Introduction Indications Psychological implications Collection of records Treatment plan Different surgeries- maxilla- mandible References
ORTHOGNATHIC SURGERY is the art andscience of diagnosis treatment planning andexecution of treatment by combiningorthodontics and oral and maxillofacial surgeryto correct musculoskeletal, dento osseous andsoft tissue deformity of the jaws and associatedstructures .
It is indicated in patients who have skeletal problems, dentoalveolar problems that are too severe to be corrected byorthodontics alone, in whom growth is completed and growthmodifications cannot be done.
When a jaw discrepancy accompanies a severemalocclusion, there are three broad possibilities forcorrection: (1) growth modification, (2) camouflage (orthodontic positioning of the teeth tocompensate for the jaw discrepancy),or (3) orthognathic surgery in conjunction withorthodontics to reposition the jaws and/or dentoalveolarsegments.
Proffit and Ackerman introduced the concept of theenvelope of discrepancy to graphically illustrate howmuch change can be produced by various types oftreatment. The inner circle, or envelope, represents the limitationsof camouflage treatment involving only orthodontics; the middle envelope illustrates the limits of combinedorthodontic treatment and growth modification; and the outer envelope shows the limits of surgicalcorrection.
Growth modification, generally referred to asdentofacial orthopedics, is the most desirableapproach to a severe skeletal problem when the potentialfor further growth exists. Although the pattern of growth can be favorablymodified for some patients, the capacity for majorincrements in growth is rather limited. The variation in response of individualpatients, however, suggests growth modification shouldbe attempted in preadolescent patients.
When a moderate skeletal discrepancy exists and thereis no potential for further growth (or if more change isrequired than can be accomplished through growthmodification alone), orthodontic camouflage should beconsidered. The teeth are repositioned to establish normal overjetand overbite in an effort to compensate for the jawdiscrepancy .
The final treatment option for a severe skeletaldiscrepancy is orthognathic surgery. Once growth hasceased, surgery becomes the only means of correcting asevere jaw discrepancy. Although surgery may allowgreater changes, there are still limitations to the surgicaloptions, depending on the type of problem and directionof desired jaw movement, and certain problems aremore receptive to surgical correction than others.
The term reverse orthodontics is often used in referenceto the deliberate movement of teeth in a direction thatappears to make the worse initially when preparing thedentition for orthognathic surgery.. When dentalcompensations exist, they limit the distance the jaws canbe repositioned to achieve a desirable esthetic result.
First mandibular osteotomy : HULLIHEN (1849) doneto correct a protrusive malposition of a mandibularalveolar segment. In 1927, WASSMUND introduced total maxillaryosteotomy and inverted “L” ramal osteotomy, byexternal approach. In 1959, TRAUNER and OBWEGESER introducedsagittal split osteotomy as the beginning of a new era oforthognathic surgery. The beginning of the early orthognathic surgery was inSt.Louis where the orthodontist Edward Angle and thesurgeon Vilray Blair worked togetherHISTORY
Epker, Bell and Wolford developed Lefort-1 maxillarydownward fracture ,so that we can keep the maxillastable in all 3 planes of spaces. By 1980 progress has reached to such an extentthat, it is possible to reposition either or both the jawsand to move the chin in all 3 planes of spaces & Rigidinternal fixation made it possible for comfort and betterimmobilization after surgery.AJODO. 2007 Feb;131(2):263-7
CASE(1921): To correct malocclusions to normalfunction and esthetic relationship and to beautify facialoutline. ACKERMAN AND PROFFIT(1970): To establishoptimal proximal and occlusal contact of the teethwithin the framework of acceptable facialesthetics, normal function and stability. LINDQUIST(1985): To improve facial esthetics, toalign the teeth evenly; to create good occlusalrelationships; static and functional; to obtainpsychological benefits; to maintain healthy supportingstructures and stable dentition. ROTH(1992): To serve the patient‘s needs in the fivecategories of facial esthetics, dental esthetics, functionalocclusion, periodontal health and stability.
