CASE REPORT

Abstract Kozlowskisyndrome is the mostcommon type of spondylometaphysealdysplasia (SMD). It is characterizedby short stature (130 to 150 cm), pectus carinatum,limited elbowand hip movement,mild bowlegdeformity, and curvature of the spinal column.Children with Kozlowskidwarfism usually are not recognizedat birth, since they havenormal clinical features, weight, andsize. This article reports the dentaltreatment and oral findingsof a 14-year-oldfemale patient with Kozlowskidwarfism. (Pediatr Dent15:49-52, 1993)

Spondylometaphysealdysplasia (Kozlowski type): case report CynthiaM. Guzman,DMD Gerald R. Aaron,DDS, MS Introduction Spondylometaphysealdysplasia (SMD)is a disorder Schmidt.4 Sporadiccases of metaphysealdysostosis asso- comprising a group of diseases in which the spine and dated with generalized platyspondyly and with radio- metaphysesof the tubular are affected. The most graphic alterations predominantlyin the spine, pelvis, commontype of spondylometaphyseal dysplasia is and the proximal femora, were termed spondylo- Kozlowskidwarfism; several forms of this syndromehave metaphyseal5 dysostosis. been defined by radiographic and genetic analysis. Spondylometaphysealdysplasia (SMD)is a generic term Children with Kozlowski usually are not for a heterogeneousgroup of skeletal dysplasias in which recognizedat birth, since they have normalclinical fea- spinal involvement(platyspondyly) is associated with tures, weight, and size. This disease is recognizedin pre- varying degrees of metaphysealabnormality. ~ The most school age as shortening of stature and kyphoticappear- thoroughlydefined SMD(Kozlowski type, a form of short- ance.1 Patients with Kozlowski dwarfism often were trunk dwarfism)is diagnosed readily by characteristic reported to have Morquio’sdisease, becauseof the similar radiographic findings which include: 1) generalized characteristics. In Morquio’sdisease, patients have short platyspondylywith anterior tapering of vertebrae (espe- stature, short neck, and "knockknees," but are differenti- cially in the thoracic region); 2) generalizedmetaphyseal ated by their cornealopacities, cardiac problems,specific dysplasia, whichoften is mostsevere in the femoralnecks dental2 findings, and urinary excretion of keratin sulfate. (coxa vara is common)but variable in other sites; and Also present in Kozlowski dwarfism are pectus apparent retardation of boneage in the carpal and tarsal carinatum, limited elbow and hip movement,mild bow- bones.5,7 leg deformity,and kyphosis(curvature of the spinal col- Kozlowski-type SMDshould be differentiated from umn). Theseassociated problemsoften require surgical Morquio’sdisease. Morquio’sdisease is a rare skeletal treatment. Patients reach 130 to 150 cmin height,2 and dysplasia characterized by abnormalmetabolism of the usually have a normallife span. mucopolysaccharide keratin sulfate. Patients with This article reports the oral findings and dental treat- Morquio’sdisease have disproportionate short stature, ment of a patient with Kozlowskidwarfism. neckshortness, sternal protrusion, laxity of the ligaments, "knockknees," flat feet, and disproportionatelylong ex- Literature Review tremities.8 It is inherited as an autosomalrecessive trait, The term "metaphysealdysostosis" first was used to andis estimatedto occurin 1 / 40,000births.9 Thepattern of designate a condition with extreme shortness and changes in Morqulo’s disease depends very much metaphysealirregularities of the lowerlimbs and hands.3 upon the patient’s age. Theplatyspondyly in Morquio’s A milder form of metaphysealdysostosis wasreported by disease, like Kozlowski’sdwarfism, is characterized by a central anterior tongue-likeprotrusion, hypoplasiaof the vertebralbodies at the thoracolumbarjunction, and hypo- Thisarticle is a workof the UnitedStates Government and maybe plasia of the odontoidprocess.2 Just as in Kozlowskidwarf- reprintedwithout permission. One of the authorsis an employeeof ism, associated thoracic kyphosisin Morqulo’susually is the UnitedStates Army at Fort Clayton,Republic of Panama.Opin- prominent. Corneal opacities and dental anomalies are ionsexpressed therein, unless otherwise specifically indicated, are thoseof the authors.They do not purportto expressviews of the constant features in Morquio’sdisease. In Morquio’s,the UnitedStates Army or anyother Department or Agency of the United enamellayer of the teeth is very thin, and the teeth are States Government. smaller and more opaque than usual. 8 The permanent

