**2. Preliminary patient evaluation**

**1. Preliminary patient evaluation** A systematic examination is necessary to adequately evaluate and treat patients A systematic examination is necessary to adequately evaluate and treat patients with dentofacial deformities. Treatment planning should start only when the orthodontist and surgeon have agreed on a final treatment plan. It is mandatory that the patient be well informed about the treatment plan and related possible disadvantages.

**Figure 1 : Factors influencing stability in orthognthic surgery treatment.[1]**

Indeed, efficacy is guaranteed when there is clear and effective communication

between the orthodontist and the maxillofacial surgeon from the outset.


with dento‐facial deformities. Treatment planning should start only when the orthodontist and surgeon have agreed on a final treatment plan. It is mandatory Indeed, efficacy is guaranteed when there is clear and effective communication between the orthodontist and the maxillofacial surgeon from the outset.

that the patient be well informed about the treatment plan and related possible Routine evaluation includes [1]:

disadvantages.

Routine evaluation includes [1]:

**•** Evaluation of patient's medical history

**1.1. Stability criteria of ortho-surgical treatment**

134 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

with collaborating partners upon initial consultation (**Figure 1**). [1]


**movement** 

**Figure 1.** Factors influencing stability in orthognthic surgery treatment.[1]

the treatment plan and related possible disadvantages.

orthodontist and the maxillofacial surgeon from the outset.

**2. Preliminary patient evaluation**

Routine evaluation includes [1]:







A systematic examination is necessary to adequately evaluate and treat patients with dentofacial deformities. Treatment planning should start only when the orthodontist and surgeon have agreed on a final treatment plan. It is mandatory that the patient be well informed about

Indeed, efficacy is guaranteed when there is clear and effective communication between the

**Influencing Factors**

consultation (Figure 1). [1]

**1. Preliminary patient evaluation**

Routine evaluation includes [1]:

disadvantages.

The management of dento-skeletal dysmorphosis requires a team of specialists that mainly include orthodontists and maxillofacial surgeons. The ultimate aim of orthodontists is both to meet the patients' expectations, and make effective sustainable interventions. Three treatment objectives, which form the basis in treating patients with dento-facial deformities, are funda‐ mental in orthognathic surgery namely function, esthetics, and stability. Skeletal relapse is the most common complication following orthognathic surgery. Optimal treatment planning for maxillofacial surgery requires an understanding of postoperative skeletal stability, dentoalveolar position and the soft tissue response to skeletal movement. Accurate treatment planning and careful orthodontic and surgical protocols are essential to the achievement of treatment objectives; these have to be planned with collaborating partners upon initial

**MEDICAL‐EDITED CHAPTER FOR AOMFS VOL 2**

The management of dento‐skeletal dysmorphosis requires a team of specialists that mainly include orthodontists and maxillofacial surgeons. The ultimate aim of orthodontists is both to meet the patients' expectations, and make effective sustainable interventions. Three treatment objectives, which form the basis in treating patients with dento‐facial deformities, are fundamental in orthognathic surgery namely function, esthetics, and stability. Skeletal relapse is the most common complication following orthognathic surgery. Optimal treatment planning for maxillofacial surgery requires an understanding of postoperative skeletal stability, dento‐alveolar position and the soft tissue response to skeletal movement. Accurate treatment planning and careful orthodontic and surgical protocols are essential to the achievement of treatment objectives; these have to be planned

**Figure 1 : Factors influencing stability in orthognthic surgery treatment.[1]**

A systematic examination is necessary to adequately evaluate and treat patients

orthodontist and surgeon have agreed on a final treatment plan. It is mandatory that the patient be well informed about the treatment plan and related possible

Indeed, efficacy is guaranteed when there is clear and effective communication

between the orthodontist and the maxillofacial surgeon from the outset.


with dento‐facial deformities. Treatment planning should start only when the


The initial consultation aims to discuss the possible need for surgical procedure as part of the treatment to achieve optimal results. However, before treatment, it is important to put emphasis on those elements that are directly related to stability; some of these include operative age, the soft tissue and muscles, and mandibular inclination. [2, 3]

#### **2.1. Preoperative age**

Growth following surgery may result in relapse; surgical osteotomy and osteosynthesis have little influence on the mandibular jaw growth. The initial growth of the patient's face and continuous remodeling processes may lead to an advantageous or disadvantageous change of position of the mandible after sagittal split osteotomy. [3] The inability to predict the potential growth of the mandible can lead to failure or recurrence when the surgical indication is established before the end of growth. This leads practitioners to adopt a cautious attitude. To minimize the risks of relapse due to continuous growth, surgery should only be recommended to patients when growth is complete.

