Original Article
A COM PUTERIZED TOM OGRAPHIC STUDY OF UNCINATE PROCESS
OF ETHM OID BONE
N. V inay Kumar *
1, E. Kamala
2, T. S. Guga Priya
3, S. D. NalinaKumari
4.
ABSTRACT
Address for Correspondence: Dr. N. Vinay Kum ar, Assistant Professor, Depart m ent of Anat omy, Chennai M edical College Hospital and Research Cent re, Irungalur, Trichy 621105, Tam ilnadu, India.
E-M ail: vinaydr1981@gm ail.com
* 1,2 Assistant professor, Depart m ent of Anat omy, Chennai M edical College Hospital and Research Cent re, Trichy, Tam ilnadu, India.
3
Associate professor, Depart m ent of Anat omy, Chennai M edical College Hospital and Research Cent re, Trichy, Tam ilnadu, India.
4
Professor and Head, Depart m ent of Anat omy, Chennai M edical College Hospital and Research Cent re, Trichy, Tam ilnadu, India.
Background: The uncinat e process is an im port ant landm ark in t he anat om y of ost eo-m eat al com plex of f ront al recess w hich also plays a vit al role in t he vent ilat ion of m iddle m eat us and sinuses. It s superior at t achm ent show s great anat om ic variabilit y. The aim of t his st udy w as t o observe and classify superior attachm ent and presence of pneum at isat ion in uncinat e process.
M at erials and methods:Com put ed t om ographic im ages of paranasal region from 100 pat ient s w ere st udied ret rospect ively. In 100 pat ient s, 54 belonged t o m ale and 46 fem ale and w ere in t he age group of 11 t o 75 years w it h an average of 32.7 year s. The superior at t achm ent of uncinat e pr ocess w as obser ved and t abulat ed according t o Landsberg and Friedm an classificat ion and pneum at isat ion of uncinat e process w as also not ed. The result s w ere analysed stat ist ically.
Results:The superior at t achm ent of uncinat e process w as observed in 200 sides out of 100 pat ient s and it s at t achm ent t o t he agger nasi cells (t ype - 2) w as found in 36% w hile it s at t achm ent t o lam ina papyracea (t ype – 1) and t o m iddle t ur binat e (t ype – 6) w ere found in 19% and 20% respect ively. Uncinat e process ending at t he junct ion of m iddle t ur binat e w it h cribriform plat e (t ype – 4), at t he et hm oid skull base (t ype – 5), bif urcat ing t ow ar ds lam ina papyracea and junct ion of m iddle t urbinat e w it h cribriform plat e (t ype – 3) w ere seen in 2%, 8% and 5% respect ively. In 11%, t he superior end show ed no attachm ent t o surrounding st ruct ures. The uncinat e process w as pneum at ised in 34 of 200 sides (17%), am ong w hich 45.5% w as unilat eral and 54.5% bilat er al.
Conclusion:Preoper at ively evaluat ing variat ions of uncinat e process and it s pneum at isat ion helps t o avoid int raoperat ive dam age t o surrounding st ruct ur es. The det ailed know ledge of ext ent of uncinat e process m ay also help t o deduce t he reason f or refract ory chronic sinusit is.
KEY W ORDS:Uncinat e pr ocess, Ost eom eat al com plex, Pneum at isat ion, Chr onic r hinosinusit is, Par anasal sinuses.
INTRODUCTION
Int ernat ional Journal of Ana tomy and Research, Int J Anat Res 2015, Vol 3(1):917-21. ISSN 2321- 4287 DOI: ht t p:/ / dx.doi.org/10.16965/ ijar.2015.114
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Received: 07 Feb 2015 Accept ed: 19 Feb 2015 Peer Review : 07 Feb 2015 Published (O):31 M ar 2015 Revised: None Published (P):31 M ar 2015
Int ernat ional Journal of Anat om y and Research ISSN 2321-4287
ww w.ijmhr.org/ ijar.htm
DOI: 10.16965/ ijar.2015.114
Lat eral w all of t he nasal cavit y consist s of an ost eo-m eat al unit t hat lies in bet w een t he const ant anat om ical st ruct ures, t he Uncinat e process (UP) and bulla et hm oidalis.
of bulla et hm oidalis and t he convex ant erior m argin of uncinat e is in cont act w it h lat eral nasal w all. Inferiorly it ends by joining t he et hm oidal process of t he inferior nasal concha. Du r i n g en d osco pi c si n u s su r ger ies, t h e upperm ost segm ent of unicinat e process is a blind spot for t he surgeons [1,2].
