Sir, my attention has been drawn to the letter Subperiosteal implants by H. Beddis et al. (BDJ 2012; 212: 4). This was of particular interest since I was involved as a senior maxillofacial technician in the construction of these devices when working with Professor T. Talmage Read. He was not only Dean of the Leeds Dental School until 1959, but a respected oral pathologist and innovative surgeon who pioneered the applications of these implants for patients with atrophic mandibular ridges and associated denture wearing problems.

Unfortunately, after his retirement, follow-up became sporadic so that no long term statistics are available, although I know of one case personally where the implant was still performing satisfactorily after 25 years. Indeed I had to make two new denture superstructures during this period due to the occlusal wear!

The technique used was broadly as described, but one problem of the 1950s was the limited choice of impression materials and though not ideal in accuracy terms, a thermoplastic composition was used which your senior readers will remember as 'compo'. Three impressions were taken and frameworks constructed on what were judged to be the best two models. Likewise at the second operation when the whole bony ridge area was reexposed the best fitting framework was chosen. Unlike the described case, retaining screws were not used as the healing and reattachment through the mesh structure was thought to provide adequate stability. The denture prosthesis was applied approximately ten days post-surgery.

The wider use of this implant in its original form highlighted some of the inherent problems, such as the relationship of the soft tissues to metal where the framework entered the mouth which could produce pocketing and associated infection such that the framework had to be removed. This dampened clinical enthusiasm and as stated the method has largely been abandoned in the UK, its demise being speeded by the arrival of endoseous implants and bone augmentation.

However, in America, as judged from the literature, development has continued. The correspondence mentioned the CT based CAD/CAM technology to produce a working model for framework construction thereby eliminating a first stage operation for impression taking, but perhaps more significantly, is the coating of the implant framework with hydroxyapatite. The latter is described as giving a better physical and chemical linkage to bone, plus an improved metal to soft tissue relationship at the mouth exit point. There is also the realisation that this technique is only applicable to the true atrophic jaw where no vestige of alveolus remains. It also appears that frameworks could now be made in titanium, although casting this metal does have its challenges.

In its modern guise perhaps the subperiosteal implant still deserves a place in the options list for the management of the atrophic jaw.