Dentoalveolar questions OMSITE Flashcards
Osteogenesis occurs with which of the following grafting materials? A. Allogeneic bone grafts B. Xenographic bone grafts C. Alloplastic bone grafts D. Autogenous bone grafts
Answer: D
Rationale:
Osteogenesis refers to the growth of bone from viable cells transferred within the graft. Autogenous bone is the only graft material available with osteogenic properties.
Allogeneic bone grafts (allografts) are treated in bone banks in a variety of methods, resulting in different mineralized, freeze-dried, solvent-dehydrated, or demineralized states. Allografts such as demineralized freeze-dried bone and solvent-dehydrated mineralized bone have been advocated for use in extraction sites because of their osteoconductive nature and the characteristic that they will resorb and be replaced within a relatively short period of time.
Xenografts are graft materials harvested from a species other than human, typically bovine, and are processed to remove the antigenicity by a variety of chemical and preparation techniques. The absence of proteins results in minimal immune response in vivo.
Alloplasts include forms of calcium phosphate materialsóeither dense or porous hydroxylapatite, hard tissue replacement, and bioactive glass. These materials have proved useful for retaining alveolar bulk but can be slow to resorb because of their chemical characteristics. Recent advances in adding materials or changing the chemical characteristics of these materials, however, recently have been shown to provide maintenance of form and also allow for bone formation.
Reference:
Misch, CE, Contemporary Implant Dentistry 2nd edition, page 455, Mosby 1999.
Block, MS, Treatment of the single tooth extraction site. Oral and Maxillofacial Surgery Clinics of North America, Volume 16, Issue 1, February 2004, Pages 41-63
The phase in alveolar distraction osteogenesis for implant site development, which occurs at the end of distraction until the device is removed is known as the: A. latency period. B. distraction period. C. consolidation period. D. activation period.
Answer: C
Rationale:
The consolidation period follows active distraction and continues until device removal. The length of the consolidation period is influenced by the age of the patient, distance and time of distraction, and the amount of surgical trauma at the time of surgery. In cases of increased surgical trauma, recommendations are for increasing the time of the latency period and the consolidation period. The latency period is the time between device placement/osteotomy and activation of the distractor.
The distraction period is the classic term for the time frame during which the distraction device is activated and the gap between the osteotomy segments is expanded. The activation period could also describe the distraction period, but is not classic terminology.
Reference:
Batal H, Cottrell D. Alveolar distraction osteogenesis for implant site development. Oral Maxillofacial Surg Clin N Am 16 (2004) p.94.
Peterson, LJ, Ellis, E, Hupp, JR, Tucker, MR. Contemporary Oral and Maxillofacial Surgery 4th Edition, Mosby, St. Louis, 2003, p. 582-584.
Following completion of alveolar distraction, the stabilizing device is maintained for: A. 2 - 4 weeks. B. 5 - 7 weeks. C. 8 - 12 weeks. D. 13 - 17 weeks.
Answer: C
Rationale:
The ability of the distractor to stabilize the newly formed bone within the distraction gap is key to the formation of a healthy regenerate. Unstable devices are associated with increased endochondral bone formation and delayed bone formation within the distraction gap. Stable devices lead to direct osteogenesis without intervening cartilage formation.
Reference:
Batal H, Cottrell D. Alveolar distraction osteogenesis for implant site development. Oral Maxillofacial Surg Clin N Am 16 (2004) p.93 - 94.
