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The change of maxillary sinus ostium in diameterfollowing Sinus floor elevation surgery using Cone

beam computered tomography

LivingWell Dental Hospital

LivingWell Institute of Dental Research

Ho-yeol Jang, seung-gul So, Jae-bong Park, Hyoun-chull Kim, Il-hae Park, Sang-chull Lee

Ⅰ. Introduction

The elevation of the floor of the maxillary

sinus with an autogenous bone graft in a severely

resorbed edentulous maxilla is a generally

accepted pre-implantology procedure to enable

successful placement of endosseous implants in

an optimal prosthetic position1). An often

mentioned drawback of this procedure is the

development of maxillary sinusitis after

augmentation2). The clinical diagnosis of sinusitis

is characterized by a typical triad of symptoms, i.e.

nasal congestion, pathological secretion or

obstruction, and headache3,4). When using general

accepted Ear Nose and Throat (ENT) criteria

for diagnosing sinusitis, however, development

of postoperative chronic maxillary sinusitis

has been reported to occur in 1.3% of the patients

that underwent such a procedure5).

Although not many patients develop maxillary

sinus pathology-related complaints after sinus

floor elevation surgery, this procedure carries the

inherent risk of compromising sinus physiology.

It is generally assumed that the maxillary sinus

physiology is affected by the altered anatomy

(i.e. the lifted sinus floor in combination with a

bulging or injured subsurface of the lifted sinus

mucosa). Displacement of grafts into the maxillary

sinus can result in a foreign-body reaction and

cause serious complications. Mucosal swelling

may also lead to reduction of the patency of the

ostio-meatal unit. This unit plays a key role in

the development of sinusitis, through impairment

of the mucociliar cleansing system6). If the

maxillary sinus is (partly) filled up by hematoma

or seroma and/or the patency of the maxillary

ostium is reduced, maxillary sinusitis might

develop, compromising the success of the

grafting procedure.

Therefore preoperative observation of the

ostio-meatal unit and the mucosal lining of the

maxillary sinus is of great importance to evaluate

of sinus clearance and to diagnose maxillary

sinusitis. The aim of this study was to evaluate

the change of maxillay sinus ostium and phy

siology after maxillary sinus floor elevation

surgery.

Ⅱ. Materials and Methods

A total of 35 patients(20 men and 15 women),

with a mean age of 50 years (range 19 to 76

years), were examined by cone beam computered

tomography (CBCT). The total of 40 sinuses

which are excluded by any sign of pathology had

been evaluated on the patients. Preoperative

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CBCT scanning was done parallel to the floor of

the nosal cavity, and these images were recon

structed with i-CAT program (ISI, USA). Pre

operative diameters of the maxillary sinus ostium

which is bounded below by the uncinate process

(U) and above by the lower bony portion of the

ethmoid sinuses (E) was measured from the coro

nal view perpendicular to the hard palate (Fig. 1).

Implant placement was performed simultaneously

with the sinus elevation procedure using the lateral

window technique and autogenous bone graft.

In 5 cases, sinus elevation surgery were

complicated by large perforations of the sinus

membrane, which were treated with a pericar

dium membrane (Tutoplast, Tutogen, Germmany)

that acted as a barrier. And it were administered

decongestant (pseudoephedrine HCl, 60mg/1day,

orally) in addition to antibiotics and analgesics for

3days.

Next day, postoperative CT scanning was

performed and diameters of ostium were

remeasured on same position. Obstruction degrees

of maxillary sinus cause by

III. Results

Diameters of maxiilary sinus ostium were

significantly (t-test, p-value<0.05) decreased

from a mean 3.25 mm to a mean 1.52 mm (mean

of differences ; 1.73 mm) between preoperative

and postoperative measurement. In 19 sinuses

obstruction of ostium were showed in postoper

ative CT images. And obstruction degrees of

maxillary sinus were observed; Type 1 in 7 cases,

Type 2 in 24 cases , Type 3 in 7 cases and Type

4 in 2 cases(Table 1). But none of all patients

showed symptoms or clinical signs of sinus

pathology at 3 months postoperative evaluation.

