대 한 방 사 선 의 학 회 지 1993 ; 29 (6) : 1313"-' 1319 Journal of Korean Radiological Society. November. 1993

N ormal Development of the Paranasal Sinuses in Children: A CT Study*

Hyung-Jin Kim, M.D., Eui Dong Park, M.D., Pil Youb Choi, M.D., Hae Gyeong Chung, M.D.**, Jae Hyoung Kim, M.D., Sung Hoon Chung, M.D.

Departmeηt 01 Di，α'gnositc Radiology, College 01 Medicine, Gyeongsαη~g Natioηal University

- Abstract-

To evaluate the normal development of the paranasal sinuses in children with CT, authors prospectively

studied with brain CT scans of 260 children without known sinus diseases, ranging in age from 7 days to 16

years. M값imal anteroposterior and transverse diameters(mm) and maximal cross-sectional area(mm2) of both

sides of the maxillaπ sinus were measured with the aid of computer device. As to the ethmoidal and sphenoi­

dal sinuses, we simply documented the presence of the aplastic ethmoidal sinus and calculated the age-inci­

dence of the sphenoidal sinus pneumatization, respectively.

There noted three phases in the development of the maxillaη sinus. The anteroposterior and transverse di­

ameters of the m값illay sinus increased nearly in par외lel. The former was always greater than the latter. In no

cases was the ethmoidal sinus aplastic and almost all sinuses were pneumatized even in infants 'as early as 7

days old. CT identified the conchal pattern of sphenoidal sinus pneumatization in infants as early as 11 days

old. Sphenoidal sinus pueumatization was seen in 38% of the children under the age of 1 year, 82% of the

children between the age of 1 and 2 years , and almost all children older than 2 years.

The anteroposterior and transverse diameters of the maxillary sinus seem to reach the adult size by 8 years

of age, and the conchal pattern of sphenoidal sinus pneumatization can be recognized earlier with CT than on

the plain radiographs.

Index Words: Paranasal sinuses, anatomy 23.1

Paranasal sinuses. CT 23.1211

INTRODUCTION

Knowledge of the embryology and the de­

velopmental anatomy of the paransal sinuses in

infants and children allows better understand­

ing of normal and abnormal sinuses. Plain radi­

ographs have played a role as an essential

screening method in the detection of sinus pa-

thology, but they are frequently badly

influeured by patient’s motion and position. Its

qu띠ity could be degraded by the small size of

the sinuses and overlying soft tissue densites.

The younger is the child, the more troublesome

is the case. In this regard, the cross-sectional

imaging techniques such as computed tomogra­

phy(CT) or magnetic resonance imaging(MRI)

are superior to plain radiographs in the assess-

* 이 논문은 1991년도 한국 방사선연구재단의 연구비로 이루어졌음.

**마산 성모병원 진단방사선과

** Deþartmeηt 01 Di，αgnostic Radiology, Masan Suη~gmo Hospital 이 논문은 1993년 4월 1일 접 수하여 1993년 6월 21일에 채택 되 었음.

Received April 1, Accepted June 21. 1993

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Journal of Korean Radiological Society 1993; 29 (6) 13 13~ 13 19

ment of the sinus development as well as other

sinus diseases.

Although there are abundant reports on the

embryology and development of the paranasal

sinuses(l -4), few studies were done in respect

to the development of the normal paranasal si­

nuses with CT. The purpose of this study is to evaluate the normal development of the para­

nasal sinuses in children with CT, especially em­

phasizing the development of the maxillaη and

sphenoidal sinuses.

MATERIALS AND METHODS

Between August 1990 and February 1993, we prospectively evaluated the brain CT scans

of 260 children, ranging in age from 7 days to

16 years(164 boys, 96 girls). Additional axial

scans parallel to the orbitomeatal line were ob­

tained with a 4-10mm collimation through the

region of the paranasal sinuses. All patients un­

derwent CT examination for indications other

than sinus disease , such as seizures, headache, meningitis , hydrocephalus , head trauma, brain

tumors , mental retardation, or ocular problems.