ETIOLOGIC FACTORSDentofacial deformity Developmental problem.ETIOLOGYKNOWN SPECIFICCAUSEHEREDITARYFACTORSENVIRONMENTALINFLUENCESOccasionally the deformity is due to a single specific cause,much more frequently they result from a complex interaction amongmultiple factors that influence growth and development.
FACIAL SYNDROMES ,CONGENITAL DEFECTS,WHOSE ETIOLOGY IS PRE-NATALPOST NATAL GROWTHDISTURBANCES, INCLUDING THEEFFECT OF TRAUMA1.SPECIFIC CAUSESFAS AND RELATED PROBLEMSABORMALITIES OF NEURAL CREST CELLORIGIN AND MIGRATION :Hemifacial microsomiaMandibulofacial dysostosisACHONDROPLASIAPREMATURE FUSION OF CRANIAL ANDFACIAL SUTURES:Crouzon’s syndromeApert’s syndromeTRAUMA:Maxillary traumaMandibular trauma(functionalankylosis)MUSCLE DISTURBENCESTorticollisCONDYLAR HYPERPLASIAFACIAL CLEFTING SYNDROME
2.HEREDITARY FACTORSMalocclusion is much more common now than it was inprimitive human populations. It seems logical that, the effect ofincreased Consangineous marriage among previously isolatedpopulation subgroups would be an increase in number ofindividuals requiring orthodontic –surgical treatment.The influence of inherited tendencies seems to be particularly strongfor mandibular prognathism.Craniofacial anomalies often have a genetic background.Recent advances in molecular genetics have revealed a geneticexplanation for conditions that do not even appear to be genetic inorigin .
3.ENVIRONMENTAL INFLUENCESEnvironmental influences on dento facial development includes externalinfluences such as trauma ,but more importantly , this category includesthe group of etiologic factors related to functions of jaws.Form FunctionThe form function interaction includes both the effects of activemovement and the long lasting effect of the soft tissue pressure on thedeveloping skeletal and dental structures.Soft tissue pressure on development of dentofacial skeleton
Respiratory influenceMouth breathing has been blamed for altered dentofacial developmentHarvold et al, showed that total blocking the naresled to Various moderate to severe malocclusions,Because the lower jaw was positioned forward , thedeformity always included a component of mandibularprognathism along with various displacements of teethTotal nasal obstructionDownward backward rotationLong face deformity(AJODO, vol 79. 1981).
1.When orthodontic treatment alone cannotcorrect a problem.2.To improve jaw function.3.To enhance the long term orthodontic result(stability).4.Reduction in overall treatment time.5.Change in facial appearance.6.Improved breathing.7.Improved speech.8.Improvement in jaw pain.
One answer to the question of "When is a problem toosevere for orthodontic treatment only?" is "When thecombination of tooth movement and growth modification doesnot have the potential to bring the patient to normal occlusion."
Some uncommon dentofacial deformities requiringorthognathic surgery includes, cleft lip andpalate, Pierre robin syndrome, treacher- Collins, apertssyndrome. Facial asymmetry is seen in parry- rombergsyndrome, goldenhar syndrome, hemifacial hypertrophyand unilateral ankylosis treated at early age . Mid face deficiency is seen in syndromes likecraniosynostoses, apert`s, crouzon`s, pfeiffer, binderssyndrome, achondroplasia dwarf and cleidocranialdysplasia. Mandibular deficiency is seen in pierre robin, treacher-collins, and goldenhar (hemi facial microsomia)syndrome. Mandibular prognathism is seen in gorlin –goltz syndrome, achondroplasia, klinefelter syndrome.
Facial deformity isdefined as ― aphysiognomic form thatis sufficiently negativelymarked, so as to set theindividual apart from thegeneral population‖. A dentofacialanomaly may have anadverse effect on anindividuals self esteemand self confidence aswell as evoke anundesirable socialresponse .