Fig. 1. Anatomy of maxillary sinus in CT scan andclassification of sinus obstruction levelmucosal swelling, postoperative hematoma or seromawere distinguished into 4 types (Fig. 1); Type 1 : limited to sinus floor obstructionType 2 : limitied to sinus lateral wall obstructionType 3 : below ostium not complete obstructionType 4 : complete obstruction of maxillary sinus

Table 1. CHANGE OF OSTIUM DIAMETER, FREQUENCY OF SINUS MEMBRANE PERFORATION ANDPOSTOPERATIVE SINUS OBSTRUCTION TYPE

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Fig. 2. Type 1 : limited to sinus floor obstruction

Fig. 3. Type 2 : limitied to sinus lateral wall obstruction

Fig. 4. Type 3 : below ostium not complete obstruction

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Ⅳ. Discussions

This report is the prospective evaluation of

sinus physiology in patients that had no pathologic

signs of maxillary sinus. It became clear that

negligible mucosal reactions were seen after

elevation surgery of the maxillary sinus floor.

None of all patients developed purulent maxillary

sinusitis.

The normal physiology of the maxillary sinus is

highly dependent on the proper function of both

the maxillary sinus ostium and the mucosal

lining7,8). Augmentation of the maxillary sinus does

not affect the maxillary sinus ostium, which

is located far from the operative field in the upper

portion of the medial wall. However, elevation

of the mucosa and insertion of grafts or implants

might be disturbing to the lining mucosa and

a source of chronic inflammation and sinusitis9).

Diminished maxillary sinus drainage is closely

related to structural and mucosal factors

responsible for the size of the maxillary ostium.

Therefore, all factors that disturb sinus drainage,

such as septal deviation, nasal polyposis, allergy,

obstructive lung disease, and infundibular

pathology, have to be evaluated by preoperative

screening and treated accordingly before

augmentation. The risk of developing maxillary

sinusitis is increased in patients with disturbed

clearance of the sinus10-18).

A maxillary sinus floor elevation procedure

reduces the volume of the maxillary sinus. As

a result of the iatrogenic damage caused by raising

the maxillary membrane, a transient or persisting

effect on the ciliated antral mucosa can be

expected. Among other effects, when the

maxillary sinus is filled up with blood, structural

delay of the maxillary sinus clearance is thought

to occur. This could result in blocking of the ostio-

meatal unit, which is a potential risk on

development of sinusitis. However, the results

of this study show no clinical signs of sinusitis

development in all patients. This indicates that

a normal maxillary sinus at the time of surgery

seems to have a high potential for regaining

its function postsurgery and the maxillary

sinus mucosa is capable of adapting adequately to

the changes induced by elevation procedure19,20).

Fig. 5. Type 4 : complete obstruction of maxillary sinus

Mucosal injury and postoperative swelling as

can be expected after sinus floor elevation

surgery may influence the mucociliar barrier

function and effectiveness of the cleansing system,

resulting in divergent radiographic findings.

Specially in clearance compromised patients, this

balance system of aggressive and defensive

forces is expected to be vulnerable, as represen

ted by endoscopic findings grade 3 and 4. A proper

anamnestic assessment of preexisting sinus

clearance impairment may detect patients who are

at risk for an impaired recovery of the maxillary

sinus mucosa following elevation.

The occurrence of iatrogenic sinus membrane

perforations during surgery seems not to be

related to the development of postoperative

sinusitis in healthy patients. Small perforations

of the mucosa cannot induce serious damage to

the maxillary sinus and therefore are not a

contraindication to the continuation of surgery,

provided that they do not allow the passage of

graft material inside the maxillary sinus. While

large perforations of the maxillary sinus

membrane could result in the discharge of bony

fragments into the maxillary sinus and thus

cause maxillary sinusitis. It has been reported that

large sinus membrane perforations should be

repaired with collagen membrane21-23). The patient

under consideration did not develop maxillary

sinusitis after surgery, probably because of

adequate sealing of the large iatrogenic perfo

ration in the sinus membrane. And it is better to

recommend decongestant medical therapy for

the upper airways in these cases.

