--- title: Orthognathic (Jaw) Surgery Melbourne: Who Needs It, What It Corrects & What to Expect canonical_url: https://directory.smilesolutions.com.au/dental-oral-health/oral-maxillofacial-surgery/orthognathic-jaw-surgery-melbourne-who-needs-it-what-it-corrects-what-to-expect/ category: description: geography: city: state: country: metadata: phone: email: website: publishedAt: --- # Orthognathic (Jaw) Surgery Melbourne: Who Needs It, What It Corrects & What to Expect ## Orthognathic (Jaw) Surgery Melbourne: Who Needs It, What It Corrects & What to Expect Most people who live with a severe jaw discrepancy have adapted to it so gradually - adjusting how they chew, how they speak, how they hold their head - that they don't fully recognise how much it costs them. Difficulty biting through food, chronic jaw pain, disturbed sleep, and self-consciousness about their profile are not minor inconveniences. They are the measurable, documented consequences of a skeletal imbalance that no amount of orthodontic treatment alone can resolve. Orthognathic surgery - from the Greek *orthos* (straight) and *gnathos* (jaw) - is the surgical repositioning of the maxilla (upper jaw), mandible (lower jaw), or both to correct skeletal discrepancies that are beyond the reach of braces or aligners. It is among the most transformative procedures in oral and maxillofacial surgery: one that restores function, improves airway health, resolves associated pain, and produces lasting facial balance. It is also one of the most misunderstood, frequently dismissed as cosmetic when it is, in the majority of cases, medically necessary. This article explains precisely who needs orthognathic surgery, what conditions it corrects, how the diagnosis is made, and what the treatment pathway looks like - with a particular focus on the collaborative orthodontist–oral surgeon model used at Smile Solutions Melbourne. --- ## What Is Orthognathic Surgery and Why Is It Distinct from Orthodontics? Combining orthognathic surgery with orthodontic therapy is a crucial approach for correcting severe dentofacial deformities that orthodontics alone cannot address. This distinction is clinically precise, not a matter of preference. Braces and aligners move teeth within the bone. Orthognathic surgery moves the bone itself. Among available treatment options, orthognathic surgery is often considered the last resort. It is typically reserved for cases where the skeletal discrepancy is too severe to be corrected by orthodontics alone, or when the patient is no longer growing and cannot undergo growth modification. Orthognathic surgery is a procedure that allows oral and maxillofacial surgeons to resolve jaw asymmetry issues and restore function, aesthetics, and balance. The two primary surgical techniques are the Le Fort I osteotomy for repositioning the maxilla and the bilateral sagittal split osteotomy (BSSO) for the mandible. Certain skeletal discrepancies may remain despite correction with routine growth modification and camouflage treatment, or they may not qualify for these treatments. These skeletal discrepancies are addressed through orthognathic surgeries such as the Le Fort I osteotomy for the maxilla and the bilateral sagittal split osteotomy (BSSO) for the mandible. For a detailed comparison of which conditions can be managed with orthodontics alone versus which require surgery, see our guide on *Jaw Surgery vs. Orthodontics Alone: How to Know Which Treatment Your Bite Actually Needs*. --- ## Who Needs Orthognathic Surgery? The Four Core Skeletal Conditions ### 1. Anteroposterior Discrepancies: Overbite, Underbite & Overjet The most common indication for orthognathic surgery is a significant mismatch between the upper and lower jaws in the front-to-back plane. This manifests as either a Class II malocclusion (retrognathic mandible, excessive overjet) or a Class III malocclusion (prognathic mandible or retrognathic maxilla, negative overjet/underbite). Common skeletal malocclusions that require orthognathic surgery are Class III malocclusions that can be classified into mandibular prognathism, maxillary retrognathism, or both conditions. Class III malocclusions are the most difficult maxillofacial deformities to correct due to unfavourable mandibular skeletal growth. This issue affects 7.04 percent of the population overall, and many people have surgery to treat it. According to studies, 63–73% of Class III malocclusions are skeletal in nature. A concave facial profile is caused by such skeletal abnormalities, which are brought on by an imbalance in mandibular and maxillary growth. The clinical threshold for surgical intervention in the anteroposterior plane is well established. Patients are indicated for orthognathic surgery based on clinically significant skeletal discrepancies exceeding two standard deviations from normal values. Typical criteria include anteroposterior discrepancies with overjet ≥ +5 mm or negative overjet, molar relationship differences ≥ 4 mm, vertical