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Oral findings in the Morquio syndrome (mucopolysaccharidosis IV)
oral medicine Editor: JAMES W. LITTLE,
D.M.D., M.S.D.
Chairman and Professor Department of Oral Diagnosis University of Kentucky Lexington, Kentucky 40506
and Oral Medicine
Oral findings in the Morquio syndrome (mucopolysaccharidosis IV) L. Xtefax Levi??, D.D.S., M.X.D., Rollala! J. Jorgenson, D.D.X., Carlos P. Xalixas, D.D.S., iMtimore, Md., and Charleston, X. C.
and
DIVISION
AND
DEI’ARTMENT MEDICAL
OF
MEDICAL OF
UNIVERSITY
GENETICS, PEDIATRIC OF
SOUTH
THE DEKTIXTRY,
JOHNS SCHOOL
HOPKINS OF
HOSPITAL, DESTAL
XEDICINE,
CAROLINA
The Morquio syndrome is characterized by a specific pnttrrn of platyspondyli:~, cornea1 opacities, kerntosulfate excretion in the urine, and dental abnormalities. Oral examinations were performed on twelve patients with the condition. The maxillary anterior teeth were widely spacetl and flared. The posterior teeth were tapered and had pointed cusp tips. The enamel was of normal hardness, and in some patients the surface was pitted. In roentgenogrnms, the enamel was less than one fourth its normal thickness but was of normal radiodensity. The prevalence of caries may have been reduced. The hard palates were broad and flat. The dental abnormalities in the Morquio syndrome are of a type that is unique among the group of genetic mucopolysaccharidoses. Our findings therefore support the conjecture that the biochemical defect in this condition is different from that which occurs in the other mucopolysaceharidoses.
T
he Morquio syndrome (mucopolysaccharidosis IV) is a skeletal dysplasia which was described independently by Morquiol and Brailsford2 in 1929. It is inherited as an autosomal recessive trait and occurs in one of 40,000 births.” Matalon and associates* have recently hypothesized that a deficiency of chondroitin sulfate N-acetylhexosamine sulfate sulfatase may be a cause of the disease. Persons with the Morquio syndrome have a disproportionately short stature which is manifest clinically by the age of 2 to 3 years and radiographically by the age of 1 year.” This disorder has often been confused with other spondyloThis study was supported by National Institute for Dental Research 00193 and by National Institutes of Health Grant 5 FO5 TW01849-03.
Grant
5 TO1 DE
Table
I. Summar,~ of findings in twelve patients with the Morquio
syndrome
Ilefective
Anterim qwn-bitr
Patient
Sex
1 ‘1
F M F M M F F M E’ F F F
3 4 5 6 i s $1 I0 11 12
I
.-I (Je
D.X F
Torus
enamel
i
0
+
+
8 10 11 13 19 “2 23 “9 !zl 32 35
5 0 0 4 II 6 ii 3 t t :
*Tnadequate informxtion. tPartially endentulous, inadequate :Edentulous, inadequate history. + = Yes. - 7 so.
+ + + + + + + *
+ + + + + + + + +
-
+ + + .y. + i
history.
epiphyseal tlysplasias hut is distinguished from them by the occurrence of cornea1 opacities, a specific pattern of platyspond,vlia, dental abnormalities, and urinary excretion of keratosulfate.” A variant in which kcratosulfatc is not excreted has been described.” Most authors hare not concerned themselves with a complete description of the oral abnormalities in the Norquio syndrome. Brailsford’ reported numerous carious lesions in his case. (:arn and Hurme’; reported three siblings with the clisease, in whom the teeth were smaller than normal, dull gray, and pitted, with tliastemas between them. The cusps were flat and poorlv formed. The enamel was thin, but of normal density, and flaked off easily. These three affected persons hacl a lower caries prevalence than their six unaffectecl siblings. (4arne and Hurmc suggested that the factors whicah interfered with formation of hone and of cnamcl were the same. It was suggested that defective c>alcification, rather than defeetivc matrix production, was responsible. Zellwcger and colleagurs,i reported enamel hypoplasia in two patients with tlic iVorclui0 syntlromc. The C’USJ)lips of thr l)ostrrior t&h uwc sharp. Ko mclltion was matle of the frryucney of caries. Brabant and co-authors” described enamel clcfccts in their two patients ant1 Ilotcd a retluecd predisposition to tIccay. Jlaroteaux, Lam>-, and Fouch(~P notctl gray, dysplastic teeth with pointed cusps in eight patients with the Rlorquio syndrome. The dccitluous as well as the permanent teeth were involvctl, suggesting that the disease is active at 3 to 1 months in utero. T,anger and Carey” reported thin enamel and sharp-pointetl c~usps in both the tlcciduous and permanent tlentitions in eight of ten patients whom they studied. There was a predisposition to caries. Their two oldest patients had lost all of their teeth as a result of numerous various lesions. CASE DESCRIPTIONS
Orofacial examinations were performed on twelve unrelated patients (eight females anti four males), with the Morquio syndrome (Table I). Preliminary
reports on clcvcn WCI’C ascert~ainctl
of these paticuts have appcarccl els~~h~r~.“‘~ I1 Thc~ patients OH y~~untls other tha11 the, tl<~nial al)t1ornlalit>~. Thcsir ;I~~~s
I’;l??~:.(L(I
:35
f?‘Otll
5
t0
!c’iJ?‘S.