Saulacić, N, MartÌn, M, Camacho, and GarcÌa, A Complications in Alveolar Distraction Osteogenesis: A Clinical Investigation
Journal of Oral and Maxillofacial Surgery, Volume 65, Issue 2, February 2007, Pages 267- 274
When performing alveolar ridge development using orthodontic forced eruption, what is the recommended amount of tooth movement per month? A. 1.0 - 2.0 mm B. 2.1 - 3.0 mm C. 3.1 - 4.0 mm D. 4.1 - 5.0 mm
Answer: A
Rationale:
The orthodontist needs to know what the clinician plans to gain by the forces applied to the tooth or teeth in the treatment area. Forces for crown lengthening would be rapid. By contrast, forced eruption for implant site development would be slower, approximately 1 to 2 mm per month. Caution should be taken to avoid moving the root too rapidly. In addition, the length of root in bone may affect the rate of movement and amount of applied force necessary. In a situation of severe bone loss, the remaining root in bone may be minimal (providing less resistance) and may move faster.
Reference:
Hinds K. Alveolar ridge development with forced eruption and distraction of retained natural dentition. Oral Maxillofacial Surg Clin N Am 16 (2004) p.76 - 78.
Mantzikos T, Shamus I. Forced eruption and implant site development: an osteophysiologic response. Am J Orthod Dentofacial Orthop 1999; 115(5):583ñ91.
When performing a ridge splitting technique to expand the edentulous ridge for insertion of an interpositional bone graft prior to implant placement, what is the preferred preoperative minimum ridge width? A. 1 mm B. 2 mm C. 3 mm D. 4 mm
Answer: C
Rationale:
The ridge splitting technique is used to expand the edentulous ridge for implant placement or insertion of an interpositional bone graft. This technique is only suitable for enhancing ridge width. There must be adequate available bone height for implant placement, and no vertical bone defect should be present. Although skilled surgeons may be able to expand very thin ridges, a minimum width of 3.0 mm is preferred. Splitting ridges narrower than this is technique sensitive and can result in bone fractures and resorption.
Reference:
Misch C. Implant site development using ridge splitting techniques. Oral Maxillofacial Surg Clin N Am (2004) p.65.
Fonseca, et al. Oral and Maxillofacial Surgery: Reconstructive and Implant Surgery: (Vol 7). Pages 219-221.
Which radiographic finding is most highly associated with inferior alveolar nerve exposure during surgical removal of mandibular third molars?
A. Darkening of the third molar tooth root
B. Narrowing of the third molar tooth root
C. Deflection of the third molar roots
D. Diversion of the inferior alveolar canal
Answer: A
Rationale:
IAN exposure is associated with increased incidence of IAN injury1. The radiographic finding linked with the most relative risk is darkening of the third molar tooth root 2. All other answers are associated with IAN exposure, but to a lesser amount.
Reference:
Valmaseda-Castellon E, Berini-Aytes L, Gay-Escoda C. Inferior alveolar nerve damage after lower third molar surgical extraction: a prospective study of 1117 surgical extractions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001; 92:377-383.
Sedaghatfar M, August MA, Dodson TB. Panoramic radiographic findings as predictors of inferior alveolar nerve exposure following third molar extraction. J Oral Maxillofac Surg. 2005; 63:3-7.
What is the frequency with which the lingual nerve runs superior to the lingual crest of the mandible? A. < 5% B. 10% C. 30% D. 50%
Answer: B
Rationale:
In a clinical study utilizing magnetic resonance imaging of the mandibles of normal human subjects, the lingual nerve was found to be on average 2.8mm inferior to the lingual crest and 2.5mm medial to the lingual plate. In 10% of the group, the lingual nerve was above the lingual crest and 25% were in direct contact to the lingual plate.
Reference:
Behnia H et al, An anatomic study of the lingual nerve in the third molar region.J Oral Maxillofacial Surg, 2000. 58:649.
Miloro M et al, Assessment of the lingual nerve in the third molar region using magnetic resonance imaging. J Oral Maxillofacial Surg, 1997. 55:134.
What is the most frequent postoperative complication of third molar extraction? A. Localized alveolar osteitis B. Subperiosteal abscess C. Inferior alveolar nerve injury D. Lingual nerve injury
Answer: A
Rationale:
In a prospective study involving 63 surgeons, 3,760 patients, and 8,333 third molars; it was found that the incidence of localized alveolar osteitis was 12% in mandibular molars. Other complication rates were: infection 1%, IAN injury 1.1-1.7%, Lingual nerve injury 0.3%.
