Abstract

Computer software associated with imaging techniques facilitates diagnosis, planning, and management in cases of severe maxillary atrophy, by reducing the incidence of complications and improving the postoperative course and functional outcome. This article reports on a case of a 66-year-old woman with maxillary atrophy. Computer software was used to plan and position 6 maxillary and 4 mandibular implants, taking maximum advantage of the remaining bone. Bicorticalization was sought by angulation and implant fixation in the buttresses, while rehabilitation was carried out by means of a fixed screw-retained upper prosthesis and a lower overdenture. No implants were lost after 36 months of follow-up. This technique optimized precise implant placement as planned without the need for more complex reconstruction techniques.

Introduction

Lack of bone volume and poor bone quality have led to the development of new implant surgical techniques to take maximum advantage of the available bone.1 Placing angulated implants in the parasinus region, using short implant lengths2 and wider implant diameters,3,4 and placing implants into anatomical buttresses5,7 can help to avoid the need for more complex reconstruction,5 such as sinus or ridge augmentation.8 While the choice of technique is dependent upon the characteristics of each case, these management approaches all involve increased complexity and a longer treatment time.

Computer software and 3-dimensional imaging can provide detailed information on the condition of the jaws, and facilitate surgical planning. The application of such programs during oral implant placement is intended to ensure optimum implant placement with a reduction in the risk of damage to neighboring structures and complications. Virtual 3-dimensional views of bone morphology allow the surgeon to visualize the surgery prior to implant placement. Risks such as inadequate osseous support or compromise of important anatomic structures are avoided.9,11 

This article reports on the use of case planning software in the treatment of a 66-year-old woman with severe maxillary atrophy.

Clinical Case

A 66-year-old woman presented with the complaint that she was unable to wear her upper and lower complete dentures. A review of her medical history revealed that she had arterial hypertension and allergy to penicillin, and that she had worn complete upper and lower dentures for the previous 15 years. Clinical and radiological examinations showed significant Class V12 bone atrophy (Figure 1). A maxillary computerized tomography scan was requested in DICOM 3.0 format for processing with computer software to obtain 3-dimensional reconstructions of the maxillas (Figures 2 and 3). The software program (Implametric, 3DENT, Valencia, Spain) was used to simulate implant placement in the most appropriate available zones. The simulation was, in turn, used to manufacture a surgical splint with metal rings at the points where the implants were to be placed with the required angulation.

Surgery was carried out under intravenous conscious sedation and local anesthesia (4% articaine and adrenalin 1:100 000; Ultracain, Normon, Madrid, Spain). The surgical splint was positioned on the maxilla, and a pilot drill was used to mark the implant locations through the oral mucosa and in the bone (Figures 4 through 6). A supracrestal incision was made, joining the marked points from one tuberosity to the other with 1-cm distal releasing incisions, followed by the raising of a full-thickness flap (Figure 7). Six implants (Defcon TSA, Impladent, Senmenat, Barcelona, Spain) with grit-blasted surfaces were placed (Table). In both anterior implants, the nasal fossa was lifted and augmented with bovine xenograft (Bio-Oss, Geistlich, Wolhusen, Switzerland). All implants were placed using conventional techniques under abundant irrigation with sterile saline solution (Figure 8 and Table). The distal implants were placed towards the palatal wall and anchored in the sinus septum; the middle implants were placed in the canine eminence; and the anterior implants were subjected to bicortical anchoring with the floor of the nasal fossa.

In the mandible, a crestal incision was made with central vestibular releasing incisions, and implants measuring 8.5 mm in length and 4.2 mm in diameter were placed with bicortical anchoring between the mental foramina (Figures 9 through 11). Suturing was carried out with 3/0 silk (LorcaMarin, Murcia, Spain) leaving the implants submerged. The patient's existing complete dentures were relieved and lined with tissue conditioner for use as provisional restorations.

Antibiotic (Rhodogil, Aventis Pharma, Madrid, Spain) coverage (1.5 mill. UI of spiramicin and 250 mg of metronidazole every 12 hours for 7 days) was administered together with ibuprofen (600 mg every 8 hours, during 4 days). Sutures were removed after 1 week, and second-stage surgery was performed after 4 months. All implants osseointegrated and were asymptomatic. One month later, impressions were made for fabricating the maxillary screw-retained prosthesis and mandibular overdenture (Figures 12 and 13).

Thirty-six months after delivery of the prostheses, the patient indicated satisfaction on a visual analog scale (VAS). VAS score was 9 (range 0–10). Panoramic radiographic examination at that time did not show any evidence of peri-implant radiolucency (Figure 14).

Discussion

The use of computer software with 3-dimensional imaging can greatly facilitate the surgical planning, positioning, and placement of dental implants,10,13 followed by immediate provisionalization.14 A number of authors15,18 have used computer-guided implant placement for a broad range of purposes, including measurement of the height of marginal bone, and quantification and comparison of the types of bone and the different oral regions. Parel and Triplett9 used interactive images for planning, manufacturing, and placing the prosthesis.

Krekmanov et al19 placed 75 implants in 22 atrophic maxillas in angulated positions: 19 in the palatal concavity, 11 in the anterior sinus wall, 10 in the posterior wall, and 14 in the pterygoid process. The survival rate was 94.7% after 18 months of follow-up. In this clinical case, the computer software allowed maximal bone utilization by placing implants in angulated positions and in anatomical buttresses, with great precision and safety.

In this case, computer-guided implant placement was the only way to treat this patient without more complex reconstruction techniques, such as sinus lifting or ridge augmentation procedures.

