Soft Tissue Changes Associated with Orthognathic Surgery By David R. Telles Diplomate of the American Board of Oral and Maxillofacial Surgery

Introduction Overview Orthodontic considerations Maxillary Movements Movement of dentition Maxillary Movements Mandibular Movements Surgical Techniques

Introduction Necessary to include a component of soft tissue changes in the surgical treatment plan while working to achieve a stable, functional dentoskeletal unit the surgical procedures -- to control the soft tissue changes will be presented and evaluated help the surgeon understand, control, and maximize the beneficial aspects of the facial soft tissue response to surgery.

Historically Orthognatic surgery -- used to correct skeletofacial deformities and the resultant functional problems, often at the expense of the facial soft tissue esthetics Early studies produced average ratios – which related hard/soft tissue landmarks Individual variability noted to be significant Facial soft tissue response to orthodontics and Sx was MultiFactorial Prediction equations developed to help preop evaluation for surgical planning and post-op assessment Recent development of surgical procedures to control soft tissue response to Sx: alar cinch suture and VY closure

Orthodontic Considerations Tooth position and alveolar morphology result from the sum of applied forces during their development Skeletal imbalances are accompanied by soft tissue imblanaces – result = dental compensation for skeletal malocclusions Corrections initially result in worsening of the malocclusion preoperatively + jaw-jaw discrepency to appear more severe Pre-op records to be taken as close to Sx to determine soft- tissue outcome

Cephalometric Considerations Must allow for visualization of the complete soft tissue profile Instruct pt to keep lips in repose for cephs Superimpose landmarks that remain unchanged Presence of ortho hardware changes the lip profile

Cephalometric Landmarks

Soft Tissue Considerations To predict soft/hard tissue changes is critical to Tx planning for orthognathic Sx Changes depending on surgical procedure method of wound closure the new spatial arrangement of the skeletal/dental elements adaptive qualities of soft tissues Growth orthodontic vectors o ftooth movement lip thickness. tonus, area, contact (competence), strength interlabial gap amount of overjet amount offatty tissue Musculature postoperative edema.

Soft Tissue Considerations Stabilize in approx 6 months – some studies suggest 12 months Surgical Approach Incision type may play a role – horizontal incision for the Le Fort I osteotomy may cause shortening of the lip With loss of vermillion Decrease in lip thickness Vertical approach with tunneling and palatal flap shows minimal post-op lip changes Betts et. Al. – investigated soft tissue response to Max Sx – found soft tissue changes may be more related to type/position of incision and method of closure than surgically induced hard tissue change

Soft Tissue Considerations Will mirror changes in the bony foundation should relapse occur Thin lips move more predictably than thick lips “dead space” under the lip may absorb the first portion of a bony advancement before soft tissue affected Horizontal Changes – in soft tissue more predictable than vertical changes Related to the stability of the hard tissue movements (less stable in vertical dimension)

Soft tissue – assoc. Orthodontic tooth movement

Maxillary surgical procedures Most are soft tissue changes manifested in: Nasal Labial

Maxillary surgical procedures – Nasal Affects lower aspect of the nasal dorsum Widening of the alar base regardless of vector of movement Shortening of the columellar/alar height shortening of the nasal tip projection Nasolabial angle decreases or remains constant

Maxillary surgical procedures – Nasal Superior movement Elevation of the nasal tip Widening of the alar base Decreased nasolabial angle Inferior repositioning Loss of nasal tip support Downward movement of columella and alar bases Thinning of the lip Increase in NL angle

Maxillary surgical procedures – Nasal Anterior Advancement in the upper lip Subnasale Pronasale Thinning of the lip Widening of the Alar base Increase in Supratip break if ANS in tact ***Nasal tip advances approx ½ the distance of the subnasale******* Counter clockwise rotation – raises the nasal tip Clockwise rotation – decreases superior movement of the nasal tip

Maxillary surgical procedures – Nasal

Maxillary surgical procedures – Labial Upper lip is attached to the nose – prevents 1:1 soft tissue change Widens and lengthens at the philtral columns after Max Sx w/o VY closure – can cause shortening of the upper lip with loss of exposed vermillion