The increase in bacterial growth after sinus floor

elevation might possibly be the effect of

the surgical procedure, which affected the

maxillary mucosal lining and especially the

mucosal defense system. A mildly decreased

sinus clearance probably facilitates the temp

orary presence of microorganisms. Vascular injury

following surgery, mucosal swelling, the presence

of old blood and a decrease of the patency of the

ostio-meatal unit might reduce the oxygen

pressure in the sinus, resulting in an impaired

sinus clearance24). This environment possibly

favors growth of pathogenic bacteria in the

maxillary sinus. In contrast, after recovery of the

sinus, the environment might be comparable to the

preoperative situation.

If patients develop chronic maxillary disease after

maxillary augmentation procedures, special care

is needed to prevent loss of the bone graft.

Intervention is necessary to establish adequate

drainage of the maxillary sinus and to remove

sequestra that may be responsible for maintaining

this undesirable situation. In Table 2, guidelines

for the treatment and prevention of transient

and chronic sinusitis are given. In this study, the

cases of mucosal perforation and Type 4

obstruction were administered nasal decongestant

to prevent sinitis in addition to antibiotics and

analgesics.

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TTrraannssiieenntt ssiinnuussiittiiss

1. Use of decongestants and antibiotics

2. Follow-up after 2 weeks

3. If no recovery, transient sinusitis has possibly

evolved into subacute sinusitis needing further

treatment: a. Continuation of decongestants and

antibiotics

Table 2. GENERAL GUIDELINES FOR THETREATMENT OF TRANSIENT AND CHRONICMAXILLARY SINUSITIS AFTER ELEVATION OF THEMAXILLARY SINUS FLOOR

Ⅴ. Conclusions

The placement of implants in the posterior

maxilla with the maxillary sinus floor elevation

with an autogenous bone graft is now generally

accepted as a successful and biologically sound

procedure with a reasonably good prognosis.

However the procedure is not always free of

complications. Therefore prior to sinus floor

elevation surgery, preoperative evaluation and

diagnosis through CT images should be performed.

If a normal, or mild mucosal inflammatory aspect

of the sinus mucosa is found, without any sign

of pathology in the infundibular area (containing

the ostiomeatal unit), sinus floor elevation

surgery can be performed. In this study Diameters

of maxiilary sinus ostium were significantly

decreased and sinus obstructions were observed

frequently in Type 3 after sinus floor elevation

surgey. But these siturations were transitionally,

the 3-month postoperative radiographic exami

nation revealed complete recovery of the

maxillary sinus physiology in all patients.

REFERENCES

1. Raghoebar GM, Timmenga NM, Reintsema H,

Stegenga B, Vissink A. Maxillary bone grafting for

insertion of endosseous implants: results after 12-

124 months. Clin Oral Impl Res 2001;12:279-286.

2. Timmenga NM, Raghoebar GM, Boering G, van

Weissenbruch R. Maxillary sinus clearing after

sinus lifts for the insertion of dental implants. J Oral

Maxillofac Surg 1997;55:936-939.

3. Williams, J. & Simel, D. (1993) Does this patient

have sinusitis? Journal of the American Medical

Association 270:1242-1246.

4. Yonkers, A. (1995) Sinusitis. Inspecting the

causes and treatment. Ear Nose and Throat

Journal 71:258-262.

5. Timmenga NM, Raghoebar GM, V.Weissenbruch

R, Vissink A. Maxillary sinusitis following

augmentation of the maxillary sinus floor. A report

of two cases. J Oral Maxillofac Surg 2001;59:

200-204.

6. Bertrand B, Eloy Ph. Relationship of chronic

ethmoidal sinusitis, maxillary sinusitis, and ostial

permeability controlled by sinomanometry. A

statistical study. Laryngoscope 1992;102:1281-

1284.

7. William E, Bolger M, Clifford A, et al: Paranasal

sinus bony anatomic variations and mucosal

abnormalities: CT analysis for endoscopic sinus

surgery. Laryngoscope 1991;101:56.

8. Amble FR, Lindberg SO, McCaffrey TV, et al:

Mucociliary function and endothelins 1, 2, and 3.

Otolaryngol Head Neck Surg 1993;109:634.

