Clinical
class III mandible, there is often an abun- dance of bone anteriorly and provision of a fi xed bridge – with implants placed between the foramina – while resolving the problem of the loose lower denture will, due to the point of force application in occlusion, being on or anterior to the upper ridge result in tipping and loosening of the upper denture. In such a situation, patients should either be guided to a lower over-denture restoration (for simple poste- rior support from the mandibular residual ridge and denture) or consented to the lower bridge on the understanding that implant treatment will be required in the upper (Fig 9).
Alternative option If the patient is willing to accept the lower shortened arch, then an entirely different treatment plan may be followed. Providing there is suffi cient bone remaining in the upper anterior maxillae, then splinted implants in the upper may be the only treatment necessary (Fig ı0). With a fi xed (or removable) splinted
implant supported restoration in the upper, posterior support is no longer necessary, as the potentially damaging force vectors from the lower anteriors can be negated and shared across the maxilla. Being osseointegrated and having no periodontal ligament, the implants will not drift and potential ‘off axis’ loading of the implants is not in itself likely to compromise the implant bone support2. It is important to place, and splint, as
many implants as necessary to mechani- cally protect against functional and potential parafunctional forces. When there is suffi cient bone, this treat-
ment option is often the one of choice as many of the patients criteria are addressed: • Aesthetics improved • No moving upper denture • Fixed bridge that doesn’t come out • Palate exposed • No lower denture/any denture required • Cost effective • Long term.
By no means comprehensive, the above
discussion shows that potentially crippling bone loss can be avoided through good restorative treatment and, should the CS patient present, then treatment options both conventional and implant supported are available.
®
This article was submitted by Edinburgh Dental Specialists. Please contact us if you would like further information or advice on managing similar cases,
tele-dentist@edinburghdentist.com
REFERENCES
1. The combination syndrome: a literature review. Palmquistetal J. Prosthet Dent 2003 2. Tilting of posterior mandibular and maxillary implants for improved prosthesis support. Krekmanov L et al. JOMI 2000
CPD quiz:
To gain one hour of verifi - able CPD, simply visit:
www.surveymonkey.com/s/ assessingoptions
1. Which of these is not a goal in managing the CS patient? a. To regain a healthy, stable and functional dentition
b. To achieve the patient’s aesthetic goals
c. To educate the patient on the long-term management of their condition
d. To eliminate their bruxing habit.
2. What is regarded as normal lip movement from rest to a full smile? a. 3mm b. 6mm c. 9mm d. 12mm.
Direction of occlusal forces
Loss of posterior seal and dropping of denture
Pressure and rotation on anterior residual ridge resulting in continued resorption and unstable denture
3. Which of these is not an appropriate method for taking an impression of a fl abby ridge? a. Stock tray with heavy body/wash silicone
b. Open special tray and plaster of paris
c. Spaced special tray
d. Perforated special tray over the fl abby ridge.
Fixed
implant bridge
Residual lower ridge
Fig 9
Destructive action of fi xed lower implant bridge against upper complete denture in class III mandibular relationship
4. When should a fi xed implant bridge in the lower be avoided? a. When the patient has a bruxing habit
b. When the patient has a class III mandibular relationship
c. When there is a lack of keratinised tissue
d. When the patient has a high lip line.
Scottish Dental magazine 53
Fig 10
Upper fi xed implant bridge against lower shortened arch
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