All pat,ivnts had a similar t’acial appcaranvr (I~‘ig. 1 ). The nasal hridgc was flat, tllc alaP ??:FZlC WCI’C flaWtl, il?lcl ttlc Ili1SCll tip was u~)turl1ctl. The lower tliirtl ol’ the faccl IV;IS prominent. The 11c~atI>lI)l)ci1~*<~clto sit squarely 011 the sho11ltlcrs. The palates W(‘I’C l)roi1tl antI flat. 11 flat tortIs palutinus \V;IS prcsc11t i11 tight, patients who wcw c\-wluatcti for this W1it. The clccayccl, rnissi11g, antl filled ( I~Alb’) intlcs’2 \VilS (‘VilltliltC’tl i11 cbigtit Ot of twtl?. P’onr of tticse (ilt tlicl ages 01 the 11inr pat,icnts with a full c*otnplrt??c~??t 7, 10, 11, and l!)) wcrc 1’rvc of caries. 111tliv other fo1lr (agccl 8, 1:3. 22, ;1ntI 29) the l)ilII~‘ intles i1vcragccl 4.50. TWO paticl11ts (ag~cl L!!) and 32) liacl vigtit and ninctcen teeth rctnaining, rcyxvtively. TRIP ol(lrst p;1ticnt iI1 our st1ltly (35 yri11.s Of i?.gC) Ilad l0St alI llcr tXY‘tl1 1)y the ?I@ 01’ 22. Thr ~WSOII for tooth loss i11 thcsv thrre ~ultl not hv aclccluatcly clc~tcrn1inrcl. The p(‘~1nanc11t n1axillary a11tcrior t(>c>th WPI’(: witlcly sl)i1ertl i1l1(l fl:1r~l i111tcriorlyi (Fig. 2). They wcrc slightly y(~IIow in color. Therv \YilS at1 aiitc~rior o[Wl?hitc ii1 four of eight persons inspc~c~trtl l’or this trait. Tlic tlcri~luous antI [)c‘l’tllilnent posterior tcvth WCI’C tapcrwl. Thrsc tcdh, as well ils the pcirt11:11rc>tltca~lillcs, hacl 1narkcclly pointcvl C’IIS~)til)s. 7’11~ cal1i\t11rl JV;IS ol’ 11or11r:rl I1arcl11c~ss;r11tl (lit1 11ot flake away. In addition, tl1crv was vertic+;rI tlitnplit1g in thcl lmc~~al surfaces of the I)c~rtnat1cnt ca1lincs a11tl ~IY~IIIO~~~S i11 t\\o pticnts. Tlrc~r(~ \Vi1S gc~11(‘1’;1lixt’cI pitti11g Of tllc‘ l)uc*cal surf:lcrs in ttlcl ~~~‘~~Ilil?l~~?lt tlcntitioiis of tt?rW ])iltiV?ltS. The c~11:~mtl of the tlrciduo11s :111(l p(l1*n1:111t’l1ttcc~tl1 W:~S thi11ntlr tl1il11 11ort11ill 011 radiographs Of afYWtcV1 ~)~~?30llS (Figs. :I ;111(14). IIO\\-c~\~c~1~, ttlc‘ Pl?iltll<‘l \VilS 0t normal racliotlensity and coultl 1~ disti~lguishcvl front tt1c suhjacavnt, (Iv11tin. The radiographic appc’aranvc oi’ the (lentin, pnll) (*l1;1~11l)(~1~s, ant1 root cx11uls \vas normal.
