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DENTAL
TREATMENT
Dental Implants
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Bone Grafting
Dental Implants &
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Tooth loss and the subsequent loss of alveolar bone is recognized as a significant etiologic factor in the aging appearance of the face. Removable prosthesis have been used successfully, with patients having modest amounts of remaining bone, to maintain facial form. However, as patients age and the physiologic process of bone resorption continues, the position of the dentures also shift creating an edge to edge or pseudo class III appearance (Fig 3). With continued bone resorption, vertical dimension diminishes and the mandible autorotates anteriorly and superiorly on closure (Fig 1 & 3).

This often creates an appearance of sadness in frontal view; and in profile, the chin tends to appear closer to the tip of the nose (Fig 1). In patients with extreme alveolar atrophy, particularly in the mandible, the total loss of alveolar bone requires the denture be supported by basal bone which has been known to resorb below the level of the genial tubercles (Fig 4). In conditions of extreme atrophy the thickness of the mandible may diminish to 4-5 mm in height, particularly in the area of the bicuspids. These mandibles are at risk for pathologic fracture (Fig 5).

In patients with extreme mandibular atrophy the muscle attachments move superiorly and in some cases there is little or no attached mucosa overlying the crestal bone (Fig 6). 

Reconstruction of the atrophic mandible can be accomplished ad modem Brånemark provided there is sufficient width of bone to permit placement of the titanium implants. An occlusal radiograph (Fig 7) is a valuable aid in determining mandibular width. 

A minimum bone height of 5 mm with a width of at least 7 mm, is recommended for a fixed prosthodontic implant reconstruction without bone grafting in the mandible. Implants of 3.75 mm diameter can be successfully placed in the anterior mandible. Bone quality in patients with severe atrophy is generally dense Type I or II, requiring careful tapping of the screw threads prior to implant placement. Three to four months of unloaded healing is recommended prior to the placement of the fixed prosthesis (Fig 8 & 9). With the support of a fixed prosthesis, class I occlusion, and full support of the lower third of the face can be obtained with the new prosthesis design (Fig 10). 

This clinical example illustrates treatment of a 58 year old woman who had a significant medical history. The patient had been treated for severe osteomyelitis of the legs between the ages of 6 to 12. A hysterectomy was completed 14 years prior to implant treatment. The patient also had a history of an aneurism which was treated surgically and she was diagnosed as hypothyroid and sporadically hypertensive. A diagnosis of mitral valve prolapse required premeditation prior to any surgical procedures. Medications included Synthroid (.2 mg.), aspirin (250 mg. daily), Dalmane as needed, Premarin, and Diazide. She had no history of smoking and used alcohol socially. 

The patient's chief complaint was "ill-fitting dentures" both "functionally and esthetically". Successful treatment was accomplished in 1992 with the use of six Brånemark titanium implants in the anterior mandible. Three different implant sizes were used: the most distal implant was 7 mm X 3.75 mm, the two center implants were 10 mm X 3.75 mm, and the implants in-between were 8.5 mm X 3.75 mm. Osteotomy sites were prepared through the mandible to create a tenting effect with the periosteum at the inferior border. Protrusion of the implant apex through the inferior border of the mandible can be clearly seen in Figure 8. This deliberate extension of the implant beyond the inferior boarder of the mandible is intended to induce apical bone growth over the more distal fixtures on both the right and left sides, which is quite evident when comparing the radiographs (1/7/93 to 6/19/96). Particularly evident is the bone growth over the apex of the most distal implant on the left side as well as that on the right side. It is also interesting to note an increase in mandibular bone height in the areas beneath the posterior cantilevered pontics (Fig 11 & 12).

Summary:

Patients with severe mandibular atrophy can be successfully treated with Brånemark implants. Patients undergoing implant treatment of the severely atrophic mandible must exercise extreme caution during the initial healing process (3-4 months) since the operated mandible is initially weaker and susceptible to fracture. However, following the initial 3 months of osseointegration, an internal bone remodelling stimulus created by the osseointegrated implants has been shown to improve the strength of the mandible through increased bone dimensions. 

