Orthognathic surgery

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How many primary teeth do children have?: 20
Which set of teeth (mandibular or maxillary) erupts first?: Mandibular by 1 -4 months
When do primary (deciduous)incisors typically erupt?: 6 months
When do primary (deciduous)first molars typically erupt?: 12 months
When do primary (deciduous)canines typically erupt?: 16 months
When do second molars typically erupt?: 20 months
When do secondary (or permanent) incisors erupt?: 6 - 9 years
When do secondary (or permanent) canines erupt?: 9-10 years
When do secondary (or permanent) first premolars erupt?: 10-12 years
When do secondary (or permanent) second premolars erupt?: 11-12 years
When do secondary (or permanent) first molars erupt?: 6-7 years
What are usually the first adult teeth to erupt?: First molars
When do secondary (or permanent) second molars erupt?: 11-13 years
When do secondary (or permanent) 3rd molars erupt?: 17-21 years
What is overbite?: the amount of vertical overlap of apices of teeth
What is overjet?: the amount of horizontal overlap of apices of teeth
What is proclination?: the crown of the tooth is labially angulated
What is retroclination?: The crown is inclined toward the tongue
Describe class I occlusion: normal - the mesial buccal cusp of the maxillary 1st molar lies in the buccal groove of the mandibular 1st molar
Describe class II malocclusion.: mesial buccal cusp of the 1st maxillary molar lies mesial to the buccal groove of the mandibular 1st molar
describe class III malocclusion: mesial buccal cusp of teh 1st maxillry molar lies distal to the buccal groove of the mandibular 1st molar
What is an open bite?: part of the dentition does not make contact
What is a deep bite?: a pronounced overbite
What is a crossbite?: horizontal malalignment of the teeth, especially the molars. Can be buccal or lingual
What is incisor show?: the amount of vertical show of the maxillary central incisor in repose
What is ideal incisor show?: 2-4 mm in women and 0-2 mm in men
What is centric occlusion?: Occlusion resulting in the maximal intercuspation of the teeth.
What is centric relation?: The position of the mandible relative to the maxilla in which the condyles are fully seated in the temporomandibular joint?
What is midfacial height?: distance from the soft tissue glabella to the alar base plane
What is lower facial height?: distance from the alar base plane to the soft tissue menton
What is the A point?: the most posterior point on the anterior maxilla
What is the B point?: the most posterior point on the anterior mandible
What is the sella?: The bony housing of the pituitary
What is the nasion?: the most posterior point of the nasal radix
What is vertical maxillary excess (long-face syndrome)?: Incisor show >4mm,narrow alar base, an obtuse nasolabial angle, an anterior open bite, mentalis strain, retruded chin, flattened midface, class II malocclusion, decreased SNA and SNB angles and increased ANB angle
Chronic open mouth breathing is associated with which pathologic orthognathic condition?: Vertical maxillary excess
What are the surgical goals of correction of vertical maxillary excess?: Class I occlusion and reduction of maxillary height(Assessment of the maxillary lip-tooth relationship is the most accurate study in determining the final vertical position of the maxilla)
What is the treatment of vertical maxillary excess?: LeFort I osteotomy with maxillary impaction, may need mandibular advancement and/or genioplasty
What are complications of surgical correction of vertical maxillary excess?: relapse, tooth damage, gingival anesthesia, bleeding
What are the features of vertical maxillary deficiency?: little or no incisor show, class II malocclusion, increased SNA and SNB angles
What are surgical goals of correction of vertical maxillary deficiency?: class I occlusion and 2-3 mm of incisor show
What is treatment of vertical maxillary deficiency?: LeFortI downfracture( with bone grafting for > 5mm lengthing). Mandibular surgery is also needed for significant class II malocclusion
What are the features of maxillary retrusion?: flattened or "dished-in" face, malar hypoplasia, depressed nasal tip and alar base, short upper lip, class III malocclusion with or without an anterior open bite
What are the surgical goals of maxillary retrusion?: class I occlusion, maxillary advancement
What are the features of mandibular retrusion?: posterior recesion of the lower facial third, lower lip eversion, increased ANB angle, decreased SNB angle
What are the surgical goals of mandibular retrusion correction?: class I occlusion, restoration of facial balance between midface and lower face, correction of a chin projection deficit
What are the complications associated with surgical correction of mandibular retrusion: relapse, limited mouth opening, menal nerve dysfunction (usually a neuropraxic injury that resolves within 6 months)
What are the features of mandibular prognathism?: prominence of the mandible, midfacial retrusion, mandibualr overrotation, class III malocclusion,increased SNB angle
What are the surgical goals of mandibular prognathism correction?: class I occlusion, balance of the profiles of the midface and lower face.