Ora,1 fhdings
ill Uorquio
syndrome
393
Fig. Z. Photograph of the teeth. The permanent canines and the posterior teeth have pointed cusp tips. Note the vertical dimpling on the labial surfaces of the canines and buccal surfaces of the premolars. Pitting is evident on some of the anterior teeth.
Fig. 3. The lower radiographs show the deciduous dentition of a patient with the Morquio syndrome and demonstrate the thin enamel which contrasts w-cl1 within the tlcntin. The uppex radiographs show a control matched for age and sex.
DISCUSSION
The oral findings in persons with the other genetic nlucopol~saccharitloses have been studied previouslp.l”v I* The dental abnormalities in the Morquio syndrome are of a type that is unique within this group. Our findings support the conjecture that the biochemical defect in the Morquio syndrome is different from t,hat which orcurs in the other mucopolp;vsaccharidoscs. In addition, these dental tlefects are not seen in patients with the other spontlplocpiph;r-seal tlysplasias’” and, therefore, may serve to differentiate them from Xorquio syndrome. The concurrent radiologic and microscopic abnormalities seen in the enamel, cartilage, and bone of persons with this contlition suggest that the enzyme may
Pig. 4. The lower radiographs are of the permaueut Morquio syndrome and show thin enamel which contrasts radiographs show a control mntehcd for age and sex.
dcntition well with
of a patient with the the dentin. The upper
be involrcd in a metabolic pathway common to the three structures. Although the dentin in our patients is, by radiologic criteria, normal, it is likely that its physical ant1 chemical properties are not normal since bone, cartilage, and dentin arc mesenchpmal in originl” and each contains acid mueopolysaccharides.‘“-‘” The caries prevalence in our patients appears to be less than in the general population. Our sample was small, and we laeketl an adequate control population. \\‘e were unable to use as controls the sibs of our patients. Further family studies, as well as biochemical studies of the teeth and saliva, are indicntcd. Sinccl the enamel of the deciduous teeth is defective, it must be inferred that the disease process is active early in intrauterine life. This indicates that if correction of the enzyme defect is to be accomplished, it must be done prenatally. Although radiographic examination of the skeleton makes diagnosis possible by the age of 1 year, x-ray examination of the dcntition shortly after birth may afford a means of early diagnosis in families in which there is reason to believe that both parents are carriers. Tn light of the gcncralizccl bone dysplasia, we believe that the open-bite seen in the Morquio syndrome is skeletal in nature rather than secondary to a habit or to the enamel defect. However, an X-linked dominent variety of amclogenesis imperfecta without skeletal changes has been reported in association with openbite.‘!’ The mode of inheritance and clinical and radiologic appearance serve to distinguish the X-linked form from the type seen in the Morquio syndrome. Reduced enamel thickness is also seen in teeth from patients with some of the autosomal tlominant forms of amelogrnesis imperfecta.Y” Again, the inheritance pattern ant1 the absenec of skeletal problems differentiate these forms of amelogencsis impcrfecta from the enamel changes seen in the Morquio syndrome.