The psychologic and functional benefits of a nonremovable implant supported prosthesis are enormous for patients with long standing debilitation due to edentulism. These benefits far outweigh the risks of treatment and enhance the quality of life if no treatment was performed. Long term dental stability and functional bone maintenance are enormous biologic advantages of treating the severely atrophic mandible with Brånemark implants. Rejuvenation of facial support is of course an esthetic benefit that brings joy and smiles long after the treatment has ended.

• Figure 1 Preoperative frontal & profile view of patient.
• Figure 2 Postoperative frontal view.
• Figure 3 Lateral view of existing dentures showing pseudo-Class III appearance. Lateral view of edentulous ridges at vertical dimension of occlusion.
• Figure 4 Preoperative lateral cephalometric view with radiographic markers on anterior teeth showing the position of the existing denture teeth. Note the level of bone in relationship to the genial tubercles.
• Figure 5 Preoperative panoramic view of severely atrophic mandible.
• Figure 6 Occlusal view of mandibular edentulous ridge with high muscle attachments.
• Figure 7 Occlusal radiograph used to determine the mandibular width.
• Figure 8 a Postoperative panoramic radiograph with six osseointegrated Brånemark implants supporting a fixed mandibular prosthesis.
• Figure 8 b Intraoral clinical photograph of teeth in Class I occlusion.
• Figure 9 Postoperative lateral cephalometric view with six osseointegrated Brånemark implants supporting a fixed mandibular implant restoration.
• Figure 10 Postoperative profile photograph showing improved facial support for the lower third of the face.
• Figure 11 Panoramic radiograph with six osseointegrated implants immediately following stage I surgery.
• Figure 12 Postoperative panoramic radiograph 3 1/2 years following stage II surgery showing increased bone beneath the posterior cantilevered pontics.

Skeletal bone loss in adults increases the risk of bone fractures and may contribute to the loss of teeth in healthy postmenopausal women. The relationship of skeletal osteopenia to residual ridge resorption is unclear. Low bone mass in women is attributed to heredity, estrogen deficiency, a low lifetime calcium intake, and lack of regular physical activity. A high calcium intake will promote optimal bone growth in youth and decrease the rate of bone loss in the later postmenopausal period. In early menopause, estrogen is the only effective therapy for conserving bone in women. In older women, a high plasma level of vitamin D enhances calcium absorption, whereas high sodium, protein, alcohol, and caffeine intakes will cause increased urinary losses and negative calcium balance. Women who have a low intake of dairy foods may benefit from a refined calcium carbonate supplement that contains vitamin D. This article focuses on the nutritional factors that influence bone health, and many of the patients seen for implant dentistry are of this age group.

J Prosthet Dent 73:65-72;1995

This article reviews the findings of the longest ongoing North American prospective study on the treatment and the effectiveness of implant supported fixed prostheses in edentulous patients. The study was undertaken to investigate the veracity of the original osseointegration research conducted by the Swedish team led by Professor P.I. Brånemark. The study was initiated in 1979 at the University of Toronto. It follows the treatment of 50 patients that had been completely edentulous for at least five years and could not successfully wear their dentures. The clinical features that made denture wearing uncomfortable included, severe morphological compromise of the denture bearing area, parafunctional oral activity, lack of oral muscular coordination, hyperactive gag reflex and the patient-reported inability to adapt to wearing dentures. 

Phase I of treatment involved optimization of the removable dentures by a prosthodontist, which only provided an acceptable reduction of the maladaptive signs for 3 of 50 patients. Forty-six of the 50 patients who originally presented with maladaptive complete removable dentures did not show signs of improvement with optimal removable treatment and proceeded to have osseointegrated implant supported prostheses fabricated; one patient was not a candidate for implants due to poor bone anatomy. 

Throughout the 11 to 15.5 year period of monitoring, the edentulous predicament of 44 of 45 patients have been resolved with inconsequential associated problems and complications. Retardation of bone resorption around functional implants, coupled with the absence of adverse significant soft tissue response suggests a predictable and long lasting abutment role for such patients. 

This study indicates that the technique of osseointegration can play a significant role in the prosthodontic treatment of edentulous patients.

