Dimensions for Midline and Paramidline Mandibulotomy: A Radiographic Study in the Dentate Thai Population
Wandee Apinhasmit DDS, PhD*, Soontra Panmekiate DDS, PhD**, Saruta Saengtipbovorn*, Suttinee Ittatirut*
Affiliation : * Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok ** Department of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok
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.
Materials and Methods : 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