FACE IS THE INDEX OF MIND The area of the body which maximally determinesphysical attractiveness is the face. It is a primary means ofidentification , expression and non-verbal communication. There is a high value of cosmetic characteristics in thecurrent society and severe cranio-facial deformity maycause significant psychosocial problems.
Concept of “Body image” ( Schilder and Schonfeld ) 2 components of body image are1. Body sense2. Body conceptBody senseThe actual appearance the person sees when viewing himself in amirror or photograph.Body conceptThe internal process of how the patient feels about hisappearance. Generally those patients with a good body image inspite of having a deformity are better candidates forsurgery
EXTERNAL & INTERNAL PRESSURE Edgerton & knorr pointed out the importance of external versusinternal motivation. Internal pressure’ would be that originating within the patient andusually involves depression and a sense of inadequacy. ‘External pressure’ would include the need to please others and adesire to overcome career or social problems through a change inappearance.
Selection of patients for orthognathic treatment involvesvarious factors that may ultimately influence levels ofpatient satisfaction. These include: physiological; medical; interpersonaland psychological. The majority of studies investigating the psychologicalaspects of patients undergoing orthognathictreatment, have shown that patients seeking orthognathictreatment are psychologically well adjusted prior tosurgery, and appear to have fewer deficits in theirpersonality dimensions than those patients seeking other‗cosmetic-type‘ procedures.
31Body Dysmorphic Disorder – (BD)Body Dysmorphic Disorder formerly referred to asDysmorphophobia, tends to occur in young adults equally ineither gender.These patient are characterized by certain key and associated features, because ofwhich they becomes specifically pre-occupied with a non-existent or minimalcosmetic defect of a particular body part that the person considers unattractive,(nose, cleft lip and palate, deficient chin, gummy smile ) and persistently seeksmedical attention to fix it surgically. Some clinicians feel it is a variant ofobsessive-compulsive disorderBody Dysmorphic Disorder Psycotic patientsMany do well with surgery No improvementAssociated Features:Depressed moodsomatic dysfunctionGuilt or ObsessionAnxious or Fearful or dependent personolity(Plast.Reconstr. Surg.118: 167e, 2006.)Body Dysmorphic Disorder Psycotic patientsMany do well with surgeryBody Dysmorphic Disorder Psycotic patientsNo improvementMany do well with surgeryBody Dysmorphic Disorder Psycotic patientsAssociated Features:Depressed moodsomatic dysfunctionGuilt or ObsessionAnxious or Fearful or dependent personolityNo improvementMany do well with surgeryBody Dysmorphic Disorder Psycotic patients(Plast.Reconstr. Surg.118: 167e, 2006.)Associated Features:Depressed moodsomatic dysfunctionGuilt or ObsessionAnxious or Fearful or dependent personolityNo improvementMany do well with surgeryBody Dysmorphic Disorder Psycotic patientsBody Dysmorphic Disorder Psycotic patientsBody Dysmorphic DisorderNo improvementPsycotic patientsBody Dysmorphic DisorderMany do well with surgery No improvementPsycotic patientsBody Dysmorphic DisorderAssociated Features:Depressed moodsomatic dysfunctionGuilt or ObsessionAnxious or Fearful or dependent personolityMany do well with surgery No improvementPsycotic patientsBody Dysmorphic Disorder(Plast.Reconstr. Surg.118: 167e, 2006.)Associated Features:Depressed moodsomatic dysfunctionGuilt or ObsessionAnxious or Fearful or dependent personolityMany do well with surgery No improvementPsycotic patientsBody Dysmorphic Disorder Psycotic patientsBody Dysmorphic Disorder
An orthodontist must determine at an early stage whythe patient is seeking treatment and what the patienthopes to achieve .The surgeon must then decide whether this demand canbe met surgically.