Reference:
Haug, R, et al. The American Association of Oral and Maxillofacial Surgeons Age-Related Third Molar Study. JOMS 63:1106-1114, 2005
Dentoalveolar Surgery in Peterson’s Principles of Oral and Maxillofacial Surgery, Miloro, M. et al., Editors, Second Edition, BC Decker Inc, 2004, pp. 151.
While attempting to extract an impacted tooth #16, the tooth is suddenly displaced, and is no
longer visible or palpable. The patient now has limited mandibular opening. What is the most likely position of tooth #16?
A. In the maxillary sinus
B. In the buccal space
C. In the body of the zygoma
D. In the infratemporal space
Answer: D
Rationale:
Upper third molars can be displaced distally into the infratemporal space if excessive distal elevation is used without placement of retraction distal to the tooth. In this particular case, the new finding of restricted opening gives a clue that the tooth is not in the maxillary sinus, but most probably impinging on the coronoid process, and thus is in the infratemporal fossa.
Reference:
Dentoalveolar Surgery in Peterson’s Principles of Oral and Maxillofacial Surgery, Miloro, M. et al., Editors, Second Edition, BC Decker Inc, 2004, pp. 152.
Fonseca, et al. Oral and Maxillofacial Surgery: Anesthesia/Dentoalveolar Surgery/Office Management. (Vol 1). W.B. Saunders Company. Philadelphia. 2000. p426-427.
The posterior extension of an incision designed for removal of an impacted mandibular third molar is extended laterally because:
A. this design places the incision in keratinized tissue.
B. this design avoids injury to the buccal artery.
C. this design avoids injury to the lingual nerve.
D. this design reduces postoperative trismus.
Answer: C
Rationale:
The incision design for removal of impacted third molar flares laterally to avoid possible injury to the lingual nerve. The mandibular ramus flares laterally and the lingual nerve extends above the lingual crest 10% of the time.
Reference:
Ness GM, Peterson LJ. Impacted Teeth, p. 144. In Miloro M ed. Oral and Maxillofacial Surgery, vol. 1, BC Becker, 2004.
Miloro M, Halkias LE, Slone HW, Chakeres DW. Assessment of the lingual nerve in the third molar region using magnetic resonance imaging. J Oral Maxillofac Surg 1997;52:134-7.
The best approach for surgical exposure of an impacted tooth for orthodontic bracketing is:
A. complete exposure of the CEJ.
B. partial exposure of the crown and avoiding exposure of the CEJ.
C. complete exposure of the CEJ and 1 mm of surrounding alveolar bone.
D exposure of the crown until the greatest diameter of the crown is revealed regardless of the CEJ.
Answer: B
Rationale:
The surgical exposure of an impacted tooth should be carried out conservatively so that only enough bone and soft tissue is removed to place on orthodontic bracket. Damaging effects to the periodontium have been shown to be more frequent with exposure of the CEJ.
Reference:
Zeitler DL. Management of Impacted Teeth other than Third Molars, pp.133-134. In Miloro M ed. Oral and Maxillofacial Surgery, Vol. 1, BC Becker, 2004.
Kohavi D, Becker A, Silverman Y. Surgical exposure, orthodontic movement, and final tooth position as factors in periodontal breakdown of treated palatally impacted canines. Am J Orthod 1984; 85:72-77.
Bleeding encountered during exploration for this displaced, previously impacted, maxillary third molar would most likely emanate from the:
(picture of maxillary third molar in infra temporal fossa)
A. pterygoid venous plexus.
B. sphenopalatine artery.
C. descending palatine artery.
D. masseteric artery.
Answer: A
Rationale:
This scan depicts a tooth displaced into the infratemporal fossa. Maxillary third molars that are superiorly positioned may have only a thin layer of bone separating them from the infratemporal space. Venous bleeding from the pterygoid plexus of veins often makes visualization of the tooth difficult.