A st udy had classified t he superior at t achm ent of uncinat e process as follow s [3]: (Fig. 1)
Type 1: Insert ion int o the lam ina papyracea (LP).
Type 2: Insert ion int o t he posterior wall of agger nasi cell (ANC).
Type 3: Insert ion int o t he lam ina papyracea and j un ct io n of t he m id dle t ur b inat e w i t h t he cribriform plat e (M TCP).
Type 4: Insert ion in t o junct ion of t he m iddle t urbinat e w it h t he cribriform plat e.
Type 5: Insert ion int o t he et hm oid skull base (ESB).
Type 6: Insert ion int o t he m iddle t urbinate (M T).
Fig. 1: Show ing Classificat ion of Super ior at t achm ent of UP.
Yet anot her st udy proposed only 3 t ypes w here t he uncinat e process is at t ached superiorly t o lam ina papyracea or et hm oid skull base or m iddle t urbinat e w hile cat egorizing deviat ions and pneum at izat ions separat ely [1].
Ost eo m eat al region is frequent ly prone for anat o m i cal v ar i at io n s t h at r esu l t s i n osteom eat al obstruction and blockage of m ucus drainage leading t o chronic rhinosinusit is. One su ch v ar i at i o n i s dev i at i o n i n su p er i o r at t achm ent of uncinat e process t hat im pairs vent ilat ion of ant erior et hm oid, f ront al and infundibular sinus regions leading t o chronic pat hology w arrant ing uncinect om y [4]. Few
ot her aut hor s opine t hat uncinat e pr ocess probably prevent s direct vent ilat ion of sinuses w it h cont am inat ed inspired air [1,5,6].
The im pact of superior at t achm ent of uncinat e pr ocess in pr oducing sino nasal pat hology st ands debat able and t here is a lacuna in t he know ledge about t he incidence of various m odes of it s at tachment in different populat ions. So t his st udy w as done t o observe and classify superior at t achm ent and presence of pneum at isat ion in uncinat e process.
M ATERIALS AND M ETHODS
In t his st udy, com puted t om ographic (CT) scans o f 100 co nsecut i v e p at i en t s f r o m t h e depart m ent of Radiodiagnosis w ere analyzed r et r o spect iv el y. Am on g 100 Co m p ut ed t om ographic im ages, 54 belonged t o m ale and 46 fem ale in t he age group of 11 t o 75 years w it h an average of 32.7 years. The CT scan im ages of 3m m t hickness w ere taken using GE VCT m ult i slice scanner. All t he im ages w ere analysed using RadiAnt DICOM view er. The CT im ages of pat ient s w it h previous hist ory of si non asal sur ger y, carci nom a, t raum a and ext ensive polyposis w ere excluded from t his study.
The type of superior insert ion of UP was observed in coronal CT scan im ages and classificat ion w as done according t o t he crit eria of Landsberg and Fr iedm an and t abulat ed. The exist ence of pneumatizat ion in t he uncinate process was also noted.
The result s w ere analyzed statist ically. The study w as carried out aft er clearance from inst it ut ional et hical com m it t ee.
RESULTS
Graph 1: Classif icat ion of Uncinat e Process.
Fig. 8: Show ing blunt UP (BUP).
Fig. 2: Show ing UP of Type -2. Fig. 3: Show ing UP of Type -1. Fig. 4: Show ing UP of Type -6.
Fig. 5: Show ing UP of Type -4. Fig. 6: Show ing UP of Type -5. Fig. 7: Show ing UP of Type -3.