Morquio, L.: Sur uno forme de dystrophie oswuw familiale, Bull. Sot:. PCdiatr. Paris 27: 115.152, 19”‘). Roentgcno~r:lplric and (‘linical Features of I%railsfortl, .T. F.: Cllondro-Osteo-l)ystroplly; Child With Dislocation of Vert?hrae, Am. J. Surg. 7: 404-410, 1929. McKusirk, V. A.: Hcritahle Disorders of Connwtivc Tissw, cvl. 4, St. Louis, 1972, The (1. v. Mosl,y (‘olllparly, pp. 610, 588, 585. l\lxtalon. K.. Arbowst. n.. and Dorfman. A.: Morauio’s Ryndromc: A IWic:iencv of (Zhonclroitin ‘Sulfa& N:Xrc,tylllrxosaminr &lfatc, Rulf%tasc, eediatr. Rrs. 8: 436, ‘1974 (abstr.). 5. T>xnger, L. O., and (!awy, I,. S.: The RoentrrlloRr:11’1’i(’ Featurrs of the KS Mwopolys:lwlmridosis of Morquio (Morquio-Iirailsfor(l’s l)iseasc), Am. J. Rwntgenol. 97: l-20, 1966. ti. Garn, S. M., an11 Hurme, V. 0. : I)cwtal I)r~fwts in ‘l’hrcc Siblings \Vith Morquio’s Diwasc, nr. nrnt. J. 93: 210.212, 1952. 7. Zc~llwewr. II.. Pow&i. I. V.. Pedrini. V., Stan&x. I?. H.. and van Noortltn. .J. K.: MorquioI’llricl?s i)is≻ Rr&rt of’2 (‘ascs,‘J. ecvliatr. 69: 54$-561, 1961. dentnires tlans la maladic 11e 8. lXr:ctxcnt, H., Wcwltls, H., and Klws, L.: Les :tlt&xtions Morquio, Rw. Stomatol. 63: 466-467, 1962. Btudr cliniquc, 9. Marotr:tux, I’., Lam;y, XI., rind Fouchrr, M.: I,a malndic~ tlv Morquio txdiologique ctt biolo~~qw, Presw mbtl. 71: 2091-2094, 1963. IO. I,win, I,, R., .Torgrnson, R. .J., and Salinas, (‘. E’.: 1)ental Findings in the Morquio Syrlclromcl, ‘1111.3. TIum. Genr,t. 25: 45a, 1973 (abstr.). 11. I,cvin, T,. S., .Jorgt~uson, R. J., and Salinas, C. F.: I)cwtnl Findings in the Morquio Rynof tlw Mwting of the Anwric*an Aexdrnly of Oral Pathology, Nen llromc., I’rowcvlings orlf~:lns 19i4. 1”. St:lllcl:,;diz:,tion of Reporting of Dcwtal I)iseasw ant1 Conditions, Report of an XspPrt (‘omnrittw on I)wt:tl Hwlth, Genrva, 1962, \Vorltl Health Orgnnizntion Tcchnir:rl Report Svriw #242. 13. Qarllwr, I). Q. : ‘1’11v Oral Manifestations of IIurlrr’s Snyllrom(1, OKAT. 91:~~. 32: 4,557, 1971. 14. Salirms, C. F., I,cBvin, I,. H., and dorgwson, K. .J. : Oral Findings in thr, Mucol~olys:rcc~hnri~lows. i In nrenaration. i 15. I,cvin, I,. S.,’ Snfin:&, (‘. F., a’nd .Jorg~nson, R. .T.: IJnpul~lishc~tl dnta. \V. M., liungca, K. F., and I&mgt~, M. 1s.: Ilailry’s Twtbook of Histology, (~1. Iti. (‘oprnh:rvrr, 16. lialtinlow. 1971. \Villixrns & \Vilkins (‘on~uxn~. char). I6 an11 n. 12-1. ’ E. ;2. : TIexo\nmiw and Avid Glyco17. (‘kirk, K. I).,’ Smiih, .J. G., .Tr., antI D:t&&, s:~rni,lo~I~~~:lns in Human Twth, Hiocnlwrn. Tiiophys. Acta 101: 267-272, 1965. Layer in I)c,ntinoaenic:~lly IS. Lindv, A. : (;lyc~onnx~~inogly~:~ns of thr Otlontohl:\st-Prcdrntill(, Actiw I’orcinc~ T&h, C&if. ‘l’issuc~ Rrs. 12: 281.291, 19i:<. 19). Srllultz, Ch. : ither viwn Fall van Hypoplasie drxr Hartsuhstanzrn bri Zihnrn im T%rrrirh tltls r~vhtrn Olwrkic~fcrs, J)tscll. Zallnnwxtl. %. 7: 78%800, 195%. ((‘itetl in Gorlin, H. .J., :tntl (i~lclm:tr~, TI. M.: ‘l’110ma’s Orill Patllology, ~1. 6, St. Louis, 1970, The C. 1’. Mosl)y (‘orrlpn~, 1’. l:v?.) 20. \Vitkop, f‘. .l., ant1 Sxuk, .J. .J. : Ibtal nrtd Or:11 Manifcstntions of TIcwtlit:~ry Discaw, \~orl~shop sponwre~l 1)~ the Amt~rican Araclenr~ of Oral Pathology, 1971.
