|a | a rtic le

3t a l f o r a m e n m a n d i b u l o t o m y f o r r e s e c t i n g t u m o r s o f t o n g u e

d p a r a p h a r y n g e a l s p a c e

h Z H A NG K i , GU O Chum -b in , H U A NG M i n-xian . MA O Chi and PE NG X in

m wm r of the b ng tó M se ¤ Ô m p ho ry rvgm l tum o r ¤ p m - m n ô l b m m e rt m nd iô b Ø m v -

SUØ ô l Áp p rm c h

m d RÊ ec tion of tumom ar isi ng fm m the tongue base and the paraphary ngeal space ia d i fEcul t for

End manipul at ion because of thei r obscure locat ion. Ú Ee aim of thi s study was to eval uate the surgicalof the pre-mental foram en mana M otomy fbr m eeti ng É e tum m of Ø np m base and parapharyngeal

B Fifty -one pat ients w i É tumom of tongue base and paraphar yngeal space were treated using the

,tomy appmach m the pm - mental fom men- In the pm m nt study , th is techniq ue wØ dÊ cr i bed in

ie patients were fol l owed up for three months to six yeam wi th a mem of 26 mon ths.

Ç Ee tumom of tongue M m and paraphaw nseal space could be ex® " d c learl y and k re³ cted

by surg ed appm ach of pre- mental foramen mandi btAl otomy. Ú 1e surgical compl i cations weÓ reduced.

i£ " c omm m d to other surg ed appm achü , such as l ateral ºI land i bulotomy , ºYUd ine

ô my , the suprahyoid paraphary ngeal appm ach , and paramed ian mm d ib ulotomy , we found that the

d foramen EEBand ibulotorny is the ideal choi ce for m eeting the tumom of tongue base and parapharyngeal

Chi n M d J 2Ø 5 ; I 18 ( 2 I ) : I 803 ¤I 80 7

1 o f t um o rs a ris in g f ro m th e to ng ue b a se c o m p lic at io ns -

, pa rap ha ry nge a l s pa c e is d iff ic u lt b r

ld m an iPu la Uo n b e c a us e o f th e ir o b sc u re M E T H O D S

urg ic a l a pp ro ac h is th e k ey p o int fo r

o m ratm . A s m id e a l s u rg iØ l Be tw ee n J an ua w 19 9 7 a nd A ug us t 2Þ 4 , 5 1 ü " s

w id e expo s u re . le s s d a m a g e to th e w ith t u m o r of to n g u e b a s e a n d pa ra p ha ry ngea l

Lm s , cÞ v e n ie nc e fo r he m o st as is a n d spa Ø w e re t re a te d by s u rg e ry w it h a n ap p roac h of

m d the de fec t , rad ic a l re s ec t io n of t he p re m e nta l fo ra m e n m a nd ib u lo to m y in the

less po s to p e ra t iv e d e fo m iw a re D e pa m e n t o f O Õ a n d M a x illo fac ia l S urge ry ,

- r T , , y -z

Between January 1997 and August 2004 . 51 caseswith tumor d tm gue base and parapharyngealspace wem treated by surgery with an approach ofpremental foramen martdibulotorny in theDepamnent of Oral and Maxillofacial SUØew ,Peking Unõ ô ity Scfm l of Stomatology. Amongthese 51 cases , there were 27 men and 24 w£men-Their ages ranged from 5 t0 73 years , with amedian age of 45 years-

T w en ty -s ix Ø m o m lÞ a te d in t he ton g ue base , a nd

Depaztm nt d Oral and Maxilld acid Sur- ew . Peking h ivemityschØ l × ,d HØ pitd d Stomatolog . Beij ing lÁms l . China ( YUGY - a u zª L . GØ CB . Hu na MX . MM c ®,d P¢ ¨ X }CoÐØé ndeme to: Dr. YU Gu ng-ym . Department d Oml u±

Mu ç dt id a arF EY- Peking tjnivemity ScbØl ud H± " tal dsu m tol£́ . B´ j ing l u ms1. chirm ( Tel : " -10462191Ø 9. FU :" -1046217Mm . Em ih g é @263. mt )

1804 ¤

25 in the pa rapha ry rw ea l space- Th iw -seven cases

( 72 5% ) were malignant , 14 cases ( 27 . 5% )benign- A ll d the tongue base tumors weremalignant. A ll of the beni9n tumo rs were lÞ alized to

the paraphary ngeal space-

Table 1 illustrates the histopatholog ic d iagnosis of

the tumors. Pleomo rphic adenoma represented themost com mon benlg n tumor , and sq uamous ce llca rcinoma was the most com mon malignant tumo r.

