Principles of BOI

Voorwerk

Chapter 1. Struggles and Successes

Abstract

When too many people agree on the same subject, it is high time to call it into question. Few other areas of medicine are better characterized by this statement than dental implantology. Why? Because both academic “researchers” and practitioners focus their efforts solely on crestal implants. In other words, they completely ignore any designs or concepts other than screws and cylinders, which guide the masticatory forces, into bone areas that mainly consist of cancellous tissue. If the available vertical bone supply is insufficient, measures are taken to rebuild the morphology of the bone tissue – whether by transplantation, by augmentation or by induced growth. Unless aesthetic considerations play a major role, these modifications of the bone situation are performed solely to facilitate the use of crestal implants, which would be impossible to insert otherwise. In many cases, these adjuvant measures are considerably more time-consuming and more expensive than the patient can afford. Meanwhile, no implant treatment is performed whatsoever, and the patient is left without an adequate fixed restoration. At the same time, the focus of dental implant treatment tends to shift away from the dental offices as these adjuvant measures gain respectability, towards the specialists capable of performing them. Due to the additional cost of these adjuvant measures, many patients are unable to afford adequate implant treatment. The consequence is that their masticatory function cannot be restored in a truly comprehensive manner.

Stefan Ihde

Chapter 2. History as Documented by Patents and Patent Applications

Abstract

It has been a long tradition in medicine that new ideas and treatment concepts are hardly ever invented inside the universities. Usually, practitioners – because they really face the patients’ problems day-to-day – are the ones to develop new solutions. Not until later are the techniques adopted by universities, and usually it will be necessary, of course, to pay the universities to change their way of thinking, working and teaching. The history of BOI implantology reflects this situation, as can be seen looking at the patent situation in this field. Patents applied for and, of course, patents granted are relatively objective criteria to go by. They help us judge who the people were that have genuinely set scientific milestones and broken with traditional thinking in a constructive way.

Stefan Ihde

Chapter 3. Morphology of BOI Implants and Related Designs

Abstract

Chapter 2 provided an overview of the different types of lateral implants devised, introduced and employed over the past 30 years. The present chapter will provide the reader with the necessary background to understand the differences and commonalities of these designs, as well as their applications in clinical practice. Today it is almost impossible to draw a clear line between «disk» implants and BOI implants. Over the last few years in particular, the similarities between those designs have increased in various ways. The same development has also taken place in crestal implantology. While implants of the Diskimplant type are basal implants and while they take into account the concept of bicortical support, these rigid Diskimplants do not implement the concept of isoelasticity with the bone to the same extent of actual BOI implants with a skeletal design.

Stefan Ihde

Chapter 4. Insertion Tools and Implant Designs

Abstract

To insert BOI implants a T-shaped osteotomy has to be cut into the bone. The instruments used for this are usually designed to cut either the vertical or the horizontal part. There are also instruments, however, that are designed to cut the vertical and horizontal parts simultaneously. Within limits these instruments can be replaced (e.g. with a tungsten carbide cutter) if required for intraoperative accessibility.

Stefan Ihde

Chapter 5. Equipment and Surgical Techniques

Abstract

People tend to think it is rather logical that installing fixed teeth is an advantage. But often enough it almost seems that the jaw that is receiving the requisite implants begs to differ. It is any implantologist’s desire for the jawbone to enter into a state of peaceful coexistence with the implanted object. In our opinion, this works best if the basic functions of the bone are not impaired. These basic functions include the motor function that is required for the survival of any bone and the unimpeded flow of nutrients, gases, and waste products.

Stefan Ihde

Chapter 6. Diagnostics

Abstract

The purpose of diagnosis is to explore an objective against the background of a strategic task. In accordance with this “military” definition, the dentist will not consider all the factors that may conceivably be relevant to the treatment, but only those that will help him to achieve the treatment objective. By the same token, the fact that a treatment objective can be achieved is not enough, but the dentist will only consider those objectives that will actually benefit the patient.

Stefan Ihde

Chapter 7. Treatment Planning

Abstract

Thanks to the technique of basal osseointegration, we are today in a position to treat 95% of completely or partially edentulous patients with fixed restorations. This goal can only be achieved if a number of rules are observed with regard to where the implants should be placed and when and how they should be combined with residual teeth. Most importantly, the implantologist must understand the functional requirements of the treatment and perform occlusal adjustments in a timely manner.

S. Ihde, T. Maier

Chapter 8. Aspects of BOI Treatment in Periodontally Involved Cases

Abstract

This chapter discusses various BOI treatment options in patients with periodontally involved dentitions.

S. Ihde, V. Lekovic, Z. Aleksic

Chapter 9. Four-Dimensional Considerations of Bone Morphology and Mechanics

Abstract

In this chapter, we shall explain bone properties based on a number of concepts, each illuminating one specific aspect of the osseous life cycle. All of these concepts are applicable at the same time, and they are indeed relevant for our implantological work.