Reference:
Bouloux GF et al. Complications of Third Molar Surgery. Oral and Maxillofacial Surg Clin N Am 19 (2007), p. 122.
American Board of Oral and Maxillofacial Surgery
86
2008 Oral and Maxillofacial Surgery Self Assessment Tool (OMSSAT)
Pogrel M. Complications of Third Molar Surgery. Oral and Maxillofacial Surg Clin N Am 1990; 2:441.
The best time to provide intravenous preoperative antibiotic therapy prior to removal of impacted third molars associated with pericoronal infection is: A. immediately prior to surgery. B. 0.5-2 hours prior to surgery. C. 3-4 hours prior to surgery. D. 6 hours prior to surgery.
Answer: B
Rationale:
Prophylactic antibiotic therapy for asymptomatic impacted third molars in healthy patients is not indicated. For the compromised patient or one who is actively infected, antibiotic administration should be timed so that incision is performed at the peak systemic concentration.
Reference:
Mehrabi M, Allen JM, Roser SM.. Therapeutic Agents in Perioperative Third Molar Surgical Procedures. Oral Maxillofacial Surg Clin N Am 19(2007), p. 71.
Woods RK, Dellinger EP. Current guidelines for antibiotic prophylaxis of surgical wounds. Am Fam Physician 1998; 57 (11):2731-40.
When compared to areas grafted with palatal autografts, areas grafted with acellular dermal matrix allografts demonstrate which of the following qualities?
A. Less graft shrinkage and greater amounts of keratinized tissue
B. More graft shrinkage and greater amounts of keratinized tissue
C. Less graft shrinkage and lesser amounts of keratinized tissue
D. More graft shrinkage and lesser amounts of keratinized tissue
Answer: D
Rationale:
Acellular dermal matrix grafts act as a biologically compatible framework into which fibroblasts and epithelial cells can migrate and adhere, thus repopulating and incorporating the cells into the material. These migrating tissues replace the dermal matrix, causing increased graft shrinkage and ultimately resulting in lesser amounts of keratinized tissue at the recipient site.
Reference:
Yan JJ. Tsai AY. Wong MY. Hou LT. Int J Periodontics Restorative Dent. 2006 June; 26(3):287-92
McGuire MK. Nunn ME. Evaluation of the safety and efficacy of periodontal applications of a living tissue-engineered human fibroblast-derived dermal substitute. I. Comparison to the gingival autograft: a randomized controlled pilot study. Journal of Periodontology. 76(6):867-80, 2005 Jun.
Where keratinized gingival tissue exists, the best surgical option to thicken tissue around an implant to minimize facial metal show:
A. laterally repositioned flap.
B. semilunar flap.
C. free gingival graft.
D. subepithelial connective tissue graft.
Answer: D
Rationale:
There are several indications for the use of the subepithelial connective tissue graft and dental implant sites. Thickening gingiva to eliminate metal show from the underlying dental implant is one of these indications. The subepithelial connective tissue graft can thicken the gingiva one to 3 mm, depending on the thickness of the graft and contracture/shrinkage of the graft with healing.
Reference:
Block M S et al, Atlas of the Oral and Maxillofacial Surgery Clinics of North America. Soft Tissue Esthetic Procedures for Teeth Implants, Subepithelial Connective Tissue Grafting with Dental Implants. Pages 95-107, Volume Seven, Number Two, WB Saunders, 1999.
Block M S et al, Atlas of the Oral and Maxillofacial Surgery Clinics of North America. Soft Tissue Esthetic Procedures for Teeth Implants, A Subepithelial Connective Tissue Graft Procedure for Optimum Root Coverage. Pages 11-28, Volume Seven, Number Two, WB Saunders, 1999.
