Localized Tooth-Related Factors That Modify or Predispose to Plaque-Induced Gingival Diseases or Periodontitis
These factors are considered to be those local factors that contribute to the initiation and progression of periodontal disease through an enhancement of plaque accumulation or the prevention of effective plaque removal by normal oral hygiene measures.
Tooth Anatomic Factors
These factors are associated with malformations of tooth development or tooth location. Anatomic factors such as cervical enamel projections and enamel pearls have beenassociated with clinical attachment loss, especially in furcation areas.
Cervical enamel projections are found on 15% to 24% of mandibular molars and 9% to 25% ofmaxillary molars, and strong associations have been observed with furcation involvement.
Palatogingivalgrooves, found primarily on maxillary incisors, are observed in 8.5% of individuals and are associated with increased plaque accumulation, clinical attachment, and bone loss.
Proximal root grooves on incisors and maxillary premolars also predispose to plaque accumulation, inflammation, and loss of clinical attachment and bone.
Tooth location is considered important in the initiation and development of disease. Tooth malalignment predisposes to plaque accumulation and inflammation in children and may predispose to clinical attachment loss in adults, especially when associated with poor oral hygiene.
In addition, open contacts have been associated with increased loss of alveolar bone, most probably through food impaction.
Dental Restorations or Appliances
Dental restorations or appliances are frequently associated with the development of gingival inflammation, especially when they are located subgingivally. This may apply to subgingivally placed onlays, crowns, fillings, and orthodontic bands.
Restorations may impinge on the biologic width by being placed deep in the sulcus or within the junctional epithelium. This may promote inflammation and loss of clinical attachment and bone with apical migration of the junctional epithelium and reestablishment of the attachment apparatus at a more apical level.
Root fractures caused by traumatic forces or restorative or endodontic procedures may lead to periodontal involvement through an apical migration of plaque along the fracture when the fracture originates coronal to the clinical attachment and is exposed to the oral environment.
Cervical root resorption and cemental tears may lead to periodontal destruction when the lesion communicates with the oral cavity and allows bacteria to migrate subgingivally.
Mucogingival Deformities and Conditions around Teeth:
It is defined as "a generic term used to describe the mucogingival junction and its relationship to the gingiva, alveolar mucosa, frenula, muscle attachments, vestibular fornices, and the floor of the mouth."
A mucogingival deformity may be defined as "a significant departure from the normal shape of gingiva and alveolar mucosa" and may involve the underlying alveolar bone.
Mucogingival surgery is defined as "periodontal surgical procedures designed to correct defects in the morphology, position, and/or amount of gingiva".
The surgical correction of mucogingival deformities is done for:
to enhance function,
To facilitate oral hygiene.
Mucogingival Deformities and Conditions on Edentulous Ridges usually require corrective surgery to restore form and function before the prosthetic replacement of missing teeth or implant placement.
Trauma from occlusion refers to the tissue injury that occur when occlusal forces exceed the adaptive capacity of the. An occlusion that produces such injury is called a traumatic occlusion.
Trauma from occlusion refers to the tissue injury rather than the occlusion, so an increased occlusal force is not traumatic if the periodontium can accommodate it
Excessive occlusal forces may also:
disrupt the function of the masticatory musculature
Acute trauma from occlusion results from an abrupt occlusal impact, such as that produced by biting on a hard object (e.g., an olive pit), restorations or prosthetic appliances that interfere with or alter the direction of occlusal forces on the teeth.
The results are tooth pain, sensitivity to percussion, and increased tooth mobility. If the force is dissipated by a shift in the position of the tooth or by wearing away or correction of the restoration, the injury heals and the symptoms subside. Otherwise, it will lead to:
Periodontal injury that may worsen and develop into necrosis accompanied by periodontal abscess formation.
Persist of condition as a symptom-free chronic condition.
Chronic trauma from occlusion is more common than the acute form. It most often develops from gradual changes in occlusion produced by tooth wear, drifting movement and extrusion of teeth, combined with para functional habits such as bruxism and clenching, rather than as a sequel of acute periodontal trauma.
Primary and Secondary Trauma from Occlusion:
Trauma from occlusion may be caused by alterations in occlusal forces, reduced capacity of the periodontium to withstand occlusal forces, or both.
Primary trauma from occlusion is occurs when trauma from occlusion is the result of alterations in occlusal forces.
It is considered the primary etiologic factor in periodontal destruction.
the insertion of a prosthetic replacement that creates excessive forces on abutment and antagonistic teeth
the drifting movement or extrusion of teeth into spaces created by unreplaced missing teeth
The orthodontic movement of teeth into functionally unacceptable positions.
Changes produced by primary trauma do not alter the level of connective tissue attachment and do not initiate pocket formation. This is probably because the supracrestal gingival fibers are not affected and therefore prevent apical migration of the functional epithelium.
Secondary trauma from occlusion is results from reduced ability of the tissues to resist the occlusal forces.
Secondary trauma from occlusion occurs when the adaptive capacity of the tissues to withstand occlusal forces is impaired by bone loss resulting from marginal inflammation. This reduces the periodontal attachment area and alters the leverage on the remaining tissues. The periodontium becomes more vulnerable to injury, and previously well-tolerated occlusal forces become traumatic.
Three different situations on which excessive occlusal forces can be superimposed:
1. Normal periodontium with normal height of bone
2. Normal periodontium with reduced height of bone