Stefan Ihde

Chapter 10. Functional Considerations as the Guiding Treatment Principle

Abstract

While it is easily possible for trees to adapt to the harsh realities of life, for example by growing diagonally, following the prevailing winds, the human body is able to achieve similar feats only at tremendous cost in terms of energy. By contrast with the continuous skeleton of trees, the bony skeleton of the human body consists of separate segments that are spread wide open by and between the muscles. A slanted posture or asymmetrical function requires an extra amount of energy, since the centre of gravity of the body easily threatens to wander off the human body’s relatively small base area. To avoid this and to balance the body, body mass must be relocated, resulting in local overload.

Stefan Ihde

Chapter 11. Prosthetic Treatment Considerations

Abstract

BOI implants are used almost exclusively to support fixed prosthetic restorations. Occasionally, they are also used for bar attachments. BOI implants combine well with natural abutments and other enossal implant designs. The fundamental question is whether a rigid or an elastic implant-restoration system should be established. How these systems differ and what implications they have in terms of structural integrity will be discussed later in this chapter.

Stefan Ihde

Chapter 12. Replacing Molars in Both Jaws

Abstract

Two essential treatment alternatives are available for dealing with cantilever situations in the posterior segment:

• Structures that are supported by implants only (including single-tooth implants).
• Bridge structures supported by both implants and natural teeth.

Stefan Ihde

Chapter 13. Anterior Masticatory Patterns and Class II Skeletal Relations

Abstract

This chapter deals with patients exhibiting intermaxillary relationships that can be defined as disto-oclusion by orthodontic criteria. These cases are usually associated with a large ANB angle and an intercuspidation in which both the canine and the first molar in the mandible are located too far distally in relation to their maxillary antagonists. Both for orthodontic and for implantological purposes, it is important to look not only at the ANB angle but also at the «Wits appraisal» in these cases. The ANB angle is the angle between points A, B, and N (nasion) in the teleradiograph. The ANB angle is large if the mandibular point is located far behind the maxillary point, indicating the presence of a Class II jaw base relationship. However, the ANB angle does not shed light on the relative position of the jaws: this is where the Wits appraisal comes in.

Stefan Ihde

Chapter 14. BOI Treatment in the Presence of Class III Skeletal Relations

Abstract

We are often faced with patients showing any or all of the following symptoms:

• Class III skeletal relations characterized by maxillary micrognathia, true mandibular prognathism, or both factors combined
• Edentulism in one of both jaws
• Sagittal resorption of the maxillary ridge as a result of early edentulism

S. Ihde, V. Konstantinovic

Chapter 15. Treating the Atrophied Mandible

Abstract

It is standard procedure in crestal implantology today to insert screws with a minimum length of 10–13 mm in the anterior mandibular region, provided there is enough vertical bone height. Depending on how many screw implants there ultimately is room for, the patients may receive ball abutments, bars, or – in favourable situations – cantilevered-pontic bridges according to Brånemark. When it comes to distributing forces into the interior of the bone, patients with minimal bone height at the outset are at a disadvantage. It is precisely in these patients that only a small fraction of the overall masticatory forces will be directly toward the implants when designing the superstructure. In most cases, the crestal implants in these cases will offer only rudimentary support for a removable denture that, for the most part, will be periodontally supported. While this initially seems to alleviate the problem of denture retention, the disabling loss of teeth and jaw substance is not actually addressed. We as dentists have been able and continue to be able to make money on this type of «therapy» only because this disability is relatively invisible and because patients are ashamed and unwilling to bring their problem out into the open. As the most recent publication by Godbout et al. (2002) shows, subperiosteal implants are sometimes used – despite the fact that they are difficult to produce and difficult to insert and that they require a two-stage surgical approach – to treat situations of extreme vertical atrophy of the distal mandible.

Stefan Ihde

Chapter 16. Tuberopterygoid Screws

Abstract

Since panoramic radiographs are obtained by sectional imaging, they will only reveal the structures located in the focused plane. The X-ray system is adjusted in such a way that both the maxilla and the mandible are depicted about equally well in the same image, despite the fact that both jaws are not in the same vertical plane even in patients with intact dentitions. This discrepancy is even greater in edentulous situations, as the maxilla and mandible are characterized by a centripetal and centrifugal resorption pattern, respectively. The discrepancy is greatest in the tuberosity region, since the maxilla almost appears round in that area, and the distalmost parts as well as the palatal bone and the muscular processes of the sphenoid bone fall completely outside the OPG plane. Therefore, inability to depict bone in the tuberosity area using conventional panoramic radiographs does not furnish any evidence of bone resorption but constitutes a typical false-negative finding. The distal maxilla is just as stable to resorption as the mandibular anterior segment because it harbours attachments of powerful chewing muscles. The bone volume in that area is usually abundant as well, so that long screw implants with high anchorage potential can be readily inserted. We do think that this strategy is indicated because implants of this type will help to improve stability and support in this area of high masticatory forces.