All the CT scans were performed with a

9800 scanner (GE Medical System, Milwaukee ,

WI), and all the images were photographed

with a bone-window setting. We excluded the

CT scans which showed the significant changes

of chronic sinusitis, e.g. , sclerosis and thicken­

ing of the bony walls of the maxillary sinuses

andj or atrophy, but induded ones showing the

mucosal reactions unaccompanied by bony or

atrophic changes. Subjects with craniofacial

anomaly were also exduded from the study. Pa­

tients aged less than 4 years were routinely se­

dated.

M<o‘imal anteroposterior and transverse di­

ameters(mm) and maximal cross-sectional area

(mm2) of both sides of the maxillarγ sinus were

measured with the aid of computer device(Fig.

1). Lack of a discernible cavity of the maxillary

sinus was considered to be aplastic. We simply

Fig. 1. Measurement of the maxillary sinus. The maximal cross-sectional area is obtained with computer device by drawing the line conforming to the inner margin of the m값illaη sinus. A:m었imal

anteroposterior diameter of the right maxillaη slnus. T:maximal transvere diameter of the left maxillary smus

Fig. 2. Conchal pattern of pneumatization of the sphenoidal sinus. CT scan in this 5-month-old boy shows bilateral well pneumatized air-containing spac­es(arrows) between the posterior nasal cavity anteri­orly and sphenoid bone posteriorly.

documented the presence of aplastic sinus, if

any, rather than size measurement of the eth­

moidal sinus owing to its complex shape. As to

the sphenoidal sinus, which is normally delayed

in pneumatization compared with the maxillaη

and ethmoidal sinuses, we simply documented

the presence of pneumatization and calculated

the incidence of the pneumatized sinuses in

each age group. We considered it to be the

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Hyung Jin Kim , et al : Normal Development of the Paranasal Sinuses in Children

Table 1. Meaurements of Each Side of the Maxillary Sinus According to Age

Mean Value ::1: SD NO. of

Age Right maxillary sinus Left Maxillary Sinus children

AP-D*(mm) TR- D**(mm) Area(mm2) AP-D*(mm) TR-D**(mm) Area(mm2

)

-3mo 20 9.6 ::1: 3.4 4.3 ::1: 1.0

-6mo 16 14.2 :t 3.4 7.6 :t 2.3

-9mo 20 15.3 :t3.7 8.8 :t 2.5

-12mo 12 17.0 :t 3.9 9.7 :t3.0

-lyr6mo 21 19.8 :t 3.4 11.7:t 2.8

-2 yr 12 23 .9 :t 2.6 13.7:t 2.8

-3 15 26.1 :t 2.3 16.3:t4.9

4 16 27 .9 :t 3.5 18.5 :t 3 .4 -5 15 29.6 :t 3.5 21.4 :t 3.3

-6 16 29 .9 :t 3.0 21.4 :t 3.6

-7 16 30 .5 :t 2.4 21.0 :t 3.3

-8 14 33.8 :t 2.5 24.3 :t 2.9

-9 11 34.3 :t 2.5 23.9 :t 3.2

-10 10 33.0 :t 2.1 22 .7:t 3.1

-11 14 33.0 :t4.4 22 .3:t4.1

-12 16 35.2 :t 2.3 24.9 :t 3.8

>12 16 34.9 :t3.7 24 .9 :t 5.3

* anteroposterior diameter ** transverse diameter

concha1 pattern of pneumatization of the sphe­

noida1 sinus if there was a discrete air-contain­

ing space between the posterior nasa1 cavity

and sphenoid bone on CT(Fig. 2)(5) . We did

not include the ana1ysis of frontal sinus devel­

opment in this study because of the great varia­

tions in size and shape and the reported high

rate of aplasia.

RESULT

Development of the maxillary sinus

Maxillany sinus appeared as a discernible

cavity in a11 260 children. The statistica1 data

from the maxima1 anteroposterior diameter, maxima1 transverse diameter, and maximal

cross-sectiona1 area of each side of the maxil­

larγ sinus in each age group are tabulated in

Table 1 .