PediatricDentistry: January/February, 1993- Volume 15, Number 1 49 posterior teeth have generalized pitting on the buccal sur- Unaffected in this disease are the facial appearance, face, and the permanent maxillary incisors are spade intelligence, sense organs, and viscera. Literature concern- shaped and spaced. An anterior open bite may be ob- ing the orofacial findings of Kozlowskidwarfism was not served and has been associated with the presence of an found. No description of dental abnormalities was re- enlarged, protruding tongue.I° Midface hypoplasia with a ported in the literature. depressed nasal bridge and protrusion of the mandible Case Report also have been reported by Behrman.11 In addition, chil- dren with this disorder are muchshorter than those with A 12-year-old Caucasian female diagnosed with Kozlowski dwarfism. Kozlowskidwarfism was referred to pediatric clentistry at SMD(Kozlowski type) has been reported mainly in the Fort Lewis, Washington. The patient was an alert child Europeanliterature. It usually is described as autosomal with normal mental development. dominant but probably also occurs as an X-linked reces- She was the third child of healthy parents. The preg- sive12 type with most cases representing fresh mutations nancy was uncomplicated. Her birth-weight was 6 pounds with a prevalence of one per million or fewer live births. 11 ounces and her length was 19 inches. The most commonclinical findings in SMD(Kozlowski Motor development was normal but growth was de- type) are short neck and disproportionately short trunk layed. At 3 years of age, the child was 20 inches tall, with dorsal kyphosis (curvature of the thoracic spine). making her shorter than other children of her age. This Diagnosis can be made by exposing radiographs of the difference became increasingly apparent when she first spine and pelvis. Spinal changes are well-established by 2 went to school. She sat at 7 months, walked at 14 months, years of age with platyspondylia with an anterior defor- and was completely toilet trained by 16 months. The first mity in the form of a "tongue" present in the upper tho- teeth were noted at 6 months. She reportedly developed racic, cervical, and lumbar spine. 13 The dorsolumbar ver- "knock knees" after she began walking. Since birth, she tebrae are more oval-shaped with a recessed twelfth has undergonecervical fusion, spinal fusion, and rebuild- thoracic or first lumbar vertebra. Generalized ing of hip and knees. Additional surgery is planned. platyspondylia and femoral neck changes are the two Dental history included a Class llI and main diagnostic features in a radiographic examination. TMDmusculature pain resulting from posterior Generalized platyspondylia is greatest in the high dorsal disocclusion and prognathic position in centric relation. A spine by 5 years of age. The femoral heads are well seated. night guard was fabricated, and the treatment plan was to The femoral necks are short, and the femoral neckshaft evaluate eruption guidance and recall at every six months. angle shows a mild coxa valga, which is maintained with The most striking feature of this patient at 14 years of growth23 A unique radiographic feature in childhood is age was her height of 37 1/2 inches (Fig 1). (According the thick metaphyseal collar around the femoral neck. the National Center for Health Statistics, at 14 years of age Calcium and phosphorus metabolism has not been found the average height of a female adolescent is 63 inches). to be abnormal, nor has abnormal mucopolysacchariduria Dental examination revealed a late mixed dentition been1. observed. with maxillary and mandibular primary first molars still In SMD(Kozlowski type), the thorax is described present. pectus carinatum (pigeon breast) and the pelvis has short Other significant dental findings were small perma- iliac wings with flat irregular acetabula24 Coxavara (de- nent teeth (microdontia), diastema, and an upper midline formity of the hip joint with decrease in the angle of incli- shift to the left of approximately 3 ram. The patient’s nation betweenthe neck and shaft of the ) usually is maxillary and mandibular incisors were compared to present. (knock knee) also has been ob- Moyer’s~6 average mesiodistal diameters of permanent served. Limbs have irregular metaphyses but are normal dentition in females. The maxillary centrals were on aver- in length. The elbows often are more disturbed than the age 1.3 mmsmaller than Moyer’s standard. Other anterior knees. Epiphyseal development is relatively normal and teeth also exhibited decreased size. bone age tends to be delayed. Short, stocky hands also are In addition, the patient had a relatively large tongue seen in this type of SMDdue to hypoplastic carpal bones (macroglossia), whichoverlaid the occlusal surfaces of her with late ossification. Waddlingand halting gait with limi- mandibular teeth. The patient had good oral hygiene and tation of joint mobility are characteristic of Kozlowski her soft tissues were healthy. The maxillary first molars dwarfism. This condition, plus early degenerative joint had occlusal caries. The crown of the mandibular right changes, usually lea d to great discomfort and make sur- permanent canine was fractured. gery necessary. Steiner analysis was used for the cephalometric tracing: In morphological and biochemical studies, ~5 a probable SNA-65O;SNB-67°; ANB--2°; 1/NA-29O;l\NB-28O; Occl- pathogenic mechanismof a particular biochemical defect SN-29°;°. GoGN-SN-43°; FMA-32O;IMPA-88O; 1/1- 135 was suggested as etiologic in several of the These results describe a profile of anterior divergence chondrodysplasias. Abnormalities, probably related to a with a skeletal Class llI malocclusion(Figs 2, 3). The high degradative lysosomal process of proteoglycans in angle represents a clockwise growth with dolichofacial chondrocytes, were found in SMDof the Kozlowski type25 growth trends.

