Combined Surgical and Orthodontic Treatment Dr Manar Alhajrasi BDS, Msc, SBO, M.Orth. Orthognathic surgery Orthognathic surgery refers to the surgical repositioning of the maxilla, mandible, and the dentoalveolar segments to achieve facial and occlusal balance. One or more segments of the jaw(s) can be simultaneously repositioned to treat various types of malocclusions and jaw deformities. Indications for Surgery Severity of the skeletal malrelationship (the envelop of discrepancy). Esthetic and psychological considerations. Psychological reactions to Orthognathic surgery. Development of Orthognathic Surgery :1920 1959: (Trauner Setback 1960’s: (Europe) 1980’s: 1990’s: Mandibular Setback for Mandibular Prognathism Sagittal Split Ramus Osteotomy & Obwegeser) for Mandibular and Advancement Le Fort I maxillary do fracture technique for Maxillary repositioning (modified by: Bell, Epker, Wolford ) Progress in Oral & Maxillofacial Surgery Rigid internal fixation replaced bimaxillary fixation What makes a problem too severe for orthodontics alone? Presence of a severe skeletal problem. Age of the patient has past growth modification Limitations of orthodontic tooth movement (e.g. severe intrusion in the presence of crossbite, deep/open bites, severe protrusion) Severity of the skeletal malrelationship The envelop of Discrepancy – It shows the amount of change that could be produced by orthodontic tooth movement (inner envelop); orthodontic tooth movement + growth modification (the middle envelop); and orthognathic surgery (the outer envelop). Esthetic and psychological considerations 75 %-80% of individuals referred for orthognathic surgery seek esthetic improvement. Changes in the position of the nose and chin have a greater impact on facial esthetics than changes limited to the lips. Be careful in understanding patient’s main concern. Do not over or under express problems not addressed by the patient/relative Psychological reactions to Orthog. surgery 90% of patients undergo Orthognathic surgery report satisfaction with the result. Negatives of orthognathic surgery are: – Few patients have difficulty in adapting to the significant changes in their appearance – A post surgery period of psychological adjustment must be expected. Patient education and communication is very important (Treatment conference) to prepare the pt. for surgery. Sometimes, patients did not accept the obtained results Consent form should be obtained before orthodontic or surgical intervention. There are only three possible treatment ways to treat a jaw discrepancy problem 1. Modification of growth 2. Camouflage ( dental compensation for a skeletal problem ) 3. Surgical repositioning of the jaws and/or dentoalveolar segments Surgical Procedures and Treatment Possibilities Correction of anteroposterior relationships Correction of vertical relationships Correction of transverse relationships Correction of Anteroposterior Relationships I. Maxillary Surgery: Maxillary advancement Down fracture Technique Correction of Anteroposterior Relationships Maxillary retraction: Down fracture technique: limited by the anatomic structure immediately distal to the pterygomaxillary fissure. Retraction of anterior segment by a segmental osteotomy after (extraction of 2 first premolars). Protraction of Maxillay Correction Of Anteroposterior Relationships: Mandibular Surgery Mandibular Advancement: 1. Bilateral Sagittal Split Osteotomy (BSSO) of the mandibular ramus Mandibular Advancement Correction Of Anteroposterior Relationships Bilateral sagital split osteotomy has the following advantages: Intra oral approach Broad interface of medullar (Rapid healing) Easy fixation by intra osseous wiring Rigid internal fixation (RIF) with bone screws Bilateral Sagittal Split Osteotomy ( BSSO ) drawbacks Reduced interincisal opening postoperatively Altered sensation in the lingual nerve distribution ( transient 2 - 6 months ). Paresthesia over the distribution of the inferior alveolar nerve. Correction Of Anteroposterior Relationships Mandibular Setback: 1. Bilateral Sagittal Split Osteotomy (BSSO) Excellent control of the condylar segment. Osteosynthetic screws can be employed for fixation. Mandibular set back: (cont’d.) .2The Trans Oral Vertical Oblique ramus osteotomy (TORVO) (limited to the reduction of mandibular prognathism.) Full thickness overlapping segments Less likely to produce neurosensory changes Jaw immobilization is necessary Difficult control of the