3.3:1:1 .9

8.7 :t 3.7

10.6 :t 5.0

12.6 :t 5.7

17.0 :t 5.7

23.3 :t 5.8

29.3 :t 6.7

33.1 :t 8.3

43.3 :t l0.0

44.1 :t 9.3

44.0 :t 7.9

53.1 :t 9.0

53.0 :t 10.3

49.6 :t 9.2

50.0 :t 12.7

57.3 :t l 1.9

58.1 :t 15.4

(mm)

40

30

20

9.8 ::1: 3.2

14.4:t 3.2

14.7:t3.9

16.7 :t4.0

19.9:t 3.0

23.3:t 3.2

26 .4 :t 2.6

27 .7:t 3.3

29.7 :t 3.0

29.8 :t 3.1

29.5 :t 3.0

34.0 :t 2.6

33.9 :t 2.9

33.1 :t 2.2

33.7 :t4.0

33.9 :t 3 .4 34.5 :t 3 .4

4.5 :t 0.2 3.2 :t1.7

7.4:t 2.1 7.3 :t 3.1

8.4:t 2.5 9.5 :t 3.9

10.7 :t 2.8 12.6 :t5.3

11.5 :t 2.3 16.3 :t 5.3

14.0 :t3.1 23.5:t 6.5

17.5 :t 2.4 30.0 :t 5 .4 18.6 :t 3.0 33.7 :t 8.0

20.6 :t 3.0 39 .5 :t 9.1

21. 0 :t 3.0 41.4 :t 7.9

21.8 :t 3.9 42 .2 :t 7.8

24.9 :t 3.2 53 .6 :t 10.5

25.0 :t 3.0 53 .7 :t 10 .4 25.1 :t4.6 50 .8 :t 9.9

23:5 :t 3.8 51.7:t 10.9

24.8 :t 3.5 55 .1:t 13.0

26.3 :t 5.9 58.7:t 15.8

Ap.D

05""yl y6m2y ‘ 12<

Fig. 3. Chronological changes of the anteroposterior (AP-D) and transverse diameters(TR-D) of the right maxillary sinus

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Journal 01 Korean Radiological Society 1993; 29 (6) 1313~ 1319

(mm)

40

30

20

AP. D

TR.D

(m r，끼 ')

70

60

50

40

30

20

o 'm ’V’y6m2)' ‘ 10 ’2 ‘ o 6m lyly6m2y ‘ " ’2<

Fig. 4. Chronological changest of the anteroposteri- Fig. 5. Chronological changes of the area in each or (AP-D) and transverse diameters(TR-D) of the left side of the maxillary sinus. maxillary sinus.

As shown on the line graphs which showed

the chronological changes of the anteroposteri­

or and transverse diameters in each side of the

maxillaη sinus (Fig. 3 and Fig. 4), there were

three phases in the development of the maxil­

lary sinus: the first phase was manifested as the

rather steep increment of the two dimensions

by the age of six months; the second phase as

the more gradual but steady increase by the age

of eight years; and the third phase as even

more gradual increase or the plateau-like ap­

pearance thereafter. The anteroposterior and

transverse dimensions of both side of the

maxillay sinus increased nearly in par꾀lel as the

children grew old. The length of the fromer

was always greater than that of the latter. Both

maxillany sinuses showed no significant size dif­

ference in their areas(Fig. 5).

Development of the ethmoidal sinus

All the ethmoidal sinuses examined with CT

in this study showed the discernible cavities

separated by multiple septa, and almost all of

them were pneumatized even in infants as early

as 7 days old.