Lavell et al, emphasized that satisfaction beginswith selection of appropriate patients. The selection can be represented by theacronym .....‘SAFE’S- Self-assessment of attractivenessA-AnxietyF- FearE- ExpectationsJournal of Orthodontics, Vol. 33, 2006, 107–115
High satisfaction with most of orthognathic patientstreated can be related to:-Realistic expectations with regard to outcome.Patients with a realistic expectation of post-operativediscomfort and recovery.Effective pre-operative preparation of the patient.Good psychological adjustment both pre- and post-operatively.
Data base(case history, patientexamination, Radiographicand model analysis)Problem list in priority order –DiagnosisPossible solution to the problem – Tentative treatment plan.Discussed with the patient & modifiedOptimal treatment planExecution of treatment
Phase I Includes assembling the database, synthesizing the problemlist, diagnosis and team conferencePhase ii Includes developing interdisciplinary problem list withdentofacial problems in order of priority, and possiblesolutions, which forms the tentative treatment plan. A patientparent doctor team conference is arranged to discuss the tentativetreatment plan with the patient and the family and definitive plan isarrived .Phase iii Includes the preparatory phase(Restorative, endodontic, periodontic), the definitiveorthodontic-surgical treatment and continuous teammonitoring, re-evaluation, interaction, and modification of thetherapy.Phase iv is the maintenance phase.
The patient-parent conference should include thefollowing three components:(1) A description of the problem list by the orthodontist. The patientshould have input on the prioritization of the problem list,(2) A review of the risk/ benefit considerations must be presented.The merits of each treatment alternative should be given, includingthe consideration of no treatment as an option because mostorthodontic treatment is elective, and(3) Consideration of the patients expectations and values is ofparamount importance .Informed consent requires not only obtaining thepatients permission to treat after having explainedthe risks, but also a dialogue between the clinicianand patient in deciding on the final treatment plan.
D. Additional Radiographs1. Lateral cephalometric radiograph in Rest position.2. P-A view.E. Diagnostic Occlusal splints.F. velvopharyngeal evalutions1.speech evaluation.2,Nasoendoscopy.G.Tongue Evalution1 speech evaluation2.Radographic evaluation of tongue posture.3.clinical evaluation of tongue posture
Demographic data Consists of basic chart information ofname, address (home, work or school), age, sex, maritalstatus and type of employment or school attended. Chief complaintThe first goal of the interview is to establish the patient’smajor reason for seeking treatment, which is the chiefcomplaint.Collection of Data base:
Psychological makeup of the patient is importantbecause, despite on objectively favorable treatmentresult, certain patients will express dissatisfaction withtheir results due to unrealistic patient expectationsregarding the result of the treatment .
Unrealistic expectations are most likely to occur intwo types of patients,patients with acquired deformities andThose with external motivations.Treatment of such patients must be entered into only aftercareful consideration and psychologic consultation.Frequently it is best not to treat the patients since they aregenerally unhappy with the results achieved. These kindof patients can be distinguished by a deliberate socialpsychologic evaluation.
Classification of patients Highly positive reactive / group IPatients who respond positively to all questions and are goodcandidates for surgery Neutral reactors / group IIPatients who had given positive responses with 2 or 3 negativeor slightly negative responses belong to this group. Ingeneral these patients require more than the usual amountsof attention and counseling during the preoperative phase toprevent difficulty later. Negative reactors / group IIIPatients who gives negative responses to most of the questionsare unlikely to be satisfied by the results of surgery.
Patient‘s medical information must aim to obtaininformation regarding medical conditions like history ofmedication, allergies to drug, bleeding disorder or othercongenital abnormalities . Respiratory problem, cardiacproblem, asthma, diabetics, anemia, rheumatic fever etcthat may complicate correction of a skeletaldeformities. Patients with medical problems can have surgicalorthodontic treatment but only if the medicalproblems are of great concern.
