Evaluation of the submandibular fossa and its correlation to implant placement using Cone-Beam Computed Tomography

Abstract

Background: The alveolar ridge morphology in the posterior mandibular region has many variations that may pose fatal complications if not assessed and addressed properly.

Aim: The aim of this study is to assess the different morphological variations in the posterior mandible and attempt to propose a new classification for the submandibular concavity.

Materials and Methods: Cone Beam Computed Tomography (CBCT) from 195 patients taken from the Dubai Dental Hospital (DDH) database after going through the inclusion/exclusion criteria and analyzed. The data collected included width of the alveolar bone at the crest (Wc), width of the alveolar bone at the base (Wb), alveolar ridge height (Vcb), alveolar bone height below the P point (Vb) and alveolar bone height above the P point (Vc). Furthermore, age, gender, presence or absence of the first molar and if the submandibular undercut is present or absent.

Results: The selected 195 CBCT scans included 46.2% males and 53.8% females with an age ranging from 20 years to over 70 years old. In those, U type ridge (ridge with undercut) was found to be the most prevalent type (54.4% left, 52.1% right) followed by P type (parallel ridge) (27.2% left, 33.5% right) and the least type was the C type (convergent type) (18.5% left, 14.4% right). Alveolar ridge height had correlation with age, gender, ridge type, presence or absence of the first molar and presence or absence of an undercut. Alveolar ridge width had a correlation with the width of the alveolar bone at the crest and ridge type. The concavity depth has a correlation with the presence of the first molar, presence of an undercut and the ridge type.

Conclusion: Proper understanding of the ridge morphology lead to a safe and predictable dental implant planning and treatment. The proposed new classification can help the dental practitioner to provide accurate assessment of the submandibular concavity when planning for dental implant insertion in the posterior mandible, this will lead to safe and predictable treatment outcome.