Mandibular Prognathism by BSSO Study

Mandibular Prognathism by BSSO Study methodological analysisMETHODOLOGYPopulationConsisted of all the patients who reported to the Out Patient Department of Oral And Maxillofacial mathematical process for correction of facial deformity involving maxilla and mandible.SampleConsisted of 33 patients who underwent BSSO setback for inframaxillary prognathism keeped by wet Internal Fixation at the Department Of Oral And Maxillofacial Surgery, Mar Baselios Dental College.Inclusion CriteriaPatients to a higher place age of 20 years for males 18 years for females.Patients who were treated by BSSO setback along with severe Internal Fixation for mandibular prognathism.Exclusion CriteriaPatients undergoing Bimaxillary surgeries.Patients undergoing Genioplasty along with BSSO.Patients with Medically compromised conditions.Patients with Craniofacial anomalies, Syndromes.A retrospective study was conducted on 33 patients (15 females and 18 males), with mean age of 22 years (age range of 19 28 years), who were operated for mandibular prognathism by BSSO at the department of oral and maxillofacial surgery, Mar Baselios Dental College, Kothamangalam. The patients were selected according to above mentioned inclution and forcing out criterias. The surgical procedure was done by one chief operating surgeon. No maxillomandibular reversion was employ postoperatively. Pre and postsurgical orthodontics was carried out at the department of orthodontics and dentofacial orthopaedics, Mar Baselios Dental College, kothamangalam.A assess askance skull radiograph with adequate quality and exposure was taken pre operatively and after 6 months of follow up in natural head position Frankfurts horizontal flat solid parallel to the floor, the patois in relaxed position and the mandible in centric occlusion with exposure values of 80 KVp, 10 mA, and 1.30 seconds.Tracings of the lateral cephalograms were pencil traced on acetate paper. To improve the consistency the tracings and measu rements were taken by the same(p) investigator. Horizontal audience line was taken as 7 to SN at nasion. Vertical refer line was constructed orthogonal to horizontal reference line through Sella. Superimposition of traced preoperative and postoperative lateral cephalogram was done with respect to the horizontal and vertical reference lines. The position by side(p) cephalometric delegates and measurements were used.SSella Center of sella turcicaNNasion virtually front read of frontonasal surgical seamANSAnterior nasal bone Spine Anterior tip of the nasal spinePNSPosterior Nasal Spine The most posterior aspect of the palatal boneAPoint A innermost point on contour of maxilla between anterior nasal spine and incisor toothIsIncision capital eye of incisal edge of most prominent maxillary central incisorIiIncision Inferior Midpoint of incisal edge of most prominent mandibular central incisorBPoint B Innermost point on contour of mandible between incisor tooth and bony chinP GPogonion Most anterior point on osseous contour of chinMEMenton Most inferior midline point on mandibular symphysisCmColumella point Midpoint of columella of noseSnSubnasale Point at which columella merges with upper brim in midsagittal planeSLSSuperior Labial Sulcus Point of greatest concavity in middle of upper mouthpiece between subnasale and labrale superiusLsLabrale Superius Most anterior point of upper lipLiLabrale Inferius Most anterior point of light lipSLIInferior Labial Sulcus Point of greatest concavity in midline of lower lip between labrale inferius and flabby tissue pogonionpgSoft Tissue Pogonion Most prominent or anterior point on chin in midsagittal planemeSoft Tissue Menton Lowest point on contour of soft tissue chinStomsStomion Superius Most inferior point of upper lipStomiStomion Inferius Most superior point of lower lipSn-StomsUpper lip distanceStomi-meLower lip lengthG-Sn-PGFacial Convexity be given between soft tissue glabella, subnasale and soft tissue pogonionCm-Sn-LsNasolabial Angle Angle between columella and labrale superiusLi-SLI-pgLabiomental Fold Angle between lower lip and chin contourResearch methodologyIn the horizontal plane linear budges at following hard tissue ANS, A, Is, Ii, B, PG, ME and soft tissue Sn, SLS, Ls, Li, SLI, pg, me, Stoms, Stomi cephalometric points were measured in millimeters with mean and standard deviations were calculated.In the vertical plane linear changes at following hard tissue ANS, A, Is, Ii, B, PG, ME and soft tissue Sn, SLS, Ls, Li, SLI, pg, me, Stoms, Stomi cephalometric points were measured in millimeters with mean and standard deviations were calculated.Scatter patch diagram with Correlation Regression Analysis was done for the following points Li vs Ii, SLI