Effect of Nail Biting Habit on Mandibular Bone Structure: A Retrospective Radiological Study
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Onychophagia. Basic parameters: 8 years — 10 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Evaluation of the Effects of Nail Biting Habit on Mandibular Bone Structure Using Fractal Analysis and Panoramic Morphometric Indices: A Retrospective Radiological Study
Overview
Nail biting (onychophagia) is a common parafunctional habit characterized by repetitive and non-functional biting behavior. Although the effects of nail biting on dental structures and occlusion have been reported, its potential effects on mandibular bone structure remain unclear. This retrospective radiological study aims to evaluate the association between nail biting habit and mandibular bone characteristics using fractal analysis and panoramic morphometric indices. Existing panoramic radiographs of individuals with and without nail biting habits will be retrospectively analyzed. Trabecular bone complexity, mandibular cortical width, panoramic mandibular index, and Klemetti index values will be compared between groups to investigate whether nail biting habit is associated with alterations in mandibular bone morphology.
Detailed description
Nail biting (onychophagia) is classified as a body-focused repetitive behavior and represents a common parafunctional habit, particularly among children and adolescents. Continuous repetitive mechanical forces generated during nail biting may affect the stomatognathic system; however, the possible effects of this habit on mandibular bone structure have not been sufficiently investigated.
Fractal analysis is a radiological assessment method used to evaluate trabecular bone architecture by quantifying structural complexity. Higher fractal dimension values indicate increased complexity of bone patterns. In addition, panoramic morphometric indices such as mandibular cortical width, panoramic mandibular index, and Klemetti index provide information regarding cortical bone quality and quantity.
In this retrospective case-control study, existing panoramic radiographs of individuals with and without nail biting habits will be evaluated. Radiological parameters including fractal dimension, mandibular cortical width, panoramic mandibular index, and Klemetti index will be compared between groups. This study aims to determine whether nail biting habit is associated with measurable changes in mandibular trabecular and cortical bone characteristics.
Primary outcome measures
- Mandibular Trabecular Bone Structure Assessed by Fractal Dimension Analysis [Time frame: Baseline]
Secondary outcome measures (1)
- Panoramic Mandibular Index (PMI) [Time frame: Baseline]
Eligibility criteria
Inclusion criteria
- Children aged 8-10 years who were examined at the Department of Pediatric Dentistry, Faculty of Dentistry, Recep Tayyip Erdoğan University.
- Systemically healthy participants.
- Participants with available diagnostic-quality panoramic radiographs obtained during routine dental examinations.
- Participants with and without a history of nail biting habit.
- Panoramic radiographs with sufficient image quality for fractal dimension analysis and mandibular morphometric measurements.
- Radiographs without periapical pathology in teeth adjacent to the regions of interest (ROI) used for fractal analysis.
- Participants with at least 20 existing teeth.
- Radiographic records with available parental radiographic information and consent documentation.
Exclusion criteria
- Participants with systemic diseases or conditions that may affect bone metabolism, including diabetes mellitus, osteoporosis, osteomalacia, renal diseases, hypothyroidism, or hyperparathyroidism.
- Participants using medications that may influence bone density or bone metabolism.
- Participants with temporomandibular joint disorders affecting the subcondylar region.
- Participants with mandibular pathological conditions, including cysts, tumors, or other lesions affecting mandibular bone structure.
- Participants with periapical pathology adjacent to the regions selected for fractal analysis.
- Participants with fewer than 20 teeth.
- Panoramic radiographs with insufficient diagnostic quality or image artifacts that prevent reliable measurements.
- Radiographs that do not allow accurate evaluation of mandibular cortical and trabecular bone parameters.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Case-crossover
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07740889 · 2026/315