Family historyIncludes information regarding the marriage of theparents consanguineous/ non consanguineousmarriage, about the siblings, sibling’s general anddental conditions, history of familial disease if anyand Parent’s concern for treatment.Dental history.Knowledge about previous orthodontic therapy, or existingactive orthodontic treatment carries important. Anyprevious records if available or narrative descriptionabout treatment from the previous orthodontistregarding the nature of treatment and evaluation ofresults should be reviewed
Dental history The patient‘s interpretation of past orthodontic,periodontic and prosthetic experiences will give someinsight regarding his willingness to co-operate andpersonal motivation level. A previous history of periodontal disease should alertthe surgeon to potential problems in hygiene and patientcompliance. The incidence of TM dysfunction and possibility ofaggravating any problems makes pre operativedocumentation essential. Many maneuvers involved in orthodontic therapy cancomplicate diagnosis If overlooked may result inunusual post surgical results.
- Study models.- Panoramic and lateral cephalometric radiographs- PA cephalogram in patients with significantasymmetry- Photographs: A minimum set of five intra oralphotographs.- Photographs: A minimum set of four extra oralphotographs
Facial proportions and esthetics.A precise and detailed soft tissue evaluation is always essential toderive proper diagnosis and accurate treatment plan whichmaximizes the patient‘s benefit.The most important point in proper analysis of facial esthetics isthe use of a clinical format.Examination should not be based on static laboratory x-ray filmand photographic representation of the patient alone.
Three important parameters which are to be checked beforeproceeding with clinical examination are:-Natural head positionCentric relationRelaxed lip postureOnce after these 3 things are established one can go ahead withfacial examination.
Outline form & symmetry.General outline form & symmetry of face are noted.The widest dimension of the face is the zygomaticwidth.According to the normal values established by Farkaswith Anthropometric studies the bigonial width isapproximately 30% less than the bizygomaticdimension.
Facial levelTo examine facial levels a reliable horizontallandmark is necessary. With the patient in natural head posture,the pupils are assessed for level with the horizon. If pupils arelevel, they are used as the horizontal reference line and adjacentstructures are measured relative to this line. Structurescompared with the pupil line are:-Upper canine levelLower canine levelChin & jaw level
Midlines are assessed withposteriosuperior most condyleposition and first tooth contact.If occlusal slides alter jointposition, no reliable midlineassessment can be made.The relative positions of soft tissuelandmarks (nasal bridge, nasaltip, philtrum, and chin point)and dental midline landmarks(upper incisor midline, lowerincisor midline) are assessed formidline alignment..Philtrum is usually a reliable midline structure and can be used as thebasis for midline assessment most often.
Symmetry.Right and left comparison.Absence of obvious asymmetryis necessary for goodesthetics.Balance.Well balance between thirds.Morphology.Determined by dividing thewidth of each facial thirdby the total facial hight.Upper 3rd-bitemporal.Middle third-bizygomaticLower 3rd-bigonial.
Eyes and Orbits.Mesurements of intercanthal and interpupilarydistances.Telecanthus-Hypertelorisam.Occulo orbital symmetryBy true horizontal line between inner and outercanthus of eyeLateral canthal dystonia.Occular muscle imbalance,sclera discolration,sclerabetween lower eye lid and pupil --SKELETALDEFICIENCY IN MIFACIAL AREA
NoseDeformities- glabelle,dorsum,tip,oralar base width.Normal –(34+/-4mm)CHEEKSassement of malar eminence, infraorbotal rims,paranasalareas,for normal symmetry andprojection.
The Central Fifth: Delineated by the innercanthus of the eyes. Inner canthal distance= alarbase of nose The Medial Fifth: Width of mouth=interpupillary distance Line from the outer canthusshould coincide with thegonial angles Outer fifth From the pinnaRULE OF FIFTHS
This area of facial analysis isextremely important in surgicalorthodontic diagnosis and treatmentplanning. The importance of relaxedlip position for these measurementsshould be overemphasized.
The lips are measuredindependently in arelaxed position. Thenormal length fromsubnasale to upper lipinferior is 19 to 22mm.The lower lip is measuredfrom lower lip superior tosoft tissue menton andnormally measure in arange of 38 to 44mm.
