Orthodontic Management of Orthognathic cases

1. 1 Orthodontic Orthodontic M Management of of Orthognathic cases Orthognathic cases anagement Prepared by: Prepared by: Dr. Mohammed Alruby Dr. Mohammed Alruby Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

2. 2 Introduction History Classification of maxillary fractured Lefort Special consideration for orthognathic surgery -Patient selection: Age of patient Assessment of patient motivation and expectation The nature and severity of skeletal dysplasia Systemic evaluation -Patient evaluation: (1)General evaluation (2)Esthetic evaluation (3)Functional evaluation (4)Radiographic evaluation a-Ceph --- PA Lateral: ------ soft and hard b-Panorama c-CBCT d-Periapical Protocol for basic orthognathic record collection Treatment planning -Time of treatment -Objective of orthodontic treatment Pre-surgical Post-surgical -Sequence of treatment: Pre-surgical phase Orthodontic in theatre Post-surgical treatment Surgery without orthodontics Stability and clinical success complications Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

3. 3 Introduction: Sever skeletal dysplasia may be behind the scope of orthodontic treatment alone, particularly in adults. In such cases a combined orthodontic –orthognathic approach is a team work in which oral surgeon, maxillofacial surgeon and orthodontist are the primary members Because of many adult patients undergoing orthognathic surgery may require an additional dental, medical, and physiological preparation There are other members team like: -Occlusion specialist -ENT -Periodontist -Orthodontist -Physical therapist -Pedodontist -Plastic surgeon -Psychiatrist: All members in this team should work together in close association a co-operation during all phases of treatment History: Von Langenback 1859, the first described the removal of nasopharyngeal polyp Cheever 1867, first American report maxillary osteotomy for treatment of complete nasal obstruction Lefort 1901, published his classic description of the natural planes of maxillary fracture Hullihen 1949, correct a patient with anterior open bite and mandibular dento-alveolar protrusion with an intra-oral osteotomy Obwegeser 1965, suggested complete mobilization of maxilla Drommer and Luhr 1980 – 1981: rigid fixation of maxillary osteotomies Classification of maxillary fracture by Lefort: 1-Lefort I: transverse fracture: Occurs transverse through maxilla above the level of the teeth, the fractured segment contains: -Alveolar process -Portion of wall of maxillary sinus -Lower portion of pterygoid process of sphenoid bone -Palate 2-Lefort II: pyramidal fracture: Involve nasal bones and frontal process of maxilla Pass laterally through lacrimal bone then pass through zygomatico maxillary suture, then backward along the lateral wall of maxilla through the pterygoid plate to pterygo-maxillary fossa 3-Lefort III: craniofacial dysfunction: Separate the facial bone from their cranial attachment The fracture occurs through: -Zygomatico frontal -Maxillary frontal -Naso-frontal -Floor of orbit Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

4. 4 -sphenoid bone -ethmoid bone Consideration for orthognathic management I- Patient selection: a-Age of patient: = as a general rule, adult patients should be referred to orthognathic surgery unless other consideration force us to early intervention: -children with severe facial disfigurement causing psychic trauma -adolescent with severe facial disfigurement and unfavorable growth pattern = the patient should be informed that other surgery may be required when growth is over b-Assessment of patient motivation and expectation: = careful assessment of these items is the key of success in surgical orthodontics because the pot operative dissatisfaction is a common problem that is not necessarily result from fault of operator but may be due to failure of patient communication = important factors in patient communications: -evaluation of patient motivation: internal motivation are better candidates than external -evaluation of patient psychology: to determine psychology – bad risk patient -evaluation of patient perception: to assess and improve patient education -evaluation of patient expectation: to determine unrealistic patient -finally inform before perform: the patient should be informing about the nature, cost and benefits of surgery. The benefits / risk ratio should be analyzed, so that the patient decision will be an informed consent = external motivates, unrealistic and psychologically bad risk, if one cannot modify their behavior, they should be contraindicated for surgery c-The nature and severity of skeletal dysplasia: = as a general rule, the malocclusion should be beyond the scope of orthodontic camouflage = patient with sever skeletal dysplasia represent no problem in the treatment decision because they are clear- cut surgical candidates At contrast, patients with moderate discrepancy (border line) represent a great problem d-Systemic evaluation: Proper evaluation of the patient general health is an important factor in patient selection, special attention should give for cardiovascular, endocrinal, allergic, pulmonary, neurologic, hematologic, which complicate general anesthesia. For serious complication surgery is contraindicated Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