condyles Correction Of Vertical Relationships Maxillary Surgery: Correction of skeletal open bite (long face) deformity by: Le Fort I down fracture of the maxilla with superior repositioning of the maxilla (maxillary impaction) after removal of bone from the lateral wall of the nose, sinus and nasal septum. Correction of Skeletal Open Bite (cont’d.) The overall facial height is shortened as the mandible responds by rotating upward and forward, altering both its occlusal and postural positions. ( autorotation ) Excellent stability post surgically. Sliding genioplasty is needed in case of deficient chin. Correction Of Sleletal Open Bite (cont’d.) Long- face problems are best treated by intrusion of the maxilla leading to Mandibular rotation around the (autorotation) condyle Reduction of mandibular plane angle Shortening of the face Closure of the open bite Correction of Skeletal Open Bite Correction Of The Vertical Relationships (cont’d.) Mandibular Surgery 1. Surgery to reduce mandibular plane angle and close the open bite by rotating the mandible down posteriorly and up anteriorly is highly unstable due to: a. Lengthening the ramus and stretching the muscles of the pterygomandibular sling b. Lack of neuromuscular adaptation in these powerful muscles. Vertical maxillary excess Vertical maxillary excess Correction of Vertical Relationships (cont’d.) “Skeletal deep bite” or patients with a “short face” problem (seen in Cl. II div.2 cases) are characterized by a long mandibular ramus, square gonial angle, and short nose-chin distance. Best treated by Sagittal Split Mandibular Ramus Surgery to rotate the mandible slightly forward downward after orthodontic leveling of the lower arch. Correction Of Vertical Relationships Short - face problems are best treated by mandibular ramus surgery that allows the mandible to move downward only at the chin. This will lead to: increase in the mandibular plane angle by shortening of the ramus opening of the gonial angle Short Face Problems Treated by Maxillary Surgery Le Fort I down fracture of the maxilla to increase face height is not stable, therefore not used. The use of synthetic hydroxylapatite and simulataneous osteotomy of the mandible increases stability. Correction Of Transverse Relationships Expansion & narrowing of the dental arches It is possible to move the maxillary segments both away from and toward the midline with relative ease and stability. Correction Of Transverse Relationships ( cont’d. ) Rapid palatal expansion Not feasible in adults, because of the increasing resistance of the midpalatal & lateral maxillary sutures. Correction Of Transverse Relationships Surgically-assisted palatal expansion 1. 2. 3. to reduce the resistance of the segments include: lateral antral wall. Mid palatal corticotomy. Corticotomies in the midline or Two para-midline vertical cuts Correction Of Transverse Relationships (cont’d) 3. Could be done under local anesthesia 4. The jackscrew ( RPE ) is cemented before the surgery. 5. Activated after the bone cuts are made to continue for 10 -14 days followed by a period of stabilization. Correction of Transverse Relationship Expansion and narrowing of the dental arches constriction of the maxilla when it coexist with vertical and sagittal problems Done in the course of the Le Fort I down fracture, (segmenting the maxilla) Asymmetry Mandibular asymmetry often leads to a secondary maxillary deformity ex: More vertical mandibular growth produces: compensatory changes in maxillary growth tilt of the occlusal plane Asymmetry Mandibular deviation also leads to compensatory changes in the mandibular alveolar process and the chin deviates more than the dental midline. Surgical correction of asymmetry often requires a Le Fort I osteotomy + BSSO for Mandibular ramus correction. Repositioning the chin may also be needed. GENIOPLASTY Is an osteotomy to free a wedge-shaped portion of the symphysis and inferior border that remains pedicled on the genioglossus and geniohyoid muscles. GENIOPLASTY This segment can be: Advanced (advancement genioplasty). Moved backward (reduction genioplasty). Shifted sideways to correct asymmetry. Down-grafted to increase lower face height. By splitting the segment vertically, the wedge can be flared or compressed. GENIOPLASTY The chin can be augmented (in all three planes of space ) by using: 1. An implant material such as porous hydroxylapatite, ( not silicone). 