Increased or decreased anatomic upper lip lengthIncreased or decreased maxillary skeletal lengthThick upper lip expose less incisor than thin upper lips,allother factors being equal. The angle of view changesthe amount of incisor visible to the viewer.The distance from upper lip inferior to maxillary incisal edge is measured.The normal range is 1 to 5 mm. Women show more within this range.Surgical and orthodontic vertical changes are based primarily on thismeasurement .
With the lips relaxed, aspace of 1 to 5mmbetween upper lipinferior and lower lipsuperior is present.Females show a larger gapwithin the normal range.This measurement is alsodependent on lip lengthsand vertical dento-skeletal height.
Increase in inter labial gapare seen with anatomicshort upper lip, verticalmaxillary excess, andmandibular protrusionwith open bite secondaryto cuspal interferences.Decreased interlabial gap isfound with verticalmaxillarydeficiency, anatomicallylong upper lip (naturalchange with ageing, esp.in males) and mandibularretrusion with deep bite.
The closed lip position alsoreveals disharmony betweenskeletal and soft tissue lengths.Increased mentalis contraction, lipstrain, and alar base narrowingare observed in vertical skeletalexcess, anatomic short upper lipand in some cases of mandibular protrusionwith open bite.
Ideal exposure with smileis three-quarters of thecrown height to 2mm ofgingiva. Females showmore gingival exposurethan males.Reveals 75% to 100% of the maxillaryanterior teeth and the interproximalgingiva
Excess gingival exposuremay be caused by a shortupper lip,.vertical maxillary excess, .short clinical crown,. andlarge lip elevationBecause of etiological variability surgical shortening of the maxilla is indicatedonly when excess gingival exposure is found in combination with increasedinterlabial gap, increased incisor exposure, increased lower facial height.
UPPER 3RD.Forehead is sloped antero –inferiorly,withprojected supraorbital margins.normally theyare 5 to 10mm beyond the most anteriorprojection of globe.Distinction should be madeFrontal bossing,Supra orbital hypoplasia.Globular angle -G-nasion –pronasale.132+/-150excessive- frontal bossing ordepressed dorsum
Relationship of the forehead is considered to thebizygomatic width. It can be described as Narrowor wide. The lateral forehead contour or the slope of theforehead could be Flat, protruding, steep. Thedental bases are more prognathic than incases witha flat forehead.
.Nose 5 to 8mm ant to the globes.Dorsum.- normal, concave ,converse,.Nasal tip projection, turned up ordown.Horizontal plane nasal tip-sub nasale,,subnasale to alar base is 2:1.1;1 suggest lack nasoskeletal supportfor alar base ,or maxillary ormiddle third face defficency.MIDDLE THIRD
The vertical nasal length measures 1/3rd of the totalfacial ht. (dist. From hairline to gnathion) The relationship b/w vertical & horizontal length of thenose is 2:1. Microhinic type: The root of the nose is high, shortnasal bridge & an elevated tip.
This angle is formed by theintersection of theupper lip anterior andcolumella at subnasale.This angle can changenoticeably withorthodontic and surgicalprocedures that alter theantero-posterior positionor inclination of themaxillary anterior teeth.Desirable range of 90 to110 degrees
Evaluation of noseBell described three type of noseLeptorrhine-long, high and narrow nostrils.Mesorrhine-lack of dorsal height andcolumellar support.Platirrhine-flat broad nose and wide nostrilsAlar base width is equal to the intercanthal width of eyeof which is influenced by inherited ethnic characters.Lefort 1 osteotomies affect the alar base width, superiorrepositioning is associated with widening of alar base.simultaneous rhinoplasty is indicated if siginificantchange in alar base width is expected during surgery.
The nasal projection measuredhorizontally from subnasale to nasal tip isnormally 16 to20mm ,. Nasal projection is an indicator ofmaxillary antero posterior position.This length becomes particularlyimportant when planning for anteriormovement of maxilla.Nasal projection
The orbital rim is an antero-posterior indicator ofmaxillary position.Deficient orbital rims maycorrelate positionally with aretruded maxillary positionbecause the osseous structuresare often deficient as groups,rather than in isolation.The Eye globe normally ispositioned 2-4mm anterior tothe orbital rim.