5. 5 N: B: Dilemma of border line cases: One of the most difficult decisions facing orthodontist is whether the patient border line skeletal discrepancy can be successfully treated with orthodontist alone, the decision should be made from the beginning because the orthodontic preparation for surgery is completely differ from orthodontic treatment for camouflage as extraction and type of tooth movements = helpful guidelines: -Arch length -Vertical skeletal dysplasia -Transverse skeletal dysplasia -Soft tissue relationship Arch length deficiency amount: Ideally, space deficiency more than 4 -6mm with moderate skeletal discrepancy is an indication for orthognathic surgery If such case is treated orthodontically, most of extraction space will be directed to relief crowding, levelling, little space for camouflaging the underlying skeletal pattern The associated vertical skeletal dysplasia: Patient associated with excessive vertical proportion and skeletal open bite are better candidates for surgery, because the orthodontic mechanics tends to extrude posterior teeth that worse the case Patient associated with reduced skeletal proportion and deep bite can be treated with orthodontic camouflage if one can overcome the problem relapse in such patients The associated transverse skeletal dysplasia: Transverse skeletal dysplasia in adults are indication for surgery because RME is not benefit Soft tissue relationship: If orthodontic camouflage could not result in satisfactory facial esthetics and effective lip seal to stabilize the corrected occlusion, then the orthognathic surgery is the best choice II- Patient evaluation: (1)- General evaluation: a-Medical evaluation: Special attention is given to cardiovascular, pulmonary, neurologic, endocrine problem, hematologic, allergic, may complicate general anesthesia, or surgery, direct discussion with patient physician is recommended b-Psychological evaluation: Psychological makeup is important because, some patient express dissatisfaction with their results despite these results are favorable, this may be due to: -Unrealistic patient expectation regarding to result of treatment -Failure of clinician to inform the patient for esthetic results = patient with external motivation usually show dissatisfaction and must be with conjunction with psychiatrist but patient with internal desire to improve esthetic is the best candidate Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

6. 6 c-Chief complaint: This allows a problem oriented approach d-Dental evaluation: To allow accurate estimation of the patient’s histologic and psychologic response. All previous dental procedure need to be reviewed Patient who cannot perform good home care is bad candidates, caries elimination and extraction of hopeless case are carried out Inlay, crown, partial denture is post pound after treatment (implant to enhance anchorage should place). Acute periodontal disease must be treated first Dental analysis: The dental analysis should include 5 distinct characters: 1-Horizontal tooth position: Horizontal position of the tooth should be considered in relation to the basal bone to determine the type of tooth movement required for accurate placement of the dental arches at time of surgery Some cephalometric analysis helps in determining the accurate horizontal tooth position Inappropriate horizontal incisor position may result in insufficient post treatment stability 2-Arch length – tooth size discrepancies: Crowding or spacing must view in the light of preexisting incisor angulation. Diagnostic set up is required to determine: = the actual space requirement, = type of teeth movement = anchorage requirement and method of space creation Relief of crowding depend on the magnitude of discrepancy as: re-approximation, expansion, distalization, or even extraction 3-Vertical tooth position: The depth of curve of spee should be taken into consideration when planning space requirement, and alter whether the overbite should be corrected by intrusion of anterior teeth or extrusion of posterior teeth Flat occlusal plane is a major requirement in pre-surgical phase of orthodontics, because it allow a precise horizontal positioning of the dental arches to class I occlusion at time of surgery without dental interference ==The dental vertical analysis should include: a-Tooth to tip relation: Incisor – stomion distance: normally the upper lip show 2mm from the labial surface of upper incisors. Excessive incisor show and gummy smile may indicate vertical maxillary excess which require anterior maxillary impaction Lower incisor- lower lip relation: normally the lower lip and incisal edges of lower incisors lies on the same horizontal level at rest. Excessive mandibular incisor show may require orthodontic intrusion or even mandibular anterior subapical osteotomy b-Inter-labial gap: = While the patient is fully relaxed and lips in repose, an inter-labial gap up to 4mm may considered normal, increase inter-labial gap may be an indication of lip incompetence which either due to deficient lip length or excessive lower face height Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

7. 7 = cephalometric tracing is helpful in appreciating changes in facial height and inter-labial gap c-Anterior facial height: balance Facial height balance can be measured by the ratio of : UAFH : LAFH N--- ANS: ANS ---- GNth 0.8 : 1.0 Imbalance in facial height is vertical problem that can corrected in adult by combined orthodontic and surgery 4-Midline symmetry: = the selection of treatment midline is based on careful evaluation of facial and apical base midlines -Facial midline: is an imaginary midline bisecting the face into two equal halves. It is easily determined clinically by a variety of landmarks taken in the midline of patient face -Dental midline: maxillary and mandibular midline are defined by the mesial contact to the central incisors of the halfway distance of existing diastema and the frenal attachment -Apical base midline: can be assessed to the midpoint between the roots of central incisors, the projection of these point perpendicular to occlusal plane is used to assess the discrepancy in the apical base, this evaluation occurs in PA cephalometric radiograph N: B: facial, dental, apical base midline, should be coincident 5-Transverse dental analysis: = When dealing with transverse discrepancies, it is important to assess whether the problem is skeletal or dental in nature. = Transverse cast and PA analysis is helpful = When posterior buccal cross bite exists and transverse analysis demonstrated normal bucco- lingual axial inclination of posterior teeth, then the problem skeletal. = If posterior teeth were tipped buccally or lingually then the problem may be dental = In some cases buccal cross bite exist while no apparent dental or skeletal compensation, in such cases it is most likely to be positioned and is commonly associated with class II or III pattern = It is spontaneously improved once the class I occlusion is obtained by surgical repositioning of the jaws N: B: Other general evaluations: Canting of maxillary occlusal plane: A common method of assessing canting of maxillary occlusal plane is by placing a wooden tongue spatula a cross premolars and relating it to the inter-pupillary line Care should be taken to avoid being misled by over-erupted teeth or canine cusps of different lengths, which may tip the spatula in a way that does not accurately reflect the skeletal base History of dentofacial dysmorphology: History should be taken from patient regarding to the development of their dentofacial problems as: a-Congenital anomalies: growth abnormalities, condylar hyperplasia, hemifacial microsomia b-Familial trait c-Acquired anomalies: Traumatic: TMJ trauma before and after cessation of growth Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