#### **2.2. Soft tissue and muscles**

Although long-term studies of surgical orthodontic stability are sparse, many authors predict the importance of active and /or passive contractions exerted by muscles and/or post surgical skeletal recurrences due to soft tissue. [2] An examination of cervical soft tissues and orofacial muscles (in particular the tongue) at rest and during function requires due attention. This is illustrated in case 1 which was a 19-year-old female admitted for burn injuries following a home accident at the age of 6 yrs. Aesthetic imbalance and significant dento-skeletal deformity is due to post-burn contractures of the neck (Figures 2 and 3). Facial appearance is the patient's main concern. Radiographic evaluation and cephalometric analysis showed the patient presented high values for mandibular length and plane angle (FMA= 38°). The Wits appraisal indicated a large anteroposterior discrepancy between the maxilla and mandible (AO‐ BO=-6.5mm) (Figure 4). Only surgery can improve the aesthetics. The expected dental and soft tissue changes to be affected by the preoperative orthodontic treatment are illustrates by cephalometric tracing. The surgical plan consisted of two-jaw surgery (Figure 5).

stability.

*gap.* 


Preoperative orthodontic treatment planning included teeth alignment without extraction and provision of good arch form assisted by maxillary expansion (Figure 6).

But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after orthognathic surgery. Lingual Frenectomy, re-education for tongue position during swallowing are modalities that help stability. réparatrice des tissus cutanés du cou, seule garante d'une stabilité après chirurgie orthognathique. La frenectomie linguale et la réeducation de la posture linguale et de la déglutition constituent également un gage de stabilité. But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after orthognathic surgery. Lingual Frenectomy, re-education of the tongue as well as swallowing are modalities that help prompte réparatrice des tissus cutanés du cou, seule garante d'une stabilité après chirurgie orthognathique. La frenectomie linguale et la réeducation de la posture linguale et de la déglutition constituent également un gage de stabilité.

But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after

*Figure 2: Frontal view, profile and smile of patient before treatment: W, 19 years of age, had characteristics of the long face pattern, with prognathism, and vertical growth pattern, scare contracture due to neck burn and increased interlabial gap.*  **Figure 2.** Frontal view, profile and smile of the patient before treatment: Female, 19 years of age, characteristics long face pattern, prognathism and vertical growth pattern, scar contracture due to neck burn and increased interlabial gap. *Figure 2: Frontal view, profile and smile of patient before treatment: W, 19 years of age, had characteristics of the long face pattern, with prognathism, and vertical growth pattern, scare contracture due to neck burn and increased interlabial* 

*Fig. 3: Pre-treatment intra-oral photographs: frontal lateral occlusion There is serious open bite. So, maxillary anteroposterior and transverse deficiency (maxillary arch –shaped lyre) explains Fig. 3: Pre-treatment intra-oral photographs: frontal lateral occlusion There is serious open bite. So, maxillary anteroposterior and transverse deficiency (maxillary arch –shaped lyre) explains crowding in the anterior maxillary arch*  **Figure 3.** Pre-treatment intra-oral photographs: frontal lateral occlusion shows severe open bite and maxillary antero‐ posterior and transverse deficiency. Constricted maxillary arch explains the crowding in the anterior maxilla.

*crowding in the anterior maxillary arch* 

**Figure 3: Pre‐treatment intra‐oral photographs: frontal lateral occlusion** 

**Figure 3: Pre‐treatment intra‐oral photographs: frontal lateral occlusion** 

**MEDICAL‐EDITED CHAPTER FOR AOMFS VOL 2**

**MEDICAL‐EDITED CHAPTER FOR AOMFS VOL 2**

**shows severe open bite and maxillary anteroposterior and transverse deficiency.**

**shows severe open bite and maxillary anteroposterior and transverse deficiency. Constricted maxillary arch explains the crowding in the anterior maxilla.** 

**Figure 4: pre‐treatment orthopantomogram and lateral teleradiogram of skull**. **Figure 4.** Pre-treatment orthopantomogram and lateral teleradiogram of skull.

**•** Lefort I maxillary osteotomy is used to perform advancement and expansion of the maxilla and a slight superiorly repositioning is needed to allow the mandible to auto-rotate and

Preoperative orthodontic treatment planning included teeth alignment without extraction and

But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after orthognathic surgery. Lingual Frenectomy, re-education

**Figure 2.** Frontal view, profile and smile of the patient before treatment: Female, 19 years of age, characteristics long face pattern, prognathism and vertical growth pattern, scar contracture due to neck burn and increased interlabial gap.

réeducation de la posture linguale et de la déglutition constituent également un gage de stabilité.

réeducation de la posture linguale et de la déglutition constituent également un gage de stabilité.

réparatrice des tissus cutanés du cou, seule garante d'une stabilité après chirurgie orthognathique. La frenectomie linguale et la

But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after orthognathic surgery. Lingual Frenectomy, re-education of the tongue as well as swallowing are modalities that help prompte

réparatrice des tissus cutanés du cou, seule garante d'une stabilité après chirurgie orthognathique. La frenectomie linguale et la

But the project initially conceived can only succeed after surgical repair of cervical skin tissue, the only guarantee of stability after orthognathic surgery. Lingual Frenectomy, re-education of the tongue as well as swallowing are modalities that help prompte