Fig. 9: Show ing unilat eral pneum at isat ion UP (ULP).
Fig. 10: Show ing Bilat eral pneum at isat ion UP (BLP).
Table 1:Com parat ive tabulat ion of super ior attachm ent of Uncinat e process.
Type -1 Type -2 Type-4 Type-5 Type -6 Blunt
Turgut s et al [8 ] 3 14 8
-Tuli et al [9] 7 9.8 - - 1 6.6 7 3.57
-Krzeski A et al [10 ] 17.83 - - 3 3.1 2 14.3 3
-M in Y et al [11] 54 - - 24.5 21 .5
-PRESENT STUDY 19 3 6 5 8 20 11
-2
Aut hor Types of superior at t achm e nt of Uncinat e process (in %) Type-3
DISCUSSION
The uncinat e pr ocess had been claim ed t o p er f o r m a d ef in i t e f u nct i on al r o l e i n t h e vent ilat ory physiology of t he nasal cavit y and t he sinuses rat her t han being just a vest igial rem nant [7].
The superior at tachment of uncinat e process had been st udied and docum ent ed by few st udies. In t he present st udy apart from t he six t ypes of superior at t achm ent a blunt t ype of uncinat ed process w hich had no superior at t achm ent w as also docum ent ed and com pared wit h incidences of previous st udies (Table-1).
The incidence of Pneum at izat ion of uncinat e process from previous report s ranged from 0.4%-4% and am ong t hem few st udies have also described 0.5%-2.5% ext ensive pneum at isat ion of uncinat e pr ocess called uncinat e bulla [ 5,9,10,12,13] . Also a st udy declar ed t hat ant erosuperior region w as t he predom inant posit ion for pneum at isat ion [5]. It has been proposed t hat pneum at izat ion is due t o grow t h of agger nasi cells int o t he m ost ant ero-superior region of the uncinat e process [14].The very high incidence observed in t his st udy necessit at es large scale future study in the general population and it s associat ion w it h pat hological condit ions of sino nasal region.
Few studies had described deviations of uncinate process eit her m edially or lat erally leading t o narrow ing of t he infundibulum , f ront al and ant erior et hm oidal recess producing im paired sin us v en t i lat i on i n m axi l lar y, f r on t al an d et hm oidal sinuses [14-17]. Cont radict ing claim s by som e st udies t hat deviat ions of uncinat e process prevent s cont am inat ed air ent ering t he sinuses [1,5,6]. Thus t his challenges injudicious r em o v al o f t h e u n cin at e p r ocess d u r i n g endoscopic sinus surgery.
CONCLUSION
Alm ost all chronic sinusit is are associat ed w it h anat om ical variat ion t hat alt ers vent ilat ion. So t he preoperat ive evaluat ion of variat ions of uncinat e process and it s pneum at isat ion helps t o avoid int raoperat ive dam age t o surrounding st ruct ures t hat alt ers norm al vent ilat ion. The det ail ed k no w l ed ge o f ext ent o f su per i or at t achm ent of uncinat e process m ay also help
t o deduce t he reason for refract ory chronic sinusit is in m any cases.
Th e r evo lut io nar y chan ges in t h e sur gical t reat m ent of rhino sinusit is in recent years, part icularly in endoscopic surgery, require t he surgeons t o have det ailed know ledge of t he anat om y of ost eom et al unit and of t he large num ber of anat om ical variant s in t he region. Preoperat ive det ect ion of anat om ic variat ions of t he uncinat e helps avoid int ra-operat ive dam age t o t he nasolacrim al duct , m edial orbit al wall, sphenopalat ine artery.
Conflicts of Interests: None
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How to cite this article:
N. Vinay Kum ar, E. Kam ala, T. S. Guga Priya, S. D. NalinaKum ari. A COM PU TERIZED TOM OGRAPHIC STUDY OF UNCINATE PROCESS OF ETHM OID BONE. Int J Anat Res 2015;3(1):917-921.