8. 8 Pathology: pituitary adenoma d-Racial characteristic: Anterior bi-maxillary protrusion: black African, Zygomatico maxillary hypoplasia It is important to recognize progressive facial dysmorphology as: -Gradual increase in anterior open bite: idiopathic condylar resorption -Progressive late mandibular growth: pituitary adenoma -Progressive mandibular a symmetry: Unilateral condylar hyperplasia Unilateral condylar a symmetry Unilateral condylar resorption Unilateral condylar tumor Hemi mandibular elongation Hemi mandibular hypertrophy Stature and body form: = The patient height and general body shape should be noted early in the assessment = Over weight patient is clearly contraindicated for elective orthognathic surgery, in such cases, the patient may be required to reduce their weight before treatment (body mass index is helpful guide BMI). (2)- Esthetic facial evaluation: {frontal evaluation- bird’s eye view evaluation- worm’s eye view evaluation- profile evaluation} = should be done careful and is in symmetric manner giving special attention to the front of the face which see in mirror = evaluation done with patient seat comfortably which FH plane and inter-pupillary line parallel to the floor = photographs are essential to document the pretreatment esthetics; the minimum record photographs are: -Extra-oral: Frontal face with teeth lightly together and lips in repose Frontal face smile Right and left with teeth lightly together and lips in repose Submental and ¾ oblique view in some cases as deformities in neck or nose (FH plane and inter-pupillary line should be horizontal) (long hair should be placed behind the ears and shoulder) Bird’s eye view Worm’s eye view -Intra-oral: Upper and lower occlusal Frontal right and left with teeth in occlusion Overjet or reversed overjet A-Frontal facial evaluation: 1-Symmetry: While no face is perfectly symmetric, major facial a symmetry should be recorded by relating various facial structure to a fixed reference plane (FHP or midsagittal plane) so we called normal a symmetrical face Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

9. 9 2-Balance: Total facial height (distance from trichion to Gnathion) is clinically divided into thirds Upper 1/3 : trichion to glabella: 30% Middle 1/3 : glabella to subnasal : Lower 1/3 : subnasal to Gnathion: Upper 1/3: tri to N: 30% Middle1/3: N to Sn: 30% Lower 1/3: Sn to Gn: 30% 3-Morphology: Determined by relating the width of any 1/3 to TFH (total facial height) Upper 1/3 width: bi-temporal / TFH: 65% Middle 1/3 width: bi-zygomatic / TFH: 75% Lower 1/3 width: bi-gonial / TFH: 66% 4-Canting of the maxillary occlusal plane: = a common method of assessing canting the maxillary occlusal plane is by placing a wooden tongue spatula cross the premolars and relating it to the inter-pupillary line = care should be taken to avoid misled by over erupting teeth or canine cusps of different lengths, which tip the spatula in a way which does not reflect the skeletal base 5-Vertical mandibular a symmetry: Which is evident in patients with unilateral condylar hypoplasia, which affect the height of the rami: -Downward bowing in lower border -Cant of mandibular occlusal plane that can assessed by using tongue spatula - 6-Transverse proportion: The face can be divided into fifths to allow transverse proportion to be assessed. This important for patient planned to Lefort I advancement or impaction osteotomy. The middle fifth should equal the width of alar base and the inter-canthus distance The width of stomion should equal the inter-iris distance Alar base length = width of inner canthus of eye 7-Evaluate midline symmetry: = facial midline: line passing from forehead through dorsum of the nose and philtrum of upper lip, the facial midline is dropped perpendicular to the inter-pupillary line provided the orbits are level = dental upper midline: evaluated by relating it to the facial midline during rest = lower dental midline: related to upper midline and facial one Any deviation must be noted and measured by mm 8-Ear shape and position: Any abnormal shape or position of ear should be noted during clinical assessment Unilateral abnormalities of the ear shape may be a part of hemi-facial microsomia 9-Sclera show and eye lid shape: The lower eye lid should normally rest at the inferior border of the iris with no sclera on display Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