The biologic width refers to the distance between the:
A. gingival margin and the crestal bone.
B. base of the sulcus and the alveolar crest.
C. gingival margin and the junctional epithelium.
D. base of the sulcus and the cementoenamel junction.
Answer: B
Rationale:
The biologic width is defined as the distance from the base of the sulcus to the crest of the alveolar ridge. Accurate sulcus depth can be problematic to measure with implants since there is no direct connective tissue fiber insertion into the implant surface; so in theory a periodontal probe (especially of excessive pressure is used) can pass through the top of the implant epithelial attachment (the bottom of the sulcus) to the top of the alveolar ridge crest. Biologic width (usually at least 2mm) is maintained between any microgap in the fixture/abutment interface.
Reference:
Misch, CE, Dental Implant Prosthetics, pages 74-75, Mosby, Inc. 2005.
Fonseca, R J et al, Oral and Maxillofacial Surgery Volume Seven, Soft Tissue Considerations, page 341, WB Saunders 2000.
For a subantral osseous augmentation, non-resorbable HA is added to autogenous bone in order to:
A. add bulk to the graft.
B. improve initial implant stability. C. decrease infection rate.
D. improve osteogenesis.
Answer: A
Rationale:
When mixed to a 1:1 ratio with an allograft or autograft, nonresorbable hydroxyapatite helps compensate for the nature loss of bone volume that is seen with the grafts alone. It is also stable in its volume independently and therefore acts as a latticework providing structural support.
Reference:
Babbush, CA, Dental Implants: The Art and Science, WB Saunders, 2001, pp 158-9 Block, MS: Treatment of the single tooth extraction site, Oral Maxillofacial Surg Clin N Am 16 (2004) 41ñ63
Local contraindications to a four-millimeter diameter posterior single tooth implant include:
A. an adjacent tooth that requires a crown.
B. mesiodistal bone width <7mm.
Answer: B
Rationale:
Contraindications to implant placement in this situation include inadequate bone volume of <7mm in the mesiodistal direction. Also, more than one adjacent tooth of a moderate to advanced mobility is considered unacceptable. Both adjacent teeth requiring crowns is a relative indication for a fixed partial denture restoration (influenced by the long-term prognosis of the adjacent tooth or teeth.)
Reference:
Misch, CE, Dental Implant Prosthetics, Mosby, 2005, pp 354-5
Manual of Dental Implants: David P. Sarment, D.D. S., M.S., page 14
Fonseca, et al. Oral and Maxillofacial Surgery: Reconstructive and Implant Surgery: (Vol 7). Pages 211-242.
Which of the following is a limitation of the palatal connective tissue graft technique?
A. High incidence of poor healing
B. Dependence on smooth palate donor site
C. Graft availability is dependent on donor site thickness
D. High incidence of neurovascular injury
Answer: C
Rationale:
Connective tissue grafting extremely useful in that is does not depend upon a smooth palate and heals very well. The incidence of neurovascular injury is also very low if harvested in the classic manner (anterior to the maxillary first molar.) Depending upon the thickness of a particular patient’s tissue, the amount of graft available may be minimal and therefore some patients may require secondary grafting several months later.
Reference:
Sclar A, Alpha Omegan, Volume 93, number3, Aug/Sept 2000, pg 38-46.
Fonseca, et al. Oral and Maxillofacial Surgery: Reconstruction and Implant Surgery. (Vol 7). WB Saunders Company. Philadelphia. 2000, pp 335-8.
Which of the following is considered the least beneficial transport medium in the management of avulsed permanent teeth? A. Milk B. Saliva C. Hankís solution D. Blood
Answer: D
Rationale:
Acceptable transport media for avulsed permanent teeth include Hank’s balanced salt solution, milk, saliva (vestibule), saline, and water (if none of the above is available). Blood is not an acceptable form of transport media according to the recommended guidelines of the American Association of Endodontists since it does not replenish PDL cellular metabolites. Hank’s solution is a balanced salt solution with a physiologic pH.
