Award Date

5-15-2026

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Dental Medicine

First Committee Member

Brian Chrzan

Second Committee Member

Charles Hill

Third Committee Member

John Colombo

Fourth Committee Member

Maxim Gakh

Number of Pages

59

Abstract

Objective:

Accurate evaluation of transverse skeletal relationships is essential for orthodontic diagnosis and treatment planning. Dentition may compensate for skeletal discrepancies through buccolingual tipping of posterior teeth, potentially masking underlying transverse imbalance. The purpose of this study was to investigate the relationship between transverse skeletal width and posterior tooth angulation using cone-beam computed tomography (CBCT).

Methods:

Sixty-six pre-orthodontic adult CBCT scans were analyzed. Maxillary and mandibular transverse skeletal widths were measured at the level of the first molar furcation using buccal cortical plate– to–buccal cortical plate landmarks. Buccolingual angulation of the first and second premolars and first and second molars in both arches was measured using a standardized three-point angular method. Pearson and Spearman correlations were used to evaluate the relationship between maxillary and mandibular transverse widths. Linear regression models were performed to explore associations between transverse dimensions and tooth angulation. To account for clustering of teeth within patients, repeated-measures analyses using generalized estimating equations and mixed-effects regression models were conducted. Correlations between transverse width discrepancy (maxillary width minus mandibular width) and individual tooth angulation were evaluated, with Bonferroni correction applied for multiple comparisons.

Results:

The mean maxillary transverse width was 60.91 mm (SD = 4.57) and the mean mandibular transverse width was 57.21 mm (SD = 3.52). A strong positive correlation was observed between maxillary and mandibular transverse widths (Pearson r = 0.708, p < 0.001). Correlation analysis between transverse width difference and tooth angulation demonstrated significant associations for teeth #3, #4, and #31 after Bonferroni correction. Teeth #3 and #4 exhibited negative correlations with transverse discrepancy, while tooth #31 demonstrated a positive correlation. Grouped tooth-type analyses and mixed-effects regression models did not identify statistically significant global relationships between transverse discrepancy and tooth angulation.

Conclusions:

Maxillary and mandibular transverse widths demonstrated a strong coordinated relationship in adult orthodontic patients. While certain individual teeth exhibited localized associations between transverse discrepancy and tooth angulation, consistent patterns across broader tooth groups were not observed. These findings suggest that dentoalveolar compensation related to transverse discrepancies may occur at specific teeth rather than uniformly across the dental arch. CBCT evaluation of both skeletal width and tooth angulation may improve identification of transverse discrepancies and associated compensatory dental changes.

Controlled Subject

Orthodontics--Diagnosis; Orthodontics--Practice; Musculoskeletal system

Disciplines

Dentistry | Medicine and Health Sciences | Osteopathic Medicine and Osteopathy

File Format

PDF

File Size

999 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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