References

References
1
Sorní
,
M.
,
J.
Guarinos
,
O.
García
, and
M.
Peñarrocha
.
Implant rehabilitation of the atrophic upper jaw: a review of the literature since 1999.
Med Oral Patol Oral Cir Bucal
2005
.
10
:
45
56
.
2
Balshi
,
T. J.
Preventing and resolving complications with osseointegrated implants.
Dent Clin North Am
1989
.
33
:
821
868
.
3
Langer
,
B.
,
L.
Langer
,
Y.
Hermann
, and
L.
Jörneus
.
The wide fixture: a solution for special bone situation and a rescue for the compromised implant.
Int J Oral Maxillofac Implants
1993
.
8
:
400
408
.
4
Hallamann
,
M.
A prospective study of treatment of severely resorbed maxillae with narrow nonsubmerged implants: results after one year of loading.
Int J Oral Maxillofac Implants
2001
.
16
:
731
736
.
5
Malevez
,
C.
,
M.
Abarca
,
F.
Durdu
, and
P.
Daelemans
.
Clinical outcome of 103 consecutive zygomatic implants: a 6–48 months follow-up study.
Clin Oral Implants Res
2004
.
15
:
18
22
.
6
Stella
,
J.
and
M.
Warner
.
Sinus slot technique for simplification and improved orientation of zygomaticus dental implants: a technical note.
Int J Oral Maxillofac Implants
2000
.
15
:
889
893
.
7
Boyes-Varley
,
J.
,
D.
Howes
,
J.
Lownie
, and
G.
Blackbeard
.
Surgical modifications to the Brånemark zygomaticus protocol in the treatment of the severely resorbed maxilla: a clinical report.
Int J Oral Maxillofac Implants
2003
.
18
:
232
237
.
8
Johansson
,
B.
,
K.
Wannfors
,
J.
Ekenbäck
,
J. I.
Smedberg
, and
J.
Hirsch
.
Implants and sinus-inlay bone graft in a one-stage procedure on severely atrophied maxillae: surgical aspects of a 3-year follow-up study.
Int J Oral Maxillofac Implants
1999
.
14
:
811
818
.
9
Parel
,
S. M.
and
R. G.
Triplett
.
Interactive imaging for implant planning, placement and prosthesis construction.
Int J Oral Maxillofac Surg
2004
.
62
:
41
47
.
10
Ganz
,
S. D.
Presurgical planning with CT-derived fabrication of surgical guides.
Int J Oral Maxillofac Surg
2005
.
63
:
59
71
.
11
Fortin
,
T.
,
J. L.
Bosson
,
J. L.
Coudert
, and
M.
Isidori
.
Reliability of preoperatory planning of an image-guided system for oral implant placement based on 3-dimensional images: an in vivo study.
Int J Oral Maxillofac Implants
2003
.
18
:
886
893
.
12
Cawood
,
J. I.
and
R. A.
Howell
.
A classification of the edentulous jaws.
Int J Oral Maxillofac Surg
1988
.
17
:
232
236
.
13
Hassfeld
,
S.
and
J.
Muhling
.
Computer assisted oral and maxillofacial surgery: a review and an assessment of technology.
Int J Oral Maxillofac Surg
2001
.
30
:
2
13
.
14
Sudbrink
,
S. D.
Computer-guided implant placement with immediate provisionalization: a case report.
Int J Oral Maxillofac Surg
2005
.
63
:
771
774
.
15
Leblebicioglu
,
B.
,
S.
Ersanli
,
C.
Karabuda
,
T.
Tosun
, and
H.
Gokdeniz
.
Radiographic evaluation of dental implants placed using an osteotome technique.
J Periodontol
2005
.
76
:
385
390
.
16
Rodriguez
,
A.
,
G. E.
Anastassov
,
H.
Lee
,
D.
Buchbinder
, and
H.
Wettan
.
Maxillary sinus augmentation with deproteinated bovine bone and platelet rich plasma with simultaneous insertion of endosseous implants.
Int J Oral Maxillofac Surg
2003
.
61
:
157
163
.
17
Norton
,
M. R.
and
C.
Gamble
.
Bone classification: an objective scale of bone density using the computerized tomography scan.
Clin Oral Implants Res
2001
.
12
:
79
84
.
18
Holst
,
S.
,
M. B.
Blatz
, and
S.
Eitner
.
Computer-guided implant placement: using 3D planning software and fixed intraoral reference points.
Int J Oral Maxillofac Surg
2007
.
65
:
393
399
.
19
Krekmanov
,
L.
Placement of posterior mandibular and maxillary implants in patients with severe bone deficiency: a clinical report of procedure.
Int J Oral Maxillofac Implants
2000
.
15
:
722
730
.

Miguel Peñarrocha, DDS, PhD, is a professor of Oral Surgery and director of the Master of Oral Surgery and Implantology, Valencia University Medical and Dental School, Valencia, Spain.

Araceli Boronat, DDS, is Master of Oral Surgery and Implantology, Valencia University Medical and Dental School, Valencia, Spain.

Celia Carrillo, DDS, is a resident of the Master of Oral Surgery and Implantology, Valencia University Medical and Dental School, Valencia, Spain.

Salvador Albalat, DDS, is director of MedicLab, Valencia University Politechnic, Valencia, Spain.

Address correspondence to Miguel Peñarrocha, Facultad de Medicina y Odontología Gascó Oliag 1, 46021 – Valencia, Spain. (miguel.penarrocha@uv.es)