Maxillary Advancement Greatest effect on the nose/upper lip Ppts adv of upperlip, subnasale and nose Shortening of upper lip Thinning of upper lip (approx. 2 mm) Widening of Alar base Deepening of supratip depression if ANS left intact Progressive increase in horizontal soft tissue displacement seen from tip of nose to free end of upper lip Decrease in NL angle

Maxillary Advancement Carlotti et. al. – determined that the ratio of horizontal change of upper incision to vermillion border of the upper lip with use of the alar cinch suture and the VY closure The ratio reduces with larger advancements due to soft tissue stretching: 0.6:1 vs. 0.9:1

Maxillary Advancement

Maxillary Impaction – superior Elevation of nasal tip Widening of alar base (2-4 mm) Decrease in NL angle Nasal changes occur w/o changes in angulation of upper lip Lip follows superiorly approx 40% of the vertical maxillary plane Lip shortening accentuated with combined anterior/superior max movements If no VY – amnt of vertical soft tissue change increases progressively from nasal lip to stomion with loss of vermillion

Maxillary Impaction

Maxillary inferior repositioning Loss of nasal tip support Downward repositioning of the columella and alar bases Thinning of the lip Increase NL angle

Maxillary posterior repositioning Loss of nasal tip support - due to movement of ANS - movement of bony area around piriform aperture Lip rotation Posterior and superiorly about SubNasale Increased NL angle

Maxillary Setback

Multi-direction Maxillary movements

Mandibular surgical procedures Generally soft tissues follow hard tissues closely Exception is lower lip Types of movements Anterior Posterior Anterior segmental Autorotation Genial Segmental procedures

Mandibular surgical procedures - anterior Mandibular Advancement Limited to the structures below the superior labial sulcus Little change in the upper lip and none above the ANS Lower lip advancement is variable and lip often lengthens Lower labial sulcus and chin adhere to the bony structure and follow underlying osseous structures Leads to opening of labio-mental fold

Mandibular surgical procedures - anterior Mandibular Advancement Facial Height In high angle II cases – results in large increase in FH Lower lip position Affected by upper, lower incision and its contact with the upper lip In class II – lower lip may touch the upper lip/incisor and fold forward – correction of this is necessary to approximate true post-op position

Mandibular advancement

Mandibular surgical procedures - Posterior Mandibular Setback No net effects on subnasale or tissues superior to it Soft tissues follow mandible posteiorly Chin most closely Lower lip Shortens More protrusive and curls out Labiomental fold deepens + becomes more acute

Mandibular Setback

Mandibular surgical procedures Anterior Segmental Osteotomy

Mandibular Surgical Procedures -- autorotation Soft tissues follow the osseous landmarks approx 1:1 Except lower lip – falls slightly lingual to the arc of rotation

Mandibular Surgical Procedures -- Genioplasty Anterior

Mandibular Surgical Procedures -- Genioplasty Posterior -- setback

Mandibular Surgical procedures – Vertical Augmentation/reduction Genio Soft tissues follow hard tissues very closely in augmentation genio compared to reduction

Controlling Soft Tissue Poor Surgical Results Surgical Techniques VY closure Cinch Suturing Figure 8 technique Dual alar cinch suture Contouring ANS Double VY closure Bilateral alar base wedge resection Septoplasty Advancement genioplasty / liposuction – excess submental adipose tissue and/or short cervicomental distance

Controlling Soft Tissue

Controlling Soft Tissue

Controlling Soft Tissue VY closure

Controlling Soft Tissue Cinch Suture – figure 8

Controlling Soft Tissue Dual Alar cinch Suture

Controlling Soft Tissue Contouring of ANS

Controlling Soft Tissue Double VY

Controlling Soft Tissue Bilateral Alar Base wedge resection

Controlling Soft Tissue Septoplasty Cartilagenous septum – should be reduced during maxillary impactions of > 3 mm to prevent post-op deviation Avoid over reduction – as it can cause saddle nose deformity or poly-beak deformity