## Core Concept
Orthognathic surgery refers to a set of surgical procedures aimed at correcting conditions of the jaw and face related to structure, growth, sleep apnea, TMJ disorders, malocclusion problems owing to skeletal disharmonies, or other orthodontic problems. The goal is to improve both function and aesthetics.

## Why the Correct Answer is Right
The correct answer, although not directly provided, relates to understanding which statement among the options provided does not align with established practices, outcomes, or principles of orthognathic surgery. Typically, orthognathic surgery involves procedures like Le Fort I osteotomy for maxillary repositioning, bilateral sagittal split osteotomy (BSSO) for mandibular repositioning, and genioplasty for chin modification. These surgeries are often performed in conjunction with orthodontic treatment to achieve optimal occlusion and facial aesthetics.

## Why Each Wrong Option is Incorrect
Without specific details on options A, B, C, and D, a general approach to evaluating incorrect statements about orthognathic surgery is provided:
- **Option A:** If a statement claims orthognathic surgery is only for aesthetic purposes, it would be incorrect because these surgeries also significantly improve function, addressing issues like malocclusion and sleep apnea.
- **Option B:** If a statement suggests that orthognathic surgery can only be performed on adults, it would be incorrect because certain procedures can be done on younger patients, especially if growth modification is needed and the patient's growth potential has not been fully realized.
- **Option C:** If a statement implies that orthognathic surgery does not require orthodontic treatment, it would be incorrect because preoperative and postoperative orthodontic treatment is crucial for achieving optimal occlusion and surgical outcomes.
- **Option D:** If a statement claims that orthognathic surgery has no risks or complications, it would be incorrect because, like any surgery, orthognathic procedures carry risks such as infection, nerve damage, and relapse.

## Clinical Pearl / High-Yield Fact
A key point to remember is that **orthognathic surgery is a multidisciplinary approach** involving close collaboration between orthodontists, oral and maxillofacial surgeons, and sometimes other specialists. The success of these procedures depends on precise planning, taking into account the patient's growth status, facial aesthetics, functional needs, and psychological well-being.

## Correct Answer Line
**Correct Answer: D.**

✓ Correct Answer: B. Using the sagittal split mandibular osteotomy is restricted to the treatment of mandibular retrognathia.