An introduction into the evolution of human jaw size
Men have a robust skeletal frame and women have a more delicate bone structure. Before the advent of civilizations, agriculture and community living, when man was a hunter gatherer, it was the men who went out to hunt for food. The prey of course did not like becoming food and these encounters often turned violent. Prey charging the hunters and the hunters suffering injuries or even dying was common occurrence. It was the men with more robust skeletons who better withstood the brunt of these often violent hunts and evolution took care of the rest in the form of genetic encoding.
There are occasions when this genetic coding results in women developing prominent jaws, which gives them a masculine look. The advent of cosmetic surgery in recent times allowed these women to get their jaws sculpted by cosmetic surgeons to give them a feminine jaw. The following surgical procedure involves the reduction of jaw size in a young lady who presented with the complaint of prominent jaws.
A young lady with complaints of a very prominent mandible and facial asymmetry
This young lady from Chikmagalur in Karnataka had always felt that her mandible was too prominent. She also felt that she had a short lip. This had caused her to use scarves to conceal her mandible as she felt it was very masculine in appearance. A friend of hers had encouraged her to get it surgically corrected through surgery as that was affecting her day to day functioning.
She had presented to a board certified plastic surgeon whose area of specialization include cosmetic surgery involving eyelid surgery, tummy tucks, skin grafting and breast augmentation surgery. This surgeon examined her and obtained various studies. He explained to the patient that a narrower mandible would make her face look longer and more feminine.
She had also been involved in a road traffic accident that had resulted in facial injuries a year ago. She felt that this had aggravated her problem even more. Thus, she wanted to undergo surgical correction of her prominent mandible as a long term or permanent solution. She however did not have an open bite. She wanted more feminine facial features.
The plastic surgeon had recommended to her that an oral and maxillofacial surgeon would be the right person to perform this corrective jaw surgery. He thus referred her to Balaji Dental and Craniofacial Hospital as we are renowned for facial cosmetic surgery and jaw reconstruction surgery. Our hospital rigorously adheres to the rules and regulations laid down by the American Association of Oral and Maxillofacial Surgeons. All cosmetic surgery procedures of the head and face are performed at our hospital.
Treatment planning after initial evaluation and imaging studies at our hospital
Dr SM Balaji, jaw reconstruction surgeon and a specialist in orthognathic surgery examined the patient. Orthognathic surgery is performed for patients with jaw size complaints. He obtained facial biometric studies and ordered comprehensive imaging studies for the patient. The 3D CT scan revealed that she had prominent masseter muscles bilaterally along with bimaxillary protrusion. He explained to the patient that she needed bilateral reduction of her masseter muscles, bilateral reduction of the angle of her mandible, Le Fort I osteotomy with anterior maxillary and supapical osteotomy. It was explained to the patient that this surgery would result in a narrower mandible, which would give her a longer facial profile and a feminine appearance. The patient and her parents expressed their desire to proceed and gave written informed consent for the surgery.
Surgical correction of the patient’s prominent jawbone
Under general anesthesia, an incision was first placed in the mandibular retromolar region on the right side. This was followed by elevation of a mucoperiosteal flap. The angle of the mandible was then accessed through this incision and the bone was reduced using a round bur. The periosteum was then dissected and the masseter muscle identified. This was then partially excised bilaterally. The same procedure was then performed on the left side.
Correction of the patient’s prominent upper and lower jaws
Following completion of the masseter and angle reduction, an incision was placed in the maxillary sulcus and mucoperiosteal flap elevated. Le Fort I osteotomy bone cuts were then made in the maxilla using a reciprocating saw. Pterygomaxillary dysjunction was then performed following which the maxillary segment was mobilized and pushed back. An anterior maxillary osteotomy was then performed and the anterior maxillary segment was pushed back. Occlusion was then checked and the bone was stabilized and fixed in place using titanium plates and screws.
Following this, a sulcular incision was made in the anterior mandible and mucoperiosteal flap elevated. Bone cuts were then made below the apices of the teeth using a reciprocating saw and the anterior mandible was set back. The mandibular segment was checked for occlusion and fixed using transosseous wires. Hemostasis achieved and closure done with suction drain in place.
Patient and parents fully satisfied with the results of the surgery
The patient was very pleased with the results of the surgery. She liked the new tapered appearance to the face, which was the result of the narrowing done at the angle of the mandible. She also was very happy with the appearance of her lips and her new facial profile. She had a correct bite and her occlusion was perfect.