原文題目

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口腔病理科 On-Line KMU Student Bulletin

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原文題目(出處)： Cleidocranial dysplasia: a review of the dental, historical, and practical implications with an overview of the South African experience Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:46-55

原文作者姓名： Tina Roberts, Lawrence Stephen, Peter Beighton

通訊作者學校： Faculty of Health Sciences University of Cape Town, Observatory 7925, Cape Town, South Africa

報告者姓名(組別)：李爵安 (Intern I 組)

報告日期： 102.5.7

內文：

1. INTRODUCTION:

 Cleidocranial dysplasia (CCD) is an uncommon but well-known genetic skeletal condition, hyperdontia and other developmental abnormalities of the teeth are a major feature and may require special dental management.

 The purpose of this article was to review the dental manifestations and management of cleidocranial dysplasia(CCD)：The history, genetic background, and general manifestations of CCD are also outlined and an overview is presented.

 Over the past 40 years, the authors have encountered more than 100 affected persons in Cape Town.

2. CLEIDOCRANIAL DYSPLASIA:

 supernumerary teeth (hyperdontia) in the primary and secondary dentition may lead to dental crowding and malocclusion.

 Retention of the deciduous teeth may exacerbate this situation

 Cleidocranial dysplasia is inherited as an autosomal dominant trait, with generation-to-generation transmission.

 Owing to the founder effect, the condition is comparatively common in the mixed ancestry community of Cape Town, South Africa

 Whereas the worldwide prevalence of CCD is generally regarded as being about 1 per million, in this Cape Town community,

the minimum prevalence is 100 per million.

3. CLINICALMANIFESTATIONS

 General features

i. clavicular hypoplasia

ii. delayed fusion of cranial sutures

iii. dental abnormalities, The number of teeth may be excessive (hyperdontia)

iv. Patency of the anterior fontanelle can produce a bulky configuration or a depression in the mid-upper forehead

v. Skeletal abnormalities, including slight stature, short terminal phalanges, spinal malalignment, genu valgus (knock knees), and pes planus (flat feet)

vi. Recurrent infections of the upper respiratory tract owing to maldevelopment of the sinuses

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vii. Other skeletal abnormalities include a wide pubic symphysis, dysplastic scapulae, coxa vara, and a variety of vertebral anomalies

 Dental features in CCD

i. leads to dental impaction, overcrowding, and malocclusion, while midfacial hypoplasia can exacerbate these problems

ii. Articulation and mastication may be compromised

iii. delayed eruption and retention of the primary and secondary dentition

iv. The crowns of the teeth sometimes appear abnormal, the enamel may be hypoplastic, and dentigerous cysts and taurodontia

v. Rounded gonion angles, kyphotic sphenoid bones, and Wormian bones in the cranial sutures

4. DIFFERENTIAL DIAGNOSIS OF

CLEIDOCRANIAL DYSPLASIA AND HYPERDONTIA

 The presence of clavicular hypoplasia is strongly suggestive of CCD i. as an isolated nonsyndromicentity, which is usually unilateral

ii. Complete absence of both clavicles is a manifestation of the Yunis-Varon syndrome

1. rare genetic disorder, intellectual dysfunction and anomalies of the hands and feet are associated with malformations in other systems

 Defective cranial ossification leading to patency of the anterior fontanelle and Wormian bones in the sutures is an important feature of CCD

i. osteogenesis imperfecta (frequent fractures) ii. pycnodysostosis (skeletal density)

iii. congenital hypothyroidism (disturbed thyroid metabolism)

 Hyperdontia may also be a component of specific genetic syndromes, including the

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i. Gardner syndrome (familial polyposis of the colon and osteomata), ii. Hallerman-Streiff syndrome (narrow face, hypotrichosis,

microphthalmia)

iii. orofaciodigital syndrome type I 5. DENTAL MANAGEMENT IN CCD:

 The aim of dental management in CCD is to achieve an optimal functional and cosmetic result by early adulthood. Surgical procedures are usually uneventful in CCD but atlanto-axial subluxation with consequent damage to the spinal cord has been documented. This causes potential hazard during anesthesia

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 These procedures are all undertaken over a long period. It is relevant that patient compliance is essential to a favorable outcome for any of these modalities

 In South Africa, the dental and orthodontic approach to CCD has several constraints. Extensive medical expertise is available, but access is limited and costly

題號題目

1 鎖骨顱骨發育不全可能影響?

(A) 鎖骨和恥骨聯合 (B) 頭顱骨和顏面骨 (C) 脊椎骨和附肢骨 (D) 以上皆是

答案(D) 出處：oral and maxillofacial pathology

題號題目

2 下列關於牙齒發育異常的敘述，何者錯誤？

(A) Fusion 之牙常有個別的牙髓腔 (B) Germination 之牙有共同的牙髓腔 (C) Cleidocranial dysplasia 常先天多生牙

(D) Macrognathia 可見於軟骨發育不全(anchondroplasia)或鎖骨顱骨 (Cleidocranial)發育不全

答案(D) 出處：oral and maxillofacial pathology 101 年第二次專門職業及技術人員高等考試