vs B, PG vs pg, ME vs me were done in some(prenominal) horizontal and vertical plane.Change in length of lower third of face upper lip Sn-Stoms length and lower lip Stomi-me length were calculated along with mean and standard d eviation.The mean change in facial profile, Nasolabial angle and mentolabial fold were calculated.The ratio of change in the soft tissue reference points will be comp atomic number 18d with movements of corresponding 4 hard tissue references Li to Ii, SLI to B, PG to pg and ME to me in the horizontal plane. functional PROCEDUREAll the patients had undergone BSSO for correction of horizontal mandibular excess mandibular prognathism. All surgeries were carried out by the same surgeon.During the positioning of the patient before surgery the head end of the table is tilted by round 15. Hypotensive anaesthesia technique was used. Both these are intended to reduce intra operative eject.At the beginning of the procedure 2% lignocaine hydrochloride with 1 2,00,000 epinephrine is infiltrated into the buccal vestibule upto the midramus region of the mandible on both sides.Incision and dissectionThe incision is set(p) over the anterior aspect of the ramus extending from the midramus region r unning blue over the external oblique ridge upto the first molar region where it curves down to the buccal vestibule. Retracting the soft tissues buccally, before placing the incision go ons the initial exposure of the buccal fat pad. A sharp dissection is done in the ramus upto the periosteum.Periosteal dissection is started on the lateral aspect of the mandibular body from anterior ramus upto the second molar region extending to the inferior border. On the lateral aspect of the ramus dissection may be minimal only to achieve proper entryway and visibility. Medial dissection is done subperiosteally with a Howarths periosteal elevator and should be above the level of lingula and mandibular abatement which usually coincides with the deepest concavity of the anterior border of ramus. Later a channel retractor is inserted for average retraction so as to protect the mandibular neurovascular bundle.OsteotomyOsteotomy is done with surgical micromotor and burs. Its initiated on the c ortical bone of the medial side of ramus above the lingula extending from behind the mandibular foramen half to two-third of the anteroposterior dimension of the ramus running down onto the superior aspect of the body of the mandible and then extended to the external oblique ridge over the lateral aspect of the mandibular body upto the 1st molar region.Extending the cut towards the 1st molar region gives better accessibility for intraoral plating. The discretion of the cut should be minimal only to reach the cancellous bone. The vertical cut is extended to embarrass the inferior border so that the direction of the split is controlled. During the vertical cut a channel retractor is placed on the lateral aspect so as to protect the buccal soft tissues and facial artery.following the osteotomy, a small spatula osteotome is malleted into the site beginning from the medial cut, down the ramus, over the body upto the vertical cut. The spatula osteotome is tell laterally beneath the cor tical plate so that the neurovascular bundle is protected. Later larger osteotomes are used and finally the fragments are prised apart using a Smith spreader.As the fragments are prised the neurovascular bundle is fancy and care is taken to maintain it to the medial tooth bearing fragment. If the neurovascular bundle is found to be attached to the proximal condylar segment a small periosteal elevator is used to free the bundle and bring it to the medial fragment. Once this is done osteotomes in a wedging fashion or the Smith spreader is used vigourously until the spilt of the fragments are completed. The osteotomy is repeated on the opposite side of the mandible. When the mandible is setback, release of the medial pterygoid and masseter muscle is stripped, if needed to prevent the displacement of the condylar segment posteriorly.Later the tooth bearing medial segment is pushed back as a great deal as needed and the overlapping buccal plate of the proximal condylar segment is trimm ed such that the proximal segment rest passively on the cancellous part of medial segment with condyle in proper position.Stabilization and fixationThe position of jaw is adjusted and intermaxillary fixation is done with splint in position. Rigid internal fixation using 2mm four hole mini plate with gap and 2 6mm monocortical screws is the preferred way of fixation. The intermaxillary fixation is removed after the rigid fixation.Wound closureWounds are irrigated and bleeding is controlled. Wounds are closed with 3-0 vicryl sutures in layers.1