10. 10 Sclera show in patient with infra-orbital rim deficiency as in cases of class III 10-Upper incisors show: The average tooth display is about 2 -3mm or 1/3 of clinical central incisor crown during rest Normally no lower incisors show and may be occurs due to: -Poor support of lower lip due to AP chin deficiency -Sever mandibular dentoalveolar protrusion -Hypotonic lower lip 11-Transverse mandibular a symmetry: Evaluate the chin point to the facial midline 12-Lip form a symmetry: The shape of vermilion border and symmetry of cuspids bow should assessed The line between the lips (inter-labial line) must be assessed in relation to both vertical and horizontal reference lines Inter-labial clearance: 0 -3mm Commissural width is slight less than IDP B-Bird’s eye view evaluation: Viewing the face from above and allow assessment of: 1-Orbital rim: The view from above helps to assess the anterior posterior position of the supra and infra orbital rims Deficiency of infra orbital rims will usually zygomatico orbital defect and usually a manifestation of mid face deficiency 2-Nasal deviation: Bird’s view allows the dorsum and tip of the nose to be assessed of transverse deviation As from frontal view take facial midline as reference line to evaluate any deviation of nose or chin point 3-Upper dental center line: This view allows evaluation of central dental midline with reference to facial midline same as frontal view 4-Transverse mandibular a symmetry: Bird’s view is essential for assessing the position of chin point relative to facial midline as from frontal view C-Worm’s eye view: Viewing the face from below and allow assessment of: 1-A symmetries of the mandible: Vertical and transverse a symmetry of mandibular inferior border or gonial angles are only fully appreciated from Worm’s eye view -Vertical a symmetry at gonial angle -Medio-lateral shift of the chin is also seen All related to the facial midline 2-A symmetries of alar base: Any a symmetry of alar base to facial line or any deviation of columella ------ related to facial line Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

11. 11 N: B: Submental and neck area: Skin: should be examined for laxity by stretching from below the ears Hyoid bone level: normally it is no more than 20mm. below the mandibular border When it is more anterior and / or inferior position, so isolated soft tissue Cosmetic in the neck will have limited results D-Profile evaluation: = The patient should be seated comfortably with their back in an upright position and ask patient to look in a mirror mounted straight ahead of them or positioning FHP parallel to floor may be place them in an artificial position = NHP more reliable than FHP, in appropriate head positioning can result in a false perception of the anterior posterior jaw relationship = It is important for the all perioral soft tissue to be relaxed to allow accurate evaluation of patient = avoid any tilting of head in any position either right or left, for patient that have condition that produce involuntary tilting such as torticollis (due to shortening of one of the sterno-mastoid muscles) should be accepted that normal posture unlikely to improve as a result of surgery = viewing the face from lateral aspect allow assessment of: -Jaw relationship and facial convexity -Forehead -Nose -Para-nasal region -Upper lip -Lower lip and chin -Lower lip and submental plane angle -Mandibular plane angle 1-Jaw relationship and facial convexity: The left and right sides of head should be examined separately, since characteristic differences will be detected in a symmetric face = examine the convexity of the face: class II cases ----- convex profile = class III cases:--- concave profile, upper lip can mask underlying maxillary deficiency = high angle cases: not common to see bimaxillary protrusion, most likely to see bimaxillary retrusion due to backward and downward position of chin = in case of maxillary deficiency, there is paranasal hollowing 2-Forehead: The position and shape of forehead will remain completely unchanged by orthognathic surgery If frontal bossing is present or forehead is forehead is flat, should be taken in account when assessed the case position 3-Infra-orbital rim: Infra-orbital rim relative to globe of eye and supra orbital ridge assessed for any defect as in maxillary deficiency or part of midface hypoplasia 4-Nose: Shape of nasal dorsum and angle of nasal tip may be affected by maxillary osteotomy as: -In patient with maxillary deficiency who already has a tuned up nasal tip, the Lefort I advancement osteotomy worsen this features -In patient with long facial type and downward nasal tip, there is an improvement of the case and nasal profile by Lefort I impaction osteotomy Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

12. 12 5-Paranasal region: The contour of the skin overlying the area just lateral to the alar base can be seen from the side view Lack of bony support at this region as in case of maxillary deficiency produce depression at this area It is also commonly associated with class II cases with bimaxillary retrusion 6-Upper lip: It is important to assess the form and angle of the upper lip -Assess upper lip to FH -Assess upper lip to nose: nasolabial angle -Assess upper lip to lower lip: normal lip seal or anterior labial gap 0 -3mm In case of retrognathic maxilla or retroclined upper anterior, have retruded position of upper lip In some cases, the lower border of nose (columella) may be turned down that give rise to acute angle, so it is important to relate the upper lip to FH and relate columella also to FHP 7-Lower lip and chin: The curvature of lower lip is dependent mainly on the depth of labiomental fold Reduced lower anterior face height with progenia will produce accentuated labiomental fold Flat lower lip will be associated with retrognathia and increase vertical dimension 8-Lower lip and submental plane angle: The angle of lower lip to submental plane (throat) is important to pleasing facial esthetics and should be close to right angle (110) degree -Neck chin length about 50mm -Neck chin angle is increase in case of upward and forward mandibular rotation as class II but angle is decrease in case of downward and backward rotation as in case of class III 9-Mandibular plane angle: This angle can be assessed by placing ruler along the lower border of mandible and relate to FH, the intersection between these two planes should just behind the back of head where the angle is average -Angle is increased as in case of long face and decrease in case of short face (3)- Functional evaluations: Centric occlusion and centric relation compatibility Tooth attrition and prematurity All muscles should examine for any trigger painful area or insufficient occlusal force during eating All mandibular movement must be evaluated and restored if impaired (normal incisal opening 50mm) Patient examined for TMJ pain, by asking patient to bite over tongue plate at molar and canine and incisors, bite on left side load the right joint and vice versa TMJ must be examined for popping- crepitation or any other signs Examine the case for path of closure. (4)- Radiographic evaluations: A-Cephalometric evaluation: Posterior anterior cephalometric radiograph: commonly used to assess facial symmetries Now it can replace by CBCT because it is 3D imaging Lateral cephalometric radiograph Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

