Evaluation of mandibular morphology in different facial types

Area of Science:

• Dentistry
• Anthropology
• Orthodontics

Background:

• Mandibular morphology varies across facial types.
• Understanding these variations is crucial for diagnosis and treatment planning in orthodontics and maxillofacial surgery.

Purpose of the Study:

• To evaluate mandibular morphology in different facial types (vertical, horizontal growth patterns).
• To analyze specific cephalometric parameters and assess sexual dimorphism.

Main Methods:

• Lateral cephalograms of 110 subjects (55 males, 55 females, aged 18-25) were analyzed.
• Subjects were classified into normodivergent, hypodivergent, and hyperdivergent groups using Jarabak's ratio.
• Parameters included symphysis height/depth/ratio/angle, antegonial notch depth, ramal height/width, mandibular depth, gonial angles, and mandibular arc angle.

Main Results:

• Vertical growth patterns (hyperdivergent) were associated with larger symphysis height, smaller depth, smaller ramus height/width, smaller mandibular depth, increased gonial angle, and decreased mandibular arc angle compared to horizontal patterns (hypodivergent).
• Sexual dimorphism observed: females had smaller symphysis height/depth but larger symphysis ratio; males had greater ramus height/width and mandibular depth.
• Hyperdivergent mandibles showed underdeveloped processes, resembling infantile characteristics.

Conclusions:

• Mandibular morphology is strongly correlated with facial growth patterns and exhibits significant sexual dimorphism.
• Distinct cephalometric differences exist between vertical and horizontal facial types.
• Hyperdivergent facial types may present with underdeveloped mandibular structures.