Background: Mandibulotomy is an important surgical approach of the oral cavity, oropharynx, and parapharyngeal space.
Objective: To provide dimensions for placement of bone cuts for midline (between two central incisors) and paramidline (between lateral incisor and canine) mandibulotomy.
Material and Method: Two hundred and sixteen periapical radiographs with the mandibular anterior teeth of 72 healthy Thai dental patients (30 males, 42 females) were selected. The angles between the long axes of the two central incisors (M) and between the lateral incisor and canine (PM) were bilaterally measured using computerized imaging. The horizontal distances (at crestal, middle, and apical levels) between the roots and the alveolar bone heights of the aforementioned teeth were also measured.
Results: The angles between the PM (0.00-9.26o) were less convergent than those between the M (0.00-11.66o) (p < 0.05). The distances between the PM were 0.60 - 8.03 mm, whereas those between the M were 0.47-6.63 mm (p < 0.05). Mean alveolar bone height is 15.88 + 1.72 mm in the canine.
Conclusion: The paramidline mandibulotomy is done in a wider space than the midline cut and could have a better chance to avoid the extraction of a central incisor and preserve the origin of the genioglossus, geniohyoid, and digastric muscles.

Keywords: Midline mandibulotomy, Paramidline mandibulotomy, Periapical radiograph, Dimension