Stefan Ihde

Chapter 17. Functional Prosthodontic Treatment and Restoration of the Vertical Dimension in Craniomandibular Disease

Abstract

Implants have been widely used to support fixed prosthetic restorations since the early 1980s. Implantological treatment options were, and still are, a highly controversial issue in situations characterized by advanced ridge resorption and severe forms of periodontitis. After all, these conditions usually involve both the maxilla and the mandible, and dysfunctions associated with loss of the vertical dimension are routinely present.

Stefan Ihde

Chapter 18. Implant Treatment Along the Maxillary Sinus

Abstract

The fact that tooth loss is usually accompanied by vertical bone loss adds to the problems of crestal implant therapy in the distal maxilla.

V. Konstantinovic, S. Ihde

Chapter 19. Bar Attachments on BOI Implants

Abstract

Implant treatment to support removable restorations is the exception rather than the rule but may be desirable in some patients for a number of reasons. The following factors may prompt the dentist to take this route in specific cases.

Stefan Ihde

Chapter 20. Aesthetics

Abstract

In situations of advanced bone resorption, it is necessary to discuss with the patient whether the treatment should consist solely of replacing the missing teeth or whether additional measures should be taken to compensate for the missing bone volume along the ridge. Such augmentative techniques are expensive and time-consuming. The spectrum of applicable techniques ranges from relatively simple procedures based on extraneous grafting materials up to extensive surgical protocols in which autologous bone is harvested from the hip (iliac bone) or cranium (parietal bone). Osseodistraction is another technique to modify the shape of bone structures.

Stefan Ihde

Chapter 21. Mechanics Meets Biomechanics

Abstract

The technique of basal osseointegration draws on the empirical finding that the jaw bone is continuously subjected to deformation and torsion. BOI implants are therefore inserted in such a way that they are somewhat more rigid than the jaw itself in order to avoid total isoelasticity. On the other hand, the rigidity must not reach a point where the implant-bone interface is subjected to peak forces that would give rise to osteolysis or avulsion.

Stefan Ihde

Chapter 22. Primary Augmentation Using BOI Implants

Abstract

Basal osseointegrated implants are designed such that they afford optimum anchorage or retention for dental restorations even in the severely atrophied maxilla or mandible. Any augmentation measures with the sole objective of stabilizing an implant or implants are therefore unnecessary. The surgical procedure is performed as a one-step procedure and is relatively non-traumatic.

T. Maier, V. Konstantinovic, S. Ihde

Chapter 23. Histology of BOI Implants

Abstract

Histological studies offer valuable insights. Since a great many histological studies have been published in the field of crestal implantology, it was an obvious approach to generate corresponding data for BOI implants as well.

Stefan Ihde

Chapter 24. Counselling and Case Acceptance

Abstract

Patients can only legally commit to dental implant treatment if they were informed in an adequate and comprehensive manner (Oehler 2003; Ries et al. 2002; von Ziegner 2001; Schinnenburg 2000; Ratajczak 2000; Gaisbauer 1995,1997; Fallschüssel 1985; Könning 1989; Deutsch 1983). This principle is universally valid in the European and North American legal systems and is a logical consequence of every patient’s right to self-determination and personal liberty (Fischer and Lilie 1999). It is incumbent on the implantologist, based on his knowledge of the literature and his own experience, to critically appraise and re-define the precise meaning of «adequate», «comprehensive» and «state of the art» on a continuous basis. Dentists are not generally required to inform their patients of any outdated treatment techniques if newer, simpler, cheaper or less invasive techniques are available. They are required, however, to inform their patients of any new techniques known to yield similar results if they offer tangible benefits for the patient, even though these techniques may not be widely used (German Dental Association 2003). This provision can make it mandatory for users of traditional techniques to inform their patients of BOI, particularly when indications show that the patient does not wish to be treated with bone grafts harvested from the iliac crest or skull.

Michael Zach

Chapter 25. Legal Aspects of Therapeutic Alternatives and Costs: Court Decisions and Health Insurers

Abstract

With every implant procedure, the dental implantologist is faced with the fact that the bone situation is invariably different in different patients. In actual practice, this has led to a situation where, if there is not enough bone volume available in the maxilla or mandible, the bone of the respective jaw will be rebuilt to suit the requirements of a common type of implant in the vast majority of cases.

Michael Zach

Chapter 26. Maintenance

Abstract

Recall sessions should follow a standardized plan so that nothing is overlooked. All findings are communicated to the patient. Important findings and those findings requiring the cooperation or some activity on the part of the patients can be documented in writing. The guideline followed could be the Check-up Report (Form A11), a copy of which is included with the patient’s dental records, while the original is handed to the patient.

Stefan Ihde

Chapter 27. From Knowledge and Skill to Action

Abstract

Experienced housekeepers will know exactly what they have to pay attention to when caring for houseplants. They will consider various factors: the size of the pot, the size and nature of the plant, its location, the quality of the soil, the size of the windows, heating and ventilation, sunlight, the season (incident sunlight angles, amount of sunlight, excessive heat in summer), the last time the plant was repotted, and regular watering and fertilization – to name just a few of them. Some factors will be immediately obvious to anyone – other factors belong to the realm of the housekeeper’s special knowledge.

Stefan Ihde

Nawerk