D.M.D., M.S.D.
Chairman and Professor Department of Oral Diagnosis University of Kentucky Lexington, Kentucky 40506
and Oral Medicine
Oral findings in the Morquio syndrome (mucopolysaccharidosis IV) L. Xtefax Levi??, D.D.S., M.X.D., Rollala! J. Jorgenson, D.D.X., Carlos P. Xalixas, D.D.S., iMtimore, Md., and Charleston, X. C.
and
DIVISION
AND
DEI’ARTMENT MEDICAL
OF
MEDICAL OF
UNIVERSITY
GENETICS, PEDIATRIC OF
SOUTH
THE DEKTIXTRY,
JOHNS SCHOOL
HOPKINS OF
HOSPITAL, DESTAL
XEDICINE,
CAROLINA
The Morquio syndrome is characterized by a specific pnttrrn of platyspondyli:~, cornea1 opacities, kerntosulfate excretion in the urine, and dental abnormalities. Oral examinations were performed on twelve patients with the condition. The maxillary anterior teeth were widely spacetl and flared. The posterior teeth were tapered and had pointed cusp tips. The enamel was of normal hardness, and in some patients the surface was pitted. In roentgenogrnms, the enamel was less than one fourth its normal thickness but was of normal radiodensity. The prevalence of caries may have been reduced. The hard palates were broad and flat. The dental abnormalities in the Morquio syndrome are of a type that is unique among the group of genetic mucopolysaccharidoses. Our findings therefore support the conjecture that the biochemical defect in this condition is different from that which occurs in the other mucopolysaceharidoses.
T
he Morquio syndrome (mucopolysaccharidosis IV) is a skeletal dysplasia which was described independently by Morquiol and Brailsford2 in 1929. It is inherited as an autosomal recessive trait and occurs in one of 40,000 births.” Matalon and associates* have recently hypothesized that a deficiency of chondroitin sulfate N-acetylhexosamine sulfate sulfatase may be a cause of the disease. Persons with the Morquio syndrome have a disproportionately short stature which is manifest clinically by the age of 2 to 3 years and radiographically by the age of 1 year.” This disorder has often been confused with other spondyloThis study was supported by National Institute for Dental Research 00193 and by National Institutes of Health Grant 5 FO5 TW01849-03.
Grant
5 TO1 DE
Table
I. Summar,~ of findings in twelve patients with the Morquio
syndrome
Ilefective
Anterim qwn-bitr
Patient
Sex
1 ‘1
F M F M M F F M E’ F F F
3 4 5 6 i s $1 I0 11 12
I
.-I (Je
D.X F
Torus
enamel
i
0
+
+
8 10 11 13 19 “2 23 “9 !zl 32 35
5 0 0 4 II 6 ii 3 t t :
*Tnadequate informxtion. tPartially endentulous, inadequate :Edentulous, inadequate history. + = Yes. - 7 so.
+ + + + + + + *
+ + + + + + + + +
-
+ + + .y. + i
history.
epiphyseal tlysplasias hut is distinguished from them by the occurrence of cornea1 opacities, a specific pattern of platyspond,vlia, dental abnormalities, and urinary excretion of keratosulfate.” A variant in which kcratosulfatc is not excreted has been described.” Most authors hare not concerned themselves with a complete description of the oral abnormalities in the Norquio syndrome. Brailsford’ reported numerous carious lesions in his case. (:arn and Hurme’; reported three siblings with the clisease, in whom the teeth were smaller than normal, dull gray, and pitted, with tliastemas between them. The cusps were flat and poorlv formed. The enamel was thin, but of normal density, and flaked off easily. These three affected persons hacl a lower caries prevalence than their six unaffectecl siblings. (4arne and Hurmc suggested that the factors whicah interfered with formation of hone and of cnamcl were the same. It was suggested that defective c>alcification, rather than defeetivc matrix production, was responsible. Zellwcger and colleagurs,i reported enamel hypoplasia in two patients with tlic iVorclui0 syntlromc. The C’USJ)lips of thr l)ostrrior t&h uwc sharp. Ko mclltion was matle of the frryucney of caries. Brabant and co-authors” described enamel clcfccts in their two patients ant1 Ilotcd a retluecd predisposition to tIccay. Jlaroteaux, Lam>-, and Fouch(~P notctl gray, dysplastic teeth with pointed cusps in eight patients with the Rlorquio syndrome. The dccitluous as well as the permanent teeth were involvctl, suggesting that the disease is active at 3 to 1 months in utero. T,anger and Carey” reported thin enamel and sharp-pointetl c~usps in both the tlcciduous and permanent tlentitions in eight of ten patients whom they studied. There was a predisposition to caries. Their two oldest patients had lost all of their teeth as a result of numerous various lesions. CASE DESCRIPTIONS
Orofacial examinations were performed on twelve unrelated patients (eight females anti four males), with the Morquio syndrome (Table I). Preliminary
reports on clcvcn WCI’C ascert~ainctl
of these paticuts have appcarccl els~~h~r~.“‘~ I1 Thc~ patients OH y~~untls other tha11 the, tl<~nial al)t1ornlalit>~. Thcsir ;I~~~s
I’;l??~:.(L(I
:35
f?‘Otll
5
t0
!c’iJ?‘S.
