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Treatment Of Mandibular Fracture (Broken Lower Jaw)

A  mandibular fracture can be defined as a broken lower jaw. In Malaysia, mandibular fracture has the highest incidence rate (51.2%)4 sustained when compared to the other bony parts of the oral and maxillofacial region.

What is a mandibular fracture (broken lower jaw)?

The image below shows a schematic drawing2 of the mandible (lower jaw) and the most common sites of mandibular fracture.

Gambarajah Anatomi Rahang Bawah Manusia
Anatomy of Lower Jaw
Source : https://www2.aofoundation.org 

Common causes of mandibular fracture

  • Motor-vehicle or road-traffic accidents./li>
  • Assault.
  • Fall.
  • Sports injury.
  • Non-accidental injury (abuse).

Rare causes of mandibular fractures 

  • Accidental fracture during third molar ( wisdom tooth ) surgery./li>
  • Pathological fracture due to osteoporosis or tumour.
  • Warfare.

Signs and Symptoms 

  • Facial swellings – over your chin, lips and lower jaw.
  • Laceration (cut) on the skin or in the mouth.
  • Inability to open your mouth wide.
  • Inability to close your mouth.
  • Difficulty in biting or chewing.
  • Paraesthesia (numbness) over the injured area such as your lower lip / gums / lower teeth / part of your tongue / lower jaw.

Severe complications that may arise are :-  

  1. Difficulty in spontaneous breathing due to gross swelling, causing a risk to the airway.
  2. Fractured mandible at the chin area may lead to difficulty in breathing.This is due to the backward displacement of the tongue towards the throat.
  3. Profused bleeding from the fractured mandible. This will not only result in severe blood loss but may also compromised the airway.

Intraoral Clinical Presentation

Gambarajah Klinikal1     Gambarajah Klinikal2
Photo credits : Oral & Maxillofacial Surgery Clinic, Dental Specialist Clinic, Hospital Tuanku Ja’afar


Radiographic investigations that may aid in diagnosis are dental panoramic radiographs. Whereas, CT (computed tomography) scans of the mandible will give a more comprehensive detailed view of the fracture sites.

Treatment of mandibular fracture

Patients with mandibular fractures are usually prescribed with antibiotics to avoid infection and analgesics (painkillers) to relieve the pain.

Minor mandibular fractures with mild occlusal discrepancies (bite alignment) may heal by simple limitation of movement. In general, patients will be given soft dietary advice to avoid chewing food and also advised to limit opening their mouths wide. This is in order to avoid further displacement of the fractured bone due to actions of the muscle.

A patient may sustain either a single fracture or multiple fracture sites. For multiple mandibular fractures, a patient may require multi-step treatment or surgery under general anaesthesia. The broken jaw must be immobilised into proper alignment and secured with plates and screws or wires where indicated. The aim of surgery or treatment is to achieve correct bite for the patient in order for rehabilitation of function especially biting, chewing and speech.

The above image shows placement of upper and lower archbars (as shown by the yellow arrows) in a patient’s mouth with mandibular fracture. This treatment option can be done to stabilise the occlusion prior to surgery or for those who refuse any surgery.

Definitive treatment option is surgery under general anaesthesia. The aim of surgery is to immobilise the fractured segments which will then be secured by using plates and screws (depicted by the red circle) as shown in the dental panoramic image below.

Fracture of Mandible associated with Third Molar Surgery
Photo credits : Yuen Kar Mun: Fracture of Mandible associated with Third Molar Surgery. Mal. J. Oral Maxillofac. Surg. 2013; 11: 29-32

The image below shows pre and post-operative radiographic images of a more complicated mandibular fracture with multiple fracture sites. In the radiographic images below, you are able to see the discrepancies of the fractured segments and also the immobilized fracture segments with plates and screws post-operatively

Photo credits : Parumo R, Ma BC, Sujak R, Jelon A: Retromandibular Transparotid Approach to
Subcondylar Fractures: Our 4 Years Experience. Mal. J. Oral Maxillofac. Surg. 2013;11: 17-25.

Essential post-operative advice given :

  1. To complete antibiotic prescription to avoid any infection
  2. To take analgaesics (painkillers) when necessary.
  3. To maintain good oral hygiene care.
  4. Dietary advice as suggested – pureed food or soft diet
  5. To attend follow-up appointments as scheduled by your surgeon.

Generally, bone healing will be fully achieved within 6 to 8 weeks. It is adamant to seek treatment by an oral and maxillofacial surgeon who will follow-up your treatment till satisfactory healing has been achieved.


  1. http://www.njms.in/articles/2012/3/2/images/NatlJMaxillofacSurg_2012_3_2_159_111371_f7.jpg
  2. https://www2.aofoundation.org
  3. Marzuki ZA 2012 Oral and Maxillofacial Injuries , Portal MyHEALTH http://www.myhealth.gov.my/index.php/en/oral-a-maxillofacial-injuries
  4. Mustafa WM et al. 2006 The Pattern of Maxillofacial Fractures in Ministry of Healths’ Hospital Malaysia.
  5. Parumo R, Ma BC, Sujak R, Jelon A: Retromandibular Transparotid Approach to Subcondylar Fractures: Our 4 Years Experience. Mal. J. Oral Maxillofac. Surg. 2013;11: 17–25.
  6. Yuen Kar Mun: Fracture of mandible associated with third molar surgery. Mal. J. Oral Maxillofac. Surg. 2013; 11: 29–32


Last Reviewed : 6 October 2015
Writer / Translator : YM Tengku Dr. Intan Baizura bt. Tengku Jamaluddin
Accreditor : Dr. Marzuki bin Zainal Abidin