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Effects of Functional Septoplasty on the Facial Growth of Ferrets
MAJ Timothy M. Cupero, MC, USA;
MAJ Charles E. Middleton, MC, USA;
Andrew B. Silva, MD
Arch Otolaryngol Head Neck Surg. 2001;127:1367-1369.
ABSTRACT
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Objective To determine the effects of functional septoplasty on the facial growth
of ferrets.
Design Pilot study.
Setting Medical center.
Materials Nine 4-week-old female ferrets.
Interventions The ferrets were divided into 3 groups of 3. The first group served
as the control group and only had bilateral mucoperichondrial flaps raised.
The second group had a 5 x 3-mm piece of septal cartilage removed with
preservation of the dorsal and caudal septal struts. The third group had a
4-mm piece of vomer (bone) excised with preservation of all septal cartilage.
All groups had the mucoperichondrium preserved. The ferrets grew until 14
weeks of age (well beyond their growth spurt) and were then killed. Lateral
cephalograms were then performed and facial analysis conducted to discern
any changes in facial growth.
Main Outcome Measures Facial growth based on cephalometric analysis.
Results Analysis of variance testing showed no statistically significant differences
in facial growth either within or between the 3 groups.
Conclusion Functional septoplasty has no effect on the facial growth of ferrets.
INTRODUCTION
NASAL AIRWAY obstruction from deformed cartilage or bone is frequently
encountered in the pediatric population. Causes of such deformities are frequently
traumatic and usually result from birth injuries or falling while learning
to walk. Early surgical correction of cartilage and/or bony obstruction is
often necessary to reestablish the nasal airway and to avoid secondary nasal
deformities. Concern about correcting such deformities either before or during
adolescence has been raised because of the potential adverse effect on long-term
facial growth. Demonstrating whether certain types of septal deformities (cartilage
vs bone) could be corrected safely without altering facial growth would be
invaluable to those treating the pediatric population.
MATERIALS AND METHODS
The protocol was approved by the institutional review board of the Madigan
Army Medical Center, Tacoma, Wash, and all guidelines regarding animal experimentation
were followed. Because septoplasty on ferrets has not been previously described
in the literature, a pilot study was undertaken to ensure that this was an
appropriate animal model. Nine 4-week-old female ferrets were divided into
3 groups of 3. Prior to any surgical intervention the ferrets were sedated
and lateral cephalograms were performed. The ferrets were placed in a head-holding
device to ensure uniformity.
Because 4-week-old ferrets are rather small, all procedures were performed
using binocular microscopy. The approach to the septum involved a sublabial
transverse incision. Elevation of the soft tissues allowed entrance into the
nasal cavity and exposure of the cartilage and bony septum. The first group
served as the control group and only had mucoperichondrial flaps raised. The
second group had a 5 x 3-mm piece of septal cartilage removed with preservation
of the dorsal and caudal septal struts. The third group had a 4-mm piece of
vomer (bone) excised with preservation of all septal cartilage (Figure 1). All groups had the mucoperichondrium preserved.
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Figure 1. Anatomy of the ferret skull illustrating
the removal of septal cartilage and vomer (bone) in groups 2 and 3, respectively.
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Postoperatively the ferrets were allowed to grow beyond their growth
spurt to 14 weeks of age. The animals were than killed. Lateral cephalograms
were again taken using the same head-holding device. Using points common to
all cephalograms, measurements were made and statistical analysis was performed
to determine any alterations in facial growth.
RESULTS
Preoperative and postoperative cephalograms were analyzed and the results
were compared. Because cephalometric analysis has not been previously described
in ferrets, 4 common, easily identifiable points were chosen for analysis.
These points included the most anterior extent of the nasal rim (1), the most
posterior aspect of the calvaria (2), the most posterosuperior extent of the
zygomatic arch (3), and the most anterior point of the maxillary alveolar
ridge (4) (Figure 2). Data points
were derived and statistical analysis was undertaken using the following combination
of linear and angular measurements: angle 1-2-3, angle 3-1-4, line 1-2 (in
centimeters), line 2-3 (in centimeters), line 1-4 (in centimeters), and line
3-4 (in centimeters). (See above text or Figure 2 for an explanation of the 4 common points of the ferret
skull.) Analysis of variance testing was used for analysis because of its
ability to account for any preoperative differences between the ferrets. Testing
revealed that there were no statistically significant differences in facial
growth of the ferrets either within or between groups (Figure 3).