All pat,ivnts had a similar t’acial appcaranvr (I~‘ig. 1 ). The nasal hridgc was flat, tllc alaP ??:FZlC WCI’C flaWtl, il?lcl ttlc Ili1SCll tip was u~)turl1ctl. The lower tliirtl ol’ the faccl IV;IS prominent. The 11c~atI>lI)l)ci1~*<~clto sit squarely 011 the sho11ltlcrs. The palates W(‘I’C l)roi1tl antI flat. 11 flat tortIs palutinus \V;IS prcsc11t i11 tight, patients who wcw c\-wluatcti for this W1it. The clccayccl, rnissi11g, antl filled ( I~Alb’) intlcs’2 \VilS (‘VilltliltC’tl i11 cbigtit Ot of twtl?. P’onr of tticse (ilt tlicl ages 01 the 11inr pat,icnts with a full c*otnplrt??c~??t 7, 10, 11, and l!)) wcrc 1’rvc of caries. 111tliv other fo1lr (agccl 8, 1:3. 22, ;1ntI 29) the l)ilII~‘ intles i1vcragccl 4.50. TWO paticl11ts (ag~cl L!!) and 32) liacl vigtit and ninctcen teeth rctnaining, rcyxvtively. TRIP ol(lrst p;1ticnt iI1 our st1ltly (35 yri11.s Of i?.gC) Ilad l0St alI llcr tXY‘tl1 1)y the ?I@ 01’ 22. Thr ~WSOII for tooth loss i11 thcsv thrre ~ultl not hv aclccluatcly clc~tcrn1inrcl. The p(‘~1nanc11t n1axillary a11tcrior t(>c>th WPI’(: witlcly sl)i1ertl i1l1(l fl:1r~l i111tcriorlyi (Fig. 2). They wcrc slightly y(~IIow in color. Therv \YilS at1 aiitc~rior o[Wl?hitc ii1 four of eight persons inspc~c~trtl l’or this trait. Tlic tlcri~luous antI [)c‘l’tllilnent posterior tcvth WCI’C tapcrwl. Thrsc tcdh, as well ils the pcirt11:11rc>tltca~lillcs, hacl 1narkcclly pointcvl C’IIS~)til)s. 7’11~ cal1i\t11rl JV;IS ol’ 11or11r:rl I1arcl11c~ss;r11tl (lit1 11ot flake away. In addition, tl1crv was vertic+;rI tlitnplit1g in thcl lmc~~al surfaces of the I)c~rtnat1cnt ca1lincs a11tl ~IY~IIIO~~~S i11 t\\o pticnts. Tlrc~r(~ \Vi1S gc~11(‘1’;1lixt’cI pitti11g Of tllc‘ l)uc*cal surf:lcrs in ttlcl ~~~‘~~Ilil?l~~?lt tlcntitioiis of tt?rW ])iltiV?ltS. The c~11:~mtl of the tlrciduo11s :111(l p(l1*n1:111t’l1ttcc~tl1 W:~S thi11ntlr tl1il11 11ort11ill 011 radiographs Of afYWtcV1 ~)~~?30llS (Figs. :I ;111(14). IIO\\-c~\~c~1~, ttlc‘ Pl?iltll<‘l \VilS 0t normal racliotlensity and coultl 1~ disti~lguishcvl front tt1c suhjacavnt, (Iv11tin. The radiographic appc’aranvc oi’ the (lentin, pnll) (*l1;1~11l)(~1~s, ant1 root cx11uls \vas normal.