9. Westrin KM, Stierna P, Carlsoo B, et al: Mucosal

fine structure in experimental sinusitis. Ann Otol

Rhino1 Laryngol 1993;102:639.

b. Maxillary drains for sinus irrigation

c. CT scanning and consideration of functional

endoscopic sinus surgery if no recovery within 3

weeks

CChhrroonniicc ssiinnuussiittiiss

1. Use of decongestants and antibiotics

2. CT scanning and functional endoscopic sinus

surgery

NOTE. Table created from data from references 10-18.

79

80

10. Kennedy D: Prognostic factors, outcomes and

staging in ethmoid sinus surgery. Laryngoscope

1992;102:1.

11. Davis W, Templer J, Lamear W: Patency rate

of endoscopic middle meatus antrostomy.

Laryngoscope 1991;101:416.

12. Schaefer S, Manning S, Close L: Endoscopic

paranasal sinus surgery: Indications and

considerations. Laryngoscope 1989;99:1.

13. Stammberger H: Endoscopic endonasal

surgery: Concepts in treatment of recurring

rhinosinusitis. Otolaryngol Head Neck Surg

1986;94:147.

14. Kennedy D: Functional endoscopic sinus

surgery. Arch Otolaryngol 1985;111:576.

15. Hartog B: Diagnosis and treatment of chronic

maxillary sinusitis. Thesis. Nieuwkoop, The

Netherlands, De Boer, 1997.

16. Lanza D, Kennedy D: Adult rhinosinusitis

defined. Otol Head Neck Surg 1997;117:1.

17. Timmenga NM, Raghoebar GM, Boering G, et

al: Maxillary sinus clearance after sinuslifting for

the insertion of dental implants. J Oral Maxillofac

Surg 1997;55:936.

18. Buiter C: Endoscopy of the upper airways.

Thesis. Amsterdam, The Netherlands, Exerpta

Medica, 1976.

19. Stammberger H. Endoscopic endonasal

surgery: concepts in treatment of recurring

rhinosinusitis. Otolaryngol Head Neck Surg

1986;94:147-156.

20. Jensen OT, Shulman L, Block MS, Iacono VJ.

Report of the sinus consensus conference of 1996.

Int J Oral Maxillofac Impl 1998;13:11-41.

21. Raghoebar GM, Timmenga NM, Reintsema H,

Stegenga B, Vissink A. Maxillary bone grafting for

the insertion of endosseous implants: Results after

12-.124 months. Clin Oral Implants Res

2001;12:279-286.

22. Sullivan SM, Bulard RA, Meaders R, Patterson

MH. The use of fibrin adhesive in sinus lift

procedures. Oral Surg Oral Med Oral Pathol Oral

Radiol Endod 1997;84:616-619.

23. Block MS, Kent JN. Bone maintenance 5 to 10

years after sinus grafting. J Oral Maxillofac Surg

1998;56:706-714.

24. Aust R, Drettner B. Oxygen tension in the

human maxillary sinus under normal and

pathological conditions. Arch Otolaryngol

1974;78:264-269.

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Abstract

Cone beam computed tomography를 통해상악동 거상술 시행한 환자에서 상악동구 직경 변화에 한 연구

장호열, 소승걸, 박재봉, 김현철, 박일해, 이상철

리빙웰 치과 병원, 리빙웰 치의학 연구소

상악동은 관골 돌기부터 비강에 이르는 상악체 속에 존재하는 피라미드형의 빈 공간이다. 상악동은 비강

외벽의 전상방에 존재하는 상악동구를 통해 중비도로 개구된다. 퇴축된 상악 구치부의 무치악부에서

lateral window를 통해 상악동 거상술을 시행하고 임프란트를 식립하는 술식은 보편화된 방법이다. 하지

만 상악동 거상술 시 점막의 손상이나 술 후 부종으로 인해 상악동구의 개방성이 감소되거나 폐쇄될 수

있고 심할 경우 상악동염과 같은 술후 합병증을 유발할 수 있다. 본 연구에서는 술 전 술 후의 CBCT 상

의 분석을 통해 상악동 거상술을 시행한 환자의 상악동구의 직경의 변화를 측정한 결과 또한 임프란트

시술 전 술 후 상악동염의 발병율의 위험을 높이는 상악동 질환의 존재 여부에 한 확인의 중요성에

해 고찰하고자 한다.