2. An osteotomy to reposition the symphysis, is better than cutting a wedge of bone. Limitations Of Orthodontic Treatment: Both dental and orthopedic approaches to attain ideal occlusion through orthodontic appliances alone may be unsuccessful. 1. Skeletal deformity may be too great. 2. Completion of jaw growth may limit the amount of orthodontic treatment possible. Limitations of Orthodontic Treatment 3. Patient may refuse to wear orthodontic appliances. 4. Loss of posterior teeth may limit available anchorage. 5. Some orthodontic movement are difficult or impossible (significant intrusion). 6. Esthetic consideration (gummy smile). 7. Economic consideration. Limitations Of Surgical Treatment: Surgery alone is not enough and may be unsuccessful due to: 1. 2. 3. Teeth need to be properly aligned. Arch forms must be compatible. Dental compensations should be eliminated, so that teeth are well related with respect to individual jaws. Timing and Sequencing of Surgical Treatment General rules: Early jaw surgery has little inhibitory effect on further growth. Orthognathic surgery should be delayed until growth is completed. Orthognathic surgery can be considered earlier in growth deficiencies TIMING OF TREATMENT 1. Actively growing patients with mandibular prognathism can be expected to outgrow their correction. “Pelapse`’ 2. Psychosocial problems may justify early surgery to correct prognathism, however retreatment may be needed 3. The Hand-wrist films to determine bone age are not accurate for planning the exact Timing of Surgery. TIMING OF TREATMENT 4. 5. The best method is serial cephalometric tracings, until good documentations that the adult deceleration of growth has occurred. Long Face (skeletal open bite) patients due to vertical maxillary excess, are reported to continue to develop vertically after surgery that was done between 1019 years. Long term follow-up of these patients are needed. Sequence of an Orthodontic/Surgical Plan I. Sequence: 1. Orthodontics to correct alignment and inclinations of teeth (no attempt for skeletal correction.) Note: Malocclusion may temporarily look worse. 2. Surgery to reposition the jaws. 3. Finishing Orthodontics. Objectives Of Pre-Surgical Orthodontics .1Place teeth in their proper relationships to mandible or maxilla. i.e. decompensation of teeth 2. Level both arches independently: It is sometimes necessary to level teeth in segments, independently. 3. Align the teeth within the arches. ex. Lower segmental osteotomy (Independent leveling) Pre Surgical Orthodontic Objectives To level and align the arches and make them compatible to resolve crowding and/or spacing to establish anteroposterior and vertical position of incisors (decompensate) to place teeth relative to their own supporting bone Pre-Treatment Evaluation: Records Needed: 1. Dental casts 2. Dental radiographs 3. Facial photographs (frontal and profile) 4. Cephalometric radiographs Check List for Treatment Planning A-P relationships amount of deficiency Vertical relationships { maxillary deficiency/protrusion mand prognathism/deficiency open bite deep bite Transverse relationships crossbites before surgery expansion surgically assisted expansion during surgery TREATMENT PLANNING: .1Start with problem list determined from analyzing records and patients examination. 2. Determine upper incisors and lip position by cephalometric analysis. (Surgical prediction cephalometric tracing) Treatment Planning.… (cont’d.) .3Eliminate dental compensation (i.e. backward orthodontics ) a. In orthodontic approach only the disharmony is camouflaged. b. In orthodontic / surgical approach, the disharmony is accentuated by decompensating the teeth, to place the teeth in their proper inclinations with respect to each jaw independently. Treatment Planning… (cont’d.) .4Determine where to reposition the jaws.Work toward average facial proportions for the appropriate ethnic or racial groups. i.e. (Chinese, Blacks, Mexicans, Americans) 5. Predict the soft tissue relationships & analyze to predict & insure pleasing results. Treatment Planning… (cont’d.) .6Consult with patient regarding anticipating changes and patient expectations. 7. Make decisions for orthodontics or surgery combined treatment before starting any treatment. Mounting of the maxillary model Models with completed skeletal and dental reference lines Model (Mock) surgery The splint: A acrylic splint is made in the laboratory to transfer the model relationship to the patient during surgery Orthognathic surgery