The surgical maxillary versus mandibular decision isinfluenced by the orbital rim position.Deficient orbital rims dictates the need for maxillaryadvancement with all other parameters being normal..
Cheekbone contourCheekbone assessment requires frontal and profile examinationsimultaneously. Cheekbone contour(CC) correlates with maxillaryantero-posterior position, frequently the cheek bone contour isdeficient in combination with maxillary retrusion..
Continuation of the cheekbone contour line. This areais an indicator of maxillaryand mandibular skeletalanteroposterior position. Normal position is indicatedby the maxilla point (Mxp). Mxp is continuum of thecheekbone nasal lip contourand is indication ofmaxillary anteroposteriorposition.
Maxillary retrusion is indicated by a straight or concave atMxp, when this anatomic area is concave are flat , maxillaryadvancement is necessary.
Mandibular protrusion interupts the nasal base –lip inthe length of the upper lip. When this line is interrupted within the height of theupper lip mandibular set back may be indicated.
Normally this sulcus isgently curved and givesinformation regardingupper lip tensionMaxilla should not be retracted significantly when a deeply curvedthick lip is present since this produces poor lip support.If possible maxilla should be moved forward towards the curved lipto improve lip support.
Angle between lower lip ,chin ,R-point,Should be approximately 900.Increased in-Chin deficiencyLower lip procumbency.Excessive sub mental fat.Low hyoid bone position.Lip-chin throatangle
Also termed cervicomentalangleVaries between 105-120º.Absolute 110 o.Distance Between pogonianto neck chin angle is50mm.
The relationship of lips to thesn-pg’ line is an important aid inorthodontic soft tissue analysis andtreatment.Tooth movement changes therelationship of the lips to the sn-pg’line and therefore the esthetic result.SUBNASALE - POGONION LINE ( SN-PG’)
Burrstone reported that the upper lip is in front of the sn-pg‘ line by 3.5mm 1.4mm, and lower lip in front of theline by 2.2mm 1.6mm.All tooth movements should be assessed in regard to theanticipated lip change to the sn-pg‘ line.
Developed by Charles Burstone et alPresented first in Journal of Oral Surgery. 1978 April.Followed by Soft tissue Cephalometric Analysis for Orthognathicsurgery in Journal of Oral Surgery. 1980 .Data derived from samples obtained from Child Research Centre,Univ. of Colorado school of medicine.Sample type: Northern european descentSample Size = 2716 females11 males
A constructed plane called Horizontal Plane whichis surrogate Frankfort Horizontal planeconstructed by drawing a line 70 from SN plane Most measurements will be made from projectionseither parallel or perpendicular to the HorizontalPlane
Chosen landmarks and measurements can be altered byvarious surgical procedures.The appraisal includes all facial bones and a cranial basereference.Rectilinear measurements can be readily transferred to astudy cast for mock surgery.Critical facial components can be examined.Standards and statistics are available for variations inage and sex from 5 to 20Consists of a series of measurements that can becomputerised.
GLABELLA NASIONANS PNSPOINT A POINT BSELLA PORIONBASION POGONIONGNATHIONMENTONGONIONORBITALECEPHALOMETRICLANDMARKS
CRANIAL BASEConstruction of horizontal planeLength of cranial baseN-A-Pg angleN-AN-pog
By William Arnett and Robert BergmanAJODO 1999 Sequale to Facial keys to orthodontic diagnosis andtreatment planning. Part I and IIAJODO 1993
“We only treat what we are educated tosee. The more we see, the better the treatmentwe render our patients”-Arnett.
