Presentation on theme: "Wisdom Tooth Wisdom Demystifying the Past And Planning for the Future Ted Fields, DDS, PhD."— Presentation transcript:
Wisdom Tooth Wisdom Demystifying the Past And Planning for the Future Ted Fields, DDS, PhD
Course Outline Part I: To Remove or Not to Remove 1. Development 2. Wisdom teeth as an asset 3. Wisdom teeth as a liability 4. Alternatives to removal 5. Timing of removal
Course Outline Part II: Treatment Approach 1.Assessing the difficulty of removal 2.Patient counseling and preparation 3.Anesthesia 4.Instrumentation 5.Technique
Course Outline Part III: Management of Infected Teeth
Course Outline Part IV: It Aint Over Till Its Over 1.Complications 2.Post-operative care 3.Documentation
The Difficulty in Understanding 3 rd Molars 1.European third molar surgery is much different than that in the U.S. Lingual fracture technique Different instrumentation Different economic influences on dental care
The Difficulty in Understanding 3 rd Molars 2. Many research papers of the past 20 years set out to prove or disprove old ideas – many of which themselves are outdated. Will the 3 rd molar erupt? Is there enough arch length for eruption? Does removal of the 3 rd molar compromise the 2 nd molar?
The Difficulty in Understanding 3 rd Molars 3.Much of the developmental literature is written from an orthodontic viewpoint. There is an outcome bias towards younger individuals (what is the result in a 16-yr- old?) The 3 rd molar is judged in relation to orthodontic needs, rather than the patients overall needs.
The Difficulty in Understanding 3 rd Molars 4. Many changes in technology have been totally neglected. Implants Electric handpieces Antibiotics Hemostatic agents Bone augmentation materials
The Difficulty in Understanding 3 rd Molars 5.The topic is not covered in any depth in most dental schools. Knowing when it is in the patients best interest to remove 3 rd molars is a judgment that requires detailed knowledge of the risks and benefits associated with tooth retention and with tooth removal.
Initial calcification Occurs as early as 7yrs, more typically age 9.
Crown Mineralization Usually completed by age 12 to 14.
Root Formation Usually half-formed by age 16.
Root Completion Fully formed roots with open apices are usually present by age 18.
Eruption Most teeth that will erupt are erupted by age % of all teeth that will erupt are erupted by age 24. A limited number of third molars appear to erupt, at least to some degree, in young adults.
Predicting Eruption – Who Cares? Does it matter if a wisdom tooth erupts? Does it matter when a wisdom tooth erupts?
The Key Issue Does it affect the Risk:Benefit Ratio?
Since Risk of retention and Benefit of removal are essentially the same concept, these terms may be combined. Since Benefit of retention essentially = 0, the equation may be simplified:
Evaluating Risk:Benefit You must consider 2 separate assets of each risk and each benefit: 1.Magnitude of risk or benefit 2.Probability of risk or benefit
Magnitude Is it major or minor? Does it require hospitalization? Is it permanent? Does it affect your daily routine? If so, for how long?
Probability The most overlooked aspect of most consultations. Fortunately most real bad outcomes are real uncommon What is the likelihood of certain problems? How much does treatment alter this likelihood?
The Difficulty of Accurate Risk:Benefit Assessment 1.The literature is not very complete or very helpful. Complication rates vary widely. Different people view these complications very differently (complication doesnt always equal perception of the complication) Ogden GR, Bissias E, Ruta DA, Ogston S: Quality of life following third molar removal: a patient versus professional perspective. Br Dent J 1998;185:
The Difficulty of Accurate Risk:Benefit Assessment 2. The wide variety of different complications and the wide range in the incidences of each potential complication result in a complex body of data to assimilate.
Risk:Benefit Are erupted 3rds more or less subject to disease? Are erupted 3rds more or less beneficial?
Wisdom Teeth as an Asset
What Impacts Treatment? Eruption into occlusion should not be the sole criterion of usefulness. The issue is not can you save it but should you save it.
Benefits of 3rds Functional occlusion – what is this? Is it any different than just occlusion? Is all occlusion functional? Is all functional occlusion important? If so, is it all equally important? Without evaluating questions such as these, how can you determine the true benefit of 3rds?
Benefits of 3rds – Part II Orthodontic repositioning to replace missing or grossly compromised 1 st molars Transplantation – poor long-term survival With dental implants, these are rarely reasonable treatment alternatives.
