Jaw-dropping Insights: Understanding Jaw Alignments and Surgeries

Corrective jaw surgery, or orthognathic surgery, can correct the alignment of your jaw bones and teeth to improve function and facial appearance.

Orthognathic” comes from the Greek words “ortho,” meaning straight/to straighten, and “gnathia,” meaning jaw.

This surgery is typically recommended for jaw problems that can’t be resolved with orthodontics alone. You must wear braces before and after the surgery to ensure proper healing and alignment.

This article explains different types of jaw alignments to help you make an informed decision about your surgery and treatment.

But first, let us understand the terminologies associated with jaw alignments to see how corrective surgeries can improve the outcomes. 

Refer to the table below for a detailed overview:

Features	Jaw position	Characteristics	Treatment
Orthognathism	Balanced alignment of the head, maxilla, and mandible	Upper teeth slightly overlap the lower teeth both vertically (overbite) & horizontally (overjet)A balanced facial profile	Dental braces only – if teeth alignment needs correction
Retrognathism	Upper jaw is positioned behind relative to the facial bones	Reduced overjet – Upper teeth are horizontally forwardConcave appearance of the face on the side view	Surgically reposition the upper jaw to bring it forward
	Lower jaw is positioned behind relative to the facial bones	Front teeth crossbite – Lower teeth are ahead & horizontally forwardConvex appearance of the face on the side view	Surgically reposition the lower jaw to bring it forward
Prognathism	Upper jaw is positioned forward relative to the facial bones	Increased overjet – Upper teeth are horizontally forwardConvex appearance of the face on the side view	Surgically reposition the upper jaw to place it backward
	Lower jaw is positioned forward relative to the facial bones	Front teeth crossbite – Lower teeth are ahead & horizontally forwardConcave appearance of the face on the side view	Surgically reposition the lower jaw to place it backward
Receding Chin	Chin is positioned backward relative to the face	Convex appearance of face on side view. Teeth are not affected.	Surgically make the chin prominent
Protruding Chin	Chin is positioned forward relative to the face	Concave appearance of face on side view	Surgically reduce the chin prominence

Source: NCBI^[1] PubMed^[2] John Hopkins Medicine^[3]

Here’s an overview of common jaw alignment classes and their characteristics.

Jaw alignment is classified into three types – Class I, Class II & Class III.

Types of Jaw Alignment

Class	Characteristics	Cause	Type of Orthognathic surgery
Class I	Orthognathism	Ideal jaw alignment where maxillary jaw & teeth slightly overlap the mandibular jaw & teeth.	No surgery needed
Class II	Mandibular Retrognathism	Due to a deficient mandible, the maxilla becomes prominent	Mandibular advancement using Bilateral Sagittal Split Osteotomy (BSSO) or Chin Augmentation
Class III	Mandibular Prognathism	Due to a deficient maxilla or prominent mandible	Mandibular Osteotomy (Example – Bilateral Sagittal Split Osteotomy – BSSO) or Genioplasty

For more detailed information on the surgeries and treatments, please refer to our parent article on Orthognathic surgery in Tijuana, Mexico.