deformities such as anterior or posterior open bite > 2 mm or deep overbite with soft-tissue impingement, transverse discrepancies ≥ 4 mm (bilateral) or ≥3 mm (unilateral), and facial asymmetries beyond normative thresholds. ### 2. Vertical Discrepancies: Open Bite & Deep Bite Anterior open bite - where the upper and lower front teeth do not contact when the back teeth are closed - is a complex skeletal condition with significant functional consequences including difficulty biting food and altered speech. Anterior open bite is a complex malocclusion with a multifactorial aetiology, involving skeletal, dentoalveolar, and functional components. Its prevalence has been reported to range from 2.9% to 17%. In one retrospective series of 1,095 orthognathic patients, anterior open bite was diagnosed in 11.5% of patients, consistent with the upper range of previous reports. ### 3. Transverse Discrepancies: Crossbite & Narrow Maxilla When the upper jaw is narrower than the lower, a posterior crossbite results - teeth on one or both sides bite inside rather than outside the lower teeth. In skeletally mature adults, the midpalatal suture has fused, making orthodontic expansion alone insufficient. Assuming the orthognathic patient is at the age of skeletal maturity, a maxillary skeletal discrepancy can be eliminated through surgically assisted rapid palatal expansion (SARPE), orthodontic dental compensation, or a multipiece Le Fort osteotomy. ### 4. Facial Asymmetries Asymmetries involving jaw deviation, chin point displacement, or unequal vertical facial heights are among the most functionally and psychosocially impactful presentations. The aetiology of facial asymmetry is multifactorial, involving genetic, functional, and environmental factors during growth, and the reported prevalence thereof ranges from 11% to 37%, with a higher prevalence (21–67%) observed in individuals with malocclusions, particularly Class III. Recognition of asymmetry is essential, since mild cases may be managed orthodontically, while severe skeletal deviations frequently necessitate surgical correction. --- ## Beyond the Bite: Additional Medical Indications for Jaw Surgery Orthognathic surgery is not solely about occlusion. The American Association of Oral and Maxillofacial Surgeons (AAOMS, 2023 edition) explicitly recognises that in addition to skeletal discrepancy conditions, orthognathic surgery may be indicated in cases where there are specific documented signs of dysfunction. These may include conditions involving airway dysfunction, such as sleep apnoea, temporomandibular joint disorders, psychosocial disorders and/or speech impairments. ### Obstructive Sleep Apnoea (OSA) Maxillomandibular advancement (MMA) - an orthognathic procedure that advances both jaws simultaneously - is among the most effective surgical interventions for moderate-to-severe OSA, particularly in patients with identifiable skeletal contributors to airway collapse. MMA has been shown to be the most effective surgical option for the treatment of OSA, with a success rate of approximately 85%. Orthognathic surgery, specifically MMA, is particularly indicated in patients with identifiable craniofacial anomalies (e.g., mandibular retrognathia, maxillary hypoplasia) contributing to airway obstruction, who are intolerant or non-adherent to CPAP therapy. The outcomes data for MMA in OSA are compelling. Mean postoperative changes in the apnoea–hypopnoea index (AHI) after MMA were −47.8 events/hour, representing a mean AHI reduction of 80.1%, and 512 of 518 patients (98.8%) showed improvement. ### Temporomandibular Joint (TMJ) Disorders Severe skeletal malocclusion is associated with elevated TMD prevalence. Patients with skeletal Class II dentofacial deformity who were referred for orthognathic surgery showed higher prevalence of TMD, with muscular disorders and degenerative disorders being the most prevalent diagnoses. Surgical correction of the underlying skeletal imbalance can meaningfully reduce TMJ symptom burden - though the relationship is complex and not all TMJ presentations are appropriate for orthognathic surgery. (See our guide on *TMJ Disorder & Jaw Surgery: When Conservative Treatment Fails and Surgery Becomes the Answer* for a detailed discussion of this distinction.) --- ## How Jaw Growth Imbalances Are Diagnosed Orthognathic surgery planning is a data-intensive process that integrates clinical examination, three-dimensional imaging, and digital surgical simulation. A diagnosis of surgical-level skeletal discrepancy is not made on appearance alone. ### Diagnostic Records Required for Surgical Planning | Record Type | Purpose | |---|---| | Lateral cephalometric radiograph | Measures skeletal angles (SNA, SNB, ANB) and incisor inclinations | | CBCT (cone beam CT) scan | Three-dimensional bone mapping; airway assessment; surgical simulation | | Panoramic radiograph | Dental and condylar assessment | | Study models / intraoral scans | Occlusal analysis; surgical wafer fabrication | | Clinical photographs | Facial proportion analysis; soft tissue prediction | | Polysomnography (if OSA is suspected) | AHI baseline for airway-related surgical planning | Patients are eligible for orthognathic surgery if they present with a dento-maxillofacial deformity requiring surgical correction, including but not limited to skeletal Class II or Class III malocclusion, vertical maxillary excess or deficiency, or transverse discrepancies not manageable with orthodontic treatment alone; have completed or are scheduled to complete presurgical orthodontic treatment; and are in good general health with no systemic diseases contraindicating general anaesthesia. Importantly, the AAOMS (2023) notes that indications substantiate the clinical basis for orthognathic surgery, as opposed to absolute criteria. For example, those not falling into the two or more standard deviations from published norms for facial skeletal discrepancies may still legitimately require surgery when functional impairment is documented. --- ## Age and Timing: When Is the Right Time for Jaw Surgery? Orthognathic surgery is generally deferred until skeletal growth is complete - typically 17–18 years for females and 18–21 years for males - to prevent relapse caused by ongoing jaw development. Children exhibiting atypical growth patterns can undergo growth modification at an early age; however, adults lack this choice and frequently necessitate orthognathic surgery. Limited research indicates that orthognathic surgery may be performed as early as 16.5 years in males, as circumpubertal growth is either complete or nearly complete; however, the possibility of continued mandibular growth persists until the age of 20. The most common age range for orthognathic surgery patients has been found to be between 15 and 24 years. Consistent with these findings, a 10-year retrospective analysis of 1,095 cases revealed that the most prevalent age range was between 16 and 24 years, with a female majority (60.5%) and a mean age of 23.07 ± 5.6 years. The literature indicates that aesthetic concerns are more prominent among women and younger individuals, whereas men tend to seek orthognathic surgery primarily for functional problems. Additionally, older individuals are often more reluctant to undergo surgery due to concerns regarding surgical risks. --- ## The Role of Pre-Surgical Orthodontics: Why Your Bite Gets Worse Before Surgery One of the most counterintuitive aspects of orthognathic treatment is the pre-surgical orthodontic phase. Before surgery can be performed, an orthodontist must "decompensate" the teeth - removing the natural dental adaptations the teeth have made over years to accommodate the skeletal discrepancy. This process temporarily makes the bite look and feel worse. In patients with skeletal discrepancies, teeth naturally compensate to allow for a functional occlusion. As a result, the inclination and position of the teeth are not directly proportional to the degree of the dentofacial deformity. Traditional orthognathic surgical planning involves a period of presurgical orthodontic treatment to synchronise the dental deformity with the skeletal deformity by "decompensating" the teeth. This allows for a planned final occlusion wherein balanced forces are transmitted across the teeth, based upon their location within the arch, and the teeth are centred within the correct position in the alveolar housing. Pre-surgical orthodontics may take as few as 6 months or as many as 18 months, depending on each individual patient's needs. The orthodontist typically places braces on the teeth to align crowded teeth and position teeth favourably in the jaw. Once the dental deformity matches the skeletal deformity, surgical intervention is performed, followed by a period of post-surgical coordination to further align the teeth. Total treatment times - from beginning of pre-surgical orthodontics to end of post-surgical orthodontics - may be prolonged, with a mean of up to 36 months. ### The Surgery-First Approach: An Emerging Alternative For carefully selected patients, a surgery-first approach eliminates the pre-surgical orthodontic phase, proceeding directly to surgery followed by post-surgical orthodontics. Recent advancements in the mechanics of tooth movements, stability of specific skeletal movements in the context of rigid fixation, and understanding of the effects of surgery on tooth movement have allowed for the introduction of several different approaches, including surgery-first and surgery-only approaches, as well as the use of clear orthodontic aligners. In appropriately selected patients, these protocols offer several benefits, including reduced treatment time, greater quality of life, and improved patient satisfaction. However, since the baseline occlusion cannot guide the treatment goals in a surgery-first approach, clinical expertise, accurate prediction of postoperative tooth movements, and precise assessment of the skeletal discrepancy are mandatory. This