Tooth Transplantation Under ideal conditions, 27 oral surgeons transplanted 291 teeth: 5-yr survival rate: 76.2% 10-yr survival rate 59.6% Schwartz O, Bergman P, Klausen B: Resorption of autotransplanted teeth. A retrospective study of 291 transplantations over a period of 25 years. Int J Oral Surg 1985;14:
Conclusion 3 rd molars provide no proven functional benefit and no obvious esthetic benefit. Rarely, they may provide a treatment option that, at best, is third-line treatment.
Wisdom Teeth as a Liability
What Impacts Treatment? Failure of eruption should not be the sole criterion for removal. Successful eruption should not be the sole criterion for retention. Eruption is not always a yes or no proposition.
Problem #1 – Soft Tissue Even with adequate arch length and full eruption, 3 rd molars are often surrounded by thin, unkeratinized, highly distensible lining mucosa of the buccal vestibule. Encourages pathogenic bacteria retention Poorly withstands hygiene measures
Problem #2 – Periodontal Compromise Bone loss distal to the 2 rd molar after removal of the 3 rd molar is controversial, at best. Even with some loss of bone, the result is stable and cleansable – the goal of periodontal therapy.
Bone Loss Distal to the 2 nd Molar A reduction in pocket depth with no change in bone height on the distal of the 2 nd molar. Szmyd and Hester Groves and Moore Grondahl and Lekholm
Bone Loss Distal to the 2 nd Molar Alveolar bone crest healing distal to the 2 nd molar is enhanced in younger patients with incompletely developed 3 rd molar roots. Ash, Costich, and Hayward Ziegler
Augmentation with Freeze- Dried Bone or Bone Substitutes Why? There is no independent evidence of benefit Why graft a contaminated site? Why graft a site you cant close primarily? Your goal is to maintain bone height on the distal of the 2 nd molar without pocket formation, not to augment potential defects more posteriorly.
Augmentation: Conclusion It wont improve your outcome. It will undoubtedly increase your infection rate Why would you want to augment this area anyway?
Measuring Bone Height
Problem #2 – Periodontal Compromise The role of pathogenic bacteria retention in 3 rd molar pockets is unknown. How does this affect the rest of the dentition? Hygenic compromise of the 2 nd molar can result in a difficult to restore situation if this tooth is lost.
How Do You Treat Missing 2 nd Molars? If the entire dentition is healthy and a mandibular 2 nd molar needs extraction, what is the recommended treatment? Cantilevered abutment? Implant? Partial denture? Remove opposing tooth at same time? Nothing. Allow opposing tooth to supererupt.
The Missing 2 nd Molar Dilemma Your treatment plan for this scenario illustrates the value you place on 2 nd molars. Most people will subconsciously do a cost:benefit analysis and conclude that restoration is not necessary.
Problem #3 – 3 rd Molar Caries
Problem #4 – 2 nd Molar Caries
Problem #5 - Infection Can turn an elective procedure into an urgent or emergent situation Unscheduled loss of work Increased pain and healing time Compromise of adjacent teeth Compromise of patients systemic health
Types of Infection 1.Simple dental caries and periodontal disease 2.Pericoronitis 3.Abscess 4.Cellulitis 5.Abscess extension into adjacent fascial spaces 5. Abscess spread to distant sites 6.Recurrent infections 7.Infections resistant to initial local and systemic treatment measures
Pericoronitis The most common cause of therapeutic 3 rd molar removal.
Pericoronitis A failure of preventive measures A failure of early recognition, or a failure to seek proper treatment A step along the pathway of infection Pericoronitis should be a warning sign that initiates immediate and aggressive treatment with careful observation.
Problem #6 - Resorption
Problem #7 - Supereruption
Problem #8 - Cysts Dentigerous Cyst
Dentigerous Cyst Supernumerary 4 th Molar
Types of Cysts Follicular cyst (Dentigerous Cyst) OKC (Odontogenic Keratocyst) Ameloblastoma (several varieties) Not all radiolucencies are cysts! - Lymphoma - Myeloma - Metastatic carcinoma
Without the radiolucency, would you have recommended removal? Is the removal of this better or worse with the radiolucency?
When would you recommend removal of this 3 rd molar?
Cysts – A Few Facts May be prevented by early removal – when normal dental follicle is still evident. The pericoronal pocket, or residual follicle, is responsible for most cystic pathology. All cystic tissues should be removed and biopsied.
Cysts Cysts themselves are not catastrophic – the problem is that we dont know exactly what they are until they are histopathologically examined – which necessitates removal. All cysts result in bone loss. Some cysts recur more than others.
Treatment of Large Cysts Aspirate first – rule out vascular lesions Consider decompression (only after biospy confirmed diagnosis) Consider marsupialization Consider bone grafting Consider possibility of mandible fracture Consider extensive followup
Problem #9 - Tumors Benign vs. malignant Odontogenic vs. non-odontogenic Primary vs. secondary Each of these factors has important treatment implications.
Problem #10 – Risk of Fracture
3 Days Post-extraction
8 Days Post-extraction
Problem #11 - Fracture
Problem #12 - Orthodontics Prevent loss of post- retention stability Allow distalization of 2 nd molars These are controversial indications
Alternatives to Removal 1.Restoration 2.Periodontal therapy 3.Operculectomy 4.Removal of another tooth 5.No treatment
Timing Removal of 3rds When is the best time for prophylactic removal?
Age 7-11: Mandibular 3rds 1.Germs are first visible during this time 2.They usually appear in a superficial location close to the alveolar crest 3.After age 11, they are located deeper in the mandible
Age 7-11: Mandibular 3rds Very close to ridge crest. Minimal if any bone removal will be needed.
Age 7-11: Mandibular 3rds 1.Mineralization is either not present or only mineralized cusps are evident 2.Remove requires a flap and minimal, if any, bone removal 3.Psychological factors and parental support should be carefully evaluated on a case by case basis
Age 7-11: Mandibular 3rds Close to, but not at, ridge crest. Some bone removal will be needed.
Age 7-11: Mandibular 3rds Bone removal will be necessary. Is it better to remove this 3 rd molar or wait?
Age 7-11: Mandibular 3rds There has been less published about removal of thirds at this age than at other ages, so intervention at this time tends to be more controversial Much of the controversy has traditionally revolved around the difficulty in predicting eruption and arch length – probably not valid
Removing 3 rd Molar Germs Bjornland T, Haanaes HR, Lind PO, Zachrisson B: Removal of third molar tooth germs: study of complications. Int J Oral Maxillofac Surg 1987;16: Half as much postop pain medication was required One third quicker procedure Well-tolerated with local anesthesia
Age 7-11: Maxillary 3rds These teeth tend to be high in the maxilla Their small size can make them difficult to locate Their size and location can increase the risk of injury to the developing 2 nd molar Increased operating time and frustration Increased postop edema and discomfort
Age 7-11: Maxillary 3rds
Age 7-11: 3 rd Molars
Age 7-11: Conclusion 1.Lower 3rds are often very simple, upper 3 rd are almost always very difficult and pose risk to the 2 nd molars 2.In older individuals, 90% of the morbidity is from removal of the lower 3rds 3.Early removal may obviate the need for any sedation at any time 4.Psychological evaluation is critical
Age Crown mineralization progresses Distance of lower 3rds from ridge crest increases Lower 3rds become more difficult to remove Upper 3rds may still be quite difficult Psychologically, many patients may be less prepared at this age.
Age Root formation has begun and may progress to near completion. Most patients are psychologically accepting of surgery at this age. Most studies agree that complication rates are least in this age range.
The follicle allows for relatively easy removal once the tooth is accessed. No PDL is present – there is no attachment of the tooth to bone. The portion of the follicle deep to the forming roots acts as a safety zone between the tooth and the nerve.
Age The periphery of the deepest mineralized tooth surface may be quite sharp, allowing laceration of the neurovascular bundle if it too is housed within the follicular space. The tooth may spin and be difficult to stabilize while sectioning and elevating.
Age Root development is not always complete during this period, making it still a favorable time for 3 rd molar removal.
Age Nearly all patients in this age group will have fully developed 3 rd molar roots – this potential advantage is lost. The bone still has a good ratio of elastic collagen matrix to mineral content, usually simplifying removal and even more frequently improving most parameters of healing. Most of these patients are healthy.
Age Most patients are still ASA I or II The mineral content of the mandible increases during this time. Many 3 rd molars must be removed during this time for therapeutic reasons.
Over Age 45 The complication rate is highest in this group. The incidence of nerve injury is highest in this group – and recovery is the poorest. Even routine healing tends to be prolonged and associated with increased morbidity. Patient health may be compromised.
With Increasing Age Narrowing of PDL and pericoronal space Thickening of cortical bone Increased risk of infection, bone loss, and other pathoses
Advantages of Early Removal Wide pericoronal space Incomplete root development Straight roots Away from IAN Away from sinus Less risk of infection Less risk of fracture Patient more likely in good health Better chance for primary closure Smaller teeth require less bone removal