The Journal
This study was conducted to objectively
evaluate changes in the oro-pharyngeal airway
space by analysis of cephalometric radiographs
of patients undergoing mandibular distraction
osteogenesis. Of the radiographic tracings, 25% were
randomly reviewed by repeating the tracings
after 2 week intervals and comparison of the
measurements was done to eliminate intra-
examiner variability.
Material and Methods The cephalometric landmarks used to identify
the anterior and posterior limits of the oro-
pharyngeal airway space are defined in Figure
1. Linear measurements were made between
these landmarks to evaluate the dimensions of
the space. Measurements were made at the
level of the soft palate, the tongue, lower
pharyngeal wall and epiglottis and at the level of
the 2nd and 4th cervical vertebra[7,8]. These
measurements were then entered into a
spreadsheet for further analysis.
The study protocol was reviewed and approved
by the ethics committee of the institute. The
study was conducted by evaluation of
cephalometric radiographs of patients with
facio-mandibular deformity requiring surgical-
orthodontic correction of the same. Detailed
diagnosis of the facial deformity of each patient
was done by clinical and radiographic
evaluation of the maxillofacial region. Inclusion
criteria included patients with mandibular
deficiency or retrognathia requiring surgical
correction, where conventional orthognathic
surgery without bone grafting was not possible,
and distraction osteogenesis of the mandible
was deemed as the treatment of choice.
Standardized surgical protocol was followed
and the patients were operated under general
anesthesia wherein an extra-oral mandibular
distractor (Orthomax India Limited) was fixed to
the osteotomized mandible via a
submandibular approach. After a 4 day lag
period, distraction was commenced at the rate
of 1mm per day for the required elongation,
followed by 4 weeks of
stabilization for
consolidation.
Predistraction and postdistraction lateral
cephalometric radiographs of all patients were
procured. All radiographs were exposed on a
PM2002 CC Proline unit (M/S Planmeca OY,
Helsinki, Finland)
by the same operator.
Lateral cephalometric tracings were made on a
single intensity view box on 36 micron lead
acetate paper with a 0.5mm lead pencil by a
single operator. Standardized landmarks were
used to generate measurements of the oro-
pharyngeal airway space for further analysis.
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Results
A total of 13 patients who underwent
mandibular distraction osteogensis for
correction of mandibular deficiency were
enrolled in this study. Of these, 7(54%)
underwent unilateral mandibular distraction
and ¬¬¬¬6(46%) underwent bilateral
mandibular distraction. The age range of the
enrolled patients was from 10 to 31 years, with 5
males and 8 females in the sample (Table1). All
patients showed an increase in the oro-
pharyngeal airway space.
The mean change was 3.77mm at the level of
the soft palate, 2.69mm at the level of the
tongue, 1.39mm at the level of the lower
pharyngeal wall and epiglottis, 2.73mm at the
level of the 2nd cervical vertebra and 1.65mm at
the level of the 4th cervical vertebra. Statistical
analysis of the measurements was done using
Student’s t-test.
The increase in dimensions of the oro-
pharyngeal airway space was significant in all
patients (n=13), irrespective of unilateral or
bilateral distraction of the mandible (Table 2).
Vol. 14 No. 1
Jan-Apr 2018