Helen Tippetts References for her lecture on Definitions and Aetiology

PDF list of all further reading and references can be found here.

Select references can be found below

Polder 2004
Neiminen 1995
Khalaf 2014
Fleischmannova 2008
Brook et al. 2002

Dental management of Rapp-Hodgkin syndrome associated with oral cleft and hypodontia

Rapp-Hodgkin syndrome (RHS) is a rare type of autosomal dominant disorder characterized by association of ectodermal dysplasia (ED) with cleft lip/palate. The main features include dry, brittle hair with alopecia in adulthood, dental anomalies (hypodontia, microdontia with delayed eruption, fissured tongue, and retruded maxilla), hypohidrosis, dysplastic nails, and clefting. Palmar-plantar keratoderma is seen frequently. RHS has signs and symptoms that overlap considerably with those of ankyloblepharon-ED-clefting syndrome and ectrodactyly-ED-clefting syndrome. 

The below link takes you to an article that discusses a case of RHS, one of the four members in three generations who had ED with variable degree of involvement of hair, teeth, nail, and sweat glands.

Rapp-Hodgkin Syndrome

Kings College Hospital Hypodontia Study Day on 4th of May 2016

The annual Kings College Hospital Study Day will take place on the 4th of May 2016 at the Weston Education Centre, Denmark Hill. The program will be delivered by staff of Kings who are directly involved in management of both adolescent and adult patients on a number of multidisciplinary clinics. Subject covered will include management of the developing dentition, orthodontic considerations, the provision of adhesive dentistry such as composite masking and resin bonded bridges in addition to the placement of implants. 

Hypodontia program 4th May 2016

Hypodontia Booking form May 2016

Gremlin gene associated with Hypodontia ! Yes Gremlin !

As a child of the 80's I loved the Gremlins films as well as Back to the Future Indiana Jones etc. So it turns out that there is a Bone Morphogenic Protein antagonist that is known to regulate BMPs in embryogenesis and tissue development. Have a look at the abstract of some research by a group from Thailand.  

Gremlin 2 BMP

Certain genes are related to certain patterns of missing teeth

I could never profess to knowing anything about genetics in any great detail ! In this graphic the two main genes in Hypodontia are illustrated. MSX1 shows a significantly different pattern of tooth loss to PAX9 which is heavily associated with the commonly missing lateral incisors and premolars. Have a read of the below article for more information.  

Orphanet Article on Genes and Hypodontia

Hypodontia in orthodontically treated children

The frequency of hypodontia in orthodontically treated children, both male and female, and the association between tooth type, the upper or lower arch, the affected side and Angle’s classification were studied using interviews, oral, study cast and panoramic radiographic examinations of 212 patients with a mean age of 12 years 7 months. A hypodontia frequency of 11.3 per cent was found for the total sample. This was higher than the incidence of hypodontia reported in other studies of orthodontically treated children. The most frequently missing teeth were the maxillary lateral incisors, and maxillary and mandibular second premolars. The missing teeth were more often absent on the right (54.2 per cent) than on the left (45.8 per cent) side, in both males and females. One tooth was absent in 29.2 per cent of patients, two in 58.5 per cent, but seldom three or more. Orthodontic space closure was the treatment of choice in 87.5 per cent of the subjects.

Click on the article below for more information. 

Hypodontia in orthodontically treated children

What Are The Treatment Options in Patients with Unilateral Congenitally Missing Second Mandibular Premolars?

In this article by Gerassimos Angelopoulos, an orthodontist in Greece, the issue of missing second premolars and the management of the retained deciduous molar is discussed and the relative advantages and disadvantages of each are outlined but not entirely addressed. In my experience retention of the primary molar is a realistic option which obviously depends on the tooth's restorative status and how it relates to the occlusal plane. Where infraocclusion is significant enough to result in an increased chance of caries then extraction may need to be seriously considered. Where the tooth is at an acceptable level in the absence of ankylosis the occlusal surface can be restored to maintain contact with the opposing unit. If the deciduous tooth is extracted resin bonded bridges or implants may be an option if space closure is not possible.  Alternatively the patient may just be happy with having a space there with no further elective treatment ! Much a dentists head has been scratched on hypodontia clinics thinking about what the best option may be. 

Have a read of an orthodontists view. 

Angelopouos on the missing second mandibular premolar

Is there a link between hypodontia and ovarian cancer ?

There is emerging evidence that Hypodontia is a risk marker for Ovarian cancer. Ovarian cancer ranks as the 8th commonest cancer in women and only 30% of patients survive as such it is the 5th leading cause of cancer amongst women. In a recent study 20% of ovarian cancer patients had signs of hypodontia. Please click on the link below which will take you to Anna Yu's presentation from the University of Kentucky.  

Click here for a presentation exploring the link.

Is hypodontia a wholly genetic condition ?

An article in the British Dental Journal from 2007 reviews current knowledge on the aetiological basis for hypodontia as well as various types of presentation and classification. Syndromes that are associated with congenitally missing teeth are also illustrated in a table. Click on the link below for the full article. 

Hypodontia-Is it all in the genes ?

Hypodontia is ideally treated in a multidisciplinary setting- A case report

The purpose of this article is to describe a team approach to treatment of hypodontia in adolescent dentition. A case report of hypodontia with a microdontic lateral incisor in a Class I malocclusion illustrates the principles of case management. Multidisciplinary consultation during treatment planning and coordination and appropriate timing of subsequent interdisciplinary dental care enables the clinician to provide the optimum care. The scope of orthodontic and restorative management depends on the severity of the hypodontia.

Multidisplinary management of hypodontia in adolescents: case report.