13. 13 Soft tissue profile analysis: Soft tissue profile cephalometric landmark: Tr Trichion: the anterior hairline in the midline. G Glabella: the most anterior point on the oft tissue outline of the brow ridge. N’ Soft tissue nasion: the deepest point on the soft tissue outline below glabella. Prn Pro-nasal: the most anterior point on the outline of the nose. Cm Columella: the most anterior point on the columella of the nose. Sn Sub-nasale: the junction of the upper lip and the columella. A’ Soft tissue A point: the deepest point on the anterior outline of the upper lip below Sn. Ls Labrale superius: the muco-cutaneous junction of the upper lip. Sts Stomion superius: the lowermost point on the vermillion of the upper lip. Sto Stomion: the point of contact, in the midline, between the upper and lower lips, where the lips are competent. Sti Stomion inferius: the uppermost point on the vermillion of the lower lip. Li Labrale inferius: the muco-cutaneous junction of the lower lip. B’ Soft tissue B point: the deepest point on the anterior outline of the lower lip, above Pg’ Pg’ Soft tissue pogonion: the most anterior point on the soft tissue outline of the chin below B’. Me’ Soft tissue menton: the most inferior Summary of soft tissue variables: -Angle of facial convexity -Full soft tissue convexity -Nasolabial angle -Labiomental angle -E-plane esthetic line -H line -Zero degree meridian -Lip chin-submental plane angle -Submental plane neck angle -FH –MP angle -LAFH / TAFH ratio -Upper lip length -Lower lip length Hard tissue cephalometric landmarks Landmark Definition: S Sella: the centre of the sella turcica, determined by inspection. N Nasion: the most anterior point of the frontonasal suture. Or Orbitale: the lowest point on the infraorbital margin.* Po Porion: the uppermost point on the outline of the bony external auditory meatus.* Ar Articulare: the point of intersection between the outlines of the posterior cranial base and the dorsal condyle.* ANS Anterior nasal spine: the tip of the anterior nasal spine. PNS Posterior nasal spine: the tip of the palatine bone in the hard palate. A Point A (sub-spinale): the deepest point on the anterior outline of the maxilla below ANS. B Point B (supramentale): the deepest point on the anterior bony outline of the mandibular symphysis. Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

14. 14 Uia Upper central incisor apex: the apex of the root of the most prominent upper central incisor. Uie Upper central incisor edge: the tip of the crown of the most prominent upper central incisor. Lie Lower incisor edge: the tip of the crown of the most prominent lower central incisor. Lia Lower incisor apex: the apex of the root of the most prominent lower central incisor. UM Upper molar cusp: the tip of the mesiobuccal cusp of the upper first molar. LM Lower molar cusp: the tip of the mesiobuccal cusp of the lower first molar. Pg Pogonion: the most anterior point on the outline of mandibular symphysis below B point. Me Menton: the lowest point on the outline of the mandibular symphysis. Go Gonion: the most inferior and posterior point on the outline of the gonial angle of the mandible. Constructed point, found by bisecting the angle formed by tangents to the posterior and inferior borders of the mandible. Cephalometric reference lines: SN SN line: Line through Sella and Nasion. Represents the anterior cranial base. FP Frankfort Plane: Line through Porion and Orbitale. Also termed “Frankfort horizontal”. Max Maxillary Plane: Line through PNS and ANS. FOP Functional Occlusal Plane: Line through the tips of cusps of the lower first molars and premolars. Mand Mandibular Plane: Line through Go and Me. Anterior posterior jaw relationship: -SNA -SNB -ANB -Bo – Ao -A – N perpendicular -Pg – N perpendicular Vertical jaw relationship: -FMPA -MMA -Sn-Max -UAFH -LAFH -TAFH -LAFH % -UPFH -LPFH -TPFH -LPFH% -Ar- Go -Ar – Go – Me Dentoalveolar dimension: -Ui-Max Or Ui – FH -Li – mand -Ui – Li -LADH Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

