Figure 1. The Farmand appliance from a frontal view.
Figure 2. The Farmand appliance from a lateral view.
Figure 3. Before-treatment picture of a patient with mandibular
deficiency. Figure 4. After-treatment picture of the same patient treated with
the Farmand appliance.
has ever compared the treatment effects of the
Farmand appliance and FR-2; therefore, the aim of
this study was to compare the dentoskeletal effects
of the Farmand appliance with FR-2 in the treatment
of prepubertal Class II division 1 malocclusion
patients with mandibular deficiency. selected from patients treated with the Farmand
appliance (Figs. 1-2) and twenty-eight subjects
were selected from patients treated with the FR-2
appliance.
At the beginning of the treatment, all patients were
in the prepubertal stage (CS1 and CS2), according
to the recently improved version of the Cervical
Vertebral Maturation (CVM) method as described
by Franchi et al. 19 and Baccetti et al. 20
The mean age of the patients treated with the
Farmand appliance in the experimental group was
11.1 (SD 1.4) years and the average treatment time
was 16 (SD 1.7) months.
The Farmand appliance is a passive tooth borne
appliance. It consists of two extended flexible
labial bows, a tongue bow, four rests (stop), and
an acrylic plate. The acrylic plate extends from the
occlusal surface to the lingual shields. A heavy wire
(1 mm diameter), which acts as a tongue bow, is
positioned posteriorly to connect the right and
left acrylic parts on the palatal aspect in order to
reinforce the appliance. The upper and lower labial
bows are constructed with 0.8 mm stainless steel
wire extended from canine to canine with horizontal
loops in the canine region. The rests (stop) are
placed on the mesial of the upper and lower first
molars. The construction bites of the patients were
taken with the upper and lower anterior teeth in an
edge-to-edge occlusion with 2 to 3 mm posterior
clearance.
The FR-2 group consisted of 28 patients (15 girls,
13 boys) with the mean age of 11 (SD 1.5) years that
were treated with the FR-2 appliance. The treatment
time was 16.5 (SD 3.5) months.
2. Materials and Methods
This retrospective study was reviewed and approved
by the Institutional Review Board (IRB) of the School
of Dentistry, Shiraz University of Medical Sciences,
Shiraz, Iran and the Tehran Dental Branch, Islamic
Azad University, Tehran, Iran and in accordance with
the Helsinki Declaration of 1975, as revised in 2000.
A pilot study was conducted on 10 patients (5 in
each group) and the SNB was chosen as the primary
outcome. The sample size of the present study was
calculated based on a significance level of 0.05
and a power of 90%, to detect a minimum clinically
significant change of 1.6° in SNB. Using a two-tailed
paired t-test (PASS 2011, NCSS software, Kaysville,
Utah, USA), 26 samples would be required in each
group. All subjects met the following inclusion
criteria:
1) ANB>5°, SNB<77°, overjet>5 mm at the initial
lateral cephalograms;
2) No syndromic or medically compromised patients;
3) No previous surgical intervention;
4) No use of other appliances before or during the
period of functional treatment;
5) No skeletal asymmetry;
6) Profile improvement by mandibular advancement
in clinical examination.
Twenty-seven subjects (17 girls, 10 boys) were
Stomatology Edu Journal
Effects of Farmand and Fränkel-2 functional appliances on
mandibular deficiency in late mixed dentition
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