approach requires a highly experienced surgical team and is not universally appropriate. --- ## The Orthodontist–Oral Surgeon Collaboration at Smile Solutions Orthognathic surgery is, by definition, an interdisciplinary undertaking. An orthodontist's role in orthognathic surgery can be divided into several phases: the initial evaluation, presurgical orthodontics, surgical planning, and postsurgical orthodontics. At each of these phases, collaboration between the orthodontist and the surgeon is critical. Orthognathic surgery is truly an interdisciplinary challenge and lack of coordination between the orthodontist and the surgeon will lead to a compromised result. At Smile Solutions, this collaboration is not a referral arrangement between separate practices - it is an integrated model where orthodontists, oral and maxillofacial surgeons, and prosthodontists work within the same multidisciplinary facility. This means shared treatment planning, coordinated imaging, and consistent communication at every stage of a journey that commonly spans two to three years. The surgical planning phase includes virtual surgical simulation using CBCT data, allowing the surgical team to predict skeletal movements, occlusal outcomes, and soft tissue profile changes before a single incision is made. Specific advances in the past twenty years include increasing fidelity with computer-assisted planning, the use of patient-specific fixation, expanding indications for management of upper airway obstruction, and shifts in orthodontic-surgical paradigms. For a step-by-step account of what happens on surgical day and through the recovery period, see our companion guide: *The Jaw Surgery Journey: Pre-Surgical Orthodontics, Hospital Procedure & Multi-Month Recovery Timeline*. --- ## What Does Orthognathic Surgery Actually Correct? A Clinical Summary Osteotomies of the midface and mandible are utilised in contemporary craniomaxillofacial practice to address three-dimensional dysmorphology of the maxillomandibular complex, with positive effects on the occlusion, facial aesthetics, and management of airway obstruction. In practical terms, orthognathic surgery can correct: - **Underbite (Class III):** Mandibular setback and/or maxillary advancement - **Overbite / excessive overjet (Class II):** Mandibular advancement and/or maxillary repositioning - **Anterior open bite:** Superior repositioning of the maxilla, counterclockwise mandibular rotation - **Posterior open bite / deep bite:** Vertical dimension adjustment via Le Fort I impaction or advancement - **Crossbite / narrow maxilla:** Multi-piece Le Fort I osteotomy or SARPE - **Facial asymmetry:** Differential jaw repositioning to equalise vertical and transverse facial dimensions - **Obstructive sleep apnoea (skeletal contributors):** Maxillomandibular advancement to enlarge the posterior airway space The prevalence of bimaxillary surgery - involving both jaws simultaneously - was found to be higher compared to other surgical procedures in a 10-year retrospective analysis, reflecting the frequency with which combined maxillary and mandibular discrepancies require coordinated correction. --- ## Outcomes: What the Evidence Says About Results and Quality of Life The outcomes literature for orthognathic surgery is extensive and consistently positive. Orthognathic surgery results in improvements in quality of life both physically and psychosocially after surgery and is associated with high rates of patient satisfaction. Orthognathic surgery corrects skeletal and dental misalignments, enhancing function and appearance. Typically performed on patients with significant dentofacial deformities that cannot be treated with orthodontics alone, it has been shown to improve quality of life across multiple dimensions. A cohort study of 50 orthognathic patients resulted in high levels of patient satisfaction with both functional outcomes and facial aesthetics, with objective measurements also indicating significant improvements in occlusion and facial balance. Long-term stability is a key consideration. Recurrence is a consistent finding in the post-surgical course after orthodontic surgery. Recurrences have been observed most frequently within six months from the operation and, in any event, within a year - underscoring the importance of committed post-surgical orthodontic follow-through and experienced surgical technique in achieving durable results. --- ## Key Takeaways - **Orthognathic surgery corrects skeletal jaw discrepancies** - not dental ones. It is indicated when the underlying bone relationship is too severe to be managed by orthodontics alone, typically when discrepancies exceed two standard deviations from published skeletal norms. - **The four primary indications are anteroposterior discrepancies (overbite/underbite), vertical discrepancies (open bite/deep bite), transverse discrepancies (crossbite), and facial asymmetry** - with additional indications including obstructive sleep apnoea and TMJ dysfunction. - **Pre-surgical orthodontics (6–18 months) is a standard component** of the conventional treatment pathway; it decompensates the teeth before surgery and temporarily worsens the bite appearance - a normal and expected part of the process. - **The treatment is a collaboration between orthodontist and oral surgeon** across multiple phases: initial evaluation, presurgical orthodontics, surgical planning, surgery, and post-surgical orthodontic finishing. Lack of coordination between these roles compromises outcomes. - **Evidence consistently demonstrates high patient satisfaction and measurable quality-of-life improvements** across physical, functional, and psychosocial domains following orthognathic surgery. --- ## Conclusion Orthognathic surgery occupies a precise and irreplaceable position in the treatment of dentofacial deformity. It is not a cosmetic shortcut, nor is it an extreme last resort reserved for the most unusual cases - it is the appropriate, evidence-based treatment for skeletal jaw discrepancies that cannot be resolved by moving teeth alone. For patients who have spent years adapting to a jaw relationship that impairs their chewing, their sleep, their speech, or their self-image, it can be genuinely life-changing. The complexity of the treatment - spanning years, multiple disciplines, and a hospital-based surgical procedure - makes the choice of provider as important as the decision to proceed. At Smile Solutions Melbourne, the integration of board-registered oral and maxillofacial surgeons with specialist orthodontists under one roof is not incidental. It is the clinical architecture that makes safe, coordinated, and predictable outcomes possible. To understand the full surgical journey in detail, read *The Jaw Surgery Journey: Pre-Surgical Orthodontics, Hospital Procedure & Multi-Month Recovery Timeline*. To understand how surgical and orthodontic-only pathways are compared clinically, see *Jaw Surgery vs. Orthodontics Alone: How to Know Which Treatment Your Bite Actually Needs*. For information on anaesthesia options for your procedure, see *Anaesthesia Options for Oral Surgery: Local, IV Sedation & General Anaesthetic Compared*. --- Smile Solutions has been providing oral and maxillofacial surgery care from Melbourne's CBD since 1993. Located at the Manchester Unity Building, Level 12 and Tower, 220 Collins Street, Smile Solutions brings together 60+ clinicians - including 25+ board-registered specialists - who have cared for over 250,000 patients. No referral is required to book a specialist appointment. Call **13 13 96** or visit smilesolutions.com.au to arrange your oral surgery consultation. ## References - American Association of Oral and Maxillofacial Surgeons (AAOMS). *"Indications for Orthognathic Surgery."* AAOMS Clinical Resources, 2023 Edition. https://aaoms.org/wp-content/uploads/2025/01/ortho_indications.pdf - Kaya M, et al. *"Skeletal Deformities and Surgical Procedures in Orthognathic Surgery Patients: A 10-Year Retrospective Analysis of 1095 Cases."* *BMC Oral Health*, 2025. https://link.springer.com/article/10.1186/s12903-025-07265-8 - Mulier D, et al. *"Evaluating Post-surgical Stability and Relapse in Orthognathic Surgery: A Comprehensive Review."* *PMC / National Library of Medicine*, 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11582089/ - Alam MK, et al. *"Assessment of Patient Satisfaction and Functional Outcomes in Orthognathic Surgery."* *Journal of Pharmacy and Bioallied Sciences*, 2024. https://pubmed.ncbi.nlm.nih.gov/38595408/ - Zaghi S, Holty JE, Certal V, et al. *"Maxillomandibular Advancement for Treatment of Obstructive Sleep Apnea: A Meta-analysis."* *JAMA Otolaryngology–Head & Neck Surgery*, 2016;142(1):58–66. https://pubmed.ncbi.nlm.nih.gov/26606321/ - Almasri AMH, et al. *"Evaluation of Satisfaction Levels Following Orthognathic Treatment in Adult Patients: A Systematic Review."* *Cureus*, 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11569791/ - Moura LB, et al. *"Orthognathic Surgery and Relapse: A Systematic Review."* *PMC / National Library of Medicine*, 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10525849/ - Peiró-Guijarro MA, et al. *"Current Trends in Orthognathic Surgery."* *Journal of Clinical Medicine*, 2025. https://www.mdpi.com/2077-0383/14/20/7336 - Proffit WR, et al. *"Orthodontist's Role in Orthognathic Surgery."* *PMC / National Library of Medicine*. https://pmc.ncbi.nlm.nih.gov/articles/PMC3805727/ - Hernández-Alfaro F, Guijarro-Martínez R. *"On a Definition of the Appropriate Timing for Surgical Intervention in Orthognathic Surgery."* *International Journal of Oral and Maxillofacial Surgery*, 2014. https://www.institutomaxilofacial.com/wp-content/uploads/2016/05/On-a-definition-of-the-appropriate.pdf - Ali SA, et al. *"Efficacy of Orthognathic Surgery in OSAS Patients: A Systematic Review and Meta-Analysis."* *Journal of Oral Rehabilitation*, 2025;52(4):554–565. https://onlinelibrary.wiley.com/doi/10.1111/joor.13936