Wednesday 19 October 2016

What congenital anomalies do patients with Downs Syndrome present with ?





A low powered study from Brazil has illustrated some evidence for hypodontia being highly prevalent amongst patients with Downs Syndrome. In this study 96 individuals were clinically and radiographically examined. 

Hypodontia was found to be the most prevalent condition at 36%, followed by microdontia at 10%, conical teeth at 7%. Taurodontic teeth were rarer at 3% with other anomalies such as dens invaginatus 1% of cases. 

The authors concluded that the occurrence of hypodontia was high amongst this patient cohort and is likely to impact on their management not only in their interaction with orthodontics and paediatric dentistry but also with special care dentists managing them in adulthood. 

The link can be found below

http://www.stephenhancocks.com/download.php?op=view_article&article_id=395

Thursday 1 September 2016

Is there a link between ovarian cancer and hypodontia ?

A systematic review by Iavazzo and colleagues revealed a possible link between ovarian cancer and hypodontia although the research associated with this was very weak at best.

In total, 385 patients were included in this study. Control group was present in 3 out of 4 studies (340 patients). Hypodontia was present in 20%. Only in 2 out of 4 studies, the number of missing teeth was mentioned (47 teeth), while the majority of them were either maxillary second premolars or maxillary lateral incisors. 

Unilateral distribution of the missing teeth was present in 28 out of 46 patients, while bilateral distribution of the missing teeth was present in 18 out of 46 patients. The presence of ovarian cancer in the family medical history occurred in 12 out of 33 patients. Only 1 out of 4 studies examined the presence of genes with mutations in the included patients. Based on these findings, the lack of clinical studies was the principal obstacle to clarify the possible predictive value of hypodontia in the early prediction of patients with higher risk of ovarian cancer.

Tuesday 26 July 2016

New evidence shows patients prefer closing spaces versus opening spaces when teeth are missing




Qadri and colleagues have surveyed lay members of the public to try and measure their perception of different types of orthodontic treatment and subsequent restorative treatment. Opening of lateral incisor spaces can be difficult to get right especially if there are other complicating factors. The closure of spaces obviously has its advantages. It removes the need for ongoing maintenance of a restoration such as a resin bonded bridge, this can be even more complicated and involved where implant restorations are planned in these sites which will potentially need grafting and long life maintenance...lets not mention the potential for complications ! 

Other issues to consider with space closure include the gingival profile of the canine, the depth of colour of the canine and its size and ability to be disguised with bleaching and bonding as a lateral incisor. In this research from a group in Sheffield (UK) they found that patients and laypeople preferred space closure from an aesthetic sense as opposed to having a restoration in the lateral incisor position.    


LINK TO ABSTRACT

Sunday 1 May 2016

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

Friday 12 February 2016

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. 


Saturday 6 February 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

Friday 8 January 2016

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.  





Friday 1 January 2016

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. 

Saturday 26 December 2015

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