Nahoum Index in Brachyfacial Patients: A Pilot Study

Area of Science:

• Dentistry
• Orthodontics
• Cephalometrics

Background:

• Class II malocclusion, deep bite, and short face syndrome present complex therapeutic challenges.
• Cephalometric analysis is crucial for diagnosing and planning treatment for these conditions.
• The Nahoum Index offers a potential tool for assessing vertical dimension and guiding treatment decisions.

Purpose of the Study:

• To evaluate the efficacy of the Nahoum Index in cephalometric analysis for adult patients with Class II malocclusion, deep bite, or short face syndrome.
• To determine the index's utility in differentiating between orthodontic and surgical treatment needs.
• To establish a limit value for the Nahoum Index to guide therapeutic orientation.

Main Methods:

• Twenty-three patients with molar Class II and overbite >4 mm were divided into surgical orthodontic (G1) and orthodontic (G2) groups.
• Cephalometric tracings were analyzed pre- and post-treatment to calculate the ANB angle and Nahoum Index.
• Statistical analysis was performed to compare the differences in index and angle values between groups and treatment phases.

Main Results:

• In the surgical orthodontic group (G1), the Nahoum Index decreased significantly from 0.954 to 0.797, and the ANB angle decreased from 5.2° to 3.2°.
• In the orthodontic group (G2), the Nahoum Index decreased slightly from 0.825 to 0.817, and the ANB angle decreased from 4.4° to 4°.
• The difference in the Nahoum Index was significant post-treatment only in G1.

Conclusions:

• The Nahoum Index is a valuable adjunct in cephalometric analysis for patients with Class II malocclusion, deep bite, or short face syndrome.
• A Nahoum Index of 0.934 is proposed as a limit value, distinguishing patients suitable for orthodontic-only treatment from those requiring surgical intervention.
• The index range of 0.81-0.934 indicates borderline cases, while values above 0.934 suggest a need for surgical treatment, aiding therapeutic orientation.