Pneumatization of the sphenoidal sinus

(Table 2)

The conchal pattern of sphenoidal sinus

Table 2. Pneumatization of the Sphenoidal Sinus According to Age

NO.of No. of children with Age children pneumatized sphenoid sinus(%)

-3 mo 20 4(20) -6 mo 16 7(44) -9 mo 20 9(45) -12 mo 12 6(50) -1yr6 mo 21 16(76) -2 yr 12 11 (92) -3 15 14(93) -4 16 16(100) -5 15 14(93) -6 16 15(94) -7 16 15(94) -8 14 13(93) -9 11 11 (1 00) -10 10 9(90) -11 14 14(100) -12 16 16(1 00) > 12 16 16 (1 00)

pneumatization was found in infants as early as

11 days old(Fig. 6). Thirty-eight percent(26/

68) of children under 1 year of age had

pneumatized sphenoidal sinus: 20%(4/20) by 3

months, 44%(7/ 16) by 6 months, 45%(9/2이 by

9 months, and 50%(6/ 12) by 12 months of age.

Eighty-two percent(27/33) of children between

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Hyung Jin Kim , et al : Normal Development of the Paranasal Sinuses in Children

Fig. 6. Pneumatization of the sphenoidal sinus in an infant with 11 days of age. CT scan shows the con­chal pattem of pneumatization of the primitive sphe­noidal sinus bilaterally (arrows) which is separated with the posterior nasal cavity by the faint septum.

1 year and 2 years of age showed pneumatized

sinus: 76%(16/ 21) by 18 months and 92%(1 1/

12) by 24 months of age. In almost all children

older than 2 years, the pneumatized sphenoidal

sinus was clearly seen on CT scans.

DISCUSSION

Embryology and Developmental

Anatomy of the Paranasal Sinuses

The development of paranasal sinuses is initiat­

ed with the evaginations of the mucous mem­

brane of the nasal meatuses. Embrγologic evi­

dence of the origins of the sinuses is present at

the third to fourth month of fetal life(6), but

much of expansion into the skeletal elements

takes place postnatally.

The Maxillary Sinus:

The maxillary sinus is the first sinus devel­

oping in the human fetus as an outpouching

structure from the lateral wall of the ethmoidal

infundibulum(2 ,5). At birth, a rudimentary

sinus, approximately 7 -8mm in length

(anteroposterior diameter) , 4-6mm in height

(vertical diarneter) , and 3-4mm in width (trans­

verse diameter) , is present (4). The growth rate

is 2mm vertic떠ly and laterally and 3mm

anteroposteriorly each year until the ninth year

of life (1). Thereafter, growth is slower but con­

tinues in all directions until 15 -18 years, when

the sinus reaches the adult size(1 ,6). The

average dimensions of the adult maxillaη sinus­

es are 32-34mm in length, 28-33mm in height, and 23-25mm in width(2 ,7) , and their volurne

ranges from 8.5 to 15rnl(7).

The Ethmoidal Sinus:

The initial outpouchings of the ethmoidal cells are evident as early as the fourth fetal

month(2), and arise from recesses in the lateral

walls of the middle , superior, and supreme me­

atuses. The ethmoidal cells are always present

at birth(6). They continue to expand until late

puberty. Each adult ethmoidal sinus consists of

3 to 15 cells(2) and has an average size of 33 , 27 , and 14mm in length, height, and width, respectively(5).

The Frontal Sinus:

The frontal sinus begins to develop in the

region of the frontal recess during the fourth

or fifth month of fetallife(2). A definitive fron­

tal sinus is rarely seen at birth and is frequently

not present until the second or third year of

life(4,7) . It is the most variable sinus in devel­

opment and is said to fail to develop in 4% of

the population(5) . Shapiro and Schorr(8) as­

cribed the pronounced variability in frontal

sinus pneumatization to three factors , i.e. , craniofacial configuration, thickness of the

frontal bone, and growth horrnones. Generally

radiographically the frontal sinus cannot be de­

tected before the age of 5 to 7(6 ,7). It contin­

ues to grow until puberty, when it reaches the

adult size and shpae.