*Figure 2: Frontal view, profile and smile of patient before treatment: W, 19 years of age, had characteristics of the long face pattern, with prognathism, and vertical growth pattern, scare contracture due to neck burn and increased interlabial* 

*Figure 2: Frontal view, profile and smile of patient before treatment: W, 19 years of age, had characteristics of the long face pattern, with prognathism, and vertical growth pattern, scare contracture due to neck burn and increased interlabial* 

*There is serious open bite. So, maxillary anteroposterior and transverse deficiency (maxillary arch –shaped lyre) explains* 

*There is serious open bite. So, maxillary anteroposterior and transverse deficiency (maxillary arch –shaped lyre) explains* 

**Figure 3.** Pre-treatment intra-oral photographs: frontal lateral occlusion shows severe open bite and maxillary antero‐ posterior and transverse deficiency. Constricted maxillary arch explains the crowding in the anterior maxilla.

**•** Bilateral sagittal split osteotomy for setback of the mandible.

136 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

provision of good arch form assisted by maxillary expansion (Figure 6).

for tongue position during swallowing are modalities that help stability.

*Fig. 3: Pre-treatment intra-oral photographs: frontal lateral occlusion* 

*Fig. 3: Pre-treatment intra-oral photographs: frontal lateral occlusion* 

*crowding in the anterior maxillary arch* 

*crowding in the anterior maxillary arch* 

close the openbite.

stability.

stability.

*gap.* 

*gap.* 


**Figure 5 : The orthodontic visual treatment objective Figure 5 : The orthodontic visual treatment objective illustrates the desired presurgical orthodontic tooth movement and predicts the Figure 5.** The orthodontic visual treatment objective illustrates the desired presurgical orthodontic tooth movement and predicts the surgical repositioning of the jaws and subsequent soft tissue changes. It has a key role in choosing dental extractions, if needed.

 *Fig. 6 : Immediate preoperative intraoral photographs Treatment does not need dental teeth extraction and the aim of preparatory orthodontic stage was to establish a good arch form in the maxillary and mandibular archs.*  **Figure 6.** Immediate preoperative intraoral photographs. Treatment did not need dental teeth extraction and the aim of preparatory orthodontic stage was to establish a good arch form in the maxillary and mandibular arches.

mandibular advancement or setback should not be perfomed for patients with high mandibular plane angles. [3]


preliminary occlusal obstacles and the rebalancing of the dentoalveolar system.

responsible for the smooth implementation of the various steps of the treatment plan. 

proportional and comparative data. We can record all the prescriptions in it. [6] (Figure 7)

The influence of the mandibular plane angle on horizontal and vertical skeletal stability has been shown in several studies. [3, 4] High angle patients have a greater risk of relapse after receiving bilateral sagittal split ramus osteotomy than low and normal–angle patients. Patients with a low mandibular plane angle, compared to high and normal angle patients, appear to have a more predictable procedure. Then, patients with a low mandibular plane angle have increased vertical relapse when advancement surgery is indicated; whereas patients with a high mandibular plane angle have more horizontal relapse. [3] Because the muscles of mastication are lengthened in the ramus area, they tend to return to their original positions, rotate the mandible in a clockwise movement, open the bite, and cause relapse. To minimize the risk of relapse, patients should be selected carefully ; isolated

Therapy planning should be clear and precise and the objectives need to be defined with collaborative partners before a final


Starting cases orthodontically and then, if unsuccessful, referring them for surgery often produces compromised results. [5] It is, therefore, important to prioritise problems and think of potential solutions;; this way you can define the objectives of each treatmant step. The initial treatment plan must be established following a discussion between the different parties 

In fact, cephalometric and occlusal simulation setup permi the practioner to project the occlusal dental and facial skeletal result, to ascertain and determine a suitable orthodontic surgical protocol. Those set- up demonstrates the general reharmonization of the teeth, the jaw and the face. It can then be used as a reference instrument in discussions with the surgeon and patient, and can be modified at all times according to the particular needs. The set-up is, and remains, an estimation which supplies simple quantitative

1.3- Presurgical skeletal pattern

**2- Defining treatment objectives** 

treatment planning decision:

### **2.3. Presurgical skeletal pattern**

The influence of the mandibular plane angle on horizontal and vertical skeletal stability has been shown in several studies. [3, 4] High angle patients have a greater risk of relapse after receiving bilateral sagittal split ramus osteotomy than low and normal–angle patients. Patients with a low mandibular plane angle, compared to high and normal angle patients, appear to have a more predictable procedure. Then, patients with a low mandibular plane angle have increased vertical relapse when advancement surgery is indicated; whereas patients with a high mandibular plane angle have more horizontal relapse. [3] Because the muscles of mastication are lengthened in the ramus area, they tend to return to their original positions, rotate the mandible in a clockwise movement, open the bite, and cause relapse. To minimize the risk of relapse, patients should be selected carefully; isolated mandibular advancement or setback should not be performed for patients with high mandibular plane angles. [3]
