Do implants provide the best aesthetic outcome for patients with hypodontia ?

A study by Hvaring and colleagues has looked at the outcomes for patients with hypodontia and more specifically the treatment for missing teeth. They looked at a cohort of 50 patients with 6 missing teeth or more with a mean age of 26. These patients were examined clinically assessing mucosal discolouration, crown morphology, colour, and papilla index. 

Deciduous teeth showed good outcomes whereas implants had poorer results. Changes in gingiva colour was seen only for implants and occurred for all fixtures in the anterior mandible and the majority of those in the anterior maxilla. As you would expect papilla index scores were poorer for implants and conventional bridges when compared with orthodontic space closure.

A pubmed link to the paper is below 

Hvaring et al. 2016

Implants are a popular treatment modality in the management of patients with hypodontia as they provide tooth replacement without the need for adjacent tooth support or retention. Over time those working in the hospital services have seen case from 5 years or more return with either mechanical or biological complications. Patients with hypodontia may have adequate bone stock around the top of the ridge but this becomes more compromised higher in the alveolus. Over time the alveolus is likely to continue to resorb as illustrated in the above research resulting in mucosal discolouration due to the slow exposure implant threads. In such patients, who have such underdeveloped ridges, alternative tried and tested treatments maybe wiser to consider. Resin bonded bridges are predictable, efficient with good long term outcome data. Consideration for the patients long term maintenance-especially if treated in late adolescents-needs to be a significant consideration. 

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

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

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

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

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

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