The Sphenoidal Sinus:

The sphenoidal sinus emerges in the third

or fourth fetal month as invaginations of the

posterosuperior part of the sphenoethmoidal

recess. The invaginations become pouch-like

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Journal of Korean Rad io logica l Society 1993; 29 (6) 1313~ 1319

cavities(conchal sinuses) within the sphenoidal

concha(ossides of Bertin) which becomes at­

tached inferiorly to the sphenoidal body around

three to five years of age postnatally. Following

fusion of the sphenoidal concha to the sphenoi­

dal boey, pneumatization progresses into the

presphenoid and later the basisphenoid parts of

the sphenoid bone, with the sphenoidal concha

remaining as the anterior sinus wall(7 , 9,10).

The patterns of pneumatization of the sphenoi­

dal sinus vary greatly in individuals, and are

cIassified into conchal, presphenoidal, basis­

phenoidal, and occipitosphenoidal(7, 1 0 ,11).

The sinus reaches the adult size in adolescence

、and its volume ranges from 1 to 6ml.

CT examination provided us the valuable in­

formations about the development of the maxil­

laη sinus. Our data on the measurement of the

m강ållaη sinus are comparable to those by oth­

ers except that it seems to reach the adu1t size

somewhet earlier than previously described(l,6 , 8). In our series, the size increment of the max­

illary sinus in the anteroposterior and trans­

verse diameters is steadily progressive until

eight years of age. During the earliest part of

this period, that is , until six months of age , the

growth rate is somewhat faster than during the

rest of period. Mter eight years of age, the de­

velopment of the maxillaπ sinus is much slower

or even stable. Our results show the

anteroposterior diameter of the maxillaη sinus

is always greater than the transverse diameter

regardless of the age as stated by Schaeffer(8), and these two dimensions run in almost parallel

fashion

It is the major drawback of this study that

the vertical dimension(height) and volume of

the maxillary sinus were not measured in the

evaluation of the normal postnatal development

of the maxillaη sinuses. This drawback is as­

cribed to the inherent limitation of CT; for ob­

taining the height of the maxillary sinus, the

coronal scans should be done with the patient’s

head repositioned. This should inevitably in-

crease the irradiation dose to the patient. The

coronal-reconstituted images are too crude to

be considered appropriate for the accurate

measurement.

Aplasia of the maxillary sinus is rare.

Karmody et al, (12) reported three patients

with the aplastic maxillaη sinus in their roent­

genographic review of 750 adu1t patients. In

our CT study of 260 children, there was no

case of the aplastic maxillary sinus either unilat­

erally or bilaterally. As far as we know, aplasia

of the ethmoidal sinus is virtually absent(6). In

our study, we could constantly detect the eth­

moidal cells as the multiloculated cavities. Most

of them were pneumatized

Our results concerning pneumatization of

the sphenoidal sinus are somewhat different

from those of others. According to Fujioka and

Young(l O) , the radiographic evidence of

pneumatization of the sphenoidal sinus could

not be detected in children less than six months

of age. They also stated that 50% and 90% of

children were pneumatized by 2 and 4 years of

age, respectively. In contrast, our study shows

that the most primitive type of pneumatization

of the sphenoidal sinus, i.e ., the conchal pat­

tern, is not infrequently visible even in children

less than 6 months of age( l1 j 36, 31 %) on CT

scans. Seventy-six percent of children between

12 and 18 months of age had sphenoidal sinus

pneumatization. Thereafter, almost all children

showed pneumatization of the sphenoidal sinus.

On the basis of our results, we presume that

the anteroposterior and transverse diameters of

the maxillaπ sinus seem to almost reach the

adult size by eight years of age in most of pop­

ulation. The conchal pattern of sphenoidal

sinus pneumatization can be recognized earlier

with CT than on the plain radiographs. We

think CT is a valuable method in the evaluation

of the development of the paranasal sinuses

more dearly.

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Hyung Jin Kim . et al : Normal Development of the Paranasal Sinuses in Children

REFERENCES

1. Davis WB. Anatomy of the nasal accessoπ sinus­

es in infancy and childhood. Ann Otol 1918; 28:

940-967

2. Schaeffer JP. The nose, paranasal sinuses, naso­

lacrimal passageways and olfactory organ in man.