JADA 1996;127:59-65

This study reports on edentulous and dentate male health professionals with respect to intake of specific nutrients and foods. The specific items examined were fruits; vegetables; fresh pears, apples and carrots; dietary and crude fiber; vitamin C and carotene; and cholesterol and saturated fat. 

Edentulous participants consumed fewer fruits and vegetables, less fiber and carotene, and more cholesterol, saturated fat and calories than participants with 25 or more teeth. 

These factors could increase the risks of cancer and cardiovascular disease. After adjusting for age, profession, exercise level and smoking status, the mean differences between the two groups ranged from 2 to 13 percent with significant trends across tooth categories. Longitudinal analyses suggest that tooth loss may lead to detrimental changes in diet.

JADA 1996;127:459-467

A total of 61 patients with severe mandibular resorption underwent restoration with 303 Brånemark endosseous implants. If the bone height was greater than 4 mm and the width was greater than 5 mm, a bone graft was not used. A simultaneous composite onlay bone graft from the anterior iliac crest was used if the bone height was less than 44 mm and the width was less than 6 mm. Nine patients require bone grafts, and 52 patients did not need bone grafts. Two hundred sixty implants were placed in the non-bone graft group, and 43 were placed in the bone graft group. 

The median follow-up was 59 months for the non-bone graft group, and 42 months for the bone graft group. Eighteen implants were removed from the non-bone graft patients (93% survival) and four implants were removed from the bone graft patients (91% survival). The majority of implants were lost from the two most distal implant positions. Implant loss did not vary significantly in relation to implant length. Two non-bone graft patients experienced a stress fracture during the healing phase, and one bone graft patient experienced a fracture following facial trauma. These fractures healed with conservative management. 

Several patients developed hyperplastic tissue adjacent to implants that required surgical management. Temporary mental nerve paresthesia was common in all patients and resolved unless it was present before implant placement. Marginal bone loss was noted in 12 implants. An increase in bone volume was observed in most patients.

The author concludes that endosseous implants can be used to support dental prostheses in patients with advanced mandibular bone resorption. In addition, placement of implants may prevent further bone resorption in these patients.

J Oral Maxillofac Surg 1995;53:305-320

The successful rehabilitation of a patient with severe vertical overlap resulting from the loss of posterior occlusal support and excessive wear of the mandibular incisors is described. The treatment plan necessitated extraction of the remaining periodontally compromised mandibular teeth and placement of eight implants. Lost occlusal vertical dimension and morphologic facial height were restored using a fixed detachable implant supported mandibular prosthesis, and the maxillomandibular relationship was transformed from Class II to Class I.

Int J Prosthodont 1996:9

This article discusses research that identifies the positive relationship between self-esteem and physical attractiveness. It further suggests that society rewards according to a person's physical attractiveness. Research indicates that people of higher physical attractiveness earn higher annual salaries than less physically attractive people. Such an important societal reward sends a strong message to individuals about their self-worth and a person's self-esteem is influenced accordingly.

In a national survey 94% male respondents and 99% female respondents indicated that they would change something about their appearance if they could. When determining one's level of physical attractiveness, the ranked order of importance is face, weight and height. The face is the most important single factor in a person's physical appearance.

The connection of this research to dentistry is that individual factors can be changed to lead to improved physical attractiveness overall and ultimately improved self-esteem. The reasonable conclusion is that improvements made to the teeth and oral region are likely to produce the greatest impact upon self esteem by improving physical attractiveness.

J Esthetic Dentistry 1996;(8)3:144-147

This study reviews 29 consecutively treated patients who underwent a variety of autogenous alveolar augmentation procedures to their resorbed maxilla or mandible followed by delayed placement of Brånemark dental implants. One additional patient had frozen femoral head alogenic bone as a graft. A suggested treatment protocol is outlined for rehabilitation of the resorbed maxilla and mandible without the need to compromise the basic areas. Twelve implants were removed from three patients. This represents a success rate of 100% in the mandible and 86% in the maxilla. As a result of this treatment, 28 patients wear fixed implant supported prostheses, and two patients wear overdentures.

Int J Oral Maxillofac Implants 1996;11:476-488