND DESIGN OF STUDY The study sample will consist of 15 growing females with
skeletal class II and Angle's Class II division 2 malocclusion indicated for functional
appliance therapy using Twin Block appliance.
The patients attending the regular OPD at the Department of Orthodontics and Dentofacial
Orthopedics will be screened to match the inclusion criteria. Lateral Cephalograms will be
taken to assess CVMI stage and growth pattern. Skeletal Class II Div 2 adolescent females
with growth phase CVMI stage 2-4 having average to horizontal growth pattern as assessed by
SN-MP (Go-Gn) angle will be included in the study.
Following detailed clinical examination, cephalometric analysis and treatment planning , the
patients who will be ready to receive treatment will undergo pre-treatment MRI of
condyle-glenoid fossa complex,then these patients will be treated with pre-functional therapy
to correct retroclined incisors. After this, MRI of the TMJ of all these patients will be
taken, that is after unlocking of mandible. Then these patients will undergo functional
appliance therapy to achieve class 1 occlusion for an average of 6-8 months. After that, post
fuctional MRI of the TMJ of all the patients will be taken.
The MRI protocol will include T1 weighted (T1W) spin echo sequences (TR 450/TE 15/Fov 160*160
mm), Proton density weighted spin echo sequences (TR 1500/TE 30/Fov 150*150) in coronal
oblique and sagittal oblique planes of 3 mm slice thickness with no interslice gap. All
records, including MRI scans will be collected at three stages and will be traced for various
angular and linear measurements to document the alterations within the condyle glenoid fossa
complex.
1. Stage- I (pre-treatment),
2. Stage- II (after pre-functional therapy)
3. Stage-III (After 6-8 months of functional appliance therapy that is after correction to
Class I molar relation ANGULAR AND LINEAR MEASUREMENTS The eminence angle and the
sagittal disc position measured in relation to two reference lines: the posterior
condylar line (PC line) and the Frankfurt Horizontal plane (FH Plane). The PC line to be
drawn directly on the MRI scan, while the FH plane transferred from the lateral
cephalogram to the MRI scan, according to the method given by Nebbe et al.
Transfer of FH plane Determination of long axis of the condyle will be done by two step
circle center method by Nebbe et al.
ANGULAR MEASUREMENTS 1-2) The eminence angle and the coronal disc position will be evaluated
by the method described by Chintakanon et al.
3) The sagittal disc position will be evaluated using PC line and FH plane as described by
Chintakanon et al.
4) Sagittal condylar concentricity will be evaluated using the method described by Pullinger
et al.
5) The glenoid fossa angle will be measured on the sagittal films as the angle between the
tangents to the anterior and posterior slopes of the glenoid fossa.
LINEAR MEASUREMENTS 6) Condyle and glenoid fossa displacements: The position of the glenoid
fossa, and that of the condyle, will be evaluated with respect to the centre of the external
auditory meatus (c-EAM). by marking one point at the centre of condyle (c-CH) and the linear
distance of the c-CH from the c-EAM will be evaluated as the shortest distance from the
constructed FH perpendicular.
7) Distance between c-PGS (crest of the post-glenoid spine ) & c-EAM : One point will be
marked at the crest of the post-glenoid spine (c-PGS) and the linear distance of the c-PGS
from the c-EAM will be evaluated as the shortest distance from the constructed FH
perpendicular.
8) Superior joint space will be measured from the shortest distance between the most superior
point of the condyle and the most superior point of the mandibular fossa.
Statistical analysis:-The data recorded will be processed by standard statistical analysis
