RESORBED MANDIBLE CASE: BEST TREATMENT PLAN? Reply to Dr John Carroll in Osseonews

Resorbed Mandible Case: Best Treatment Plan?.....A Reply to Dr John Carroll in Osseonews

Dear John Carroll,

Thank you for posting one reference to support your claim on having the numbers and facts on your side. Let me quote the full conclusion that was given in the study that you quoted......

“The results therefore support caution when considering the applicability of implants <= 3mm diameter for single tooth and FPD restorations. Standardized fatigue testing reports for commercially available implants is recommended.”

The keyword is “caution”. The study does not proscribe or condemn outright the use of minis. Instead, it advocates caution because it realizes that its conclusion is deficient and inconclusive because of the following:-

• Insufficient data. Only 9 samples from Straumann 3.3mm NN, NobelDirect 3.0 and Hi-Tec TRI-N-13 were tested as prescribed.
• It is a simple overload test and not a cyclic loading test. A simple overload test is one in which you just keep pressing on to the test object until it breaks or bend. A cyclic loading test presses onto the test object intermittently at forces equivalent to those common in the average mouth until it breaks or bend.
• The introduction to the study itself confesses to its deficiency, “ Cyclic loading tests mimicking years of functional use should ideally be used to test implant designs [Bragger 1999]......ISO 14801; 2003.” Thus a simple overload test is deficient and not conclusive.

Before taking a position, we need much more evidence than from one study that has clear shortcomings. The literature to support the increasing use of minis is quite a lot. I will quote just a few:-

• The effect of maximum bite force on marginal bone loss of mini-implants supporting a mandibular overdenture: a randomized control trial. Clinical Oral Implants Res. 2010 Feb.
• Immediate obturator stabilization using a mini dental implants. J Prosthodont. 2008 Aug.
• Mini-implants to reconstruct missing teeth in severe ridge deficiency and small interdental  space: a 5-year series. Implant Dent. 2004 Dec.
• Clinical evaluation of single-tooth mini-implant restorations: a five-year retrospective study. J Prosthet Dent. 2000 Jul.
• Mini dental implants: An adjunct for retention, stability, and comfort for the edentulous patient. Oral Surg/Med/Pathol/Radiol/Endod 2005
• Immediate loading of narrow-diameter implants with overdentures in severely atrophic mandibles. Sang-Choon Cho, Stuart Froum, Chih-Han Tai, Young Sung Cho, Nicholas Elian, Dennis P. Tarnow.

The gold standard is a double blind randomized control trial. Until that comes, we have to depend on case studies and reviews on minis which is currently quite substantial. We should use both regulars and minis judiciously as both has their pros and cons.

Sincerely, 

K.F. CHOW BDS., FDSRCS

SOMETHING TO GAIN BESIDES THE PATIENT'S BEST INTEREST.

                                          
                                          THREE YEARS LATER

This gentleman was 78 when he saw me. He was one of those dream patients who never quibbled about payment. He could not eat steak anymore and he wanted to eat steak. "Can you help me doc?"

So we started our rescue of this dental cripple who could not eat, talk or smile properly without having his chrome denture falling down each time. He was rich though and paid me whatever I billed him.....no questions asked.

First we placed conventional sized implants in all the posterior areas where it was necessary. When it came to the front, I had a difficult tussle with my conscience. If I placed conventionals, I would have to do bone grafts and wait from 3 to 6 months before completion. And I would be able to charge him top dollar for the conventionals and the bone grafts. What did I do?

I placed in 4 minis.......yeah...just 4 minis and placed in a PFM bridge, all within a month in 2 visits. And I charged him a third what I would have charged him if I placed him conventionals.

I decided that if he is my father, thats what I would have done ! The best option at his age and lack of bone in the area were minis ! But I will make less dough !  Hang the profits........yea .....tough.......besides gaining the patient's best interest....I gained a sense of satisfaction and a good conscience.

The last picture was taken recently at age 82. Yeah, I did gain more than the patient's best interest.




Here are some more cases. For the atrophic maxillary anterior ridge, minimized dental implants should be the treatment of choice !!

Bone Climbing Up The Mini Dental Implant

Bone Climbing Up The Mini Dental Implant

The OPG shows the bridge failing with a fracture on the upper right canine. The bridge was removed and 2 minis were placed together with a new 4 unit bridge 5 years ago. 2 natural teeth were joined with 2 mini implants in a bridge.

The patient did not come back for recall until recently, 5 years later. The bridge was still present and an xray showed healthy cortical bone and not only preservation of bone height but also some bone gain up the distal mini implant. In addition, the 2 natural teeth were preserved. The patient was already in the seventies five years ago.

Bone Climbing Up The Mini Dental Implant

The lower right first molar was extracted and after a short healing period, 2 minis were placed.
A PFM was placed and the patient happily used it for 2 years but came back then to complain of a toothache which he assumed must be due to the implant we placed for him.

An xray showed that the toothache was due to the second molar distal caries. The incidental finding was a very healthy and strong looking cortical bone around the minis. Amazingly also, bone has climbed at least 2 thread widths up the mini dental implant ! Is this, should this be the new standard of care in implant dentistry ?

Should we then consider using minis more often ? Are minis  advantageous over conventionals in some areas ? These are questions that need to be asked objectively and scientifically without prior assumptions.