Ora,1 fhdings
ill Uorquio
syndrome
393
Fig. Z. Photograph of the teeth. The permanent canines and the posterior teeth have pointed cusp tips. Note the vertical dimpling on the labial surfaces of the canines and buccal surfaces of the premolars. Pitting is evident on some of the anterior teeth.
Fig. 3. The lower radiographs show the deciduous dentition of a patient with the Morquio syndrome and demonstrate the thin enamel which contrasts w-cl1 within the tlcntin. The uppex radiographs show a control matched for age and sex.
DISCUSSION
The oral findings in persons with the other genetic nlucopol~saccharitloses have been studied previouslp.l”v I* The dental abnormalities in the Morquio syndrome are of a type that is unique within this group. Our findings support the conjecture that the biochemical defect in the Morquio syndrome is different from t,hat which orcurs in the other mucopolp;vsaccharidoscs. In addition, these dental tlefects are not seen in patients with the other spontlplocpiph;r-seal tlysplasias’” and, therefore, may serve to differentiate them from Xorquio syndrome. The concurrent radiologic and microscopic abnormalities seen in the enamel, cartilage, and bone of persons with this contlition suggest that the enzyme may
Pig. 4. The lower radiographs are of the permaueut Morquio syndrome and show thin enamel which contrasts radiographs show a control mntehcd for age and sex.
dcntition well with
of a patient with the the dentin. The upper
be involrcd in a metabolic pathway common to the three structures. Although the dentin in our patients is, by radiologic criteria, normal, it is likely that its physical ant1 chemical properties are not normal since bone, cartilage, and dentin arc mesenchpmal in originl” and each contains acid mueopolysaccharides.‘“-‘” The caries prevalence in our patients appears to be less than in the general population. Our sample was small, and we laeketl an adequate control population. \\‘e were unable to use as controls the sibs of our patients. Further family studies, as well as biochemical studies of the teeth and saliva, are indicntcd. Sinccl the enamel of the deciduous teeth is defective, it must be inferred that the disease process is active early in intrauterine life. This indicates that if correction of the enzyme defect is to be accomplished, it must be done prenatally. Although radiographic examination of the skeleton makes diagnosis possible by the age of 1 year, x-ray examination of the dcntition shortly after birth may afford a means of early diagnosis in families in which there is reason to believe that both parents are carriers. Tn light of the gcncralizccl bone dysplasia, we believe that the open-bite seen in the Morquio syndrome is skeletal in nature rather than secondary to a habit or to the enamel defect. However, an X-linked dominent variety of amclogenesis imperfecta without skeletal changes has been reported in association with openbite.‘!’ The mode of inheritance and clinical and radiologic appearance serve to distinguish the X-linked form from the type seen in the Morquio syndrome. Reduced enamel thickness is also seen in teeth from patients with some of the autosomal tlominant forms of amelogrnesis imperfecta.Y” Again, the inheritance pattern ant1 the absenec of skeletal problems differentiate these forms of amelogencsis impcrfecta from the enamel changes seen in the Morquio syndrome.
