Raymond A. Kopczyk

Incidence of anterior ridge deformities in partially edentulous patients

A random sample of 416 diagnostic casts was evaluated to determine the incidence and type of ridge deformities present in anterior ridges of partially edentulous patients. Loss of teeth resulted in 91% (31 of 34) of ridge deformities. The most prevalent defect was the class III or combination labiolingual and apicocoronal type of deformity.

Potential for Keratinization of the Sulcular Epithelium in the Dog

The normal human gingival crevice is lined by a thin, nonkeratinized, stratified squamous epithelium devoid of rete ridges. During development of the sulcus, odontogenic epithelium eventually is replaced by oral epithelium (McHUGH, J Periodontol 35: 338-348, 1964), which may have the potential to keratinize when stimulated (MERZEL, VIEGAs, and MUNHOZ, J Periodontol 34: 127-133, 1963). Of all the generally available laboratory animals, only the dog and monkey resemble man in having a nonkeratinized sulcular epithelium. This is a preliminary report of an effort to induce keratinization of the sulcular epithelium in the dog by mechanical stimulation. Five beagle dogs received a prophylaxis a week before the experimental period. The teeth on the experimental side were subjected to daily subgingival brushing for 20 seconds with a 0.007-inch, multi-tufted toothbrush (GILSON, CHARBENAU, and HILL, J Mich Dent Assoc 51: 347-361, 1969) . The 20-second duration was based on the average time 14 clinic patients spent brushing under supervision. Teeth on the control side were cleaned daily with a rubber cup in a dental handpiece; care was taken to avoid contact between the rubber cup and the sulcular epithelium. Gingival biopsy specimens were obtained from four dogs at 0, 6, 14, and 21 days with the aid of restraint procedures, a tranquilizing drug,

Method to Investigate Bioelectric Regeneration of Bone in Periodontal Defects

A piezoelectric potential may be generated when bone is stressed artificially or by function (FuKADA and YASUDA, J Physiol Soc Jap 12: 11581168, 1957; BASSETT, Sci Am 213: 18-25, 1965). Minute electric currents applied during bone repair and growth produce physical change (LAVINE ET AL, Science 175: 1118-1120, 1972; NORTON and MOORE, J Dent Res 51: 1492-1499, 1972). In view of these findings, it was hypothesized that new bone growth may be directed into a pathologically occurring defect by the application of current. To test this hypothesis, it was necessary to design a tissue-compatible miniature power source with low current values and long life, find a suitable experimental animal, and perfect a surgical implantation technique. A power source was designed which consisted of a 1.35 v hearing aid battery, a 1/ w 12 megolhm resistor and two dissimilar electrode wires. A direct current of 1.1 x 10-4 amperes was generated (SMITH, Ann NY Acad Sci 238: 500-507, 1974). Wire connections were made with a silver-filled epoxy compound., The power source was encapsulated with an epoxy resinb and reencapsulated in silastic elastomere (Fig 1). Adult beagle dogs with chronic periodontal disease were selected as the experimental animals. Beagles are a suitable size for surgical implantation and manifest a periodontal bone loss sim-

Method of Managing Dogs for Dental Research

The method used to manage experimental dogs is dictated by the experiment itself, the physical condition of the dogs, and the ability and experience of the operator. The most widely used method entails the intravenous administration of barbiturates or tranquilizing drugs or both until a state of general anesthesia is obtained. Saxe et al (Periodontics 5:217, 1967) used a canvas immobilization sling to carry out regular tooth cleaning procedures. Egelberg (Odont Rev 16:31, 1965) needed better control with his experimental procedure; therefore, he used tiopenthalsodium [sic] intravenously to obtain general anesthesia for the placement of filter strips to evaluate sulcular exudate. Studies that require frequent intravenous medication have been troubled by the problem of accomplishing venipuncture in regions that have become thrombosed or scarred or both by attempts to administer drugs intravenously. This becomes an even greater problem when an inexperienced operator attempts a venipuncture after the animals have undergone weeks of frequent intravenous medication. A combination of a canvas immobilization sling, intramuscular acepromazine,* and local anesthesia was used to manage experimental dogs in a recent study (Illustration). The experimental procedures involved daily probing of the gingival sulcus, placement of filter strips to collect sulcular exudate, determination of a giingival inflammation index, and a soft tissue biopsy procedure. To avoid a daily intravenous injection, the dogs were restrained in the canvas sling apparatus and an intramuscular injection of acepromazine (a phenothiazine derivative) was administered. With the aid of this combination of physical restraint and tranquilizing agent, the

Forty-four-month evaluation of a patient treated by surgical orthodontics: Report of a case

Abstract This article reports a 44-month follow-up of a patient treated by surgical orthodontics. A multidisciplinary approach with emphasis on occlusion is employed in the postoperative evaluation. Indications and complications are reviewed. A relapse tendency was found, and probable causes are discussed.