Some anatomical considerations for implant supported restorations in edentulous patients.

STATEMENT OF PROBLEM: After the loss of the natural teeth, the alveolar process and part of the basal bone remodels, resulting in edentulous residual jaws. In edentulous patients, the residual arches provide the vital tissues on which to place the denture bases and the artificial teeth into their selected positions. The residual arches also furnish the foundation of osseo-integrated implants for the planned restorations. PURPOSE: To examine some characteristics of the edentulous arches, the relations between the occluding jaws and their clinical importance. MATERIAL AND METHODS: 212 stone casts mounted in centric relation, from one hundred and six edentulous patients were examined and surveyed. The measurements included the length, the width of the maxillary and mandibular edentulous arches and the inter jaw distances at anterior and posterior regions. RESULTS: Of the one hundred and six participants, 62.3% were female and 37.7% male subjects. The maximallary arch length and width varied from 36 to 71mm, and between 36 to 58mm, respectively. The mandibular length and width differed from 32 to 55mm, and between 48 to 62mm. Higher width values of maxilla and mandibles were found among males as compared to females (p<0.001). The vertical inter jaw distances varied from 9 to 28mm in both anterior and posterior regions. The horizontal inter jaw distances and relation modes varied widely at both anterior and posterior regions. CONCLUSIONS: There is a large disparity in sizes and shapes of the edentulous arches and varied spatial inter arch characteristics. CLINICAL IMPLICATIONS: Before the placement of osseo integrated implants and rehabilitation of the edentulous patients, it is essential to identify the anatomy and relations of the occluding residual arches to contribute to a successful dental treatment.

[Materials and technologies for fabricating denture bases].

The materials and technologies for fabrication of denture bases have developed during the last 150 years. The requirements of the ideal material are versatile and include functional, physical and esthetical demands. The current manuscript classifies denture base materials according to their chemical characteristics into polymers, reinforced polymers and light cured polymers. Poly Methyl Metacrylate (PMMA) was developed 70 years ago, and is still the major material for fabrication of denture bases due to its esthetic characteristics, high processing and polishing abilities, relining and rebasing possibility and low cost. The main disadvantages of PMMA are its dimensional changes during polymerization, porosity and allergic/cytotoxic effects. PMMA may be reinforced by metal, polyethylene or glass fibers. Other materials used for fabrication of denture bases are Nylon and Urethane dimethacrylate. Their advantages are better esthetics, low modulus of elasticity and reduced cytotoxicity. This review presents the advances in materials and techniques used for denture bases, the different materials, their advantages and disadvantages, the chemical reactions associated with their production, and their allergic and cytotoxic side effects.

Prosthetic care for a mentally ill patient.

A manic-depressive 64 old female arrived to the clinic for prosthetic treatment. She was fully edentulous and wore an old poor set of complete dentures. Her general attitude was apathy, nonattached and almost indifferent to the general environment as well as to the proposed oral care. This behavior can change for the worse at any stage during treatment, especially after the delivery stage, with the possibility of a change from an indifferent to a hostile, non cooperative attitude. The intended care was explained in detail to the patient and her accompanying daughter. After their approval, we were able to perform successfully a new set of complete dentures with improved esthetics and functional capabilities. Flat bony ridges with shallow mucosal coverage precluded vertical mandibular denture extension at the lingual surface. Consequently the resulting prosthesis had reduced lateral lingual flanges with limited support and retation.

The importance of correct diagnosis in complete dentures treatment.

A 68 years edentulous female, wearing unsuccessful complete dentures, was treated by making a new set of dentures. The main initial complains were unaesthetic teeth, excessive gums display, speech impairment and severe difficulties in mastication. With the patient's full collaboration and following sound established prosthodontics principles, a successful set of full dentures was provided. The main changes performed with the new set of dentures were: A. Provision of three millimeters interocclusal rest space between the vertical dimension while in occlusion and the vertical dimension of rest. B. The full anterior and premolars maxillary teeth and the incisal's third of the mandibular anterior teeth were displayed when patient was speaking, smiling and laughing. No artificial gums were displayed during any normal facial or oral activities. C. The occlusal plane was established after the selection of the anterior teeth. The plane was made parallel to the ala tragus (Camper's) line.

Prosthodontic treatment of a patient with Papillon Lefevre syndrome.

Papillon Lefevre Syndrome is an autosomal recessive disorder. One of the most destructive forms is a periodontal disease. A 19 year female with the syndrome, came for dental treatment. Most of her natural dentition was missing. The remaining five natural teeth had extensive carious and periodontal lesions. Two poor dentures replaced the missing teeth. Her main oral complaints were poor esthetics, teeth sensitiveness, and dentures instability. All the remaining natural teeth were removed and the dentures repaired and rebased in one session. Following wound healing and the maturation of the residual ridge, a set of complete dentures was made. Two years after the delivery of the full dentures, an additional set of dentures were provided for social and emotional reasons. 9 years after the last extractions, the patient refuses to undergo bone augmentation and osseointegrated implant procedures, for future preventive and oral rehabilitation care. There is a strong possibility of chronic bone tissue resorption conducive to dentures instability, mandibular nerves exposures and or, perforation of the maxillary sinuses.