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Figure 2. Cephalometric analysis of the
ferret skull.
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Figure 3. Example of analysis of variance
(ANOVA) testing for angle 3-1-4 showing no difference in facial growth between
the 3 postoperative groups. See Figure 2 for an explanation of the 4 common,
easily identifiable points from which the angles were calculated. Ellipses
indicate not applicable.
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COMMENT
Controversy still exists over the exact role of the septum in the development
of the midface. Some hypothesize that the septum is the primary growth center
of the midfacial skeleton, while others believe that the septal cartilage
grows only as a secondary, compensatory response to other primary growth centers.
Currently, a conservative approach to septoplasty in children has been taken.
Human studies often have conflicting results regarding facial growth. Some
have found that external septorhinoplasty does not retard facial growth,1 while others warn of the danger of retarding growth
of the nasal dorsum.2
Results of animal studies have been equally confusing. Early studies
focused on the resection of large amounts of septal cartilage without preservation
of the overlying mucoperichondrium.3-4
Sarnat and Wexler3-4 showed that
the production of such defects in young rabbits did, indeed, lead to considerable
underdevelopment of the maxilla. Since then, more conservative functional
operations have been performed. In 1973, Bernstein5
carried out submucous resection of cartilage with the preservation of the
mucoperichondrium in canine pups and found no growth disturbances. His study,
however, did not address the bony septum. In 1979, Nordgaard and Kvinnsland6 and Verwoerd et al7
found that, despite preservation of the mucoperichondrium, large resections
of septal cartilage did, indeed, adversely affect nasal growth. Neither of
these studies fully preserved the dorsal or caudal septal struts, which are
known to play an important role in supporting the nasal tip.
More recent studies by Meeuwis et al,8
in 1993, demonstrated that larger resections of septal cartilage caused a
shorter and lower nasal dorsum as well as severe septal deviation. Their study,
as well as the previously mentioned studies, does not address the osseous
portions of the nasal septum and its potential contribution to facial growth.
CONCLUSIONS
The ferret is an acceptable animal model for performing functional septoplasty.
The procedure itself is technically feasible, although challenging, and the
rapid growth rate of the ferret allows for measuring facial growth in a timely
manner. Our analysis shows no facial growth disturbances between the 3 surgical
groups after functional septoplasty. A larger sample of animals will need
to be studied to confirm this conclusion.
AUTHOR INFORMATION
Accepted for publication June 20, 2001.
Corresponding author and reprints: Timothy M. Cupero, MD, Department
of Otolaryngology–Head and Neck Surgery, Bassett Army Community Hospital,
1060 Gaffney Rd, Fort Wainwright, AK 99703.
From the Departments of Otolaryngology–Head and Neck Surgery
(Drs Cupero and Silva) and Oral-Maxillofacial Surgery (Dr Middleton), Madigan
Army Medical Center, Tacoma, Wash. Dr Cupero is now with the Department of
Otolaryngology, Bassett Army Community Hospital, Fort Wainwright, Alaska.
Dr Silva is now in private practice in Virginia.
REFERENCES
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1. Walker PJ, Crysdale WS, Farkas LG. External septorhinoplasty in children: outcome and effect on growth
of septal excision and reimplantation. Arch Otolaryngol Head Neck Surg. 1993;119:984-989.
ABSTRACT
2. Bejar I, Farkas LG, Messner AH, Crysdale WS. Nasal growth after external septoplasty in children. Arch Otolaryngol Head Neck Surg. 1996;122:816-821.
ABSTRACT
3. Sarnat BG, Wexler MR. The snout after resection of nasal septum in adult rabbits. Arch Otolaryngol. 1967;86:463-466.
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PUBMED
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in canine pups. Arch Otolaryngol. 1973;97:273-278.
PUBMED
6. Nordgaard JO, Kvinnsland S. Influence of submucous septal resection on facial growth in the rat. Plast Reconstr Surg. 1979;64:84-88.
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7. Verwoerd CD, Urbanus NA, Nijdam DC. The effects of septal surgery on the growth of nose and maxilla. Rhinology. 1979;17:53-63.
PUBMED
8. Meeuwis HL, Verwoerd-Verhoef HL, Verwoerd CD. Normal and abnormal nasal growth after partial submucous resection
of the cartilaginous septum. Acta Otolaryngol. 1993;113:379-382.
PUBMED
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