Among the 33 patients with carcinoma , 23 caseswere pHmary carcinoma. AÞ ording to the UlCC( 2Þ 2 ) .13 the clinical stages of the 23 pM ary

carcinoma patients were 2 in stage l 14 in stagen . and 7 in stage lll , respectively-

The ope ratb n was pe±o wned unde r generalanesthesia w ith nasotracheal intubat ion- Lower lip -

splitt ing inc is ion w ith late ra l extension wasdesigned . Submandibula r inc is i£n was made firstly -The facia l anery and fac ia l ve in w ere 1igated- Themandibula r marg inal branch d fac ia l new e wasprotected- Then the skin inc is ion was extended in

the m id line- The c hin and lower lip were dividedthrough the ir full th ic kness up to the mucosareflection at the ging iva labial sulcus. Five mm oflabia l mucØ a at the ging iva lab ia l sulcus was leftattached t£ the gum to facilitate c losure. A sh£¬cheek flap was elevated to exm se themandibulotomy site- T he menta l nerve wasprotected from damage. Four-h01e m iniplates were

placed on the outer c£rtex d mandible , and then theholes were d rilled acco rd ing to the p late hd es- Theminiplates were placed above a nd below the mentalforamen , respective ly ( Fig . 1 ) . Beb re the

Chin Md J Xm s 118{21} :Im3

Dsteotomy . we performed fine sulcus at the |t

boMer of mandib1e to f ix me w ire saw ternm raThe c irc le of w ire saw was cut off. The wire

was penet rated the inte rdental space betweencanine and the first pre -molar tÞ th. This loct

The c irc le of w ire saw was cut oH. The wirewas penetrated the Interdental space betweencanine and the first pre-molar tÞ th. This loct

varied betw een the f irst and second pre-molar to

depending on the posÇion of mental foramen.mandible was d ivided w ith the wire saw , andproximate segment of mandible was p¨ é d latert

A mucosa inc ision was made in the fl££r ofmouth up to the anterior pilla r of the son Palileav ing a cd of 1 cm of mucosa at the gingivefacilitate c losure of the inc ision. The mylohmuse1e was div ided. The lingual nerve 1

prese w ed w possible- The tongue was retratmedia lly in the ora l caviw to expose the tumFinally , the tumor was resected radica lly.

alJ

tum

Rgb t . Ú ¢e minipã tes wem plaØ d atmve and M b wthe b rm m . resped wely bef£re £sae£my.

Among the 5 1 cases , 27 received the reconstructi£nd defect w ith naps , as shown in Table 2. The radia|forearm flap was the most Þ mmonly used flap. Thet£ngue defects we re r± ¶ nstmeted using a platysmaf lap in tw£ cases . c £mpiete closure wÑ ô ±om edin two layers inc lud ing the muscle and mtbCosa

Ta "- a TM ©" '¤¤ mux- mmÚmd dM¢ÚFùp ½Òd " ¤"Rææ ¤ Mm hp nmaww,,. É" ' lR±©ææú´ ¦ û- w uxæ§ ÷ ©" 'P¢ ¢Ø¥ § ô nWUMãnà ,. ©" 'TOt-l a,

The cut ends of the mand ible was reduced and fixed

us ing prev iously shaped miniplates ( Fig. 2 ) . lt isimp£rtant t£ £btain a pe¶ect alignment of the two

thtnm Medkyat h aarmi za253118{21} zttm JØ7 ¤Õ· ¤

mandibular ends in orde r to resto re the normalocclusion. A suction dra in was p laced in the wound.The midline lip -sp litting and subm andibular inc isions

were closed. T racheostomy was pe¶ormed in 28patients. Nine cases received postope rativeradiothe rapy for a d£se of 50 Gy -

