Downs' analysis is the measurement to identify skeletal malformations by relating the various cephalometric points and planes.

Step 2. Open Octave and select the folder where the code files were downloaded.

Step 3. Open and run Cephalopoint.m .

Step 4. Select Downs.

Step 5. Follow the instructions.

Source Code (Version 1.0):

% Software: Downs' Cephalometric Technique

## Copyright (C) 2017 J.J. Reyes-Salgado

##

## This program is free software; you can redistribute it and/or modify

## it under the terms of the GNU General Public License as published by

## the Free Software Foundation; either version 3 of the License, or

## (at your option) any later version.

##

## This program is distributed in the hope that it will be useful,

## but WITHOUT ANY WARRANTY; without even the implied warranty of

## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

## GNU General Public License for more details.

##

## You should have received a copy of the GNU General Public License

## along with this program; If not, see <http://www.gnu.org/licenses/>.

##

## Author: J.J. Reyes-Salgado <juanjose.reyes@upaep.mx>

pkg describe image

clear

clc

% Dialog to choose image to open and file to save the measuremnts

prompt = {'Enter Image name:','Enter File name:'};

dlg_title = 'Input the X-ray Image and the File to save the measuremnts';

num_lines= 1;

def = {'Photo','DownsFile'};

resp = inputdlg(prompt,dlg_title,num_lines,def);

pict=strcat(resp{1,1},'.jpg');

sfile=strcat(resp{2,1},'.csv');

% Begin de software

B=imread(pict); % Open X ray picture

hFig = figure('units','normalized','outerposition',[0 0 1 1]);

imshow(B)

% Select Scale

promptS={'Enter the value of scale bar in cm:'};

digS='Input value of scale (cm):';

defS={'5'};

respS=inputdlg(promptS,digS,num_lines,defS);

value=str2num(respS{1,1});

% Select points

msgbox('Select the start and end point on the scale bar');

[xE,yE,bE] = ginput(2);

pix=value/abs(yE(1)-yE(2));

msgbox('Select Infraorbital (Or)','Point Or');

[xOr,yOr,bOr] = ginput(1);

msgbox('Select Menton (Me)','Point Me');

[xMe,yMe,bMe] = ginput(1);

msgbox('Select Nasion (Na)','Point Na');

[xNa,yNa,bNa] = ginput(1);

msgbox('Select A point','Point A');

[xA,yA,bA] = ginput(1);

msgbox('Select B point','Point B');

[xB,yB,bB] = ginput(1);

msgbox('Select Sella (S)','Point S');

[xS,yS,bS] = ginput(1);

msgbox('Select Gnathion (Gn)','Point Gn');

[xGn,yGn,bGn] = ginput(1);

msgbox('Select Gonion (Gon)','Point Gon');

[xGo,yGo,bGo] = ginput(1);

msgbox('Select Pogonion (Pg)','Point Pg');

[xPog,yPog,bPog] = ginput(1);

msgbox('Select Porion (Po)','Point Po');

[xPo,yPo,bPo] = ginput(1);

msgbox('Select Lower incisor crown (IIC)','Point IIC');

[xIIC,yIIC,bIIC] = ginput(1);

msgbox('Select Lower incisor root (IRC)','Point IRC');

[xIRC,yIRC,bIRC] = ginput(1);

msgbox('Select Upper incisor crown (ISC)','Point ISC');

[xISC,yISC,bISC] = ginput(1);

msgbox('Declarar Upper incisor root (ISR)','Point ISR');

[xISR,yISR,bISR] = ginput(1);

msgbox('Select InterOcclusal Molars (OA)','Point OA');

[xOA,yOA,bOA] = ginput(1);

msgbox('Select InterOcclusal Incisors (OS)','Point OS');

[xOS,yOS,bOS] = ginput(1);

% Measure of distances

rPoOr=[xOr-xPo yOr-yPo];

distPoOr=norm(rPoOr)*pix;

rNaPog=[xNa-xPog yNa-yPog];

distNaPog=norm(rNaPog)*pix;

rNaA=[xNa-xA yNa-yA];

distNaA=norm(rNaA)*pix;

rAB=[xA-xB yA-yB];

distAB=norm(rAB)*pix;

rAPog=[xA-xPog yA-yPog];

distAPog=norm(rAPog)*pix;

rSGn=[xS-xGn yS-yGn];

distSGn=norm(rSGn)*pix;

rMeGo=[xMe-xGo yMe-yGo];

distMeGo=norm(rMeGo)*pix;

rOSOA=[xOS-xOA yOS-yOA];

distOSOA=norm(rOSOA)*pix;

rII=[xIIC-xIRC yIIC-yIRC];

distII=norm(rII)*pix;

rIS=[xISC-xISR yISC-yISR];

distIS=norm(rIS)*pix;

% Measure of angles

angPFac=acosd((dot(rPoOr,rNaPog)*pix.^2)/(distPoOr*distNaPog))

angPConv=acosd((dot(rNaA,rAPog)*pix.^2)/(distNaA*distAPog))

angPAB=acosd((dot(rAB,rNaPog)*pix.^2)/(distAB*distNaPog));

angPMandi=acosd((dot(rPoOr,rMeGo)*pix^2)/(distPoOr*distMeGo))

angEjeY=180-acosd((dot(rSGn,rPoOr)*pix^2)/(distSGn*distPoOr))

angOclu=acosd((dot(rOSOA,rPoOr)*pix^2)/(distOSOA*distPoOr))

angInc=acosd((dot(rII,rIS)*pix^2)/(distII*distIS))

angPIOclu=90-acosd((dot(rII,rOSOA)*pix^2)/(distII*distOSOA))

angPIMand=acosd((dot(rMeGo,rII)*pix^2)/(distII*distMeGo))

% Point Perpendicular Pmax to Upper incisor to APg

rAISC=[xA-xISC yA-yISC];

distAISC=norm(rAISC)*pix;

angT=acosd((dot(rAPog,rAISC)*pix.^2)/(distAPog*distAISC));

Pmax=distAISC*sind(angT)

% Signo AB-NaPog

Sig=cross([rAB 0],[rNaPog 0]);

uSig=Sig./norm(Sig);

angABNPg=uSig(3)* angPAB

% Save Data

Dato=[angPFac angPConv angABNPg angPMandi angEjeY angOclu angInc ...

angPIOclu angPIMand Pmax];

fileID=fopen(sfile,'a');

for i=1:length(Dato)

fprintf(fileID, '%3.4f,',Dato(i));

end

fprintf(fileID, '%8s\n','');

fclose(fileID);