Development and Validation of Semi-automatic Segmentation Technique of Mandibular Condyles from CBCT images

• Author / Creator

  Kim, Justin

• Objectives: Mandibular condyle contains an important growth site that contributes to the eventual anteroposterior position of the mandible, and is a crucial component in establishing normal temporomandibular function. To accurately assess the change in the volume and morphology of the mandibular condyle using cone-beam computed tomography image (CBCT), it is paramount to establish a validated method to segment the mandibular condyle from the surrounding structures. In this study, a systematic review was conducted to investigate the available condylar segmentation techniques from three-dimensional images, and its reported accuracy and reliability. Semi-automatic condylar segmentation technique was developed and validated for its accuracy compared to the reference model and its reliability. A pilot study was completed to assess the condylar volumetric changes in adolescent orthodontic patients treated with different Class II fixed appliances.

  Methods: Systematic review was conducted using three electronic databases. CBCT images of three dry study skulls and three corresponding 3D-printed mandibles were used to semi-automatically segment the mandibular condyles and the computed volumes were compared to the volumes obtained from the physical models. Sixty CBCT images from thirty adolescent patients from three groups (Herbst appliance, Xbow appliance, and control group) at two time points were assessed using the developed semi-automatic condylar segmentation method.

  Results: Condylar volume computed using semi-automatic segmentation technique was found to be accurate when compared to the volume determined from dry 3D-printed mandible. Intra and Inter-rater reliability were excellent. Statistically significant increase in condylar volume was observed in adolescent patients in all three groups, but the magnitude of condylar volume increase among different groups were not statistically significant.

  Conclusion: Condylar volume computed from the described segmentation technique was highly accurate when compared to the physical condylar volume measurements; and is a reliable approach to evaluate volume changes in mandibular condyles in growing patients treated with fixed Class II appliances. The limited results from the pilot study suggests that the condylar volume increase in growing patients is primarily due to the normal condylar growth and is not necessarily enhanced or impeded by the use of fixed class II appliances.

• Subjects / Keywords

  • TMJ
  • Orthodontics
  • CBCT

• Graduation date

  Spring 2020

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-wrh5-wh16

• License

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