TISHK International University Periodontology Bone Deformities (Osseous Defects) PDF

Tishk International University Dentistry Faculty Periodontics Department Periodontology Bone Deformities (Osseous Defects) Jafar Naghshbandini DDS, MS; PhD Diplomate of American Board of Periodon...

Tishk International University Dentistry Faculty Periodontics Department Periodontology Bone Deformities (Osseous Defects) Jafar Naghshbandini DDS, MS; PhD Diplomate of American Board of Periodontology  Bone Deformities (Osseous Defects) Classifications Goldman & Cohen (1958) Glickman (1964) Karn et al (1983) Prichards (1985) Grants classification Panos & Toneiti (2000)  Panos & Toneiti (2000) classification of osseous defects Suprabony defects Infrabony defects Craters Intrabony defects 1 walled 2 walled 3 walled Combination Interradicular defects (Furcation involvement) Horizontal classification Class I Class II Class III Vertical classification  Infrabony defects Suprabony defects  Osseous craters Osseous craters are concavities in the crest of the interdental bone confined within the facial and lingual walls Craters make up about one-third of all defects and about two-thirds of all mandibular defects They occur twice as often in posterior segments as in anterior segments. Osseous craters  Craters Classification Ochsenbein divided bony craters into three basic types : Shallow crater 1 -2 mm Medium crater 3 -4 mm Deep crater 5 mm or more  Craters Classification Ochsenbein divided bony craters into three basic types : Shallow crater 1 -2 mm Medium crater 3 -4 mm Deep crater 5 mm or more  The interdental area collects Plaque Factors in craters formation and is difficult to clean. Normal flat or even concave facio-lingual shape of interdental septum in lower molar Vascular pattern from the gingiva to the center of the crest could provide a pathway for inflammation.  Buttressing Bone formation Buttressing bone formation has been Buccal alveolar bone described as the development of enlargements were found thickened or exostotic buccal alveolar bone in response to heavy occlusal in 25% of all teeth forces examined 18% were expressed as (Horning GM marginal bony lippings and ,Cohen, Neil's ) 7% as buccal exostoses  Buttressing Bone formation Bone formation sometimes occurs in an attempt to buttress ( the bony trabeculae weakened by resorption Buttressing bone formation in response to trauma from occlusion is a popular concept first proposed by Glickman and Smulow in 1965. Buttressing: provide (a building or structure) with buttresses.  Buttressing Bone formation When Buttressing bone formation occurs within the jaw, it is termed “central buttressing bone” When it occurs on the external surface, it is referred to as “peripheral buttressing bone” formation. This may cause bulging of bone contours, termed as “Lipping” Bulbous Bone Contour  LEDGES Ledges are plateau-like bone margins caused by resorption of thickened bony plates Exostoses Are outgrowths of bone of varied size and shape Palatal exostoses has been found in 40% of human skulls Buccal exostoses are seen in about 25% of all teeth, and 77% of all individuals.  Exostoses Exostoses may be expressed as alveolar margin lippings(18 % of all teeth ) or as larger and more globular buccal exostoses (7% of all teeth) Lingual Exostoses : this may be seen in 11% of all teeth, and in 50% of all individuals Multiple exostoses : Several bony overgrowth occur on the vestibular alveolar bone Etiology There is no consensus as to the etiology Some of the postulated causes include genetic, environmental factors, and masticatory hyper function of continuous growth Histology Histologically, the exostoses can be described as a mature hyperplastic bone, cortical, and trabecular aspect  Buccal exostosis They are painless and self- limiting May contribute to periodontal condition Can be removed with surgery. Buccal exostoses have no malignant potential.  Exostoses & Tori Most palatal tori are less than 2 cm in diameter but their size can change throughout life. The prevalence of palatal tori ranges from 9% - 60% of the population More common on palatal than on the mandible, known as mandibular tori (ranges from 5% - 40%) Prevalence rate for tori is 27 / 1,000 adults More common in females than in males  Surgical Technique A) Clinical photograph. B) Diagrammatic illustration. Surgical procedure for removal of torus palatinus  Incision along the midline of the palate with anterolateral and posterolateral incisions.  Mucoperiosteal flaps on either side of the exostosis. Retraction of flaps during the surgical procedure is achieved with the help of traction sutures  Sectioning of the lesion into smaller parts using a fissure bur.  Removal of the exostosis in fragments with a mono-bevel chisel  Smoothing of the bone surface with a bone bur  Operation site after the placement of sutures  Postoperative clinical photograph immediately after removal of sutures Surgical procedure for removal of Torus Mandibularis  Fenestration: Isolated areas in which the root is FENESTRATIONS denuded of bone and the root surface is covered only AND by periosteum and overlying gingiva Dehiscence: When the denuded area extends through DEHISCENCES the marginal bone, the defect is called dehiscence  They occur more often on the facial bone than on the lingual More common in anterior teeth and frequently bilateral FENESTRATIONS Important as they may complicate the AND outcome of periodontal surgery Approximately occurs on 20% of teeth DEHISCENCES Prominent root contours ,malposition and labial protrusion of the root combined with thin bony plate are predisposing factors  Reversed Architecture Reversed architecture defects are produced by loss of interdental bone, including the facial plates, lingual plates, or both, without concomitant loss of radicular bone, thereby reversing the normal architecture. They are more common in the maxilla Reversed Architecture