What is the surgical treatment of mandibular prognathism?: sagittal split ramus osteotomy or intraoral vertical ramus osteotomy for setbacks >1cm. If necessary, genioplasty
What is surgical relapse?: loss of plate fixation (malunion)
What is dental relapse?: correct jaw repositioning with malpositioned teeth, causing the jaws to move back to their presurgical state (the orthodontic "setup" was not optimal)
What is condylar relapse?: resorption of bone at the TMJ results in changes in occlusion, leading to relapse
What is soft tissue relapse?: recoil forces from the soft tissues can cause changes in bone morphology, leading to relapse
What is the condylar measurments?: 15 to 20 mm medial to lateral and 8 to 10 mm anteroposteriorly
What is the lining of the TMJ?: fibrocartilage
what type of disk is found in the TMJ?: biconcave disk composed of fibrous tissue(needs radiograph with contrast to visualize
what structure is the disk anchored to in the TMJ?: the superior head of the lateral pterygoid musle
Describe the motion of the TMJ.: first 20 to 25 mmthe this a hinge motionvia the inferior space, The last 15 to 20 mm is a slinding motion via the superior space
What are the 3 cardinal signs of TMJ dysfuction?: facial pain, TMJ click, and limited jaw opening
what is the usual cause of TMJ early morning facial pain?: bruxism
what is the usual cause of TMJ late in the day facial pain?: intracapsular origin
is a solitary click of the TMJ concerning?: no
is a reciprocal click of the TMJ concerning?: yes, it is pathologic
what are the causes of limited jaw opening?: nonreduced anterior disk displacemet, ankylosis, and coronoid impingement
what causes tinnitus?: spams of the tensor tympani muscle
what imaging studied do you order if you suspect TMJ pathology?: MRI
what imaging studied do you order if you suspect bony TMJ pathology?: CT
what are 3 major causes of myofascial pain?: Bruxism > anxiety and occlusal abnormalities
what is the treatment of myofascial pain?: splint, NSAIDs, biofeedback, soft diet
what is the operative treatment for internal derangement of the TMJ?: lavage, arthroscopy, arthrotomy
in the operative treatment for internal derangement of the TMJ, what is included in an arthrtomy?: disk repostioning, osteophte shaving, od diskectomyand temporalis flap
what are the radiographic finding in myofascial pain dysfunction?: no abnormalities seen
what are the clinial manifestation of myofascial pain dysfunction?: preauricular pain, occasional joint clicking, restricted jaw opening, and tenderness of the masticatory muscles
what is the risk of permanent damage to the inferior alveolar nerve during sagittal split osteotomy?: 5 to 10%
what is the treatment for mandibular prognathism?: sagittal split osteotomy (mandibular setback) and maxillary advancement
what is a late complication of open bite?: Progressive condylar resorption
what are the clinical manifestations found in Progressive condylar resorption?: condylar shortening, a decrease in posterior facial height, clockwise rotation of the mandible, and Angle class II malocclusion. Slow progressive posterior movement of the point B on serial cephalometric analysis
what is the most likely cause of immediate postoperative open bite?: improper seating of the condyles in the glenoid fossae during surgery
what does the alar cinch suture help?: decrease the degree of widening of the alar base
what is the most unstable orthognathic movement?: Transverse widening of the maxilla
how does Mandibular deficiency present?: true retrognathia
what is the treatment of chose for patients younger than age 2 years with mandibular hypoplasia and tongue-based airway obstruction?: mandibular distraction osteogenesis
what is the treatment of chose for patients younger than age 2 years with mandibular hypoplasia without tongue-based airway obstruction?: none,operative correction of malocclusion is inappropriate due to potential injury of the inferior alveolar nerve
what is the pathology found in acute open lock deformity?: the condyle slips into a position anterior to the articular eminence and subsequently cannot return to the normal position
what is the initial treatment for acute open lock deformity?: manual reduction with IV sedation in the ER
in patients with acute lock jaw deformity, what is the most appropriate next step after failed manual reduction?: administration of succinylcholine in the operating room with reduction
Patients undergoing Le Fort II midface advancement are at increased risk for injury of what structures?: the ethmoid area and the lacrimal system
what is the most common complication of sagittal split osteotomy: loss of lower lip sensibility
Beyond what distance of bony movement of the craniofacial skeleton is bone grafting recommended: beyond 5 mm
what happens if you perfrom aLe Fort I segment in excess of 5 mm without bone graft?: most likely it will relapse
How do you prevent excess shortening of the upper lip when doing a LeFort I osteotomy?: V-Y advancement during closure
when is an alloplastic chin augmentation indicated?: in patients with minimal sagittal deficiency of the lower face, a shallow labiomental fold, and symmetry and normal height of the lower face
what type of occlusion in common in patients with cleft palates?: class III malocclusion
when do you preform a jumping genioplasty?: to correct both horizontal (sagittal) deficiency and vertical excess
what is the definition of a gummy smile?: greater than 4 mm of incisal show with the lips in repose and greater than 2 mm of gingival show with animation

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Number of cards 96