Philadelphia: P. Blakiston’s Son & Co. 1920

3. Wasson WW. Changes in the nasal accessory si­

nuses after birth. Arch Otolaryngol 1933; 17:

197-211

4. Maresh MM. Paranasal sinuses from birth to late

adolescence. 1. size of the paranasal sinuses as

observed in routine posteroanterior roengeno.

grams. Am J Dis Child 1940; 60:55-78

5. Som PM. The paranasal sinuses. In: Bergeron

RT, Osborn AG , Som PM , eds. Head and Neck

Imaging. St. Louis: Mosby, 1984; 1-5

6. Bernstein L. Pediatric sinus problems. Otolaryn-

〈국문 요약〉

gol Clin North Am 1971 ;4:127-142

7. Moss-Salentijn L. Anatomy and embryology. In:

Blitzer A, Lawson W, Friedman WH , eds . Sur­

gerγ of the paranasal sinuses. Philadelphia:W.B

Saunders Company, 1985; 12-17

8. Shapiro R, SchoIT S. A consideration of the

systernic factors that influence frontal sinus

pneumatization. Invest Radiol 1980;15:191-202

9. Van Alyea OE. Sphenoid sinus. Arch Otolaryn­

goI1941;34:225-251

10. Fujioka M, Young LW. The sphenoidal sinuses:

radi이0밍C허 patterns of normal development and

abnormal findings in infants and children. Radi­

ology 1978; 129: 133- 136

11. Congdon ED. The distribution and mode of ori­

gin of septa and walls of the sphenoid sinus.

Anat Rec 1920;18:97-123

12. Karmody CS , Carter B, Vincent ME. Develop­

mental anomalies of the maxillary sinus. Trans

Am Acad Ophthalmol OtoI1977;84:723-728

CT를 이용한 소아 연렁에서의 부비동 발달에 관한 연구

경상대학교 의과대학 진단방사선과학교실， 마산 성모병원 진단방사선과*

김형진 • 박의동 • 최필엽 • 정혜경* • 검재형 • 정성훈

CT를 이용하여 소아에 있어서 부비동의 정상적인 발달과정을 알아보기 위하여 저자들은 지난 2년 6개월간 부비동

질환이외의 다른 목적으로 뇌CT를 시행한 260명의 아동들(생후 7일- 16세)을 대상으로 그들의 CT스캔을 전향적으

로 분석하였다. 상악동에 있어서는 상악동이 가장 크게 보이는 단면에서 컴퓨터를 이용하여 양측 상악동의 최장 길

이와 폭， 또한 단연적을 구하여 각 연령별로 평균값을 산출하였고 사골동에 있어서는 크기의 측정은 하지 않고 존재

유무만을 판단하였으며 접형동에 대하여는 각 연령별로 기포화의 빈도를 산출하였다. 상악동의 발달은 크게 3단계로

나눌수 있었는데 생후 6개월까지는 비교적 빠른 신장을 보였고 6개월부터 8세가 되기까지는 그 이전보다는 약간 성

장속도가 느렸으나 지속적인 성장추세를 보였으며 8세후부터는 거의 빗빗한 성장곡선을 보였다. 상악동의 길이와 폭

은 모든 연령군에서 길이가 폭보다 항상 크게 유지되며 성장하는 평행한 성장콕선을 보였다. 전례에서 사골동의 존

재를 관찰할수 있었으며 생후 7일된 영아를 포함한 거의 대부분에서 기포화가 관찰되었다. CT로 접형동 기포화는

생후 11일의 영아에서 갑개형(condhal pattern) 의 기포화가 최초로 관찰되었고 1세 이하의 아동중 38%와 1세이상

2세미만의 아동중 82%에서 갑개형의 기포화를 관찰할수 있었으며 2세 이상의 거의 대부분에서 접형동의 기포화를

확인할수 있었다.

이상의 결과를 토대로 저자들은 상악동의 길이와 폭은 8세가 되면 거의 성인의 크기로 성장하며 접형동의 기포화

의 증거는 단순 촬영술에서 보이는 것보다 빠른 시기에 CT로 발견할 수 있으리라고 추론한다.

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