Oral Maxillofacial Surgery #1

Notes

Infection and Inflammation

Acute periapical periodontitis - loss of lamina dura / where PDL space previously widened → rarefying osteitis

Chronic periapical periodontitis - widening of PDL space with preservation of lamina dura

Hypercementosis - Paget's disease (multiple)

Space of Infection

Cellulitis

• painful, diffuse, brawny swelling → oedema
• overlying skin is red, tense and shiny
• trismus
• cervical lymphadenopathy
• malaise
• pyrexia
• airway can be compromised
• both sides of floor of mouth → Ludwig's angina

Actinomycosis

• infection with Actinomyces species, A. israelii
• multiple discharging sinuses
• penicillin → 3-week (acute) / 6-week (chronic)

Bisphosphonate-associated Necrosis of Bone

① history of current or prior treatment using bisphosphonate - osteoporosis, Paget's disease, osteogenesis imperfecta, bony metastatic disease

② exposed bone > 8 weeks

③ no previous history of radiotherapy

👉 poor wound healing, soft tissue breakdown, exposure of bone

Dry Socket

= Focal Alveolar Osteitis

Incidence : Mb > Mx

Aetiology : excessive fibrinolytic activity, impaired vascular supply, smoking, oral contraceptives, immune defects, surgical trauma, history of radiotherapy

Surgical Removal of Teeth

Anatomical Structures

Mandibular 4, 5 region buccally - mental nerve

Mandibular 8 region lingually - lingual nerve

Maxillary 7, 8 buccally - pterygoid plexus

Palate - long palatine and nasopalatine artery

Indications for Third Molar Removal

• Pericoronitis - recurrent
• Unrestorable caries
• Non-treatable pulpal / periapical pathology
• Abscess and osteomyelitis
• Internal / external resorption of tooth / adjacent teeth
• Fracture of tooth
• Orthodontic
• Associated pathology - dentigerous cyst
• Field of tumor resection

Prophylactic removal of pathology-free impacted third molars → discontinued

Indications for Apicectomy

• Failure of conventional endodontic therapy
• Pathological change at apex of previously root-filled tooth - granuloma / cyst
• Failure during root canal treatment - overfilling, instrument fracture, lateral perforation
• Root unapproachable by conventional orthograde route - post-crowned tooth, calcified root canal
• Anatomical variations preclude normal endodontic therapy

👉 At least 3 mm of root apex should be removed

Vicryl suture - polyglycolic acid

Implantology

Osseointegration = direct and function connection between ordered, living bone and surface of a load-carrying implant

Materials

👉 Commercially pure titanium - CPT4, cold worked CPT4(cw) → ↑ tensile strength, ↓ fracture risk

👉 Titanium alloy - titanium, aluminium, vanadium (Ti6Al4V), ↑ strength ↓ manufacturing cost, non homogenous crystalline structure

👉 Titanium-zirconium alloy - ↑ tensile strength, good biocompatibility, homogenous crystalline structure - allow acid etching for improved bone healing response

👉 Zirconia - non-metallic, highly biocompatible, one-piece implant

Patient-specific Factors

• Suitability for surgery - cardiac, lung, liver, kidney disease
• Influence healing - diabetes, immunosuppression, corticosteroid therapy
• Smoking / alcohol abuse
• Periodontal disease / oral hygiene
• Mental health
• Age

Site-specific Factors

• Adequate access
• Avoidance of adjacent anatomical structures
• Absence of pathology
• Emerge through attached mucosa
• 1.5 mm between implant and tooth
• 3 mm between implants
• Ridge width 1 mm bone wall on all aspects of implant
• Bone augmentation - guided bone regeneration / onlay bone grafting / sinus lift
• Soft tissue augmentation - adequate volume of attached mucosa

Platform Switching

• Radiographic marginal bone loss of 1.5 mm during the first year, 0.2 mm each succeeding year
• ↓ diameter of restoration abutment in comparison to diameter of dental implant
• better preservation of soft and hard tissues

Type of Grafts

Autogenous grafts - patient's own tissue

Allografts - tissue from a human donor

Xenografts / heterografts - tissue from another species

Alloplastic materials - synthetically constructed tissues, biocompatible e.g. internal fixation plates and screws, resorbable materials, orbital wall / floor reconstruction materials, bone substitutes, contour materials, soft tissue crease / wrinkle obliterative materials

Guided Bone Regeneration (GBR) = directing the growth of new bone using barrier membranes that exclude the ingrowth of fibroblasts and epithelial cells, permit the more slowly growing bone to do so in a protected space