Natural head posture, Centric relation (uppermost condyle position), Relaxed lip posture True Vertical Line ( TVL )
It is a Vertical line passing throughthe Subnasale with natural headposture. It may be used to quantifyfavorable or unfavourable change inthe profile after overjet reductionand has a potential role in posttreatment analysis and research
Data base: Based on 46 white models Males = 20 Females = 26 All models had natural class I occlusion andreasonably well balanced facially
Metallic Markers are placed on right side offace to mark key midface structures. i.e1. Orbital rim marker2. The alar base marker3. The subpupil marker
Composed of five components1. Dentoskeletal factors2. Soft tissue structures3. Facial length4. Projections to TVL5. Harmony values
Have a large influence on the facial profile. When in normal range individually produce abalanced and harmonious nasal base, lip, soft tissue A’and B’, and chin relationship.
Soft tissue thickness in combination withdentoskeletal factors largely control lower facialesthetic balance. Nasolabial angle and upper lip angle are importantin assessing the upper lip and may be used by theorthodontist as part of the extraction decision.
They are antero-posterior measurements of softtissue and represent the sum of the dentoskeletalposition plus the soft tissue thickness overlyingthat hard tissue landmark. The horizontal distance for each individuallandmark, measured perpendicular to the TVL, istermed the landmark’s absolute value.
Created to measure facial structure balanceand harmony. It is the position of each landmark relative toother landmarks that determines the facialbalance. The harmony values represent the horizontaldistance between two landmarks measuredperpendicular to the true vertical
Intramandibular parts. Interjaw Orbits to jaws The total face
Landmark values are dependent on TVL placement.HOWEVERHarmony values are independent of the position of the TVLthus making it very reliable
Model surgery is the dental cast version ofcephalometric prediction of surgical results. Typically model surgery is done just prior to the actualsurgery, after orthodontic preparation has beencompleted, so there is no need to reposition teeth oncasts, but a simulation of the final occlusion can beseen prior to any treatment if a diagnostic setup hasbeen done. Mandibular advancement can besimulated, for instance, by sliding the lower castforward relative to the upper cast.
It is easier to study the possible tooth relationships if thecasts are mounted temporarily on an arbitrary articulatorso that they are held in the desired position. The better theocclusion without any tooth movement, the easier it is toarticulate the casts by hand and vice versa. If the maxilla will be repositioned vertically, it is importantto use a face-bow transfer to mount the casts on a semi-adjustable articulator so that the condyle-toothrelationships are recorded and mandibular rotation iscorrectly accounted for Doing the cephalometricprediction and articulating the casts by hand to check forarch compatibility nearly always is sufficient prior to thetreatment, but articulator mounting is necessary duringthe final surgical planning so that the surgical splints willbe accurate.
Purpose of model surgery. 1) To verify that the planned movements arepossible 2) To relate the mandibular and maxillary dentitionsin the position where the surgical splint will bemade.
ImpressionsFace-bow recordWax bite to recordPre surgical occlusion
Fit the teeth accurately.Minimum thickness – notmore than 2 mm.Excess acrylic should betrimmed off the buccalaspect, to allow forproper visualverification duringsurgery and oralhygiene maintenance.
The goal of the treatment plan is develop the plan thatwill maximise the patient benefit. It is completelybased upon diagnostic truth. Surgical treatment possibilities Logical sequence in planning surgical orthodontictreatment Treatment plan techniques of cephalometricprediction and cast prediction
The surgical treatment of deformities of the mandible mustbe considered in all 3 dimensions. The defects that affectthe various parts of the mandible may be symmetrical orasymmetrical. Preoperative assessment will identify thesite involved. Classification MANDIBLE Ramus osteotomies Oblique subcondylar osteotomy The vertical subsigmoid osteotomy The sagittal split and its modifications The inverted ‘L’ and ‘C’ osteotomies of the ramus
Condylectomy Osteotomies of the body of the mandible Segmental procedures Genioplasties• MAXILLA1. Lefort I 2.lefort II 3. lefort III4. Segmental osteotomy
BELL & PROFITT VAGHESE MANI PETERSON PRINCIPLES OF ORAL SURGERY PETER WARD BOOTH DIMITROULIS REYENEKE