Presented by :

Cita Darmastuti

INCIDENCE OF LINGUAL NERVE PARAESTHESIA FOLLOWING

MANDIBULAR THIRD MOLAR SURGERY

The surgical removal of impacted mandibular third molar :

Pain, swelling, bruising, trismusSometimes lingual nerve damage

This complication is usually unexpected and unacceptable for

the patients

introduction

Incidence of lingual nerve injury, because of

– Surgeon`s unexperience– Procedure methodology and

certain specific factors such as raising and retracting a lingual mucoperiosteal

Amongst the most studies, causes of the lingual nerve damage :

Lingual plate perforationLingual flap trauma during ostectomy or tooth sectioningUsage of lingual flap retractorSupra crestal incision

Pogral and Miloro, Kiesselback intimate relationship between the lingual nerve and mandibular lingual plate around posterior areas.

Manson no single factor to be causative but the most significant were the depth of impaction, removal of distal bone, elevation of lingual flap and length of operation time.

Aim :

To determine the clinical incidence of lingual nerve injury following mandibular third molar removal and to analyze possible etiologic factors for the lingual nerve injury.

90 patients, from january – december 2009 for surgical removal of impacted mandibular third molar.

Pre operative factors, such as depth of impaction, tooth position and bony coverage

The impacted classified by the “winter`s

classification.”

Material and methods

Local anesthesia

The same operator

The standart Terence Ward`s

incision

Reflecting the buccal flap

Gutter in the disto buccal bone

Bone removal (motor driver surgical bur, constant irigation of

normal saline)

Surgical procedure

Sensory disturbance on 1st and 7th post operative day.

Complaint concerning sensory disturbance of the lingual gingiva and mucosa of the floor of the mouth and tongue.

Assesment of post operative “do you have normal feeling in your tongue?”, and pin prick tes.

Patient

any complaint sensory

disturbance on postoperative

evaluation

advised for regular follow up

at the interval of one month,

observed up to 6 months.

6 patient were diagnosed with lingual nerve paraesthesia on 1st and 7th post operative day evaluation (6,6%)® 1 patient lost from the study after

3 month of observation geographical relocation.

® 1 patient paraesthesia persisted even after 6 months cyanocobalamin 1.500 unit/ day.

result

® 4 patients recovered within 6 months of observation.

paraesthesia horizontal and distoangulation of

impaction,impaction with the crown

approximating the CEJ of second molar, lingual inclination of tooth, state of eruption and duration of surgery.

Table 1 : number of patients with paraesthesia, tooth position, depth of impaction, state of eruption and time of recovery

patient tooth Paraesthesia area Position of tooth

Depth of impaction

Bucco-lingual inclination

State of eruption Time of resolution of paraesthesia

1

2

3

4*

5

6

48

38

48

48

38

38

Right side of tongue

Left side of tongue

Right side of tongue

Right side of tongue

Left side of tongue

Left side of tongue

Distoangular

Distoangular

Distoangular

horizontal

mesioangular

mesioangular

Level 2

Level 1

Level 3

Level 2

Level 3

Level 3

Buccally

No inclinationLingually

No inclinationLingually

lingually

Incomplete bone coverPartially erupted

Complete bone cover

Incomplete bone coverComplete bone coverComplete bone cover

2 months

1 months

No resolution up to 6 months3 months

5 months

4 months

* Patient with paraesthesia was lost from the study after approximately 3 months of observation due to geographical relocation

This study supports other retrospective report (David T. Wofford) a possible association between paraesthesia and bony impacted mandibular third molars, use of bur to remove bone during the surgical extraction, position of impaction and state of eruption.

discussion

The causative factors can be discussed under following headings :1. Lingual inclination and lingual flap ratraction

Lingual retractor was not used in any casePichler JW, Beirne lingual nerve injury is 8.8 time more likely to occur in buccal approach without lingual retractorPogrel et al and Green wood et al the lingual flap reflection and use broader retractors to protect the lingual nerve

15 patient in which third molar was lingually inclined the lingual tissue was retracted only to expose the occlusal aspect of tooth.

Out of these 15 patients, 3 patient with paraesthesia :‐ 2 patients resolved within 5 months.‐ 1 patient didn`t resolve even within 6

months follow up.Incidence of lingual nerve paraesthesia was more observed with lingually inclined tooth than buccal inclination

Table 2 : buccolingual inclination and paraesthesia

Buccolingual inclination No. Of patients Patient with paraesthesia

Buccal inclinationLingual inclinationNo inclination

451530

2 (4.4%)3 (20%)1 (3.3%)

2. State of eruption Valmeseda-Castellon

incidence of lingual nerve paraesthesia was more prone on surgical removal of unerupted mandibular third molar.

This study observed more lingual nerve paraesthesia with surgical removal of unerupted mandibular (complete bone cover) third molar.

Table 3 : state of eruption and paraesthesia

State of eruption No. Of patient Patient with paraesthesia

Partially eruptedUneruptedSoft tissue coverIncomplete bone coverComplete bone cover

63(27)

7128

1 (1.58%)0

2 (16.6%)3 (37.5%)

3. Tooth position 5 patients (horizontal-impacted) odontotomy with slight

distal bone cutting as needed in these cases and we found postoperative paraesthesia in one patient.

The distal ostectomy may be causative factor for paraesthesia in this patient

(Valmeseda-Castellon)

Table 4 : tooth position and paraesthesia

Tooth position No. Of patients Patients with paraesthesia

MesioangularHorizontalVertical Distoangular

405

3015

2 (5%)1 (20%)

0 (0)3 (20%)

4. Depth of impaction Third molar present below the CEJ

of second molar (level 3) is more significant for paraesthesia.

D. A. Mason 2005 the depth of impaction is significantly related with lingual nerve injury.

Table 5. : depth of impaction and paraesthesia

depth No. Of patients Patients with paraesthesia

Position APosition BPosition C

382527

1 (2.6%)2 (8%)

3 (11.1%)

5. Operation time Paraesthesia in one patient

seemed to be `permanent`, the tooth was placed distoangular and completely covered with bone almost 40 min.Other patient average time of removal was 20 min.

Valmeseda-Castellon the surgical time may be a contribute for lingual nerve injury

Zuniga, JR, Blackburn CW the incidence of permanent damage of lingual nerve vary between 0.5% to 2% this study 1.1%

Conclusion lingual nerve paraesthesia can occur with or without reflection of lingual flap and in spite of all the measures taken to protect it. It may be contributed to the fact of anatomical variations of lingual nerve.

Lingual nerve can be injured during surgical procedure, it should be well explained to the patient to avoid any legal litigation.

Thank you