F¼iE$- 2 . N e t.m lôe ºm½nwºnvm¢m£ m a £d f p a ô p h a µ n 9" e ± s p a cØe . A :

M R l s h £ w s ¤ e m a s s w ­ c 1e a r m a rg in in h e

p a ra p h a µ Ð p a l s p a c e - B : ¤ e t u m w w ² e x õ © e d

d e a r1y . c : t h e m a n d ib u ld o m y w a s re p a ir e d w Çh

f ixa tm u s in g p re v b Ø Iy s h a p e d m in ip la t e s -

Forty of 5 1 patients were followed up fo r a period

m ging from 3 months t0 6 years w ith a mean of 26months. Their lower lip sensitiv ities were tested w itha needle touch , and c£mpared the reaction of theym mted s ide b th´ Þ the Þ ntra late ral side -

RESULTS

The tumors were exposed ve ry clea rly and resected± ically in all me 51 patiem ( Fig. 2 ) . T he b iopsyof frozen tissue section taken at the ma rg ins ofºÊ ed ior1 showed free of tumor cells in the a ll 37mHents w ith malignant turn£ ºS.

ô infection of the wound Þ c uwed in four cases -me of which was due to the wo und dehiscence ,ò the other h ree were due to m isÞ elus ion-RÉ £nstruction plates replaced the m iniplates in 2a ses. Delayed healing of the w£ und w as achievedmh lÞ al wound care.

The X-ray f i1ms showed well-healed areas at the

ends d segments ab£ut six months after theoperat ion- W e did not detect any mal-union or non-union , and the intra -£ra l views sh£wed excellent

tongue shape and mobility - T he Þ elusion wasgo£d. No teeth were lost as a result of £sted omy-No lim itation fOº opening m£¨ h Á ß urred- Five

patients , however , did repo¬ slight numbness in thelower lip , w hic h disappeared w i¤ in six months.Among the nine patients who received postoperativeradiotherapy , no mandibular radionecros isoccurred.

Among the 40 patients wh£ were fotlowed up from 3months t0 6 years . 29 showed the tumor recurrencefree , and 1O expeHenced tumor recurrence. Adistant metastas is Þ curred in 1 case. Five patientsdied of the recurrent ca rc ino ma , w hile the other 6pat ients were alive w ith ca reim ma

DlSC USSlON

Tongue base and pa rapharyngeal space tumorspresent the maxillofac ia l o r head and nec k surgeonsw ith a challenging task . primaHly because of the irobscure location. Because there is no alterative

therapy for h e aff iliated patients , the surgeon mustreview the advantages and disadvantages of severalavauable surgica l approaches- T he options inc ludelateral mandibulotomy J 2 mid ine mandibub -tomy ," the suprahoid parapharyngealapp road 1.m pa ramedian mandibulotoryw 1112and pre-mental foramen mandibu|otomy. 14

T he ô a tio n of la te ra l m a nd ib u lo to m y is a t the a ng le

of th e m a nd ib le ( F ig . 3 ) . T he infe r io r a lveo la r

ne rv e m u s t be t ra nse c te d b y h is a pp roac h-

T ra nsec t ing th is ne w e res u lts in d e n e N a t io n o f the

tee t h d is ta l to the m a nd ib u lo to m y s ite , a nd o f the

ch in s k in . P e rm a ne n t nu m b ne s s o f th e low e r lip and

the c h in s k in is u nav £ id a b le - T h e m a nd ib uld o m y

s ite is d i rec t ly w ith in the la t e ra l p£ " a l o f the ra d ia t io n

f ie ld . T h us h e a ling de la y s a nd co m p lic at io ns Þ c ur

a t th e m a nd ib u loto m y s it e - Fo r thes e re a so ns .

la te ra l m a nd ib ulo to m y is s e ld o m used c u r re ntly

bec a u se o f its h ig h Þ m p lica tb n rate , e s pe c ia lW inpat ie nts un d e rgo ing ra d ia t io n th e ra py - 15

The 10cation of midline mandibulotomy is at theante rior m id line of h e mandible ( FW. 4 ) . Thisapproach requires extracting a central incisor t£prevent iatrogenic injury to both centra l inciso rs in

some patients- The c losure of the gingiva l tissue

Fig. 3. The diagram d the ô ation of late ral mand ibub tÁ ny-Fig. 4. The d iag ram d me lÞ auon of midline rnandibub t£my.

