International Journal of Paediatric Dentistry 2003; 13: 271–273

© 2003 BSPD and IAPD 271

Blackwell Publishing Ltd.

Increased primary tooth size in a 47,XXY male: a first case report

M. L. HUNTER, M. M. COLLARD, T. RAZAVI & B. HUNTERDental Health and Biological Sciences, University of Wales College of Medicine Dental

School, Cardiff, UK

Summary. Increased tooth size has previously been reported in association withKlinefelter syndrome. However, until now, this observation has been restricted to thepermanent dentition. In this paper, we report increased mesio-distal width in the primaryincisor and molar teeth of a 47,XXY male.

Introduction

The birth prevalence of chromatin-positive males isapproximately two per 1000. Several X-aneuploidyvariants exist, including 47,XXY, 48,XXYY, 46,XY/47,XXY, 48,XXXY, and 49,XXXXY. Occurring inapproximately 80% of cases [3], ‘classical’ Klinefeltersyndrome is associated with the 47,XXY karyotypeand is characterized by gynaecomastia at late puberty,hypogonadism (small testes, azoospermia/oligospermia),hyalinization and fibrosis of the seminiferous tubulesand elevated urinary gonadotrophins. Affected malesmay exhibit psychosocial problems and minor devel-opmental and learning disabilities, including delayedspeech and language acquisition.

Of interest to the dentist, cephalometric investi-gation reveals smaller calvarial size, smaller cranialbase angle, and larger gonial angle than normal.Both maxillary and mandibular prognathism tend tooccur [4]. In addition, various dental features havebeen observed, including taurodontism [5–7], con-genital absence of permanent teeth [5], shovel inci-sors [6], and increased permanent tooth size [1,2].

Case report

LCA, aged 8 years 7 months, was referred to the Uni-versity Dental Hospital, Cardiff by a local community

dental officer. Diagnosed as having Klinefelter synd-rome (karyotype 47,XXY), the patient had littlespeech, and delayed intellectual development hadpreviously been noted.

On extraoral examination, LCA demonstratedclassical Klinefelter facial features, including ocularhypertelorism, a broad, flat nasal bridge and low-setears. Clinical examination of the oral cavity revealedthe patient to be in the primary dentition, with ahigh, arched palate. The maxillary primary incisorswere retained, and the lower permanent central inci-sors had recently erupted without exfoliation of theirprimary predecessors. The majority of the primarymolar teeth were noted to be carious.

A panoramic radiograph (Fig. 1) taken at a previousattendance had shown developmental absence of fourpermanent teeth (15, 25, 35, 45). In addition, thedeveloping first permanent molars had been noted tobe mildly taurodont. These are features previouslyreported in association with Klinefelter Syndrome [5–7].

After assessment by a Consultant Orthodontist,LCA was listed for the provision of comprehensivecare under general anaesthesia on a day case basis.At operation, the lower right second primary molar(85) was restored, and the following teeth extracted(the extraction pattern being largely dictated by theextent of the caries):

(55, 52, 51, 61, 62, 65, 71, 74, 75, 84)It should be noted that the mandibular right primary

central incisor had exfoliated prior to operation.

Correspondence: M. L. Hunter, Dental Health and BiologicalSciences, University of Wales College of Medicine DentalSchool, Heath Park, Cardiff, CF14 4XY, UK.

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272 M. L. Hunter et al.

© 2003 BSPD and IAPD, International Journal of Paediatric Dentistry 13: 271–273

Prior to extraction, the maxillary primary centralincisor and the primary molar teeth in both archeswere subjectively considered to be unusually large(Figs 2 and 3). As a result, following extraction, andwith the consent of both patient and parent, repre-sentative examples of each tooth type were retainedfor closer inspection, and the mesio-distal width (inmillimetres) was measured with dividers. The mesio-distal width was recorded as the greatest mesio-distaldimension of the tooth crown measured on the occlusalsurface or at the incisal edge. Comparisons of thesemeasurements with known average mesio-distal widthsfor the primary dentition [8] are shown in Table 1.

Discussion

Evidence accumulated over the last four decadessupports the role of both X and Y chromosomes,

independent of secondary hormonal influences, ongrowth and development of dental structures [9–11].In general, the results of measurements of enameland dentine thickness in individuals with variouskinds of sex chromosome abnormalities indicate thatthe X chromosome primarily influences enamel thick-ness, whereas the Y chromosome promotes both enameldeposition and dentine growth [12–15].

In 1985, Townsend and Alvesalo [2] speculatedthat the presence of an extra X chromosome mightinfluence enamel thickness and hence overall toothsize. In support of this premise, the permanent toothcrowns of 47,XXY males have previously beenreported as being generally larger than those of con-trol males and females and their first degree maleand female relatives [1]. The foregoing case reportof increased tooth size in the primary dentition ofa 47,XXY male lends further support to the role of theextra X chromosome, any factor responsible for excessgrowth necessarily being in effect from early foetal life.

Résumé. Une augmentation de la taille des dents adéjà été décrite en association avec le syndrome deKlinefelter [1,2]. Cependant, cette observation n’a étéjusqu’à présent réalisée qu’à propos de la denturepermanente. Cet article décrit l’augmentation de lalargeur mésio-distale d’incisives et molaires temporaireschez un garçon de caryotype 47,XXY.

Fig. 1. Panoramic radiograph showing absence of first premolarsand first permanent molar taurodontism.

Fig. 2. Maxillary arch (mirror view).

Fig. 3. Mandibular arch (mirror view).

Table 1. Mesio-distal width (in mm) of extracted teeth versusknown average dimensions for the deciduous dentition.

Tooth LCA Average

Maxillary central incisor (51) 8 6·5Maxillary second molar (65) 11 8·4Mandibular first molar (74) 10 7·7Mandibular second molar (75) 12 9·7

Megadontia in a 47,XXY male 273

© 2003 BSPD and IAPD, International Journal of Paediatric Dentistry 13: 271–273

Zusammenfassung. Eine erhöhte Zahngröße wurdefür das Klinefelter Syndrom beschrieben. Dies warallerdings beschränkt auf Beobachtung im bleibendenGebiss. In dieser Arbeit wird eine erhöhte mesio-distale Ausdehnung bei Milchschneidezähnen undMilchmolaren bei einem Jungen mit 47,XXYGenotyp beschrieben.

Resumen. El aumento del tamaño dentario se hacomunicado previamente en asociación con elsíndrome de Klinefelter. Sin embargo, hasta ahora.Esta observación se ha restringido a la denticiónpermanente. En este artículo informamos de laanchura mesio-distal aumentada en el incisivotemporal y los molares de un varón 47,XXY.

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