Loss Of Vertical Dimension Research Articles

Orthognathic Surgery

SUMMARY Ultimately, treatment results must be evaluated by how well the individual patient is served on a lifetime basis. This is particularly difficult to assess in a highly mobile society, as it takes years to learn what the long-term consequences of early treatment decisions will be. The outcome of decisions relating to repair of lip, nasal, and palatal tissues can be evaluated by 21 years of age. For the patient appearing before cleft lip-palate review boards, it is possible to evaluate the results of soft-tissue repair techniques. The lip and nose will not change significantly except for those changes associated with the aging process. Skeletal and dental relations will likewise remain stable as long as the natural dentition is preserved. Premature loss of teeth, however, introduces a variable that many times is not widely appreciated. Treatment outcomes relating to early treatment decisions pertaining to the dentition are most difficult to evaluate on a long-term basis. The cleft patient is at greater risk for premature loss of teeth because of compromised periodontal support in the cleft areas and congenitally missing teeth that will require replacement. Traditionally, prosthetic treatment has been viewed as being more conservative than surgery. A fixed prosthesis, however, will have to be replaced several times during a lifetime and will require additional home care efforts. When this is not done, teeth are lost, complicating prosthetic treatment. Removable prosthetic devices clearly create an unfavorable environment periodontally. When they are used to compensate for underlying skeletal dysplasia and obturate fistulae, anchoring teeth may become compromised, leading to their premature loss. Thus, early treatment decisions can be viewed as being conservative only when based on the long-term consequences. “Conservative” treatment involving a removable prosthesis to compensate for underlying skeletal deformity and to obturate fistulae, rather than utilizing orthognathic surgery with simultaneous alveolar bone grafting and closure of fistulae, will have long-term ramifications. Premature loss of abutment teeth secondary to periodontal disease and fabrication of a prosthesis that may become more complicated and ultimately fail for the same reason may leave the adult in the third, fourth, or fifth decade of life edentulous with moderately advanced loss of alveolar bone, patent oral fistulae, and a shallow maxillary vestibule. Because of the loss of vertical dimension, a class III relation will become more accentuated secondary to vertical overclosure. Ultimately, an osteotomy may be necessary to enable the patient to wear a prosthesis. In retrospect, while surgery may have appeared to be the more radical form of treatment for the adolescent, when viewed in the context of long-term consequences, it may have proved to be the most conservative. One cannot therefore necessarily view nonsurgical treatment as being conservative and any treatment that involves orthognathic surgery as being radical. Surgical procedures that preserve natural structures on a lifetime basis may ultimately prove to be the most conservative treatment alternatives available.

Dental root agenesis secondary to irradiation therapy in a case of rhabdomyosarcoma of the middle ear

There have been only a few published reports on the dental-facial effects of radiation therapy and the subsequent oral management of these patients. A case involving a 13-year-old black male patient with a history of rhabdomyosarcoma is presented. The patient received 4,050 rads of radiation to the right middle ear when he was 2 years of age. His residual medical and dental difficulties are apparently complications from the initial therapy. Examination of the oral cavity revealed bimaxillary micrognathia and marked loss of vertical dimension. A Class II facial profile with Class I molar relationship was observed. The mandible was thin and hypoplastic, with a small knife-edge alveolar ridge. The remaining eighteen erupted permanent teeth were very mobile, and root development had ceased after only initial formation. All of the teeth except the first permanent molars were extracted, and immediate partial dentures were inserted at the time of surgery. A discussion of therapeutic considerations follows the case report.

Centrifuging Pour Resins

Twenty-five dentures were processed from pour resins without centrifugation and ten dentures were processed with the use of a centrifuge. The complete upper dentures were measured to determine the differences in linear dimensional change and vertical occlusal relationships. Those processed without centrifugation of the resin showed less porosity and a greater loss of vertical dimension in the molars than in the anterior teeth. Dentures processed with the centrifuge showed less loss of vertical dimension and less linear dimensional shrinkage.

Clinical, cephalometric, and densitometric study of reduction of residual ridges

1. A clinical, cephalometric, and densitometric study of the reduction of residual ridges (RRR) was carried out on 76 edentulous clinic patients (44 women and 32 men) with a mean age 65.2 years (range of 38 to 87 years). 2. In this group of patients with varying periods of time since extraction, a high proportion of maxillary ridges were high and well rounded (Order III), including 50 per cent of those 20 years or more after extraction. In contrast, only 24 per cent of the mandibular ridges were classified as high and well rounded, and of these, 80 per cent were 2 years or less postextraction with 54 per cent classified as knife-edge (Order IV). 3. The rate of total anterior RRR varied between individuals, being immeasurable in 23 per cent and 1 mm. or more per year in 20 per cent. The highest rate in one subject studied over 3 years was 2.2 mm. per year. The average rate was 0.5 mm. per year. 4. The rate of RRR varied between the upper and lower jaws averaging 0.1 mm. per year for the maxillae and 0.4 mm. per year for the mandible. Thus, the average rate for the lower jaw was four times that of the upper. Yet, 9 per cent of the subjects had a higher rate on the maxillae than on the mandible, while the rate was the same in 26 per cent. 5. There was a low correlation between the rate of RRR and several possible cofactors, including sex, age, and bone density. 6. An average rate of anterior vertical RRR of 0.5 mm. per year could represent an average loss of 5 mm. in anterior ridge height (considerably more in some patients) in 10 years, resulting in significant loss of vertical dimension, esthetics, and comfort. Such remarkable changes in millions of edentulous people represent a staggering need for prosthodontic care. 7. New methods of prevention and treatment of this disabling disease must be found.

Implant Denture Histology: Gross and Microscopic Studies of a Human Mandible with a 12-Year Subperiosteal Implant Denture

A mandible that had supported a subperiosteal implant denture for more than 12 years when the patient died of unrelated causes was studied histologically in serial sections. The following conclusions were drawn. Epithelium did not grow downward along the primary abutment struts to encapsulate the peripheral frame. The connective tissue in contact over, around, and under the buried metal was modified into flattened compressed fibers and cells with elongated nuclei. Although the crevice around an implant abutment somewhat resembled a normal tooth crevice, the implant crevice, which was lined with thin epithelium, extended under the abutment and had progressed only 2 or 3 mm. along the metal strut from the penetration in more than 12 years. Inflammatory cells in the tissue adjacent to the epithelialized implant abutment crevice were comparable to the inflammatory cells generally present around the gingival sulci of natural teeth. Every metal exposure, whether a primary exposure for the four implant abutments or an accidental secondary exposure of the substructure frame, should be regarded as a possible source of beginning epithelial downgrowth. No significant bone resorption, “settling,” or loss of vertical dimension occurred in this patient in 12 years. There was a tendency for bone to grow over the implant periphery on the lingual, especially in the mandibular torus area. Certainly these findings, based on study of a single patient, indicate that a subperiosteal implant denture can be remarkably well tolerated over a 12-year period with no histologic evidence of damage to the approximating or adjacent tissues. Patients with long-standing implant dentures seldom die under conditions which make it possible to recover their mandibles for scientific study. Maximum use must be made of such material as becomes available to advance the scientific knowledge of conditions around the buried substructure of the implant denture.

Loss of vertical dimension: Causes and effects: Diagnosis and various recommended treatments

Loss of vertical dimension: Causes and effects: Diagnosis and various recommended treatments

Effect of Loss of Vertical Dimension on Anatomic Structures of the Head and Neck

Effect of Loss of Vertical Dimension on Anatomic Structures of the Head and Neck