Reference:
Recommended Guidelines of the American Association of Endodontists
Peterson’s Principles of Oral and Maxillofacial Surgery Vol 1; Management of Alveolar and Dental fractures, BC Decker 2004
Which of the following is contraindicated true regarding replantation of avulsed teeth?
A. Primary teeth can be replanted within 1-2 hours following avulsion
B. Ankylosis following replantation of teeth is a rare complication
C. Avulsed teeth should be followed for at least 5 years to determine outcome of teeth
D. Rigid splinting is recommended in most cases following replantation of avulsed teeth
Answer: C
Rationale:
Primary teeth should not be replanted following avulsive injuries. Space maintenance is however recommended in these situations. Replantation of avulsed primary teeth may cause risk of pulp necrosis and interference with development of succedaneous teeth.
Reference:
Recommended Guidelines of the American Association of Endodontists
Fonseca Oral and Maxillofacial Trauma Vol 1; Diagnosis and Management of Dentoalveolar Injuries p 427-478, Elsevier Saunders 2005
How long should subluxed permanent teeth be treated with a flexible splint? A. 1-2 weeks B. 3-4 weeks C. 5-6 weeks D. 7-8 weeks
Answer: A
Rationale:
A flexible splint (acid-etched) should be used for 7 to 10 days on subluxed permanent teeth. A short period of time is preferred to a longer period of time in order to prevent future complications such as ankylosis. Subluxation is the defined as movement of the teeth in any direction while concussion is the physiologic/pathologic sequela of a subluxation that affects the pulpal tissue and surround PDL.
Reference:
Kaban LB, et. al. Pediatric Oral and Maxillofacial Surgery. Ch. 25 Facial Trauma II: Dentoalveolar Injuries and Mandibular Fractures, Baumann A, et. al. p.446.
Daniels A, Backland L: Traumatic Dental Injuries: Current Treatment Concepts. JADA 129 (10):1401-14 1998OK
Which of the following is true regarding avulsed teeth?
A. Permanent teeth with apical foramina less than 1 mm diameter have a better prognosis than those with greater an 1 mm diameter
B. Avulsed permanent teeth stored in Hankís solution have a more guarded prognosis than those stored in saline
C. Replanted permanent teeth should be treated with a rigid splint
D. Avulsed primary teeth are not replanted
Answer: D
Rationale:
Permanent teeth with open apices greater than 1 mm diameter have a much better prognosis than those with closed apices since there is increased potential for reestablishment of pulpal circulation. Hank’s solution is considered the ideal physiologic medium for avulsed teeth.
It contains sodium chloride, calcium chloride, potassium chloride and magnesium sulfate. Avulsed primary teeth are never replanted since they have poor prognosis and may cause ankylosis of the permanent tooth.
Reference:
Fonseca. Oral and Maxillofacial Trauma. Diagnosis and management of dentoalveolar injuries, p 427-478, 2005.
OMS Reference Guide, Trauma/Emergencies, p 149-182, 2007.
Which type of injury to teeth carries the highest degree of pulpal necrosis? A. Extrusion B. Intrusion C. Lateral luxation D. Lingual luxation
Answer: B
Rationale:
Intrusive type injuries to teeth will cause greater compression and inflammatory injury of the periapical tissues and therefore greater compromise of the pulpal vasculature and blood flow causing an incidence of 65-90% pulpal necrosis. Extrusion can cause pulpal necrosis in 64% of the time; Luxations account for the lowest incident of pulpal necrosis.
Reference:
Fonseca. Oral and Maxillofacial Trauma. Diagnosis and management of dentoalveolar injuries, p 427-478, 2005.
Peterson. Principles of Oral and Maxillofacial Surgery. Management of alveolar and dental fractures, p 383-400, 2006.
Andreasen JO. Luxation of permanent teeth due to trauma: a clinical and radiographic follow-up study of 189 injured teeth. Scan J Dent Res 1970, 78: 273.