Multi-Bracket Appliance in Management of Mandibular ...

124 Multi-bracket appliance in management ofmandibular reconstruction
Figure 3. (d) Postoperative frontal view one year after surgery. (e) Postoperative
panoramic radiograph one year after surgery.
arch-wires were applied to the proposed residual teeth (Fig. 4c).
Segmental mandibulectomy from above the left angle to the left
canine was performed. Bone defect was reconstructed with a
fibula flap from the left lowerleg. There wereno skin defectsand
a small mucosal defect was directly sutured. One year after the
operation, he was very satisfied with his facial appearance. He
alsodemonstratedstableand goodocclusion. (Figs4d,4e and4f).
DISCUSSION
Despite the smallsamplesize,the presentresults from mandibular
reconstruction using a multi-bracket appliance are very
encouraging. This technique offers two major advantages over
the conventional dental arch-bar.
First, themulti-bracket appliance keepstheoriginaldentalarch
form firmly. Brackets are bonded to the individual teeth directly
without any loosening. Rectangular arch-wires control the
individualtoothpositionthree-dimensionally and have considerable
stiffness to counter the external pressure. These properties
are helpful in maintaining occlusion of the remainig dentition
accuratelyin bonegraftingprocedureas wellas protectingagainst
postsurgical wound contraction. On the other hand, the dental
arch-bar is attached to teeth by ligature wires and often loosens
in maxillo-mandibular fixation . Furthermore, this appliancedoes
not demonstrate sufficient mechanical strength. In contrast, the
dental arch-bar, when used for mandibular fracture, enables
accuratefixation of the mandible. This is due to the lack of bony
andsoft tissuedefects. Thus,thearchedshape ofthe mandiblecan
be perfectlyrestoredwhichpreservesthe rigid maxilla-mandibular
fixation. Baurmash reports that there is little differencein the
strengthof attachment if one is dealingwitha fulldentalarch, but
the differencein strength is evidentwhen only a small numberof
anchoringsare available (4).
In the case of mandibular resection following tumor ablation,
the tissue defect is generally large and the number of remaining
teeth is small. Initially horseshoe-shaped mandibles are divided
into two relatively straightsticks. A small numberof circumdental
wires is considered to be insufficient to hold the arch-bars
rigidly whichresults inconsiderable movementof the mandibles,
even under maxillo-mandibular fixation. Therefore, holding the
mandiblesin positionpreciselyduringbonegraftingprocedureis
difficult. Furthermore, as the teethelongateduring maxilla-mandibular
fixation, circumdental wires tend to loosen a few weeks
after surgery and the supporting teeth move toward the reconstructed
direction. Re-tightening of the wires is often required
which sometimes leads to periodontal injury (5). We have
occasionally experienced deterioration of occlusion after the
removal of the arch-bars due to woundcontractionand resultant
boneremodelingwhichcontinuefor several monthsaftersurgery.
The multi-bracketapplianceappearsto solvethese problems, but
the contributionof the acrylicplate should also be considered.
The multi-bracket appliance also keeps the oral cavity clean.
This appliance is designed for long-term use in orthodontic
treatmentwhileavoidingperiodontal injury. Thus, long-term use
of this appliance maintains the occlusal relationship against
wound contraction. In contrast, arch-bars occasionally cause
gingival infection around the circumdental wires and early
removal of theseappliances is unavoidable. The wound contracture
progresses after removal and deviation of the remaining
mandible occurs, resulting in destruction of occlusion. In the
present series, multi-brackets were appliedfor 3 months without
any complications.
The goals of mandibularreconstruction are the restoration of
aestheticcontourandoral function includingmastication, speech,
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