15. 15 -UPDH -LPDH Protocol for basic orthognathic record collection: Record type ortho planning planning Pre- Pre- surgery 1 w post- op Post debond 6 1 y post op 2 y post op 3 y post op 4 y post op 5 post op y months post - op - - Sms Clinical photos DPT Lateral ceph CBCT 3D capture 4D capture yes Yes Yes Yes - - Yes Yes - - - - - Yes Yes Yes Yes Yes Yes Yes - - Yes - - - - - - - - - - - Yes Yes Yes Yes - Yes Yes - - - - Yes Yes - - - - - - - - - - Yes Yes yes - - Yes - - - - - Where: Sms: study models Dpt: dental panoramic tomogram CBCT: cone beam computerized tomogram 3D capture: 3D static stereophotogrammetry 4D capture: 4 d capture Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

16. 16 B-Panoramic radiograph: dental panoramic tomogram DPT: Panoramic radiograph allows basic radiographic assessment of teeth and jaws and is required for all patient as part of initial orthognathic assessment to allow diagnosis for the following: 1-Dental and related pathology 2-Mandibular morphology: Evaluate any abnormal morphology, Condylar head and neck Ramus, Anti-gonial region, Body, Inferior dental canal 3-Other features: Features of middle and upper face as: sharp maxillary air sinus relationship of root of posterior teeth depth of maxillary alveolar process C-Periapical radiograph: can be useful in checking the clearance between the roots prior to segmental surgery, however must be remembered that the images are only two dimensional and may not accurate for spatial position of adjacent roots D-Cone beam computerized tomography CBCT: = This radiographic scanning technique provide simultaneous 3D hard and soft tissue imaging of face and skull. = It can apply on the following: 1-Assessment and diagnosis of complex dentofacial problem 2-Three dimensional orthognathic prediction planning 3-Anatomical information: accurate information of structure which is important to know before start surgery: -Position of infraorbital nerve -position and course of inferior dental nerve -position of maxillary sinus -structure of mandibular rami -position of teeth adjacent to site of osteotomy 4-post-surgical evaluation: to allow evaluation of site of osteotomy, position of plates and screw and their proximity of anatomical structure can take after 6 months of surgery Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

17. 17 Treatment planning Treatment planning -Time of treatment -Objective of orthodontic treatment Pre-surgical Post-surgical -Sequence of treatment: a-Pre-surgical phase: Decompensation Vertical tooth movement Transverse tooth movement Perioperative procedure b-Orthodontic in theatre c-Post-surgical treatment: Post-surgical healing Post-surgical tooth movement Retention Surgery without orthodontics Stability and clinical success complications Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

18. 18 I- Timing of treatment: As a general rule, orthognathic surgery should be delayed until growth is fully expressed. In some cases, treatment may be done at an earlier age in children with severe skeletal dysplasia affecting their psychological development == in some cases we can do most of tooth movement prior to surgery because: 1-Movement of the jaws is done more accurately at surgery when the occlusion is more finished 2-Reduce risk of meeting goals 3-Some orthodontic movement must do pre-surgical anyway 4-Patient who show early facial improvement may not want to complete post-surgical orthodontic tooth movement == common technique is to do necessary tooth movement prior surgery and remaining after surgery because: 1-Patient esthetic and jaw function are improved earlier in treatment 2-Post-surgical tooth movement in probably more rapid due to metabolic accelerative phenomenon and increase rate of bone remodeling after surgery II- Objectives of orthodontic treatment: 1-Pre-surgical objectives: Alignment of teeth Levelling the occlusal plane Elimination of dental compensation (decompensation) Produce compatible arch form 2-Post-surgical objectives: Final alignment, levelling and root positioning Correction of the imperfection at the osteotomy cut Finishing and detailing the occlusion III- Sequence of treatment: A-Pre-surgical phase of orthodontics: 1-Pre-surgical orthodontic tooth movement is done mainly on an intra-oral level and to position the tooth in an ideal position within the arch 2-Correct axial inclination of teeth Derotation, eliminate tooth size, arch length discrepancy Eliminate the dental compensation to allow reflect the exact magnitude of the skeletal discrepancy, the following is the factors affect incisors decompensation: Crowding and spacing Previous extraction Soft tissue resistance Mandibular plane angle Magnitude of surgical jaw movement 3-Align the arch or arch segment and make them compatible. Establish the anterior posterior and vertical position of incisors Incisor decompensation in ------ class II div 1 ------- retract lower incisors Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