Morquio, L.: Sur uno forme de dystrophie oswuw familiale, Bull. Sot:. PCdiatr. Paris 27: 115.152, 19”‘). Roentgcno~r:lplric and (‘linical Features of I%railsfortl, .T. F.: Cllondro-Osteo-l)ystroplly; Child With Dislocation of Vert?hrae, Am. J. Surg. 7: 404-410, 1929. McKusirk, V. A.: Hcritahle Disorders of Connwtivc Tissw, cvl. 4, St. Louis, 1972, The (1. v. Mosl,y (‘olllparly, pp. 610, 588, 585. l\lxtalon. K.. Arbowst. n.. and Dorfman. A.: Morauio’s Ryndromc: A IWic:iencv of (Zhonclroitin ‘Sulfa& N:Xrc,tylllrxosaminr &lfatc, Rulf%tasc, eediatr. Rrs. 8: 436, ‘1974 (abstr.). 5. T>xnger, L. O., and (!awy, I,. S.: The RoentrrlloRr:11’1’i(’ Featurrs of the KS Mwopolys:lwlmridosis of Morquio (Morquio-Iirailsfor(l’s l)iseasc), Am. J. Rwntgenol. 97: l-20, 1966. ti. Garn, S. M., an11 Hurme, V. 0. : I)cwtal I)r~fwts in ‘l’hrcc Siblings \Vith Morquio’s Diwasc, nr. nrnt. J. 93: 210.212, 1952. 7. Zc~llwewr. II.. Pow&i. I. V.. Pedrini. V., Stan&x. I?. H.. and van Noortltn. .J. K.: MorquioI’llricl?s i)is≻ Rr&rt of’2 (‘ascs,‘J. ecvliatr. 69: 54$-561, 1961. dentnires tlans la maladic 11e 8. lXr:ctxcnt, H., Wcwltls, H., and Klws, L.: Les :tlt&xtions Morquio, Rw. Stomatol. 63: 466-467, 1962. Btudr cliniquc, 9. Marotr:tux, I’., Lam;y, XI., rind Fouchrr, M.: I,a malndic~ tlv Morquio txdiologique ctt biolo~~qw, Presw mbtl. 71: 2091-2094, 1963. IO. I,win, I,, R., .Torgrnson, R. .J., and Salinas, (‘. E’.: 1)ental Findings in the Morquio Syrlclromcl, ‘1111.3. TIum. Genr,t. 25: 45a, 1973 (abstr.). 11. I,cvin, T,. S., .Jorgt~uson, R. J., and Salinas, C. F.: I)cwtnl Findings in the Morquio Rynof tlw Mwting of the Anwric*an Aexdrnly of Oral Pathology, Nen llromc., I’rowcvlings orlf~:lns 19i4. 1”. St:lllcl:,;diz:,tion of Reporting of Dcwtal I)iseasw ant1 Conditions, Report of an XspPrt (‘omnrittw on I)wt:tl Hwlth, Genrva, 1962, \Vorltl Health Orgnnizntion Tcchnir:rl Report Svriw #242. 13. Qarllwr, I). Q. : ‘1’11v Oral Manifestations of IIurlrr’s Snyllrom(1, OKAT. 91:~~. 32: 4,557, 1971. 14. Salirms, C. F., I,cBvin, I,. H., and dorgwson, K. .J. : Oral Findings in thr, Mucol~olys:rcc~hnri~lows. i In nrenaration. i 15. I,cvin, I,. S.,’ Snfin:&, (‘. F., a’nd .Jorg~nson, R. .T.: IJnpul~lishc~tl dnta. \V. M., liungca, K. F., and I&mgt~, M. 1s.: Ilailry’s Twtbook of Histology, (~1. Iti. (‘oprnh:rvrr, 16. lialtinlow. 1971. \Villixrns & \Vilkins (‘on~uxn~. char). I6 an11 n. 12-1. ’ E. ;2. : TIexo\nmiw and Avid Glyco17. (‘kirk, K. I).,’ Smiih, .J. G., .Tr., antI D:t&&, s:~rni,lo~I~~~:lns in Human Twth, Hiocnlwrn. Tiiophys. Acta 101: 267-272, 1965. Layer in I)c,ntinoaenic:~lly IS. Lindv, A. : (;lyc~onnx~~inogly~:~ns of thr Otlontohl:\st-Prcdrntill(, Actiw I’orcinc~ T&h, C&if. ‘l’issuc~ Rrs. 12: 281.291, 19i:<. 19). Srllultz, Ch. : ither viwn Fall van Hypoplasie drxr Hartsuhstanzrn bri Zihnrn im T%rrrirh tltls r~vhtrn Olwrkic~fcrs, J)tscll. Zallnnwxtl. %. 7: 78%800, 195%. ((‘itetl in Gorlin, H. .J., :tntl (i~lclm:tr~, TI. M.: ‘l’110ma’s Orill Patllology, ~1. 6, St. Louis, 1970, The C. 1’. Mosl)y (‘orrlpn~, 1’. l:v?.) 20. \Vitkop, f‘. .l., ant1 Sxuk, .J. .J. : Ibtal nrtd Or:11 Manifcstntions of TIcwtlit:~ry Discaw, \~orl~shop sponwre~l 1)~ the Amt~rican Araclenr~ of Oral Pathology, 1971.