Fig. 5. The diag ram of the lÞ atim d paramed ian mandiM lot£my.Fig . 6. The d iagram of the b cation of pre-menta l b ramen mandibul£t£my.

over this extracted socket area is dimeu|t and mayrest»|t in exposed mandibu|ar bo ne , which isimmersed in bacteria -conta ining sa liva that cancause wound infection. 15 This technique does not

expose the tumor fully beca use the anterio r segmentremains obstructed. T ransecting the musc les aris ingf rom the genia l tube rc le , such Ø the geniohyoid andthe genioglossus musc les , is required - lt results indelayed recovery of the swallow ing function. 11

Therefore , m id line mandibulotomy is a |so notrecommended. However , fo r the benign ,

nonfiltrat ing tumors in the mid line of the tonguebase , m id ine mandibulotomy w ith mid ineglossotomy is the cho ice of surg ica | approach. 18

The suprahyoid parapha ryngeal app roac h Á 30urs atthe suprahyoid reg ion , w ithout mandibidotorny.T umor exposure by this approach is lim ited ,

especia lly fo r tumo rs in the pa rapharygeal space-Muscles attac hing the mandible and mouth f loor tend

to susta in damage , making th is approach less thanideal.

The locat ion of para med ian mandibulotofn y isbetween the latera l incisor and the canine tÞ th( Fig. 5 ) . lt is a relat ively ream nable appr¶ Ch- 13 17

However , tumor exposure is still pa¬iaHyobstructeded by the anterior segment.

The location of pre -menta l foramen mandibu|otomy

is betwee n the canine and the f irst pre -molar tÞ h

( Fig. 6 ) , and sometimes betw een the f irst and thesecond pre-mola r teeth , depending on the p£s it ion

of menta l fo ramen. This approac h prov ides goodexp£sure for tongue base and paraphary ngealspace- lt is very convenient fo r rad ica l tumorresection. Because the menta l new e can bep resew ed , most pat ients in our series repo¬ed no

lower lip or c hin skin numbness , o r the sensit iv ityrecovered quic kly - Good occ lus ion could be

?®

wdܣ @

restored by f ixatio n of the miniplates- No tootf

as a result of osteotomy- T he mandibulotomy soutside of the rad iation f ie ld center , wdec reases the chances of radiotherapy-ind

complicat ions. ln our series , nine casetmalignant tumors received m stopetrad iothe rapy- No rad ionecros is of the man

occurred. This approach fac ilitatesreconstruction by platysma f lap , if necessaµ -the above descHbed reasons , we recommend lthe pre-menta l foramen mandibulotory-1y for rese

the tumors of tongue base and paraphamspace above a ll other alternat ives.

There are some key p£ im to peºfo rmingoperat ion suÞ essfully- Gentle manipulatiotrequired to avoid the damaging the mental mThe miniplates should be placed at the upperlower pa¬s of menta l fo ramen to avoid menta l rdamage. Either a w ire saw or ultra-thin high-S|

poweº saw can avoid c reat ing a w ide space amandibulotorny s ite- A cuÎ of muÞ sa alongging iva s hould be reta ined while the mucosmouth floor is inc ised to fac ilitate mucosa clos

Co mplete closure of the ora l mucosa atsegernent ends w ill help b prevent the wdehiscence o r the formation of f istulas.

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2. Caw RJ , B£werman JE. A review d tumom d thelû e d h e pamud salwaµ gô nd. Br J Oral Maxis ur9 1986 324 :155¤168.

3. Asian G , kargi E. D£rgu M. et al Momandibub t£my appmach t£ Øm£rs d the wophaAnn Plast Suru 2Þ 1 ;46 :77¤79.

4. L£wlÈht RA , DHî ® l BP, sa³ ki CT MostØ tomy wim lag screw sã bilizatô for mand|smng. Laµ ngO׶ pe 1995 2105 3 10¤213.

tFUSeMd ² d JC¡ ,¸at XM53118(21} dan-taMW a U Fv - I×" -

S p iro A H , G e t-o M F P , S e s s io n s R B , e t a l e v ± u a a o n o f f lx a t b n m e ¤ ´ s a n e r m a n d ib u la r fo r

M a rØ iM b b m y a p p ro a c h to w o p h a ry n g e a l t u rm r s . A m w £ p h a µ n g e a l t u m £ ã . A m J S u rg 19 9 3 ; 16 6 : 4 3 1 4 3 4 .