19. 19 Incisor decompensation in ------ class III ------------- proclined lower incisors Factors affect decompensation: 1-Spacing and crowding: In class II where the lower incisors are proclined so it allows decompensation by extraction. In class III lower incisors proclined to allow decompensation General rule: = each 1mm of crowding in lower anterior need 0.5mm labial movement of teeth = in class II each 1mm space allow 0.5mm lingual movement 2-Previous extraction: Previous extraction gives some problem for complete treatment and decompensation as: in case of lower incisor proclined but put previously extract 1st premolar so retract incisors is difficult and further extraction is not ideal option 3-Soft tissue resistance: Tooth moved with soft tissue as lips and tongue which may affect proclination or retroclination of incisors 4-Magnitude of surgical jaw movement: One of main function for pre-surgical orthodontic is to create overjet or reversed overjet to allow decompensation of incisors and allow jaw correction so: inadequate decompensation ------------------- residual jaw discrepancy over decompensation: -------------------------- surgical over correction 5-Mandibular plane angle: if mandibular plane angle after surgery is outside the normal range this will affect range of incisor angulation to give good stability Method of decompensation: 1-Extraction pattern: Further proclination of incisors and extraction to allow decompensation results As: upper extraction in class III cases And: lower extraction in class II cases Extraction of 1st premolar allows more decompensation than 2nd premolar extraction 2-Bracket prescription: Preadjusted bracket control the amount of torque of incisors which will affect the final decompensation of incisors MBT prescription which has negative MBT prescription which has negative torque in lower anterior and positive torque in upper incisors, this prescription is advantageous in cases of class II to retract lower and allow and maintain large overjet, but this is disadvantageous in cases of class III so individual adaptation by inverting the lower bracket so change the torque from -6 to +6 degree that help to proclined lower incisors in class III 3-Mechanics: a-Intra-arch: as -Transpalatal arch or/ Nance appliance which reinforcement anchorage to prevent any mesial movement of posterior teeth during retraction -TADs: temporary anchorage device to give absolute anchorage which putted between molar and premolar, buccally or palatally to reinforce transpalatal arch b-Inter-arch: By using elastic traction between upper and lower Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

20. 20 Vertical tooth movements: Patient with extreme vertical jaw disproportion will usually developed increase curve of spee In upper arch ---------------- open bite cases In lower arch ---------------- deep bite cases So we need to level the occlusal plane 1-Anterior open bite: Pre-surgically we can do extrusion in posterior teeth but in some cases there is a tendency to relapse so: a-Leave curve of spee unchanged pre-surgically and during surgery, create posterior open bite through post-surgical impaction of maxilla and after surgery do extrusion of molars by orthodontic means b-Align anterior and posterior segment at different level using sectional orthodontic mechanics then level the arch through segmental surgery The two methods depend on severity of curve of spee and amount of risk of segmental surgery 2-Deep bite: With increased curve of spee: a-Maintaining curve of spee so leave the vertical position of lower incisors unchanged, avoid any change in level of arch and by surgery only do (three-point landing) by create lateral open bite and only contact at incisors and terminal molars, then after surgery, orthodontic elastics require to close the posterior open bite b-Level curve of spee orthodontically, but this method may limit increase in lower anterior facial height c-Use sectional mechanics to level anterior and posterior teeth followed by sectional surgery Transverse tooth movement: Patient with transverse arch discrepancy with narrow upper arch as in class III cases, so we must expand the arch to allow some correction using: quad helix appliance or stainless steel arch wire. But this expansion may be limited due to locked segment occlusion or high severity of collapsed arch So: we can deal with expansion post-surgically: a-RME: non surgically assisted recommended only on patient until 15 years of age but beyond this age is not benefit Signs of success: midline diastema, midline separation, low resistance to expansion Benefits of RME: -Less buccal tipping -Greater amount of expansion in compensation to arch wire expansion -Greater stability b-Surgically assisted RME: SARME: For patient beyond age of correction of collapsed arch by RME: so: -Surgical widening of maxilla as single procedure -SARME: by dividing the mid-palatal suture and use normal way for expansion RME N: B: Pre-surgical must decompensate the upper buccal segment by tipping buccal segment palatally or at least prevent further buccal flaring Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

21. 21 Pre-operative procedures: Fixed appliance preparation for surgery: -0.019 x 0.025 ss or 0.021 x 0.025 TMA wire is applied in 0.022 slot, Or 0.017 x 0.025 ss in slot 0.018 -Under tie bracket for both arches to prevent any space to open -If bonded tube is used arch wire should be cinched back behind them -Check appliance for breakage -Wire should put 4 weeks before surgery Hooks attached to wire to allows together rigid fixation or soldered to wire Pre-surgical record: CBCT ---- panorama, ----- lateral cephalometric radiograph, -------Photograph, ---------dental casts on semi-adjustable articulation, ------ periapical radiograph of interdental osteotomy sites B-Orthodontic in theatre: Some patient with segmental procedure need replace sectional arch wire In surgical widening of maxilla, it is beneficial for orthodontist to fit an E arch to assist retention Inter-occlusal or wafer splint used to guide upper and lower teeth in good occlusion and should to be thin not more than 2mm at thinnest part: -Splint stay in place during 3 – 4 weeks during initial healing -For oral hygiene should be trimmed and allow some lateral movement during jaw function C-Post-surgical treatment: Role of orthodontic following jaw surgery is to achieve final pre-panned occlusal and dental esthetic results. Short phase when compared with the pre-surgical phase of treatment 3 distinct phases: 1-Post-surgical healing: Immediate post-operative, patient have certain amount of discomfort and limited mouth opening for few weeks, also take care about (OH) measures For one week after surgery, cheek occlusion after removal of elastic and wafer still in place then the lower teeth should bite freely without any signs of mandibular displacement = if occlusion is good without wafer so we use medium weight inter-maxillary elastics that support jaw correction as class II elastics in case of mandibular advancement until initial healing is complete = protection headgear is useful for case of large advancement of maxillary deficiency (severe class III cases) = approximately after six weeks and the occlusion is still not corrected so use elastic traction = after satisfactory range of motion: -Remove the splint and put working wire to start -Move tooth to final position 2-Post-surgical teeth movement: After initial healing is over start to put the working wire: -0.017 x 0.025 TMA in slot 0.018 or, 0.012 x 0.022 TMA in slot 0.022 --- upper arch -0.016 ss ----- lower arch Elastic should be used until finished with good occlusion: -1st4 weeks’ full time wear and during eating Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