50Pediatric Dentistry: January/February, 1993- Volume15, NumberI The patient was treated with fixed appliances for correction of the anterior crossbite and closure of the midline di- astema. To encourage the permanent premolars into occlusion, the first pri- mary molars were extracted. During her limited orthodontic treatment, she de- veloped periapical radiolucencies on the mandibular left permanent canine, and the lower right mandibular central inci- sor which were asymptomatic. The teeth were treated with root canal therapy. After the crossbite and diastema closure were corrected, she developed a poste- rior crossbite on the right side which was corrected with an active transpalatal bar. Morquio's disease is one of the dis- eases whose features are similar to SMD (Kozlowski type). One of the main den- tal findings in Morquio's reported by KinironsS was spade-shaped and spaced Fig 1. Full body view showing normal Fig 2. Lateral view showing anterior permanent maxillary incisors. In this head and size and length of limbs, with a divergent profile, patient with Kozlowski dwarfism, the short body, knock knees and short and maxillary incisors were spaced but not stocky hands. shaped abnormally. Langer19 reported that eight of 10 patients with Morquio's syndrome showed thin enamel with sharp pointed cusps in both primary and permanent teeth. This patient had thin enamel, with no pitting and no pointed cusps in her primary or permanent dentition.

Major Guzman is currently a pediatric dentist in the U.S. Army, Fort Clayton, Republic of Panama. Dr. Aaron, U.S. Army retired, is in private practice in Vancouver, WA.

Fig 3. Panelipse radiograph showing delayed eruption of 1. Kozlowski K: Metaphyseal and spondylometaphyseal permanent teeth.. chondrodysplasias. Clin Orthop 114:83-93,1976. 2. Le Quesne GW, Kozlowski K: Spondylometaphy- sealdysplasia. Br J Radiol 46:685-91,1973. Discussion 3. Jansen M: iiber atypische Chondrodystrophic (Achodroplasie) und iiber eine noch nicht beschriebene Unique dental findings were observed in a patient with angeborene Wachstumsstorung des Knochensystems: a disease that has been reported in the European literature Metaphare Dysostosis. Ztschr Orthop Chir 61:253-86,1934. but is not well described in the American literature. No 4. Schmidt F: Beitrag zur Dysostosis enchondralis information was found in the literature concerning the metaphysaria. Monatsschr Kinderheilkd 97:393-97,1949. orofacial structures or dental treatment for these patients. 5. Koslowski K, Maroteaux P et al.: La dysostose spondylo- One feature of this child's dentition was microdontia. metaphysaire. Presse Med 75:2769-74,1967. According to Shafer,17 in true generalized microdontia, all 6. Sutcliffe J: Metaphyseal dysostosis. Ann Radiol 5:215-23, teeth are normally formed but smaller than normal and 1965. 7. Kozlowski K: Spondylo-metaphyseal dysplasia. Prog this occurs in some cases of pituitary dwarfism. This pa- Pediatr Radiol 4:299-308,1973. tient had a complete primary dentition (as evidenced by 8. Kinirons MJ, Nelson J: Dental findings in mucopoly- radiographs) and was developing a complete comple- saccharidosis type IV A (Morquio's disease type A. Oral ment of permanent teeth. She also had a large tongue Surg 70:176-79,1990. 18 (macroglossia), which according to McDonald and Avery 9. McKusick VA: Heritable Disorders of Connective Tissue. may cause both an abnormal growth pattern of the jaw 4th ed. St. Louis: The CV Mosby Co, 1972, p 61. and malocclusion. Flaring of lower anteriors and an Angle 10. Rose LF, Kaye D: Internal Medicine for Dentistry, St. Louis: Class III occasionally are the result of macroglossia. The CV Mosby Co, 1983, pp 1233-35.

Pediatric Dentistry: January/February, 1993 - Volume 15, Number 1 51 11. Berhrman RE, Vaughan VC III eds: Nelson Textbook of nisms in . J Bone Joint Surg Pediatrics, 13th ed. Philadelphia: WBSaunders Co, 1987, 66A:817-36, 1984. pp 326-28. 16. Moyers RE: Handbook of Orthodontics. 4th ed. Chicago: 12. Jones KL: Smith’s Recognizable Patterns of HumanMal- Year BookMedical Publishers, 1988, p 230. formation, 4th ed. Philadelphia: WBSaunders Co, 1988, p 17. Shafer WG,Hine MK, Levy BM: A Textbook of Oral Pa- 316. thology. Philadelphia: WBSaunders Co, 1983, p 37. 13. Bailey JA: Disproportionate short stature diagnosis and 18. McDonaldRE, Avery DR: Dentistry for the Child and Ado- management. Philadelphia: WBSaunders Co, 1973. lescent, 5th ed. CVMosby Co, 1987, p 157. 14. Riggs WJr, Summitt R: Spondylometaphyseal dysplasia 19. Langer LO, Carey LS: The roentgenographic features of the (Kozlowski): report of affected mother and son. Radiology KS mucopolysaccharidosis of Morquio (Morquio 101:375-81, 1971. Brailsford’s disease). AmJ Roentgeno197:1-20, 1966. 15. Stanescu V, Stanescu R, Maroteaux P: Pathogenic mecha-

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