Definition: Hemimandibulectomy is a
procedure whereby one half of the mandible is removed
surgically.
Indication:
Hemimandibulectomy
is indicated in the following conditions:
1. Carcinoma cheek
with extension to the mandible 2. Osteoradionecrosis following
irradiation of the mandible 3. Malignant tumors of mandible (i.e.
osteosarcoma)
Procedure:
This surgical procedure is
performed under general anesthesia.
Incision:
The lower lip is split, and a vertical incision is made up to the
level of chin. The incision is then turned horizontally about
1/2 inch below the lower border of the mandible. The
horizontal arm of the incision is extended up to the level of
the angle of mandible. At the level of the angle of the
mandible the incision is turned upwards vertically and
extended up to the level of the mastoid
tip.
Fig showing
the incision
The incision is deepened, mandible is
exposed. Close to the mental foramen, there may be bleeding
because of the presence of neurovascular bundle. Vessels
coming out of the mental foramen are cauterised. The
lower incisor is removed. The inner surface of the mandible is
slowly exposed by dissecting the oral mucosa. Using a gigli
saw a vertical cut is made in the mandible up to the level of
mentum. This vertically splits the mandible. The
mandible is freed anterirorly from the muscles
attached i.e.
The mandible
which is to be resected is freed from the attachments to the oral
mucosa, gently. At this stage the oral component of
the tumor is addressed. The mass is mobilised and excised
with adequate tumor margins. The medial surface of the
mandible is freed from the attachements of masseter muscle.
The second osteotomy is made just below the level of
condylar process. The whole of the mandible is freed and
removed.
The inner mucosal lining is reconstructed
using either the buccal mucosal flap or a tongue
flap.
Complications of mandibulectomy:
1.
Bleeding 2. Cosmetic defects i.e. andy gump deformity 3. Inability to chew
food
Reconstruction:
After excising one half of
the mandible the defect can be reconstructed using iliac crest
bone graft.
