Craniofacial Morphology And Sella Turcica Bridging Associated With Third Molar Agenesis.

Study Overview
=================
Brief Summary
-----------------
The aim of this retrospective study is to analyze the third molar agenesis with respect to sella turcica bridging and other craniofacial patterns in patients asking for orthodontic consultation. The main question[s] it aims to answer are: is there a relationship between third molar agenesis and sella turchina bridging? is there a relationship between third molar agenesis and craniofacial patterns?

Detailed Description
-----------------
Patients referring for orthodontic consultation at the Unit of Orthodontics and Pediatric Dentistry, Section of Dentistry, Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy, will be enrolled for the study according to the inclusion criteria. For each patient, lateral cephalometric radiograph and panoramic radiograph will be performed. For each lateral cephalometric radiograph, a cephalometric tracing will be performed with DeltaDent software (version 2.5.12, Outside Format, Pandino, Italy). Riedel's ANB angle [Riedel 1952] has been chosen to determine patients' skeletal class. Steiner's SN^GoGn angle [Steiner 1953] has been chosen to evaluate skeletal divergence. Facial axis (BaNa^CCGn), Lower Facial Height (LFH) and mandibular plan angle (FH^GoMe) from Rickett's analysis [Rickett's 1961] have been adopted to determine facial growth. According to Jaraback's cephalometric analysis [Jaraback 1985], saddle angle, articular angle, upper gonial angle, lower gonial angle will be measured to assess the growth pattern. Linear measurements of sella depth, sella diameter and interclinoid distance [Silverman 1957; Kisling 1966] will be calculated. Linear regressions between craniofacial patterns, sella turcica bridging and third molar agenesis will be calculated. A control group with no third molar agenesis will be provided.

Official Title
-----------------
Third Molar Agenesis Related To Craniofacial Pattern And Sella Turcica Bridging: A Retrospective Cephalometric Study

Conditions
-----------------
Tooth Agenesis

Intervention / Treatment
-----------------
* Diagnostic Test: Radiographic evaluation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: G stage of Demirjian's classification for third molar maturation or absence of third molar germs Patients with one lateral cephalometric digital radiograph executed in Natural Head Position (patients were asked to keep the teeth in contact and the lips relaxed). Patients with panoramic radiograph; Exclusion Criteria: Ascertained previous surgical extraction/s of third molar/s Orthopedic/orthodontic therapy Orthognathic surgery.

Ages Eligible for Study
-----------------
Minimum Age: 9 Years
Maximum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Case group<br>Patients with third molar agenesis. | Diagnostic Test: Radiographic evaluation<br>* Panoramic and lateral cephalometric radiographs with cephalometric analysis will be performed.<br>|
| Control group<br>Patients with the presence of all third molars. | Diagnostic Test: Radiographic evaluation<br>* Panoramic and lateral cephalometric radiographs with cephalometric analysis will be performed.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Linear regression between third molar agenesis and ANB | ANB is calculated according to Riedel's analysis: angle formed between Point A (maxillary sovraspinal point), point B (Bubmental mandibular point) and N (Nasion) | Baseline | 
| Linear regression between third molar agenesis and Interclinoid Distance | Distance between tuberculum sella (TS) and dorsum sella (DS). | Baseline | 
| Linear regression between third molar agenesis and Sella Depth. | Distance of a line dropped perpendicular from the interclinoid distance to the deepest point of the sella floor. | Baseline | 
| Linear regression between third molar agenesis and Sella Diameter | Distance between tuberculum sella and the farthest point on the inner wall of the sella. | Baseline | 
| Linear regression between third molar agenesis and Sn^GoGn. | Steiner's Sn^GoGn is the angle formed between 2 planes: cranial base line (SN) and mandibular plane (GoGn) | Baseline | 
| Linear regression between third molar agenesis and ArGo^GoGn | Jaraback's Ar^Go^Gn is the angle formed between the 2 planes: ArGo and GoGn | Baseline |