Solitary bone cysts (SBCs) of the jaws are often polymorphic, show scalloped borders when located between the teeth roots, are devoid of an epithelial lining, and are usually empty or contain blood or a straw-colored fluid. The numerous synonyms referring to these lesions reflect their uncertain nature (eg, traumatic bone cyst, simple bone cyst). SBC, also found in other skeletal locations, is often suspected after epidemiologic and radiologic test results and confirmed at surgery. Histology usually shows fibrous connective tissue or only bone. The various etiologic elements responsible for SBC include tumor degeneration, trauma, or abnormalities during bone growth. The pathogenesis of the SBC is unknown, but it is widely accepted that it could be the result of a vascular dysfunction leading to a local posthemorrhagic ischemia, inducing an osseous aseptic necrosis. This article reviews likely but stilldebated etiopathogenic hypotheses of lesions of the jaws and other, more frequent bony locations, such as the humeral and femoral metaphysis.

Thirty-four areas of gingival recession in ten patients were treated by a coronally repositioned flap procedure. All but four of these areas had received a free gingiva graft previously. The postoperative evaluations of the wound healing were made at 2 weeks and at 1, 2, 4, 6 and 12 months after the final surgery. In most cases the amount of gingival recession was reduced with the average tissue gain being 1.82 mm. The gingival sulcus depth was unaffected by the procedure. Several cases showed total root coverage. Although the procedure described has many advantages, the authors feel these must be carefully weighed against the disadvantages before subjecting patients to such surgery.

Stages in bone formation were studied ultrastructurally after the implantation of the following 3 bioceramic powders into human periodontal lesions: (1) beta-tricalcium phosphate whitlockite (Synthograft) consisting of particles with a mean length of 229 +/- 87 microns in SEM and appearing in TEM as crystals with a mean diameter 488 +/- 192 nm; (2) an hydroxyapatite (Bioapatite) which consisted of particles with a mean length of 283 +/- 87 microns in SEM and of crystals with a mean diameter of 146 +/- 47 nm in TEM; and finally (3), a microsized hydroxyapatite consisting of elongated platelets with a mean length of 32 +/- 4 microns in SEM, composed of small crystals with a mean diameter of 38 +/- 16 nm in TEM. In a preliminary experiment in rats, it appeared that the microsized hydroxyapatite implanted into the alveolar region after first molar extraction exhibited biocompatibility. In 6- and 12-month biopsies, it appeared that bone formation in association with the 3 bioceramics tested in human periodontal lesions occurred through similar mechanisms at the ultrastructural level. After the appearance of peripheral fibroblast-like or osteoblast-like cells with an interposed layer reminiscent of an osteoid tissue, collagen fibrils were observed in the intercrystalline spaces. These spaces subsequently underwent mineralization, with deposition of bone apatite crystals followed by the peripheral deposition of a thin inner bone layer with a granular appearance and an outer normal bone layer of either woven bone, lamellar bone or bone with parallel calcified collagen fibrils. These bone nodules, however, formed around the bioceramic particles at highly variable time intervals. Bone formation was observed around Synthograft and Bioapatite implants only in 12-month biopsies, and thicker layers of peripheral bone were observed with the latter hydroxyapatite implant. With microsized hydroxyapatite, a significant amount of peripheral bone formation had already occurred by 6 months, strongly suggesting an important effect of crystal size on bone formation.

The study describs a standardized and reproducible photometric test method for the measurement of gingival recession surfaces. A sample of 45 teeth associated with gingival recessions was selected for testing the control method. The planimetric results suggest a high reliability of the method (p > 0.98) compared to the clinical measurements of the height and the width of the recessions with a graduated periodontal probe.