J S u rg 19 8 5 ; 1 5 0 :4 6 6 4 6 9 . 12 . S h a h J P , J d m s Á 1 N W , B a t s a k is J G . O ra l c a n c e r - 1 s t

l T e n g M S . G e n d e n E M . B a c h b in d e r D , e t a l. e d L £ n d o n : M a n in D u n it z z 2 0 0 3 :2 6 3 ¤2 6 8 .

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L a m g o ß £ " 2 Þ 3 31 1 3 : 1 8 9 3 ¤1 8 9 7 . 7 7 .

s e ÝÝ i J M , p a Ø ô S J , c £ n id i£ J LJ , e t a l . T ra n s v e rs e 1 4 . B £ z z e n i A . B ig lio li F . G ia n n i A B , e t a l . M a n d ib u lo to ry1y

la g s c re w f ix a t b n i n m u li n e m a n d ib u b t o m y : a ü " fw a Á á s s b b e n ig n d e e p b b e p a ro t id t u m £ rs w it h

« " e s . A n n Á £ l R h in o l L a ry n g d 2 Þ 0 ; 1 Ø : 3 3 4 4 3 9 . p a r µ h a m g e ± e x Ie n m n : re m rt d fo u r c a s e s . J O ra l

M in a d e h B , E n a y a t i P . c h h e t r i D , e t a l u n g - te rry1 M a x il b f a c S UÛ 1 9 9 8 ; 5 6 :2 7 2 ¤2 7 6 .

s u rv iv a l o u tÞ ºm in t ra n s h y £ id re s e c u m o f b a s e d 15 . D a i T S . H m S P , C h a r19 K P , e t ± . c £ m p lm t im s d

to n g u e s q u a m o u s ¶ l l c a re im rn a - A rc h O td a ry n w l m a ru ib u b b m y : m id l in e v e m u s p e ra m id l in e -

H e a d N e c k S UÛ 2 u n z1 2 8 : 1 0 6 7 ¯ 7 0 . Á £ ù µ n g d H e a d N e c k S u r9 2 Á Z3 ; 1 2 8 : 1 3 7 ¤14 1 .

M a lo n e J P , A g ra w a l A , S d u lle r D E . s a fe t y a n d 1 6 . N a s ri s , O h Y , c a lc a t e r ra T C . T ra n s p h a ry n g e a l

e m ü c y d t rm s Ø w b a l r Ì e d im d p a ra p h a ry n g e a l a p p ro a c h b b a s e o f to n g u e t u n m rs : a c £ m p a ra tiv e

s p a Ø n e ä la m s - A n n O td R h in d L a ry n g d 2 Þ 1 : 1 1 0 : ± u d y . La m g Ø Þ p e 1 9 9 6 : 1 ¶ : 9 4 5 8 Ø .

10 9 3 ¤1 0 9 8 1 7 . P a n W L , H a o S P , L in Y S . e t a l. T h e a n a to m ic a l b a s is

U J , S u n J , 2 1a n g Z Y . s u p ra h y o id ô Õ y £ M fw m a n d ib u b t m y : m id in e v e m u s p a r a m id l in e -

p a ra p h a ºy n g e a l a ö º¶ d 1 fo r re s e c tio n d t u m £ rs in t h e L a ry n 9 0 × ¶ p e 2 Þ 3 ; 1 1 3 : 3 7 7 4 8 0 .

t£ n g u e b a s e a n d it s f u n c t b n a l s ig n if ic a n c e . J M Ø e rn

s to m a t o l 2 0 0 3 ; 1 7 : 5 1 2 ¤6 1 4 . ( R e c e i v e d J u t y 8 , 2 Þ 5 )

! S h a h J P , k u m a r a s w a m y S V , k u lk a m i V . c £ m p a ra t iv e E d i t e d b y L l U D o n g -y u n