22. 22 -4 weeks’ full time except during eating -4 weeks at night only Should finish treatment during 6 months after surgery, tooth movement occurs in all planes: a-Anterior posterior: Allow good position for all teeth Close all spaces residual in dental arch Use inter-maxillary elastics to complete finishing b-Vertical: In accentuated curve of spee allow correction of three-point landing in buccal segment and occlusal adjustment c-Transverse: Active expansion for upper and lower may be require after surgery because before there is an occlusal locking 3-Retention: Same like other normal case (non-surgical) except if maxilla was expanded transversely -Maintain expansion during finishing -Full time wear in maxilla -If transpalatal arch is placed, it should not be removed during the 1st post-surgical year Bonded retainer not allow to maintain transverse arch dimension Surgery before orthodontics Large proportion of orthognathic patients will undergo both pre and post-surgical orthodontics, there are some patients that carrying surgery 1st and orthodontic afterward is an option Advantages: 1-Facial esthetics: as many patients’ pre-surgical orthodontics may worse the facial esthetic due to decompensation as in case of class III because decompensate of lower incisors accentuate the jaw discrepancy, but when start by surgery improve the facial esthetic will start 1st 2-Resistance to tooth movement: decompensation of incisors before surgery move the incisors against resistance of lips and tongue, correction of discrepancy prior to decompensation reduce this resistance 3-Treatment duration: by limiting orthodontic treatment to post-surgical phase, reduce the overall length of treatment time Disadvantages: 1-Leaving orthodontic treatment after surgery is that occlusion produced must allow for any post-surgical adjustment of incisor inclination, this is not always straight forward so the way for the tooth to be moved within dental arch after surgery is difficult to predict 2-Patient commitment: patient who are primarily focused on the change in facial appearance that surgery will delivered may agree to post-surgical orthodontics, but once they have seen the outcome of surgery they may decline to go through with it \ Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

23. 23 Surgery without orthodontics Patients may undergo surgery without any adjunctive orthodontic treatment because of: 1-The anterior posterior position of incisors is such that the desired magnitude of surgical correction can be achieved without need for decompensation 2-Patient’s dentition is incomplete such that they are not suitable for fixed appliance 3-The predicted post-surgical occlusion and arch coordination are satisfactory, to the point where orthodontics will not significantly improve the situation Stability and clinical success Stability after surgical repositioning of the jaws depend on the: 1-Direction of movement 2-Type of fixation 3-Surgical technique More stable cases: -Maxilla up -Mandible forward -Chin in any direction Stable cases: -Maxilla forward -Maxilla asymmetry Stable by rigid fixation only: -Maxilla up -Mandibular forward -Maxillary forward -Mandibular backward -Mandibular a symmetry Less stable: -Mandibular backward -Maxillary downward -Maxilla wider Factors affect post-surgical stability: 1-Orthodontic consideration: -Growth factors -Pre-surgical and post-surgical orthodontic treatment -TMJ stability when planning the treatment -Dental stability 2-Surgical consideration: -Treatment plane -Design of osteotomy -Type of fixation -Muscle: relaxed --------- good stability results Stretched --------- less stability results -Neuromuscular rotation type -Neuromuscular adaptation: affect the muscular length not muscular orientation Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby

24. 24 Complication of orthognathic surgery 1-Physical: -Excessive blood loss -Post-operative infection -Bone fracture -Delayed healing or no healing -Sinus complication -Allergic reaction to anesthesia, antibiotic or anti-inflammatory -Neurologic injury -Secondary surgery 2-Functional: -TMJ discomfort, pain -Limitation in range of motion 3-Emotional: Self-esteem changes caused unexpected facial changes 4-Oral health: Bone loss, teeth loss, pulpal changes N: B: Oral health: = decalcification: Risk of enamel surface that associated with fixed appliance Treatment is protective = root resorption: Small amount of root resorption will occur during moving tooth Shortening of teeth was much greater than normal that lead to some degree of mobility It is common in upper incisors with large tipping or torque movement = loss periodontal support: For orthognathic patient, movement of teeth in antro-posterior or transverse may push the teeth into their cortical plate caries risk of dehiscence which can result in gingival recession In patient with history of loss bone support have risk for progressive results 2 Orthodontic Orthodontic M Management of anagement of O Orthognathic cases rthognathic cases Dr. Mohammed Alruby Dr. Mohammed Alruby